text: // TODO UITextbox features - mouse input, multi-line, clipboard, undo, IME support, number dragging.
  // TODO New elements - list view, menu bar.
  // TODO Keyboard navigation - menus, dialogs, tables.
  // TODO Easier to use fonts; GDI font support.
  // TODO Formalize the notion of size-stability? See _UIExpandPaneButtonInvoke.
  
  #include <stdint.h>
  #include <stddef.h>
  #include <stdbool.h>
  #include <stdarg.h>
  
  #ifdef UI_LINUX
  #include <X11/Xlib.h>
  #include <X11/Xutil.h>
  #include <X11/Xatom.h>
  #include <X11/cursorfont.h>
  
  #include <xmmintrin.h>
  #endif
  
  #define _UI_TO_STRING_1(x) #x
  #define _UI_TO_STRING_2(x) _UI_TO_STRING_1(x)
  
  #ifdef UI_WINDOWS
  #undef _UNICODE
  #undef UNICODE
  #include <windows.h>
  
  #define UI_ASSERT(x) do { if (!(x)) { ui.assertionFailure = true; \
  	MessageBox(0, "Assertion failure on line " _UI_TO_STRING_2(__LINE__), 0, 0); \
  	ExitProcess(1); } } while (0)
  #define UI_CALLOC(x) HeapAlloc(ui.heap, HEAP_ZERO_MEMORY, (x))
  #define UI_FREE(x) HeapFree(ui.heap, 0, (x))
  #define UI_MALLOC(x) HeapAlloc(ui.heap, 0, (x))
  #define UI_REALLOC _UIHeapReAlloc
  #define UI_CLOCK GetTickCount
  #define UI_CLOCKS_PER_SECOND (1000)
  #define UI_CLOCK_T DWORD
  #endif
  
  #if defined(UI_LINUX)
  #include <stdlib.h>
  #include <string.h>
  #include <assert.h>
  #include <time.h>
  #include <math.h>
  
  #define UI_ASSERT assert
  #define UI_CALLOC(x) calloc(1, (x))
  #define UI_FREE free
  #define UI_MALLOC malloc
  #define UI_REALLOC realloc
  #define UI_CLOCK clock
  #define UI_CLOCKS_PER_SECOND CLOCKS_PER_SEC
  #define UI_CLOCK_T clock_t
  #endif
  
  #if defined(UI_ESSENCE)
  #include <essence.h>
  
  #define UI_ASSERT EsAssert
  #define UI_CALLOC(x) EsHeapAllocate((x), true)
  #define UI_FREE EsHeapFree
  #define UI_MALLOC(x) EsHeapAllocate((x), false)
  #define UI_REALLOC(x, y) EsHeapReallocate((x), (y), false)
  #define UI_CLOCK EsTimeStampMs
  #define UI_CLOCKS_PER_SECOND 1000
  #define UI_CLOCK_T uint64_t
  
  // Callback to allow the application to process messages.
  void _UIMessageProcess(EsMessage *message);
  #endif
  
  #ifdef UI_DEBUG
  #include <stdio.h>
  #endif
  
  #ifdef UI_FREETYPE
  #include <ft2build.h>
  #include FT_FREETYPE_H
  #include <freetype/ftbitmap.h>
  #endif
  
  #define UI_SIZE_BUTTON_MINIMUM_WIDTH (100)
  #define UI_SIZE_BUTTON_PADDING (16)
  #define UI_SIZE_BUTTON_HEIGHT (27)
  #define UI_SIZE_BUTTON_CHECKED_AREA (4)
  
  #define UI_SIZE_CHECKBOX_BOX (14)
  #define UI_SIZE_CHECKBOX_GAP (8)
  
  #define UI_SIZE_MENU_ITEM_HEIGHT (24)
  #define UI_SIZE_MENU_ITEM_MINIMUM_WIDTH (160)
  #define UI_SIZE_MENU_ITEM_MARGIN (9)
  
  #define UI_SIZE_GAUGE_WIDTH (200)
  #define UI_SIZE_GAUGE_HEIGHT (22)
  
  #define UI_SIZE_SLIDER_WIDTH (200)
  #define UI_SIZE_SLIDER_HEIGHT (25)
  #define UI_SIZE_SLIDER_THUMB (15)
  #define UI_SIZE_SLIDER_TRACK (5)
  
  #define UI_SIZE_TEXTBOX_MARGIN (3)
  #define UI_SIZE_TEXTBOX_WIDTH (200)
  #define UI_SIZE_TEXTBOX_HEIGHT (27)
  
  #define UI_SIZE_TAB_PANE_SPACE_TOP (2)
  #define UI_SIZE_TAB_PANE_SPACE_LEFT (4)
  
  #define UI_SIZE_SPLITTER (8)
  
  #define UI_SIZE_SCROLL_BAR (16)
  #define UI_SIZE_SCROLL_MINIMUM_THUMB (20)
  
  #define UI_SIZE_CODE_MARGIN (ui.activeFont->glyphWidth * 5)
  #define UI_SIZE_CODE_MARGIN_GAP (ui.activeFont->glyphWidth * 1)
  
  #define UI_SIZE_TABLE_HEADER (26)
  #define UI_SIZE_TABLE_COLUMN_GAP (20)
  #define UI_SIZE_TABLE_ROW (20)
  
  #define UI_SIZE_PANE_MEDIUM_BORDER (5)
  #define UI_SIZE_PANE_MEDIUM_GAP (5)
  #define UI_SIZE_PANE_SMALL_BORDER (3)
  #define UI_SIZE_PANE_SMALL_GAP (3)
  
  #define UI_SIZE_MDI_CHILD_BORDER (6)
  #define UI_SIZE_MDI_CHILD_TITLE (30)
  #define UI_SIZE_MDI_CHILD_CORNER (12)
  #define UI_SIZE_MDI_CHILD_MINIMUM_WIDTH (100)
  #define UI_SIZE_MDI_CHILD_MINIMUM_HEIGHT (50)
  #define UI_SIZE_MDI_CASCADE (30)
  
  #define UI_UPDATE_HOVERED (1)
  #define UI_UPDATE_PRESSED (2)
  #define UI_UPDATE_FOCUSED (3)
  
  typedef enum UIMessage {
  	UI_MSG_PAINT, // dp = pointer to UIPainter
  	UI_MSG_LAYOUT,
  	UI_MSG_DESTROY,
  	UI_MSG_UPDATE, // di = UI_UPDATE_... constant
  	UI_MSG_ANIMATE,
  	UI_MSG_SCROLLED,
  	UI_MSG_GET_WIDTH, // di = height (if known); return width
  	UI_MSG_GET_HEIGHT, // di = width (if known); return height
  	UI_MSG_FIND_BY_POINT, // dp = pointer to UIFindByPoint; return 1 if handled
  	UI_MSG_CLIENT_PARENT, // dp = pointer to UIElement *, set it to the parent for client elements
  
  	UI_MSG_INPUT_EVENTS_START, // not sent to disabled elements
  	UI_MSG_LEFT_DOWN,
  	UI_MSG_LEFT_UP,
  	UI_MSG_MIDDLE_DOWN,
  	UI_MSG_MIDDLE_UP,
  	UI_MSG_RIGHT_DOWN,
  	UI_MSG_RIGHT_UP,
  	UI_MSG_KEY_TYPED, // dp = pointer to UIKeyTyped; return 1 if handled
  	UI_MSG_MOUSE_MOVE,
  	UI_MSG_MOUSE_DRAG,
  	UI_MSG_MOUSE_WHEEL, // di = delta; return 1 if handled
  	UI_MSG_CLICKED,
  	UI_MSG_GET_CURSOR, // return cursor code
  	UI_MSG_PRESSED_DESCENDENT, // dp = pointer to child that is/contains pressed element
  	UI_MSG_INPUT_EVENTS_END,
  
  	UI_MSG_VALUE_CHANGED, // sent to notify that the element's value has changed
  	UI_MSG_TABLE_GET_ITEM, // dp = pointer to UITableGetItem; return string length
  	UI_MSG_CODE_GET_MARGIN_COLOR, // di = line index (starts at 1); return color
  	UI_MSG_CODE_DECORATE_LINE, // dp = pointer to UICodeDecorateLine
  	UI_MSG_WINDOW_CLOSE, // return 1 to prevent default (process exit for UIWindow; close for UIMDIChild)
  	UI_MSG_TAB_SELECTED, // sent to the tab that was selected (not the tab pane itself)
  	UI_MSG_WINDOW_DROP_FILES, // di = count, dp = char ** of paths
  	UI_MSG_WINDOW_ACTIVATE,
  
  	UI_MSG_USER,
  } UIMessage;
  
  #ifdef UI_ESSENCE
  #define UIRectangle EsRectangle
  #else
  typedef struct UIRectangle {
  	int l, r, t, b;
  } UIRectangle;
  #endif
  
  typedef struct UITheme {
  	uint32_t panel1, panel2, selected, border;
  	uint32_t text, textDisabled, textSelected;
  	uint32_t buttonNormal, buttonHovered, buttonPressed, buttonDisabled;
  	uint32_t textboxNormal, textboxFocused;
  	uint32_t codeFocused, codeBackground, codeDefault, codeComment, codeString, codeNumber, codeOperator, codePreprocessor;
  } UITheme;
  
  typedef struct UIPainter {
  	UIRectangle clip;
  	uint32_t *bits;
  	int width, height;
  #ifdef UI_DEBUG
  	int fillCount;
  #endif
  } UIPainter;
  
  typedef struct UIFont {
  	int glyphWidth, glyphHeight;
  
  #ifdef UI_FREETYPE
  	bool isFreeType;
  	FT_Face font;
  	FT_Bitmap glyphs[128];
  	bool glyphsRendered[128];
  	int glyphOffsetsX[128], glyphOffsetsY[128];
  #endif
  } UIFont;
  
  typedef struct UIShortcut {
  	intptr_t code;
  	bool ctrl, shift, alt;
  	void (*invoke)(void *cp);
  	void *cp;
  } UIShortcut;
  
  typedef struct UIStringSelection {
  	int carets[2];
  	uint32_t colorText, colorBackground;
  } UIStringSelection;
  
  typedef struct UIKeyTyped {
  	char *text;
  	int textBytes;
  	intptr_t code;
  } UIKeyTyped;
  
  typedef struct UITableGetItem {
  	char *buffer;
  	size_t bufferBytes;
  	int index, column;
  	bool isSelected;
  } UITableGetItem;
  
  typedef struct UICodeDecorateLine {
  	UIRectangle bounds;
  	int index; // Starting at 1!
  	int x, y; // Position where additional text can be drawn.
  	UIPainter *painter;
  } UICodeDecorateLine;
  
  typedef struct UIFindByPoint {
  	int x, y;
  	struct UIElement *result;
  } UIFindByPoint;
  
  #define UI_RECT_1(x) ((UIRectangle) { (x), (x), (x), (x) })
  #define UI_RECT_1I(x) ((UIRectangle) { (x), -(x), (x), -(x) })
  #define UI_RECT_2(x, y) ((UIRectangle) { (x), (x), (y), (y) })
  #define UI_RECT_2I(x, y) ((UIRectangle) { (x), -(x), (y), -(y) })
  #define UI_RECT_2S(x, y) ((UIRectangle) { 0, (x), 0, (y) })
  #define UI_RECT_4(x, y, z, w) ((UIRectangle) { (x), (y), (z), (w) })
  #define UI_RECT_WIDTH(_r) ((_r).r - (_r).l)
  #define UI_RECT_HEIGHT(_r) ((_r).b - (_r).t)
  #define UI_RECT_TOTAL_H(_r) ((_r).r + (_r).l)
  #define UI_RECT_TOTAL_V(_r) ((_r).b + (_r).t)
  #define UI_RECT_SIZE(_r) UI_RECT_WIDTH(_r), UI_RECT_HEIGHT(_r)
  #define UI_RECT_TOP_LEFT(_r) (_r).l, (_r).t
  #define UI_RECT_BOTTOM_LEFT(_r) (_r).l, (_r).b
  #define UI_RECT_BOTTOM_RIGHT(_r) (_r).r, (_r).b
  #define UI_RECT_ALL(_r) (_r).l, (_r).r, (_r).t, (_r).b
  #define UI_RECT_VALID(_r) (UI_RECT_WIDTH(_r) > 0 && UI_RECT_HEIGHT(_r) > 0)
  
  #define UI_COLOR_ALPHA_F(x) ((((x) >> 24) & 0xFF) / 255.0f)
  #define UI_COLOR_RED_F(x) ((((x) >> 16) & 0xFF) / 255.0f)
  #define UI_COLOR_GREEN_F(x) ((((x) >> 8) & 0xFF) / 255.0f)
  #define UI_COLOR_BLUE_F(x) ((((x) >> 0) & 0xFF) / 255.0f)
  #define UI_COLOR_ALPHA(x) ((((x) >> 24) & 0xFF))
  #define UI_COLOR_RED(x) ((((x) >> 16) & 0xFF))
  #define UI_COLOR_GREEN(x) ((((x) >> 8) & 0xFF))
  #define UI_COLOR_BLUE(x) ((((x) >> 0) & 0xFF))
  #define UI_COLOR_FROM_FLOAT(r, g, b) (((uint32_t) ((r) * 255.0f) << 16) | ((uint32_t) ((g) * 255.0f) << 8) | ((uint32_t) ((b) * 255.0f) << 0))
  #define UI_COLOR_FROM_RGBA_F(r, g, b, a) (((uint32_t) ((r) * 255.0f) << 16) | ((uint32_t) ((g) * 255.0f) << 8) \
  		| ((uint32_t) ((b) * 255.0f) << 0) | ((uint32_t) ((a) * 255.0f) << 24))
  
  #define UI_SWAP(s, a, b) do { s t = (a); (a) = (b); (b) = t; } while (0)
  
  #define UI_CURSOR_ARROW (0)
  #define UI_CURSOR_TEXT (1)
  #define UI_CURSOR_SPLIT_V (2)
  #define UI_CURSOR_SPLIT_H (3)
  #define UI_CURSOR_FLIPPED_ARROW (4)
  #define UI_CURSOR_CROSS_HAIR (5)
  #define UI_CURSOR_HAND (6)
  #define UI_CURSOR_RESIZE_UP (7)
  #define UI_CURSOR_RESIZE_LEFT (8)
  #define UI_CURSOR_RESIZE_UP_RIGHT (9)
  #define UI_CURSOR_RESIZE_UP_LEFT (10)
  #define UI_CURSOR_RESIZE_DOWN (11)
  #define UI_CURSOR_RESIZE_RIGHT (12)
  #define UI_CURSOR_RESIZE_DOWN_RIGHT (13)
  #define UI_CURSOR_RESIZE_DOWN_LEFT (14)
  #define UI_CURSOR_COUNT (15)
  
  #define UI_ALIGN_LEFT (1)
  #define UI_ALIGN_RIGHT (2)
  #define UI_ALIGN_CENTER (3)
  
  extern const int UI_KEYCODE_A;
  extern const int UI_KEYCODE_BACKSPACE;
  extern const int UI_KEYCODE_DELETE;
  extern const int UI_KEYCODE_DOWN;
  extern const int UI_KEYCODE_END;
  extern const int UI_KEYCODE_ENTER;
  extern const int UI_KEYCODE_ESCAPE;
  extern const int UI_KEYCODE_F1;
  extern const int UI_KEYCODE_HOME;
  extern const int UI_KEYCODE_LEFT;
  extern const int UI_KEYCODE_RIGHT;
  extern const int UI_KEYCODE_SPACE;
  extern const int UI_KEYCODE_TAB;
  extern const int UI_KEYCODE_UP;
  extern const int UI_KEYCODE_0;
  
  #define UI_KEYCODE_LETTER(x) (UI_KEYCODE_A + (x) - 'A')
  #define UI_KEYCODE_DIGIT(x) (UI_KEYCODE_0 + (x) - '0')
  #define UI_KEYCODE_FKEY(x) (UI_KEYCODE_F1 + (x) - 1)
  
  typedef struct UIElement {
  #define UI_ELEMENT_V_FILL (1 << 16)
  #define UI_ELEMENT_H_FILL (1 << 17)
  #define UI_ELEMENT_WINDOW (1 << 18)
  #define UI_ELEMENT_PARENT_PUSH (1 << 19)
  #define UI_ELEMENT_TAB_STOP (1 << 20)
  #define UI_ELEMENT_NON_CLIENT (1 << 21) // Don't destroy in UIElementDestroyDescendents, like scroll bars.
  #define UI_ELEMENT_DISABLED (1 << 22) // Don't receive input events.
  
  #define UI_ELEMENT_HIDE (1 << 29)
  #define UI_ELEMENT_DESTROY (1 << 30)
  #define UI_ELEMENT_DESTROY_DESCENDENT (1 << 31)
  
  	uint32_t flags; // First 16 bits are element specific.
  
  	struct UIElement *parent;
  	struct UIElement *next;
  	struct UIElement *children;
  	struct UIWindow *window;
  
  	UIRectangle bounds, clip;
  	
  	void *cp; // Context pointer (for user).
  
  	int (*messageClass)(struct UIElement *element, UIMessage message, int di /* data integer */, void *dp /* data pointer */);
  	int (*messageUser)(struct UIElement *element, UIMessage message, int di, void *dp);
  
  #ifdef UI_DEBUG
  	const char *cClassName;
  	int id;
  #endif
  } UIElement;
  
  #define UI_SHORTCUT(code, ctrl, shift, alt, invoke, cp) ((UIShortcut) { (code), (ctrl), (shift), (alt), (invoke), (cp) })
  
  typedef struct UIWindow {
  #define UI_WINDOW_MENU (1 << 0)
  #define UI_WINDOW_INSPECTOR (1 << 1)
  #define UI_WINDOW_CENTER_IN_OWNER (1 << 2)
  #define UI_WINDOW_MAXIMIZE (1 << 3)
  
  	UIElement e;
  
  	UIElement *dialog;
  
  	UIShortcut *shortcuts;
  	size_t shortcutCount, shortcutAllocated;
  
  	float scale;
  
  	uint32_t *bits;
  	int width, height;
  	struct UIWindow *next;
  
  	UIElement *hovered, *pressed, *focused, *dialogOldFocus;
  	int pressedButton;
  
  	int cursorX, cursorY;
  	int cursorStyle;
  
  	// Set when a textbox is modified. 
  	// Useful for tracking whether changes to the loaded document have been saved.
  	bool textboxModifiedFlag; 
  
  	bool ctrl, shift, alt;
  
  	UIRectangle updateRegion;
  
  #ifdef UI_DEBUG
  	float lastFullFillCount;
  #endif
  
  #ifdef UI_LINUX
  	Window window;
  	XImage *image;
  	XIC xic;
  	unsigned ctrlCode, shiftCode, altCode;
  	Window dragSource;
  #endif
  
  #ifdef UI_WINDOWS
  	HWND hwnd;
  	bool trackingLeave;
  #endif
  
  #ifdef UI_ESSENCE
  	EsWindow *window;
  	EsElement *canvas;
  	int cursor;
  #endif
  } UIWindow;
  
  typedef struct UIPanel {
  #define UI_PANEL_HORIZONTAL (1 << 0)
  #define UI_PANEL_GRAY (1 << 2)
  #define UI_PANEL_WHITE (1 << 3)
  #define UI_PANEL_EXPAND (1 << 4)
  #define UI_PANEL_MEDIUM_SPACING (1 << 5)
  #define UI_PANEL_SMALL_SPACING (1 << 6)
  #define UI_PANEL_SCROLL (1 << 7)
  #define UI_PANEL_BORDER (1 << 8)
  	UIElement e;
  	struct UIScrollBar *scrollBar;
  	UIRectangle border;
  	int gap;
  } UIPanel;
  
  typedef struct UIButton {
  #define UI_BUTTON_SMALL (1 << 0)
  #define UI_BUTTON_MENU_ITEM (1 << 1)
  #define UI_BUTTON_CAN_FOCUS (1 << 2)
  #define UI_BUTTON_DROP_DOWN (1 << 3)
  #define UI_BUTTON_CHECKED (1 << 15)
  	UIElement e;
  	char *label;
  	ptrdiff_t labelBytes;
  	void (*invoke)(void *cp);
  } UIButton;
  
  typedef struct UICheckbox {
  #define UI_CHECKBOX_ALLOW_INDETERMINATE (1 << 0)
  	UIElement e;
  #define UI_CHECK_UNCHECKED (0)
  #define UI_CHECK_CHECKED (1)
  #define UI_CHECK_INDETERMINATE (2)
  	uint8_t check;
  	char *label;
  	ptrdiff_t labelBytes;
  	void (*invoke)(void *cp);
  } UICheckbox;
  
  typedef struct UILabel {
  	UIElement e;
  	char *label;
  	ptrdiff_t labelBytes;
  } UILabel;
  
  typedef struct UISpacer {
  #define UI_SPACER_LINE (1 << 0)
  	UIElement e;
  	int width, height;
  } UISpacer;
  
  typedef struct UISplitPane {
  #define UI_SPLIT_PANE_VERTICAL (1 << 0)
  	UIElement e;
  	float weight;
  } UISplitPane;
  
  typedef struct UITabPane {
  	UIElement e;
  	char *tabs;
  	int active;
  } UITabPane;
  
  typedef struct UIScrollBar {
  #define UI_SCROLL_BAR_HORIZONTAL (1 << 0)
  	UIElement e;
  	int64_t maximum, page;
  	int64_t dragOffset;
  	double position;
  	uint64_t lastAnimateTime;
  	bool inDrag, horizontal;
  } UIScrollBar;
  
  typedef struct UICodeLine {
  	int offset, bytes;
  } UICodeLine;
  
  typedef struct UICode {
  #define UI_CODE_NO_MARGIN (1 << 0)
  	UIElement e;
  	UIScrollBar *vScroll;
  	UICodeLine *lines;
  	UIFont *font;
  	int lineCount, focused;
  	bool moveScrollToFocusNextLayout;
  	char *content;
  	size_t contentBytes;
  	int tabSize;
  } UICode;
  
  typedef struct UIGauge {
  	UIElement e;
  	float position;
  } UIGauge;
  
  typedef struct UITable {
  	UIElement e;
  	UIScrollBar *vScroll;
  	int itemCount;
  	char *columns;
  	int *columnWidths, columnCount, columnHighlight;
  } UITable;
  
  typedef struct UITextbox {
  	UIElement e;
  	char *string;
  	ptrdiff_t bytes;
  	int carets[2];
  	int scroll;
  	bool rejectNextKey;
  } UITextbox;
  
  #define UI_MENU_PLACE_ABOVE (1 << 0)
  #define UI_MENU_NO_SCROLL (1 << 1)
  #ifdef UI_ESSENCE
  typedef EsMenu UIMenu;
  #else
  typedef struct UIMenu {
  	UIElement e;
  	int pointX, pointY;
  	UIScrollBar *vScroll;
  } UIMenu;
  #endif
  
  typedef struct UISlider {
  	UIElement e;
  	float position;
  	int steps;
  } UISlider;
  
  typedef struct UIColorPicker {
  #define UI_COLOR_PICKER_HAS_OPACITY (1 << 0)
  	UIElement e;
  	float hue, saturation, value, opacity;
  } UIColorPicker;
  
  typedef struct UIMDIClient {
  #define UI_MDI_CLIENT_TRANSPARENT (1 << 0)
  	UIElement e;
  	struct UIMDIChild *active;
  	int cascade;
  } UIMDIClient;
  
  typedef struct UIMDIChild {
  #define UI_MDI_CHILD_CLOSE_BUTTON (1 << 0)
  	UIElement e;
  	UIRectangle bounds;
  	char *title;
  	ptrdiff_t titleBytes;
  	int dragHitTest;
  	UIRectangle dragOffset;
  	struct UIMDIChild *previous;
  } UIMDIChild;
  
  typedef struct UIExpandPane {
  	UIElement e;
  	UIButton *button;
  	UIPanel *panel;
  	bool expanded;
  } UIExpandPane;
  
  typedef struct UIImageDisplay {
  #define UI_IMAGE_DISPLAY_INTERACTIVE (1 << 0)
  #define _UI_IMAGE_DISPLAY_ZOOM_FIT (1 << 1)
  
  	UIElement e;
  	uint32_t *bits;
  	int width, height;
  	float panX, panY, zoom;
  	
  	// Internals:
  	int previousWidth, previousHeight;
  	int previousPanPointX, previousPanPointY;
  } UIImageDisplay;
  
  void UIInitialise();
  int UIMessageLoop();
  
  UIElement *UIElementCreate(size_t bytes, UIElement *parent, uint32_t flags, 
  	int (*messageClass)(UIElement *, UIMessage, int, void *), const char *cClassName);
  
  UIButton *UIButtonCreate(UIElement *parent, uint32_t flags, const char *label, ptrdiff_t labelBytes);
  UICheckbox *UICheckboxCreate(UIElement *parent, uint32_t flags, const char *label, ptrdiff_t labelBytes);
  UIColorPicker *UIColorPickerCreate(UIElement *parent, uint32_t flags);
  UIExpandPane *UIExpandPaneCreate(UIElement *parent, uint32_t flags, const char *label, ptrdiff_t labelBytes, uint32_t panelFlags);
  UIGauge *UIGaugeCreate(UIElement *parent, uint32_t flags);
  UIMDIClient *UIMDIClientCreate(UIElement *parent, uint32_t flags);
  UIMDIChild *UIMDIChildCreate(UIElement *parent, uint32_t flags, UIRectangle initialBounds, const char *title, ptrdiff_t titleBytes);
  UIPanel *UIPanelCreate(UIElement *parent, uint32_t flags);
  UIScrollBar *UIScrollBarCreate(UIElement *parent, uint32_t flags);
  UISlider *UISliderCreate(UIElement *parent, uint32_t flags);
  UISpacer *UISpacerCreate(UIElement *parent, uint32_t flags, int width, int height);
  UISplitPane *UISplitPaneCreate(UIElement *parent, uint32_t flags, float weight);
  UITabPane *UITabPaneCreate(UIElement *parent, uint32_t flags, const char *tabs /* separate with \t, terminate with \0 */);
  
  UILabel *UILabelCreate(UIElement *parent, uint32_t flags, const char *label, ptrdiff_t labelBytes);
  void UILabelSetContent(UILabel *code, const char *content, ptrdiff_t byteCount);
  
  UIImageDisplay *UIImageDisplayCreate(UIElement *parent, uint32_t flags, uint32_t *bits, size_t width, size_t height, size_t stride);
  void UIImageDisplaySetContent(UIImageDisplay *display, uint32_t *bits, size_t width, size_t height, size_t stride);
  
  UIWindow *UIWindowCreate(UIWindow *owner, uint32_t flags, const char *cTitle, int width, int height);
  void UIWindowRegisterShortcut(UIWindow *window, UIShortcut shortcut);
  void UIWindowPostMessage(UIWindow *window, UIMessage message, void *dp); // Thread-safe.
  void UIWindowPack(UIWindow *window, int width); // Change the size of the window to best match its contents.
  
  const char *UIDialogShow(UIWindow *window, uint32_t flags, const char *format, ...);
  
  UIMenu *UIMenuCreate(UIElement *parent, uint32_t flags);
  void UIMenuAddItem(UIMenu *menu, uint32_t flags, const char *label, ptrdiff_t labelBytes, void (*invoke)(void *cp), void *cp);
  void UIMenuShow(UIMenu *menu);
  
  UITextbox *UITextboxCreate(UIElement *parent, uint32_t flags);
  void UITextboxReplace(UITextbox *textbox, const char *text, ptrdiff_t bytes, bool sendChangedMessage);
  void UITextboxClear(UITextbox *textbox, bool sendChangedMessage);
  void UITextboxMoveCaret(UITextbox *textbox, bool backward, bool word);
  
  UITable *UITableCreate(UIElement *parent, uint32_t flags, const char *columns /* separate with \t, terminate with \0 */);
  int UITableHitTest(UITable *table, int x, int y); // Returns item index. Returns -1 if not on an item.
  int UITableHeaderHitTest(UITable *table, int x, int y); // Returns column index or -1.
  bool UITableEnsureVisible(UITable *table, int index); // Returns false if the item was already visible.
  void UITableResizeColumns(UITable *table);
  
  UICode *UICodeCreate(UIElement *parent, uint32_t flags);
  void UICodeFocusLine(UICode *code, int index); // Line numbers are 1-indexed!!
  int UICodeHitTest(UICode *code, int x, int y); // Returns line number; negates if in margin. Returns 0 if not on a line.
  void UICodeInsertContent(UICode *code, const char *content, ptrdiff_t byteCount, bool replace);
  
  void UIDrawBlock(UIPainter *painter, UIRectangle rectangle, uint32_t color);
  void UIDrawInvert(UIPainter *painter, UIRectangle rectangle);
  bool UIDrawLine(UIPainter *painter, int x0, int y0, int x1, int y1, uint32_t color); // Returns false if the line was not visible.
  void UIDrawGlyph(UIPainter *painter, int x, int y, int c, uint32_t color);
  void UIDrawRectangle(UIPainter *painter, UIRectangle r, uint32_t mainColor, uint32_t borderColor, UIRectangle borderSize);
  void UIDrawBorder(UIPainter *painter, UIRectangle r, uint32_t borderColor, UIRectangle borderSize);
  void UIDrawString(UIPainter *painter, UIRectangle r, const char *string, ptrdiff_t bytes, uint32_t color, int align, UIStringSelection *selection);
  int UIDrawStringHighlighted(UIPainter *painter, UIRectangle r, const char *string, ptrdiff_t bytes, int tabSize);
  
  int UIMeasureStringWidth(const char *string, ptrdiff_t bytes);
  int UIMeasureStringHeight();
  
  uint64_t UIAnimateClock(); // In ms.
  
  bool UIElementAnimate(UIElement *element, bool stop);
  void UIElementDestroy(UIElement *element);
  void UIElementDestroyDescendents(UIElement *element);
  UIElement *UIElementFindByPoint(UIElement *element, int x, int y);
  void UIElementFocus(UIElement *element);
  UIRectangle UIElementScreenBounds(UIElement *element); // Returns bounds of element in same coordinate system as used by UIWindowCreate.
  void UIElementRefresh(UIElement *element);
  void UIElementRepaint(UIElement *element, UIRectangle *region);
  void UIElementMove(UIElement *element, UIRectangle bounds, bool alwaysLayout);
  int UIElementMessage(UIElement *element, UIMessage message, int di, void *dp);
  void UIElementChangeParent(UIElement *element, UIElement *newParent, UIElement *insertBefore); // Set insertBefore to null to insert at the end.
  
  UIElement *UIParentPush(UIElement *element);
  UIElement *UIParentPop();
  
  UIRectangle UIRectangleIntersection(UIRectangle a, UIRectangle b);
  UIRectangle UIRectangleBounding(UIRectangle a, UIRectangle b);
  UIRectangle UIRectangleAdd(UIRectangle a, UIRectangle b);
  UIRectangle UIRectangleTranslate(UIRectangle a, UIRectangle b);
  bool UIRectangleEquals(UIRectangle a, UIRectangle b);
  bool UIRectangleContains(UIRectangle a, int x, int y);
  
  bool UIColorToHSV(uint32_t rgb, float *hue, float *saturation, float *value);
  void UIColorToRGB(float hue, float saturation, float value, uint32_t *rgb);
  
  char *UIStringCopy(const char *in, ptrdiff_t inBytes);
  
  UIFont *UIFontCreate(const char *cPath, uint32_t size);
  UIFont *UIFontActivate(UIFont *font); // Returns the previously active font.
  
  #ifdef UI_DEBUG
  void UIInspectorLog(const char *cFormat, ...);
  #endif
  
  #ifdef UI_IMPLEMENTATION
  
  struct {
  	UIWindow *windows;
  	UIElement *animating;
  	UITheme theme;
  
  	UIElement *parentStack[16];
  	int parentStackCount;
  
  	bool quit;
  	const char *dialogResult;
  	UIElement *dialogOldFocus;
  
  	UIFont *activeFont;
  
  #ifdef UI_DEBUG
  	UIWindow *inspector;
  	UITable *inspectorTable;
  	UIWindow *inspectorTarget;
  	UICode *inspectorLog;
  #endif
  
  #ifdef UI_LINUX
  	Display *display;
  	Visual *visual;
  	XIM xim;
  	Atom windowClosedID, primaryID, uriListID, plainTextID;
  	Atom dndEnterID, dndPositionID, dndStatusID, dndActionCopyID, dndDropID, dndSelectionID, dndFinishedID, dndAwareID;
  	Cursor cursors[UI_CURSOR_COUNT];
  #endif
  
  #ifdef UI_WINDOWS
  	HCURSOR cursors[UI_CURSOR_COUNT];
  	HANDLE heap;
  	bool assertionFailure;
  #endif
  
  #ifdef UI_ESSENCE
  	EsInstance *instance;
  
  	void *menuData[256]; // HACK This limits the number of menu items to 128.
  	uintptr_t menuIndex;
  #endif
  
  #ifdef UI_FREETYPE
  	FT_Library ft;
  #endif
  } ui;
  
  UITheme _uiThemeClassic = {
  	.panel1 = 0xFFF0F0F0,
  	.panel2 = 0xFFFFFFFF,
  	.selected = 0xFF94BEFE,
  	.border = 0xFF404040,
  
  	.text = 0xFF000000,
  	.textDisabled = 0xFF404040,
  	.textSelected = 0xFF000000,
  
  	.buttonNormal = 0xFFE0E0E0,
  	.buttonHovered = 0xFFF0F0F0,
  	.buttonPressed = 0xFFA0A0A0,
  	.buttonDisabled = 0xFFF0F0F0,
  
  	.textboxNormal = 0xFFF8F8F8,
  	.textboxFocused = 0xFFFFFFFF,
  
  	.codeFocused = 0xFFE0E0E0,
  	.codeBackground = 0xFFFFFFFF,
  	.codeDefault = 0xFF000000,
  	.codeComment = 0xFFA11F20,
  	.codeString = 0xFF037E01,
  	.codeNumber = 0xFF213EF1,
  	.codeOperator = 0xFF7F0480,
  	.codePreprocessor = 0xFF545D70,
  };
  
  UITheme _uiThemeDark = {
  	.panel1 = 0xFF252B31,
  	.panel2 = 0xFF14181E,
  	.selected = 0xFF94BEFE,
  	.border = 0xFF000000,
  
  	.text = 0xFFFFFFFF,
  	.textDisabled = 0xFF787D81,
  	.textSelected = 0xFF000000,
  
  	.buttonNormal = 0xFF383D41,
  	.buttonHovered = 0xFF4B5874,
  	.buttonPressed = 0xFF0D0D0F,
  	.buttonDisabled = 0xFF1B1F23,
  
  	.textboxNormal = 0xFF31353C,
  	.textboxFocused = 0xFF4D4D59,
  
  	.codeFocused = 0xFF505055,
  	.codeBackground = 0xFF212126,
  	.codeDefault = 0xFFFFFFFF,
  	.codeComment = 0xFFB4B4B4,
  	.codeString = 0xFFF5DDD1,
  	.codeNumber = 0xFFC3F5D3,
  	.codeOperator = 0xFFF5D499,
  	.codePreprocessor = 0xFFF5F3D1,
  };
  
  // Taken from https://commons.wikimedia.org/wiki/File:Codepage-437.png
  // Public domain.
  
  const uint64_t _uiFont[] = {
  	0x0000000000000000UL, 0x0000000000000000UL, 0xBD8181A5817E0000UL, 0x000000007E818199UL, 0xC3FFFFDBFF7E0000UL, 0x000000007EFFFFE7UL, 0x7F7F7F3600000000UL, 0x00000000081C3E7FUL, 
  	0x7F3E1C0800000000UL, 0x0000000000081C3EUL, 0xE7E73C3C18000000UL, 0x000000003C1818E7UL, 0xFFFF7E3C18000000UL, 0x000000003C18187EUL, 0x3C18000000000000UL, 0x000000000000183CUL, 
  	0xC3E7FFFFFFFFFFFFUL, 0xFFFFFFFFFFFFE7C3UL, 0x42663C0000000000UL, 0x00000000003C6642UL, 0xBD99C3FFFFFFFFFFUL, 0xFFFFFFFFFFC399BDUL, 0x331E4C5870780000UL, 0x000000001E333333UL, 
  	0x3C666666663C0000UL, 0x0000000018187E18UL, 0x0C0C0CFCCCFC0000UL, 0x00000000070F0E0CUL, 0xC6C6C6FEC6FE0000UL, 0x0000000367E7E6C6UL, 0xE73CDB1818000000UL, 0x000000001818DB3CUL, 
  	0x1F7F1F0F07030100UL, 0x000000000103070FUL, 0x7C7F7C7870604000UL, 0x0000000040607078UL, 0x1818187E3C180000UL, 0x0000000000183C7EUL, 0x6666666666660000UL, 0x0000000066660066UL, 
  	0xD8DEDBDBDBFE0000UL, 0x00000000D8D8D8D8UL, 0x6363361C06633E00UL, 0x0000003E63301C36UL, 0x0000000000000000UL, 0x000000007F7F7F7FUL, 0x1818187E3C180000UL, 0x000000007E183C7EUL, 
  	0x1818187E3C180000UL, 0x0000000018181818UL, 0x1818181818180000UL, 0x00000000183C7E18UL, 0x7F30180000000000UL, 0x0000000000001830UL, 0x7F060C0000000000UL, 0x0000000000000C06UL, 
  	0x0303000000000000UL, 0x0000000000007F03UL, 0xFF66240000000000UL, 0x0000000000002466UL, 0x3E1C1C0800000000UL, 0x00000000007F7F3EUL, 0x3E3E7F7F00000000UL, 0x0000000000081C1CUL, 
  	0x0000000000000000UL, 0x0000000000000000UL, 0x18183C3C3C180000UL, 0x0000000018180018UL, 0x0000002466666600UL, 0x0000000000000000UL, 0x36367F3636000000UL, 0x0000000036367F36UL, 
  	0x603E0343633E1818UL, 0x000018183E636160UL, 0x1830634300000000UL, 0x000000006163060CUL, 0x3B6E1C36361C0000UL, 0x000000006E333333UL, 0x000000060C0C0C00UL, 0x0000000000000000UL, 
  	0x0C0C0C0C18300000UL, 0x0000000030180C0CUL, 0x30303030180C0000UL, 0x000000000C183030UL, 0xFF3C660000000000UL, 0x000000000000663CUL, 0x7E18180000000000UL, 0x0000000000001818UL, 
  	0x0000000000000000UL, 0x0000000C18181800UL, 0x7F00000000000000UL, 0x0000000000000000UL, 0x0000000000000000UL, 0x0000000018180000UL, 0x1830604000000000UL, 0x000000000103060CUL, 
  	0xDBDBC3C3663C0000UL, 0x000000003C66C3C3UL, 0x1818181E1C180000UL, 0x000000007E181818UL, 0x0C183060633E0000UL, 0x000000007F630306UL, 0x603C6060633E0000UL, 0x000000003E636060UL, 
  	0x7F33363C38300000UL, 0x0000000078303030UL, 0x603F0303037F0000UL, 0x000000003E636060UL, 0x633F0303061C0000UL, 0x000000003E636363UL, 0x18306060637F0000UL, 0x000000000C0C0C0CUL, 
  	0x633E6363633E0000UL, 0x000000003E636363UL, 0x607E6363633E0000UL, 0x000000001E306060UL, 0x0000181800000000UL, 0x0000000000181800UL, 0x0000181800000000UL, 0x000000000C181800UL, 
  	0x060C183060000000UL, 0x000000006030180CUL, 0x00007E0000000000UL, 0x000000000000007EUL, 0x6030180C06000000UL, 0x00000000060C1830UL, 0x18183063633E0000UL, 0x0000000018180018UL, 
  	0x7B7B63633E000000UL, 0x000000003E033B7BUL, 0x7F6363361C080000UL, 0x0000000063636363UL, 0x663E6666663F0000UL, 0x000000003F666666UL, 0x03030343663C0000UL, 0x000000003C664303UL, 
  	0x66666666361F0000UL, 0x000000001F366666UL, 0x161E1646667F0000UL, 0x000000007F664606UL, 0x161E1646667F0000UL, 0x000000000F060606UL, 0x7B030343663C0000UL, 0x000000005C666363UL, 
  	0x637F636363630000UL, 0x0000000063636363UL, 0x18181818183C0000UL, 0x000000003C181818UL, 0x3030303030780000UL, 0x000000001E333333UL, 0x1E1E366666670000UL, 0x0000000067666636UL, 
  	0x06060606060F0000UL, 0x000000007F664606UL, 0xC3DBFFFFE7C30000UL, 0x00000000C3C3C3C3UL, 0x737B7F6F67630000UL, 0x0000000063636363UL, 0x63636363633E0000UL, 0x000000003E636363UL, 
  	0x063E6666663F0000UL, 0x000000000F060606UL, 0x63636363633E0000UL, 0x000070303E7B6B63UL, 0x363E6666663F0000UL, 0x0000000067666666UL, 0x301C0663633E0000UL, 0x000000003E636360UL, 
  	0x18181899DBFF0000UL, 0x000000003C181818UL, 0x6363636363630000UL, 0x000000003E636363UL, 0xC3C3C3C3C3C30000UL, 0x00000000183C66C3UL, 0xDBC3C3C3C3C30000UL, 0x000000006666FFDBUL, 
  	0x18183C66C3C30000UL, 0x00000000C3C3663CUL, 0x183C66C3C3C30000UL, 0x000000003C181818UL, 0x0C183061C3FF0000UL, 0x00000000FFC38306UL, 0x0C0C0C0C0C3C0000UL, 0x000000003C0C0C0CUL, 
  	0x1C0E070301000000UL, 0x0000000040607038UL, 0x30303030303C0000UL, 0x000000003C303030UL, 0x0000000063361C08UL, 0x0000000000000000UL, 0x0000000000000000UL, 0x0000FF0000000000UL, 
  	0x0000000000180C0CUL, 0x0000000000000000UL, 0x3E301E0000000000UL, 0x000000006E333333UL, 0x66361E0606070000UL, 0x000000003E666666UL, 0x03633E0000000000UL, 0x000000003E630303UL, 
  	0x33363C3030380000UL, 0x000000006E333333UL, 0x7F633E0000000000UL, 0x000000003E630303UL, 0x060F0626361C0000UL, 0x000000000F060606UL, 0x33336E0000000000UL, 0x001E33303E333333UL, 
  	0x666E360606070000UL, 0x0000000067666666UL, 0x18181C0018180000UL, 0x000000003C181818UL, 0x6060700060600000UL, 0x003C666660606060UL, 0x1E36660606070000UL, 0x000000006766361EUL, 
  	0x18181818181C0000UL, 0x000000003C181818UL, 0xDBFF670000000000UL, 0x00000000DBDBDBDBUL, 0x66663B0000000000UL, 0x0000000066666666UL, 0x63633E0000000000UL, 0x000000003E636363UL, 
  	0x66663B0000000000UL, 0x000F06063E666666UL, 0x33336E0000000000UL, 0x007830303E333333UL, 0x666E3B0000000000UL, 0x000000000F060606UL, 0x06633E0000000000UL, 0x000000003E63301CUL, 
  	0x0C0C3F0C0C080000UL, 0x00000000386C0C0CUL, 0x3333330000000000UL, 0x000000006E333333UL, 0xC3C3C30000000000UL, 0x00000000183C66C3UL, 0xC3C3C30000000000UL, 0x0000000066FFDBDBUL, 
  	0x3C66C30000000000UL, 0x00000000C3663C18UL, 0x6363630000000000UL, 0x001F30607E636363UL, 0x18337F0000000000UL, 0x000000007F63060CUL, 0x180E181818700000UL, 0x0000000070181818UL, 
  	0x1800181818180000UL, 0x0000000018181818UL, 0x18701818180E0000UL, 0x000000000E181818UL, 0x000000003B6E0000UL, 0x0000000000000000UL, 0x63361C0800000000UL, 0x00000000007F6363UL, 
  };
  
  void _UIWindowEndPaint(UIWindow *window, UIPainter *painter);
  void _UIWindowSetCursor(UIWindow *window, int cursor);
  void _UIWindowGetScreenPosition(UIWindow *window, int *x, int *y);
  void _UIWindowSetPressed(UIWindow *window, UIElement *element, int button);
  bool _UIMessageLoopSingle(int *result);
  void _UIInspectorRefresh();
  void _UIUpdate();
  
  #ifdef UI_WINDOWS
  void *_UIHeapReAlloc(void *pointer, size_t size);
  #endif
  
  UIRectangle UIRectangleIntersection(UIRectangle a, UIRectangle b) {
  	if (a.l < b.l) a.l = b.l;
  	if (a.t < b.t) a.t = b.t;
  	if (a.r > b.r) a.r = b.r;
  	if (a.b > b.b) a.b = b.b;
  	return a;
  }
  
  UIRectangle UIRectangleBounding(UIRectangle a, UIRectangle b) {
  	if (a.l > b.l) a.l = b.l;
  	if (a.t > b.t) a.t = b.t;
  	if (a.r < b.r) a.r = b.r;
  	if (a.b < b.b) a.b = b.b;
  	return a;
  }
  
  UIRectangle UIRectangleAdd(UIRectangle a, UIRectangle b) {
  	a.l += b.l;
  	a.t += b.t;
  	a.r += b.r;
  	a.b += b.b;
  	return a;
  }
  
  UIRectangle UIRectangleTranslate(UIRectangle a, UIRectangle b) {
  	a.l += b.l;
  	a.t += b.t;
  	a.r += b.l;
  	a.b += b.t;
  	return a;
  }
  
  bool UIRectangleEquals(UIRectangle a, UIRectangle b) {
  	return a.l == b.l && a.r == b.r && a.t == b.t && a.b == b.b;
  }
  
  bool UIRectangleContains(UIRectangle a, int x, int y) {
  	return a.l <= x && a.r > x && a.t <= y && a.b > y;
  }
  
  #include <xmmintrin.h>
  
  typedef union _UIConvertFloatInteger {
  	float f;
  	uint32_t i;
  } _UIConvertFloatInteger;
  
  float _UIFloorFloat(float x) {
  	_UIConvertFloatInteger convert = {x};
  	uint32_t sign = convert.i & 0x80000000;
  	int exponent = (int) ((convert.i >> 23) & 0xFF) - 0x7F;
  
  	if (exponent >= 23) {
  		// There aren't any bits representing a fractional part.
  	} else if (exponent >= 0) {
  		// Positive exponent.
  		uint32_t mask = 0x7FFFFF >> exponent;
  		if (!(mask & convert.i)) return x; // Already an integer.
  		if (sign) convert.i += mask;
  		convert.i &= ~mask; // Mask out the fractional bits.
  	} else if (exponent < 0) {
  		// Negative exponent.
  		return sign ? -1.0 : 0.0;
  	}
  
  	return convert.f;
  }
  
  float _UISquareRootFloat(float x) {
  	float result[4];
  	_mm_storeu_ps(result, _mm_sqrt_ps(_mm_set_ps(0, 0, 0, x)));
  	return result[0];
  }
  
  #define _F(x) (((_UIConvertFloatInteger) { .i = (x) }).f)
  
  float _UIArcTanFloatI(float x) {
  	float x2 = x * x;
  	return x * (_F(0x3F7FFFF8) + x2 * (_F(0xBEAAA53C) + x2 * (_F(0x3E4BC990) + x2 * (_F(0xBE084A60) + x2 * _F(0x3D8864B0)))));
  }
  
  float _UISinFloatI(float x) {
  	float x2 = x * x;
  	return x * (_F(0x3F800000) + x2 * (_F(0xBE2AAAA0) + x2 * (_F(0x3C0882C0) + x2 * _F(0xB94C6000))));
  }
  
  float _UICosFloatI(float x) {
  	float x2 = x * x;
  	return _F(0x3F800000) + x2 * (_F(0xBEFFFFDA) + x2 * (_F(0x3D2A9F60) + x2 * _F(0xBAB22C00)));
  }
  
  #undef _F
  
  float _UISinFloat(float x) {
  	bool negate = false;
  	if (x < 0) { x = -x; negate = true; }
  	x -= 2 * 3.141592654f * _UIFloorFloat(x / (2 * 3.141592654f));
  	if (x < 3.141592654f / 2) {}
  	else if (x < 3.141592654f) { x = 3.141592654f - x; }
  	else if (x < 3 * 3.141592654f / 2) { x = x - 3.141592654f; negate = !negate; }
  	else { x = 3.141592654f * 2 - x; negate = !negate; }
  	float y = x < 3.141592654f / 4 ? _UISinFloatI(x) : _UICosFloatI(3.141592654f / 2 - x);
  	return negate ? -y : y;
  }
  
  float _UICosFloat(float x) {
  	return _UISinFloat(3.141592654f / 2 - x);
  }
  
  float _UIArcTanFloat(float x) {
  	bool negate = false, reciprocalTaken = false;
  	if (x < 0) { x = -x; negate = true; }
  	if (x > 1) { x = 1 / x; reciprocalTaken = true; }
  	float y = x < 0.5f ? _UIArcTanFloatI(x) : (0.463647609f + _UIArcTanFloatI((2 * x - 1) / (2 + x)));
  	if (reciprocalTaken) { y = 3.141592654f / 2 - y; }
  	return negate ? -y : y;
  }
  
  float _UIArcTan2Float(float y, float x) {
  	if (x == 0) return y > 0 ? 3.141592654f / 2 : -3.141592654f / 2;
  	else if (x > 0) return _UIArcTanFloat(y / x);
  	else if (y >= 0) return 3.141592654f + _UIArcTanFloat(y / x);
  	else return -3.141592654f + _UIArcTanFloat(y / x);
  }
  
  float _UILinearMap(float value, float inFrom, float inTo, float outFrom, float outTo) {
  	float inRange = inTo - inFrom, outRange = outTo - outFrom;
  	float normalisedValue = (value - inFrom) / inRange;
  	return normalisedValue * outRange + outFrom;
  }
  
  bool UIColorToHSV(uint32_t rgb, float *hue, float *saturation, float *value) {
  	float r = UI_COLOR_RED_F(rgb);
  	float g = UI_COLOR_GREEN_F(rgb);
  	float b = UI_COLOR_BLUE_F(rgb);
  
  	float maximum = (r > g && r > b) ? r : (g > b ? g : b),
  	      minimum = (r < g && r < b) ? r : (g < b ? g : b),
  	      difference = maximum - minimum;
  	*value = maximum;
  
  	if (!difference) {
  		*saturation = 0;
  		return false;
  	} else {
  		if (r == maximum) *hue = (g - b) / difference + 0;
  		if (g == maximum) *hue = (b - r) / difference + 2;
  		if (b == maximum) *hue = (r - g) / difference + 4;
  		if (*hue < 0) *hue += 6;
  		*saturation = difference / maximum;
  		return true;
  	}
  }
  
  void UIColorToRGB(float h, float s, float v, uint32_t *rgb) {
  	float r, g, b;
  
  	if (!s) {
  		r = g = b = v;
  	} else {
  		int h0 = ((int) h) % 6;
  		float f = h - _UIFloorFloat(h);
  		float x = v * (1 - s), y = v * (1 - s * f), z = v * (1 - s * (1 - f));
  
  		switch (h0) {
  			case 0:  r = v, g = z, b = x; break;
  			case 1:  r = y, g = v, b = x; break;
  			case 2:  r = x, g = v, b = z; break;
  			case 3:  r = x, g = y, b = v; break;
  			case 4:  r = z, g = x, b = v; break;
  			default: r = v, g = x, b = y; break;
  		}
  	}
  
  	*rgb = UI_COLOR_FROM_FLOAT(r, g, b);
  }
  
  void UIElementRefresh(UIElement *element) {
  	UIElementMessage(element, UI_MSG_LAYOUT, 0, 0);
  	UIElementRepaint(element, NULL);
  }
  
  void UIElementRepaint(UIElement *element, UIRectangle *region) {
  	if (!region) {
  		region = &element->bounds;
  	}
  
  	UIRectangle r = UIRectangleIntersection(*region, element->clip);
  
  	if (!UI_RECT_VALID(r)) {
  		return;
  	}
  
  	if (UI_RECT_VALID(element->window->updateRegion)) {
  		element->window->updateRegion = UIRectangleBounding(element->window->updateRegion, r);
  	} else {
  		element->window->updateRegion = r;
  	}
  }
  
  bool UIElementAnimate(UIElement *element, bool stop) {
  	if (stop) {
  		if (ui.animating != element) {
  			return false;
  		}
  
  		ui.animating = NULL;
  	} else {
  		if (ui.animating && ui.animating != element) {
  			return false;
  		}
  
  		ui.animating = element;
  	}
  
  	return true;
  }
  
  uint64_t UIAnimateClock() {
  	return (uint64_t) UI_CLOCK() * 1000 / UI_CLOCKS_PER_SECOND;
  }
  
  void _UIElementDestroyDescendents(UIElement *element, bool topLevel) {
  	UIElement *child = element->children;
  
  	while (child) {
  		if (!topLevel || (~child->flags & UI_ELEMENT_NON_CLIENT)) {
  			UIElementDestroy(child);
  		}
  
  		child = child->next;
  	}
  
  #ifdef UI_DEBUG
  	_UIInspectorRefresh();
  #endif
  }
  
  void UIElementDestroyDescendents(UIElement *element) {
  	_UIElementDestroyDescendents(element, true);
  }
  
  void UIElementDestroy(UIElement *element) {
  	if (element->flags & UI_ELEMENT_DESTROY) {
  		return;
  	}
  
  	element->flags |= UI_ELEMENT_DESTROY | UI_ELEMENT_HIDE;
  
  	UIElement *ancestor = element->parent;
  
  	while (ancestor) {
  		ancestor->flags |= UI_ELEMENT_DESTROY_DESCENDENT;
  		ancestor = ancestor->parent;
  	}
  
  	_UIElementDestroyDescendents(element, false);
  }
  
  void UIDrawBlock(UIPainter *painter, UIRectangle rectangle, uint32_t color) {
  	rectangle = UIRectangleIntersection(painter->clip, rectangle);
  
  	if (!UI_RECT_VALID(rectangle)) {
  		return;
  	}
  
  #ifdef UI_SSE2
  	__m128i color4 = _mm_set_epi32(color, color, color, color);
  #endif
  
  	for (int line = rectangle.t; line < rectangle.b; line++) {
  		uint32_t *bits = painter->bits + line * painter->width + rectangle.l;
  		int count = UI_RECT_WIDTH(rectangle);
  
  #ifdef UI_SSE2
  		while (count >= 4) {
  			_mm_storeu_si128((__m128i *) bits, color4);
  			bits += 4;
  			count -= 4;
  		} 
  #endif
  
  		while (count--) {
  			*bits++ = color;
  		}
  	}
  
  #ifdef UI_DEBUG
  	painter->fillCount += UI_RECT_WIDTH(rectangle) * UI_RECT_HEIGHT(rectangle);
  #endif
  }
  
  bool UIDrawLine(UIPainter *painter, int x0, int y0, int x1, int y1, uint32_t color) {
  	// Apply the clip.
  
  	UIRectangle c = painter->clip;
  	if (!UI_RECT_VALID(c)) return false;
  	int dx = x1 - x0, dy = y1 - y0;
  	const int p[4] = { -dx, dx, -dy, dy };
  	const int q[4] = { x0 - c.l, c.r - 1 - x0, y0 - c.t, c.b - 1 - y0 };
  	float t0 = 0.0f, t1 = 1.0f; // How far along the line the points end up.
  
  	for (int i = 0; i < 4; i++) {
  		if (!p[i] && q[i] < 0) return false;
  		float r = (float) q[i] / p[i];
  		if (p[i] < 0 && r > t1) return false;
  		if (p[i] > 0 && r < t0) return false;
  		if (p[i] < 0 && r > t0) t0 = r;
  		if (p[i] > 0 && r < t1) t1 = r;
  	}
  
  	x1 = x0 + t1 * dx, y1 = y0 + t1 * dy;
  	x0 += t0 * dx, y0 += t0 * dy;
  
  	// Calculate the delta X and delta Y.
  
  	if (y1 < y0) {
  		int t;
  		t = x0, x0 = x1, x1 = t;
  		t = y0, y0 = y1, y1 = t;
  	}
  
  	dx = x1 - x0, dy = y1 - y0;
  	int dxs = dx < 0 ? -1 : 1;
  	if (dx < 0) dx = -dx;
  
  	// Draw the line using Bresenham's line algorithm.
  
  	uint32_t *bits = painter->bits + y0 * painter->width + x0;
  
  	if (dy * dy < dx * dx) {
  		int m = 2 * dy - dx;
  
  		for (int i = 0; i < dx; i++, bits += dxs) {
  			*bits = color;
  			if (m > 0) bits += painter->width, m -= 2 * dx;
  			m += 2 * dy;
  		}
  	} else {
  		int m = 2 * dx - dy;
  
  		for (int i = 0; i < dy; i++, bits += painter->width) {
  			*bits = color;
  			if (m > 0) bits += dxs, m -= 2 * dy;
  			m += 2 * dx;
  		}
  	}
  
  	return true;
  }
  
  void UIDrawInvert(UIPainter *painter, UIRectangle rectangle) {
  	rectangle = UIRectangleIntersection(painter->clip, rectangle);
  
  	if (!UI_RECT_VALID(rectangle)) {
  		return;
  	}
  
  	for (int line = rectangle.t; line < rectangle.b; line++) {
  		uint32_t *bits = painter->bits + line * painter->width + rectangle.l;
  		int count = UI_RECT_WIDTH(rectangle);
  
  		while (count--) {
  			uint32_t in = *bits;
  			*bits = in ^ 0xFFFFFF;
  			bits++;
  		}
  	}
  }
  
  void UIDrawGlyph(UIPainter *painter, int x0, int y0, int c, uint32_t color) {
  #ifdef UI_FREETYPE
  	UIFont *font = ui.activeFont;
  
  	if (font->isFreeType) {
  		if (c < 0 || c > 127) c = '?';
  		if (c == '\r') c = ' ';
  
  		if (!font->glyphsRendered[c]) {
  			FT_Load_Char(font->font, c == 24 ? 0x2191 : c == 25 ? 0x2193 : c == 26 ? 0x2192 : c == 27 ? 0x2190 : c, FT_LOAD_DEFAULT);
  #ifdef UI_FREETYPE_SUBPIXEL
  			FT_Render_Glyph(font->font->glyph, FT_RENDER_MODE_LCD);
  #else
  			FT_Render_Glyph(font->font->glyph, FT_RENDER_MODE_NORMAL);
  #endif
  			FT_Bitmap_Copy(ui.ft, &font->font->glyph->bitmap, &font->glyphs[c]);
  			font->glyphOffsetsX[c] = font->font->glyph->bitmap_left;
  			font->glyphOffsetsY[c] = font->font->size->metrics.ascender / 64 - font->font->glyph->bitmap_top;
  			font->glyphsRendered[c] = true;
  		}
  
  		FT_Bitmap *bitmap = &font->glyphs[c];
  		x0 += font->glyphOffsetsX[c], y0 += font->glyphOffsetsY[c];
  
  		for (int y = 0; y < (int) bitmap->rows; y++) {
  			if (y0 + y < painter->clip.t) continue;
  			if (y0 + y >= painter->clip.b) break;
  
  			int width = bitmap->width;
  #ifdef UI_FREETYPE_SUBPIXEL
  			width /= 3;
  #endif
  
  			for (int x = 0; x < width; x++) {
  				if (x0 + x < painter->clip.l) continue;
  				if (x0 + x >= painter->clip.r) break;
  
  				uint32_t *destination = painter->bits + (x0 + x) + (y0 + y) * painter->width;
  				uint32_t original = *destination;
  
  #ifdef UI_FREETYPE_SUBPIXEL
  				uint32_t ra = ((uint8_t *) bitmap->buffer)[x * 3 + y * bitmap->pitch + 0];
  				uint32_t ga = ((uint8_t *) bitmap->buffer)[x * 3 + y * bitmap->pitch + 1];
  				uint32_t ba = ((uint8_t *) bitmap->buffer)[x * 3 + y * bitmap->pitch + 2];
  				ra += (ga - ra) / 2, ba += (ga - ba) / 2;
  #else
  				uint32_t ra = ((uint8_t *) bitmap->buffer)[x + y * bitmap->pitch];
  				uint32_t ga = ra, ba = ra;
  #endif
  				uint32_t r2 = (255 - ra) * ((original & 0x000000FF) >> 0);
  				uint32_t g2 = (255 - ga) * ((original & 0x0000FF00) >> 8);
  				uint32_t b2 = (255 - ba) * ((original & 0x00FF0000) >> 16);
  				uint32_t r1 = ra * ((color & 0x000000FF) >> 0);
  				uint32_t g1 = ga * ((color & 0x0000FF00) >> 8);
  				uint32_t b1 = ba * ((color & 0x00FF0000) >> 16);
  
  				uint32_t result = 0xFF000000 | (0x00FF0000 & ((b1 + b2) << 8)) 
  					| (0x0000FF00 & ((g1 + g2) << 0)) 
  					| (0x000000FF & ((r1 + r2) >> 8));
  				*destination = result;
  			}
  		}
  
  		return;
  	}
  #endif
  
  	if (c < 0 || c > 127) c = '?';
  
  	UIRectangle rectangle = UIRectangleIntersection(painter->clip, UI_RECT_4(x0, x0 + 8, y0, y0 + 16));
  
  	const uint8_t *data = (const uint8_t *) _uiFont + c * 16;
  
  	for (int i = rectangle.t; i < rectangle.b; i++) {
  		uint32_t *bits = painter->bits + i * painter->width + rectangle.l;
  		uint8_t byte = data[i - y0];
  
  		for (int j = rectangle.l; j < rectangle.r; j++) {
  			if (byte & (1 << (j - x0))) {
  				*bits = color;
  			}
  
  			bits++;
  		}
  	}
  }
  
  ptrdiff_t _UIStringLength(const char *cString) {
  	if (!cString) return 0;
  	ptrdiff_t length;
  	for (length = 0; cString[length]; length++);
  	return length;
  }
  
  char *UIStringCopy(const char *in, ptrdiff_t inBytes) {
  	if (inBytes == -1) {
  		inBytes = _UIStringLength(in);
  	}
  
  	char *buffer = (char *) UI_MALLOC(inBytes + 1);
  	
  	for (intptr_t i = 0; i < inBytes; i++) {
  		buffer[i] = in[i];
  	}
  	
  	buffer[inBytes] = 0;
  	return buffer;
  }
  
  int UIMeasureStringWidth(const char *string, ptrdiff_t bytes) {
  	if (bytes == -1) {
  		bytes = _UIStringLength(string);
  	}
  	
  	return bytes * ui.activeFont->glyphWidth;
  }
  
  int UIMeasureStringHeight() {
  	return ui.activeFont->glyphHeight;
  }
  
  void UIDrawString(UIPainter *painter, UIRectangle r, const char *string, ptrdiff_t bytes, uint32_t color, int align, UIStringSelection *selection) {
  	UIRectangle oldClip = painter->clip;
  	painter->clip = UIRectangleIntersection(r, oldClip);
  
  	if (!UI_RECT_VALID(painter->clip)) {
  		painter->clip = oldClip;
  		return;
  	}
  
  	if (bytes == -1) {
  		bytes = _UIStringLength(string);
  	}
  
  	int width = UIMeasureStringWidth(string, bytes);
  	int height = UIMeasureStringHeight();
  	int x = align == UI_ALIGN_CENTER ? ((r.l + r.r - width) / 2) : align == UI_ALIGN_RIGHT ? (r.r - width) : r.l;
  	int y = (r.t + r.b - height) / 2;
  	int i = 0, j = 0;
  
  	int selectFrom = -1, selectTo = -1;
  
  	if (selection) {
  		selectFrom = selection->carets[0];
  		selectTo = selection->carets[1];
  		
  		if (selectFrom > selectTo) {
  			UI_SWAP(int, selectFrom, selectTo);
  		}
  	}
  
  	for (; j < bytes; j++) {
  		char c = *string++;
  		uint32_t colorText = color;
  
  		if (j >= selectFrom && j < selectTo) {
  			UIDrawBlock(painter, UI_RECT_4(x, x + ui.activeFont->glyphWidth, y, y + height), selection->colorBackground);
  			colorText = selection->colorText;
  		}
  
  		if (c != '\t') {
  			UIDrawGlyph(painter, x, y, c, colorText);
  		}
  
  		if (selection && selection->carets[0] == j) {
  			UIDrawInvert(painter, UI_RECT_4(x, x + 1, y, y + height));
  		}
  
  		x += ui.activeFont->glyphWidth, i++;
  
  		if (c == '\t') {
  			while (i & 3) x += ui.activeFont->glyphWidth, i++;
  		}
  	}
  
  	if (selection && selection->carets[0] == j) {
  		UIDrawInvert(painter, UI_RECT_4(x, x + 1, y, y + height));
  	}
  
  	painter->clip = oldClip;
  }
  
  void UIDrawBorder(UIPainter *painter, UIRectangle r, uint32_t borderColor, UIRectangle borderSize) {
  	UIDrawBlock(painter, UI_RECT_4(r.l, r.r, r.t, r.t + borderSize.t), borderColor);
  	UIDrawBlock(painter, UI_RECT_4(r.l, r.l + borderSize.l, r.t + borderSize.t, r.b - borderSize.b), borderColor);
  	UIDrawBlock(painter, UI_RECT_4(r.r - borderSize.r, r.r, r.t + borderSize.t, r.b - borderSize.b), borderColor);
  	UIDrawBlock(painter, UI_RECT_4(r.l, r.r, r.b - borderSize.b, r.b), borderColor);
  }
  
  void UIDrawRectangle(UIPainter *painter, UIRectangle r, uint32_t mainColor, uint32_t borderColor, UIRectangle borderSize) {
  	UIDrawBorder(painter, r, borderColor, borderSize);
  	UIDrawBlock(painter, UI_RECT_4(r.l + borderSize.l, r.r - borderSize.r, r.t + borderSize.t, r.b - borderSize.b), mainColor);
  }
  
  void UIElementMove(UIElement *element, UIRectangle bounds, bool alwaysLayout) {
  	UIRectangle oldClip = element->clip;
  	element->clip = UIRectangleIntersection(element->parent->clip, bounds);
  
  	if (!UIRectangleEquals(element->bounds, bounds) || !UIRectangleEquals(element->clip, oldClip) || alwaysLayout) {
  		element->bounds = bounds;
  		UIElementMessage(element, UI_MSG_LAYOUT, 0, 0);
  	}
  }
  
  int UIElementMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	if (message != UI_MSG_DESTROY && (element->flags & UI_ELEMENT_DESTROY)) {
  		return 0;
  	}
  
  	if (message >= UI_MSG_INPUT_EVENTS_START && message <= UI_MSG_INPUT_EVENTS_END && (element->flags & UI_ELEMENT_DISABLED)) {
  		return 0;
  	}
  
  	if (element->messageUser) {
  		int result = element->messageUser(element, message, di, dp);
  
  		if (result) {
  			return result;
  		}
  	}
  
  	if (element->messageClass) {
  		return element->messageClass(element, message, di, dp);
  	} else {
  		return 0;
  	}
  }
  
  void UIElementChangeParent(UIElement *element, UIElement *newParent, UIElement *insertBefore) {
  	UIElement **link = &element->parent->children;
  
  	while (true) {
  		if (*link == element) {
  			*link = element->next;
  			break;
  		} else {
  			link = &(*link)->next;
  		}
  	}
  
  	link = &newParent->children;
  	element->next = insertBefore;
  
  	while (true) {
  		if ((*link) == insertBefore) {
  			*link = element;
  			break;
  		} else {
  			link = &(*link)->next;
  		}
  	}
  
  	element->parent = newParent;
  	element->window = newParent->window;
  }
  
  UIElement *UIElementCreate(size_t bytes, UIElement *parent, uint32_t flags, int (*message)(UIElement *, UIMessage, int, void *), const char *cClassName) {
  	UI_ASSERT(bytes >= sizeof(UIElement));
  	UIElement *element = (UIElement *) UI_CALLOC(bytes);
  	element->flags = flags;
  	element->messageClass = message;
  
  	if (!parent && (~flags & UI_ELEMENT_WINDOW)) {
  		UI_ASSERT(ui.parentStackCount);
  		parent = ui.parentStack[ui.parentStackCount - 1];
  	}
  
  	if ((~flags & UI_ELEMENT_NON_CLIENT) && parent) {
  		UIElementMessage(parent, UI_MSG_CLIENT_PARENT, 0, &parent);
  	}
  
  	if (parent) {
  		element->window = parent->window;
  		element->parent = parent;
  
  		if (parent->children) {
  			UIElement *sibling = parent->children;
  
  			while (sibling->next) {
  				sibling = sibling->next;
  			}
  
  			sibling->next = element;
  		} else {
  			parent->children = element;
  		}
  
  		UI_ASSERT(~parent->flags & UI_ELEMENT_DESTROY);
  	}
  
  #ifdef UI_DEBUG
  	element->cClassName = cClassName;
  	static int id = 0;
  	element->id = ++id;
  	_UIInspectorRefresh();
  #endif
  
  	if (flags & UI_ELEMENT_PARENT_PUSH) {
  		UIParentPush(element);
  	}
  
  	return element;
  }
  
  UIElement *UIParentPush(UIElement *element) {
  	UI_ASSERT(ui.parentStackCount != sizeof(ui.parentStack) / sizeof(ui.parentStack[0]));
  	ui.parentStack[ui.parentStackCount++] = element;
  	return element;
  }
  
  UIElement *UIParentPop() {
  	UI_ASSERT(ui.parentStackCount);
  	ui.parentStackCount--;
  	return ui.parentStack[ui.parentStackCount];
  }
  
  int _UIPanelMeasure(UIPanel *panel) {
  	bool horizontal = panel->e.flags & UI_PANEL_HORIZONTAL;
  	int size = 0;
  	UIElement *child = panel->e.children;
  
  	while (child) {
  		if (~child->flags & UI_ELEMENT_HIDE) {
  			if (horizontal) {
  				int height = UIElementMessage(child, UI_MSG_GET_HEIGHT, 0, 0);
  
  				if (height > size) {
  					size = height;
  				}
  			} else {
  				int width = UIElementMessage(child, UI_MSG_GET_WIDTH, 0, 0);
  
  				if (width > size) {
  					size = width;
  				}
  			}
  		}
  
  		child = child->next;
  	}
  
  	int border = 0;
  
  	if (horizontal) {
  		border = panel->border.t + panel->border.b;
  	} else {
  		border = panel->border.l + panel->border.r;
  	}
  
  	return size + border * panel->e.window->scale;
  }
  
  int _UIPanelLayout(UIPanel *panel, UIRectangle bounds, bool measure) {
  	bool horizontal = panel->e.flags & UI_PANEL_HORIZONTAL;
  	float scale = panel->e.window->scale;
  	int position = (horizontal ? panel->border.l : panel->border.t) * scale;
  	if (panel->scrollBar && !measure) position -= panel->scrollBar->position;
  	int hSpace = UI_RECT_WIDTH(bounds) - UI_RECT_TOTAL_H(panel->border) * scale;
  	int vSpace = UI_RECT_HEIGHT(bounds) - UI_RECT_TOTAL_V(panel->border) * scale;
  
  	int available = horizontal ? hSpace : vSpace;
  	int fill = 0, count = 0, perFill = 0;
  
  	for (UIElement *child = panel->e.children; child; child = child->next) {
  		if (child->flags & (UI_ELEMENT_HIDE | UI_ELEMENT_NON_CLIENT)) {
  			continue;
  		}
  
  		count++;
  
  		if (horizontal) {
  			if (child->flags & UI_ELEMENT_H_FILL) {
  				fill++;
  			} else if (available > 0) {
  				available -= UIElementMessage(child, UI_MSG_GET_WIDTH, vSpace, 0);
  			}
  		} else {
  			if (child->flags & UI_ELEMENT_V_FILL) {
  				fill++;
  			} else if (available > 0) {
  				available -= UIElementMessage(child, UI_MSG_GET_HEIGHT, hSpace, 0);
  			}
  		}
  	}
  
  	if (count) {
  		available -= (count - 1) * (int) (panel->gap * scale);
  	}
  
  	if (available > 0 && fill) {
  		perFill = available / fill;
  	}
  
  	bool expand = panel->e.flags & UI_PANEL_EXPAND;
  	int scaledBorder2 = (horizontal ? panel->border.t : panel->border.l) * panel->e.window->scale;
  
  	for (UIElement *child = panel->e.children; child; child = child->next) {
  		if (child->flags & (UI_ELEMENT_HIDE | UI_ELEMENT_NON_CLIENT)) {
  			continue;
  		}
  
  		if (horizontal) {
  			int height = ((child->flags & UI_ELEMENT_V_FILL) || expand) ? vSpace : UIElementMessage(child, UI_MSG_GET_HEIGHT, 0, 0);
  			int width = (child->flags & UI_ELEMENT_H_FILL) ? perFill : UIElementMessage(child, UI_MSG_GET_WIDTH, height, 0);
  			UIRectangle relative = UI_RECT_4(position, position + width, 
  					scaledBorder2 + (vSpace - height) / 2, 
  					scaledBorder2 + (vSpace + height) / 2);
  			if (!measure) UIElementMove(child, UIRectangleTranslate(relative, bounds), false);
  			position += width + panel->gap * scale;
  		} else {
  			int width = ((child->flags & UI_ELEMENT_H_FILL) || expand) ? hSpace : UIElementMessage(child, UI_MSG_GET_WIDTH, 0, 0);
  			int height = (child->flags & UI_ELEMENT_V_FILL) ? perFill : UIElementMessage(child, UI_MSG_GET_HEIGHT, width, 0);
  			UIRectangle relative = UI_RECT_4(scaledBorder2 + (hSpace - width) / 2, 
  					scaledBorder2 + (hSpace + width) / 2, position, position + height);
  			if (!measure) UIElementMove(child, UIRectangleTranslate(relative, bounds), false);
  			position += height + panel->gap * scale;
  		}
  	}
  
  	return position - panel->gap * scale + (horizontal ? panel->border.r : panel->border.b) * scale;
  }
  
  int _UIPanelMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UIPanel *panel = (UIPanel *) element;
  	bool horizontal = element->flags & UI_PANEL_HORIZONTAL;
  
  	if (message == UI_MSG_LAYOUT) {
  		int scrollBarWidth = panel->scrollBar ? (UI_SIZE_SCROLL_BAR * element->window->scale) : 0;
  		UIRectangle bounds = element->bounds;
  		bounds.r -= scrollBarWidth;
  
  		if (panel->scrollBar) {
  			UIRectangle scrollBarBounds = element->bounds;
  			scrollBarBounds.l = scrollBarBounds.r - scrollBarWidth;
  			panel->scrollBar->maximum = _UIPanelLayout(panel, bounds, true);
  			panel->scrollBar->page = UI_RECT_HEIGHT(element->bounds);
  			UIElementMove(&panel->scrollBar->e, scrollBarBounds, true);
  		}
  
  		_UIPanelLayout(panel, bounds, false);
  	} else if (message == UI_MSG_GET_WIDTH) {
  		if (horizontal) {
  			return _UIPanelLayout(panel, UI_RECT_4(0, 0, 0, di), true);
  		} else {
  			return _UIPanelMeasure(panel);
  		}
  	} else if (message == UI_MSG_GET_HEIGHT) {
  		if (horizontal) {
  			return _UIPanelMeasure(panel);
  		} else {
  			int width = di && panel->scrollBar ? (di - UI_SIZE_SCROLL_BAR * element->window->scale) : di;
  			return _UIPanelLayout(panel, UI_RECT_4(0, width, 0, 0), true);
  		}
  	} else if (message == UI_MSG_PAINT) {
  		if (element->flags & UI_PANEL_GRAY) {
  			UIDrawBlock((UIPainter *) dp, element->bounds, ui.theme.panel1);
  		} else if (element->flags & UI_PANEL_WHITE) {
  			UIDrawBlock((UIPainter *) dp, element->bounds, ui.theme.panel2);
  		} 
  		
  		if (element->flags & UI_PANEL_BORDER) {
  			UIDrawBorder((UIPainter *) dp, element->bounds, ui.theme.border, UI_RECT_1((int) element->window->scale));
  		}
  	} else if (message == UI_MSG_MOUSE_WHEEL && panel->scrollBar) {
  		return UIElementMessage(&panel->scrollBar->e, message, di, dp);
  	} else if (message == UI_MSG_SCROLLED) {
  		UIElementRefresh(element);
  	}
  
  	return 0;
  }
  
  UIPanel *UIPanelCreate(UIElement *parent, uint32_t flags) {
  	UIPanel *panel = (UIPanel *) UIElementCreate(sizeof(UIPanel), parent, flags, _UIPanelMessage, "Panel");
  
  	if (flags & UI_PANEL_MEDIUM_SPACING) {
  		panel->border = UI_RECT_1(UI_SIZE_PANE_MEDIUM_BORDER);
  		panel->gap = UI_SIZE_PANE_MEDIUM_GAP;
  	} else if (flags & UI_PANEL_SMALL_SPACING) {
  		panel->border = UI_RECT_1(UI_SIZE_PANE_SMALL_BORDER);
  		panel->gap = UI_SIZE_PANE_SMALL_GAP;
  	}
  
  	if (flags & UI_PANEL_SCROLL) {
  		panel->scrollBar = UIScrollBarCreate(&panel->e, UI_ELEMENT_NON_CLIENT);
  	}
  
  	return panel;
  }
  
  void _UIButtonCalculateColors(UIElement *element, uint32_t *color, uint32_t *textColor) {
  	bool disabled = element->flags & UI_ELEMENT_DISABLED;
  	bool focused = element == element->window->focused;
  	bool pressed = element == element->window->pressed;
  	bool hovered = element == element->window->hovered;
  	*color = disabled ? ui.theme.buttonDisabled
  		: (pressed && hovered) ? ui.theme.buttonPressed 
  		: (pressed || hovered) ? ui.theme.buttonHovered 
  		: focused ? ui.theme.selected : ui.theme.buttonNormal;
  	*textColor = disabled ? ui.theme.textDisabled 
  		: *color == ui.theme.selected ? ui.theme.textSelected : ui.theme.text;
  }
  
  
  int _UIButtonMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UIButton *button = (UIButton *) element;
  	bool isMenuItem = element->flags & UI_BUTTON_MENU_ITEM;
  	bool isDropDown = element->flags & UI_BUTTON_DROP_DOWN;
  	
  	if (message == UI_MSG_GET_HEIGHT) {
  		if (isMenuItem) {
  			return UI_SIZE_MENU_ITEM_HEIGHT * element->window->scale;
  		} else {
  			return UI_SIZE_BUTTON_HEIGHT * element->window->scale;
  		}
  	} else if (message == UI_MSG_GET_WIDTH) {
  		int labelSize = UIMeasureStringWidth(button->label, button->labelBytes);
  		int paddedSize = labelSize + UI_SIZE_BUTTON_PADDING * element->window->scale;
  		if (isDropDown) paddedSize += ui.activeFont->glyphWidth * 2;
  		int minimumSize = ((element->flags & UI_BUTTON_SMALL) ? 0 
  				: isMenuItem ? UI_SIZE_MENU_ITEM_MINIMUM_WIDTH 
  				: UI_SIZE_BUTTON_MINIMUM_WIDTH) 
  			* element->window->scale;
  		return paddedSize > minimumSize ? paddedSize : minimumSize;
  	} else if (message == UI_MSG_PAINT) {
  		UIPainter *painter = (UIPainter *) dp;
  
  		uint32_t color, textColor;
  		_UIButtonCalculateColors(element, &color, &textColor);
  
  		UIDrawRectangle(painter, element->bounds, color, ui.theme.border, UI_RECT_1(isMenuItem ? 0 : 1));
  
  		if (element->flags & UI_BUTTON_CHECKED) {
  			UIDrawBlock(painter, UIRectangleAdd(element->bounds, 
  				UI_RECT_1I((int) (UI_SIZE_BUTTON_CHECKED_AREA * element->window->scale))), ui.theme.buttonPressed);
  		}
  
  		UIRectangle bounds = UIRectangleAdd(element->bounds, UI_RECT_2I((int) (UI_SIZE_MENU_ITEM_MARGIN * element->window->scale), 0));
  
  		if (isMenuItem) {
  			if (button->labelBytes == -1) {
  				button->labelBytes = _UIStringLength(button->label);
  			}
  
  			int tab = 0;
  			for (; tab < button->labelBytes && button->label[tab] != '\t'; tab++);
  
  			UIDrawString(painter, bounds, button->label, tab, textColor, UI_ALIGN_LEFT, NULL);
  
  			if (button->labelBytes > tab) {
  				UIDrawString(painter, bounds, button->label + tab + 1, button->labelBytes - tab - 1, textColor, UI_ALIGN_RIGHT, NULL);
  			}
  		} else if (isDropDown) {
  			UIDrawString(painter, bounds, button->label, button->labelBytes, textColor, UI_ALIGN_LEFT, NULL);
  			UIDrawString(painter, bounds, "\x19", 1, textColor, UI_ALIGN_RIGHT, NULL);
  		} else {
  			UIDrawString(painter, element->bounds, button->label, button->labelBytes, textColor, UI_ALIGN_CENTER, NULL);
  		}
  	} else if (message == UI_MSG_UPDATE) {
  		UIElementRepaint(element, NULL);
  	} else if (message == UI_MSG_DESTROY) {
  		UI_FREE(button->label);
  	} else if (message == UI_MSG_LEFT_DOWN) {
  		if (element->flags & UI_BUTTON_CAN_FOCUS) {
  			UIElementFocus(element);
  		}
  	} else if (message == UI_MSG_KEY_TYPED) {
  		UIKeyTyped *m = (UIKeyTyped *) dp;
  		
  		if (m->textBytes == 1 && m->text[0] == ' ') {
  			UIElementMessage(element, UI_MSG_CLICKED, 0, 0);
  			UIElementRepaint(element, NULL);
  		}
  	} else if (message == UI_MSG_CLICKED) {
  		if (button->invoke) {
  			button->invoke(element->cp);
  		}
  	}
  
  	return 0;
  }
  
  UIButton *UIButtonCreate(UIElement *parent, uint32_t flags, const char *label, ptrdiff_t labelBytes) {
  	UIButton *button = (UIButton *) UIElementCreate(sizeof(UIButton), parent, flags | UI_ELEMENT_TAB_STOP, _UIButtonMessage, "Button");
  	button->label = UIStringCopy(label, (button->labelBytes = labelBytes));
  	return button;
  }
  
  int _UICheckboxMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UICheckbox *box = (UICheckbox *) element;
  	
  	if (message == UI_MSG_GET_HEIGHT) {
  		return UI_SIZE_BUTTON_HEIGHT * element->window->scale;
  	} else if (message == UI_MSG_GET_WIDTH) {
  		int labelSize = UIMeasureStringWidth(box->label, box->labelBytes);
  		return (labelSize + UI_SIZE_CHECKBOX_BOX + UI_SIZE_CHECKBOX_GAP) * element->window->scale;
  	} else if (message == UI_MSG_PAINT) {
  		UIPainter *painter = (UIPainter *) dp;
  		uint32_t color, textColor;
  		_UIButtonCalculateColors(element, &color, &textColor);
  		int midY = (element->bounds.t + element->bounds.b) / 2;
  		UIRectangle boxBounds = UI_RECT_4(element->bounds.l, element->bounds.l + UI_SIZE_CHECKBOX_BOX, 
  				midY - UI_SIZE_CHECKBOX_BOX / 2, midY + UI_SIZE_CHECKBOX_BOX / 2);
  		UIDrawRectangle(painter, boxBounds, color, ui.theme.border, UI_RECT_1(1));
  		UIDrawString(painter, UIRectangleAdd(boxBounds, UI_RECT_4(1, 0, 0, 0)), 
  				box->check == UI_CHECK_CHECKED ? "*" : box->check == UI_CHECK_INDETERMINATE ? "-" : " ", -1, 
  				textColor, UI_ALIGN_CENTER, NULL);
  		UIDrawString(painter, UIRectangleAdd(element->bounds, UI_RECT_4(UI_SIZE_CHECKBOX_BOX + UI_SIZE_CHECKBOX_GAP, 0, 0, 0)), 
  				box->label, box->labelBytes, textColor, UI_ALIGN_LEFT, NULL);
  	} else if (message == UI_MSG_UPDATE) {
  		UIElementRepaint(element, NULL);
  	} else if (message == UI_MSG_DESTROY) {
  		UI_FREE(box->label);
  	} else if (message == UI_MSG_KEY_TYPED) {
  		UIKeyTyped *m = (UIKeyTyped *) dp;
  		
  		if (m->textBytes == 1 && m->text[0] == ' ') {
  			UIElementMessage(element, UI_MSG_CLICKED, 0, 0);
  			UIElementRepaint(element, NULL);
  		}
  	} else if (message == UI_MSG_CLICKED) {
  		box->check = (box->check + 1) % ((element->flags & UI_CHECKBOX_ALLOW_INDETERMINATE) ? 3 : 2);
  		UIElementRepaint(element, NULL);
  		if (box->invoke) box->invoke(element->cp);
  	}
  
  	return 0;
  }
  
  UICheckbox *UICheckboxCreate(UIElement *parent, uint32_t flags, const char *label, ptrdiff_t labelBytes) {
  	UICheckbox *box = (UICheckbox *) UIElementCreate(sizeof(UICheckbox), parent, flags | UI_ELEMENT_TAB_STOP, _UICheckboxMessage, "Checkbox");
  	box->label = UIStringCopy(label, (box->labelBytes = labelBytes));
  	return box;
  }
  
  int _UILabelMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UILabel *label = (UILabel *) element;
  	
  	if (message == UI_MSG_GET_HEIGHT) {
  		return UIMeasureStringHeight();
  	} else if (message == UI_MSG_GET_WIDTH) {
  		return UIMeasureStringWidth(label->label, label->labelBytes);
  	} else if (message == UI_MSG_PAINT) {
  		UIPainter *painter = (UIPainter *) dp;
  		UIDrawString(painter, element->bounds, label->label, label->labelBytes, ui.theme.text, UI_ALIGN_LEFT, NULL);
  	} else if (message == UI_MSG_DESTROY) {
  		UI_FREE(label->label);
  	}
  
  	return 0;
  }
  
  void UILabelSetContent(UILabel *label, const char *string, ptrdiff_t stringBytes) {
  	UI_FREE(label->label);
  	label->label = UIStringCopy(string, (label->labelBytes = stringBytes));
  }
  
  UILabel *UILabelCreate(UIElement *parent, uint32_t flags, const char *string, ptrdiff_t stringBytes) {
  	UILabel *label = (UILabel *) UIElementCreate(sizeof(UILabel), parent, flags, _UILabelMessage, "Label");
  	label->label = UIStringCopy(string, (label->labelBytes = stringBytes));
  	return label;
  }
  
  int _UISplitPaneMessage(UIElement *element, UIMessage message, int di, void *dp);
  
  int _UISplitterMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UISplitPane *splitPane = (UISplitPane *) element->parent;
  	bool vertical = splitPane->e.flags & UI_SPLIT_PANE_VERTICAL;
  
  	if (message == UI_MSG_PAINT) {
  		UIRectangle borders = vertical ? UI_RECT_2(0, 1) : UI_RECT_2(1, 0);
  		UIDrawRectangle((UIPainter *) dp, element->bounds, ui.theme.buttonNormal, ui.theme.border, borders);
  	} else if (message == UI_MSG_GET_CURSOR) {
  		return vertical ? UI_CURSOR_SPLIT_V : UI_CURSOR_SPLIT_H;
  	} else if (message == UI_MSG_MOUSE_DRAG) {
  		int cursor = vertical ? element->window->cursorY : element->window->cursorX;
  		int splitterSize = UI_SIZE_SPLITTER * element->window->scale;
  		int space = (vertical ? UI_RECT_HEIGHT(splitPane->e.bounds) : UI_RECT_WIDTH(splitPane->e.bounds)) - splitterSize;
  		float oldWeight = splitPane->weight;
  		splitPane->weight = (float) (cursor - splitterSize / 2 - (vertical ? splitPane->e.bounds.t : splitPane->e.bounds.l)) / space;
  		if (splitPane->weight < 0.05f) splitPane->weight = 0.05f;
  		if (splitPane->weight > 0.95f) splitPane->weight = 0.95f;
  
  		if (element->next->next->messageClass == _UISplitPaneMessage 
  				&& (element->next->next->flags & UI_SPLIT_PANE_VERTICAL) == (splitPane->e.flags & UI_SPLIT_PANE_VERTICAL)) {
  			UISplitPane *subSplitPane = (UISplitPane *) element->next->next;
  			subSplitPane->weight = (splitPane->weight - oldWeight - subSplitPane->weight + oldWeight * subSplitPane->weight) / (-1 + splitPane->weight);
  			if (subSplitPane->weight < 0.05f) subSplitPane->weight = 0.05f;
  			if (subSplitPane->weight > 0.95f) subSplitPane->weight = 0.95f;
  		}
  
  		UIElementRefresh(&splitPane->e);
  	}
  
  	return 0;
  }
  
  int _UISplitPaneMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UISplitPane *splitPane = (UISplitPane *) element;
  	bool vertical = splitPane->e.flags & UI_SPLIT_PANE_VERTICAL;
  
  	if (message == UI_MSG_LAYOUT) {
  		UIElement *splitter = element->children;
  		UI_ASSERT(splitter);
  		UIElement *left = splitter->next;
  		UI_ASSERT(left);
  		UIElement *right = left->next;
  		UI_ASSERT(right);
  		UI_ASSERT(!right->next);
  
  		int splitterSize = UI_SIZE_SPLITTER * element->window->scale;
  		int space = (vertical ? UI_RECT_HEIGHT(element->bounds) : UI_RECT_WIDTH(element->bounds)) - splitterSize;
  		int leftSize = space * splitPane->weight;
  		int rightSize = space - leftSize;
  
  		if (vertical) {
  			UIElementMove(left, UI_RECT_4(element->bounds.l, element->bounds.r, element->bounds.t, element->bounds.t + leftSize), false);
  			UIElementMove(splitter, UI_RECT_4(element->bounds.l, element->bounds.r, element->bounds.t + leftSize, element->bounds.t + leftSize + splitterSize), false);
  			UIElementMove(right, UI_RECT_4(element->bounds.l, element->bounds.r, element->bounds.b - rightSize, element->bounds.b), false);
  		} else {
  			UIElementMove(left, UI_RECT_4(element->bounds.l, element->bounds.l + leftSize, element->bounds.t, element->bounds.b), false);
  			UIElementMove(splitter, UI_RECT_4(element->bounds.l + leftSize, element->bounds.l + leftSize + splitterSize, element->bounds.t, element->bounds.b), false);
  			UIElementMove(right, UI_RECT_4(element->bounds.r - rightSize, element->bounds.r, element->bounds.t, element->bounds.b), false);
  		}
  	}
  
  	return 0;
  }
  
  UISplitPane *UISplitPaneCreate(UIElement *parent, uint32_t flags, float weight) {
  	UISplitPane *splitPane = (UISplitPane *) UIElementCreate(sizeof(UISplitPane), parent, flags, _UISplitPaneMessage, "Split Pane");
  	splitPane->weight = weight;
  	UIElementCreate(sizeof(UIElement), &splitPane->e, 0, _UISplitterMessage, "Splitter");
  	return splitPane;
  }
  
  int _UITabPaneMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UITabPane *tabPane = (UITabPane *) element;
  	
  	if (message == UI_MSG_PAINT) {
  		UIPainter *painter = (UIPainter *) dp;
  		UIRectangle top = element->bounds;
  		top.b = top.t + UI_SIZE_BUTTON_HEIGHT * element->window->scale;
  		UIDrawRectangle(painter, top, ui.theme.panel1, ui.theme.border, UI_RECT_4(0, 0, 0, 1));
  
  		UIRectangle tab = top;
  		tab.l += UI_SIZE_TAB_PANE_SPACE_LEFT * element->window->scale;
  		tab.t += UI_SIZE_TAB_PANE_SPACE_TOP * element->window->scale;
  
  		int position = 0;
  		int index = 0;
  
  		while (true) {
  			int end = position;
  			for (; tabPane->tabs[end] != '\t' && tabPane->tabs[end]; end++);
  
  			int width = UIMeasureStringWidth(tabPane->tabs, end - position);
  			tab.r = tab.l + width + UI_SIZE_BUTTON_PADDING;
  
  			uint32_t color = tabPane->active == index ? ui.theme.buttonPressed : ui.theme.buttonNormal;
  
  			UIRectangle t = tab;
  
  			if (tabPane->active == index) {
  				t.b++;
  				t.t--;
  			} else {
  				t.t++;
  			}
  
  			UIDrawRectangle(painter, t, color, ui.theme.border, UI_RECT_1(1));
  			UIDrawString(painter, tab, tabPane->tabs + position, end - position, ui.theme.text, UI_ALIGN_CENTER, NULL);
  			tab.l = tab.r - 1;
  
  			if (tabPane->tabs[end] == '\t') {
  				position = end + 1;
  				index++;
  			} else {
  				break;
  			}
  		}
  	} else if (message == UI_MSG_LEFT_DOWN) {
  		UIRectangle tab = element->bounds;
  		tab.b = tab.t + UI_SIZE_BUTTON_HEIGHT * element->window->scale;
  		tab.l += UI_SIZE_TAB_PANE_SPACE_LEFT * element->window->scale;
  		tab.t += UI_SIZE_TAB_PANE_SPACE_TOP * element->window->scale;
  
  		int position = 0;
  		int index = 0;
  
  		while (true) {
  			int end = position;
  			for (; tabPane->tabs[end] != '\t' && tabPane->tabs[end]; end++);
  
  			int width = UIMeasureStringWidth(tabPane->tabs, end - position);
  			tab.r = tab.l + width + UI_SIZE_BUTTON_PADDING;
  
  			if (UIRectangleContains(tab, element->window->cursorX, element->window->cursorY)) {
  				tabPane->active = index;
  				UIElementMessage(element, UI_MSG_LAYOUT, 0, 0);
  				UIElementRepaint(element, NULL);
  				break;
  			}
  
  			tab.l = tab.r - 1;
  
  			if (tabPane->tabs[end] == '\t') {
  				position = end + 1;
  				index++;
  			} else {
  				break;
  			}
  		}
  	} else if (message == UI_MSG_LAYOUT) {
  		UIElement *child = element->children;
  		int index = 0;
  
  		UIRectangle content = element->bounds;
  		content.t += UI_SIZE_BUTTON_HEIGHT * element->window->scale;
  
  		while (child) {
  			if (tabPane->active == index) {
  				child->flags &= ~UI_ELEMENT_HIDE;
  				UIElementMove(child, content, false);
  				UIElementMessage(child, UI_MSG_TAB_SELECTED, 0, 0);
  			} else {
  				child->flags |= UI_ELEMENT_HIDE;
  			}
  
  			child = child->next;
  			index++;
  		}
  	} else if (message == UI_MSG_GET_HEIGHT) {
  		UIElement *child = element->children;
  		int index = 0;
  		int baseHeight = UI_SIZE_BUTTON_HEIGHT * element->window->scale;
  
  		while (child) {
  			if (tabPane->active == index) {
  				return baseHeight + UIElementMessage(child, UI_MSG_GET_HEIGHT, di, dp);
  			}
  
  			child = child->next;
  			index++;
  		}
  	} else if (message == UI_MSG_DESTROY) {
  		UI_FREE(tabPane->tabs);
  	}
  
  	return 0;
  }
  
  UITabPane *UITabPaneCreate(UIElement *parent, uint32_t flags, const char *tabs) {
  	UITabPane *tabPane = (UITabPane *) UIElementCreate(sizeof(UITabPane), parent, flags, _UITabPaneMessage, "Tab Pane");
  	tabPane->tabs = UIStringCopy(tabs, -1);
  	return tabPane;
  }
  
  int _UISpacerMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UISpacer *spacer = (UISpacer *) element;
  	
  	if (message == UI_MSG_GET_HEIGHT) {
  		return spacer->height * element->window->scale;
  	} else if (message == UI_MSG_GET_WIDTH) {
  		return spacer->width * element->window->scale;
  	} else if (message == UI_MSG_PAINT && (element->flags & UI_SPACER_LINE)) {
  		UIDrawBlock((UIPainter *) dp, element->bounds, ui.theme.border);
  	}
  
  	return 0;
  }
  
  UISpacer *UISpacerCreate(UIElement *parent, uint32_t flags, int width, int height) {
  	UISpacer *spacer = (UISpacer *) UIElementCreate(sizeof(UISpacer), parent, flags, _UISpacerMessage, "Spacer");
  	spacer->width = width;
  	spacer->height = height;
  	return spacer;
  }
  
  int _UIScrollBarMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UIScrollBar *scrollBar = (UIScrollBar *) element;
  
  	if (message == UI_MSG_GET_WIDTH || message == UI_MSG_GET_HEIGHT) {
  		return UI_SIZE_SCROLL_BAR * element->window->scale;
  	} else if (message == UI_MSG_LAYOUT) {
  		UIElement *up = element->children;
  		UIElement *thumb = up->next;
  		UIElement *down = thumb->next;
  
  		if (scrollBar->page >= scrollBar->maximum || scrollBar->maximum <= 0 || scrollBar->page <= 0) {
  			up->flags |= UI_ELEMENT_HIDE;
  			thumb->flags |= UI_ELEMENT_HIDE;
  			down->flags |= UI_ELEMENT_HIDE;
  
  			scrollBar->position = 0;
  		} else {
  			up->flags &= ~UI_ELEMENT_HIDE;
  			thumb->flags &= ~UI_ELEMENT_HIDE;
  			down->flags &= ~UI_ELEMENT_HIDE;
  
  			int size = scrollBar->horizontal ? UI_RECT_WIDTH(element->bounds) : UI_RECT_HEIGHT(element->bounds);
  			int thumbSize = size * scrollBar->page / scrollBar->maximum;
  
  			if (thumbSize < UI_SIZE_SCROLL_MINIMUM_THUMB * element->window->scale) {
  				thumbSize = UI_SIZE_SCROLL_MINIMUM_THUMB * element->window->scale;
  			}
  
  			if (scrollBar->position < 0) {
  				scrollBar->position = 0;
  			} else if (scrollBar->position > scrollBar->maximum - scrollBar->page) {
  				scrollBar->position = scrollBar->maximum - scrollBar->page;
  			}
  
  			int thumbPosition = scrollBar->position / (scrollBar->maximum - scrollBar->page) * (size - thumbSize);
  
  			if (scrollBar->position == scrollBar->maximum - scrollBar->page) {
  				thumbPosition = size - thumbSize;
  			}
  
  			if (scrollBar->horizontal) {
  				UIRectangle r = element->bounds;
  				r.r = r.l + thumbPosition;
  				UIElementMove(up, r, false);
  				r.l = r.r, r.r = r.l + thumbSize;
  				UIElementMove(thumb, r, false);
  				r.l = r.r, r.r = element->bounds.r;
  				UIElementMove(down, r, false);
  			} else {
  				UIRectangle r = element->bounds;
  				r.b = r.t + thumbPosition;
  				UIElementMove(up, r, false);
  				r.t = r.b, r.b = r.t + thumbSize;
  				UIElementMove(thumb, r, false);
  				r.t = r.b, r.b = element->bounds.b;
  				UIElementMove(down, r, false);
  			}
  		}
  	} else if (message == UI_MSG_PAINT) {
  		if (scrollBar->page >= scrollBar->maximum || scrollBar->maximum <= 0 || scrollBar->page <= 0) {
  			UIDrawBlock((UIPainter *) dp, element->bounds, ui.theme.panel1);
  		}
  	} else if (message == UI_MSG_MOUSE_WHEEL) {
  		scrollBar->position += di;
  		UIElementRefresh(element);
  		UIElementMessage(element->parent, UI_MSG_SCROLLED, 0, 0);
  		return 1;
  	}
  
  	return 0;
  }
  
  int _UIScrollUpDownMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UIScrollBar *scrollBar = (UIScrollBar *) element->parent;
  	bool isDown = element->cp;
  
  	if (message == UI_MSG_PAINT) {
  		UIPainter *painter = (UIPainter *) dp;
  		uint32_t color = element == element->window->pressed ? ui.theme.buttonPressed 
  			: element == element->window->hovered ? ui.theme.buttonHovered : ui.theme.panel2;
  		UIDrawRectangle(painter, element->bounds, color, ui.theme.border, UI_RECT_1(0));
  		
  		if (scrollBar->horizontal) {
  			UIDrawGlyph(painter, isDown ? (element->bounds.r - ui.activeFont->glyphWidth - 2 * element->window->scale) 
  					: (element->bounds.l + 2 * element->window->scale), 
  				(element->bounds.t + element->bounds.b - ui.activeFont->glyphHeight) / 2,
  				isDown ? 26 : 27, ui.theme.text);
  		} else {
  			UIDrawGlyph(painter, (element->bounds.l + element->bounds.r - ui.activeFont->glyphWidth) / 2 + 1, 
  				isDown ? (element->bounds.b - ui.activeFont->glyphHeight - 2 * element->window->scale) 
  					: (element->bounds.t + 2 * element->window->scale), 
  				isDown ? 25 : 24, ui.theme.text);
  		}
  	} else if (message == UI_MSG_UPDATE) {
  		UIElementRepaint(element, NULL);
  	} else if (message == UI_MSG_LEFT_DOWN) {
  		UIElementAnimate(element, false);
  		scrollBar->lastAnimateTime = UI_CLOCK();
  	} else if (message == UI_MSG_LEFT_UP) {
  		UIElementAnimate(element, true);
  	} else if (message == UI_MSG_ANIMATE) {
  		UI_CLOCK_T previous = scrollBar->lastAnimateTime;
  		UI_CLOCK_T current = UI_CLOCK();
  		UI_CLOCK_T delta = current - previous;
  		double deltaSeconds = (double) delta / UI_CLOCKS_PER_SECOND;
  		if (deltaSeconds > 0.1) deltaSeconds = 0.1;
  		double deltaPixels = deltaSeconds * scrollBar->page * 3;
  		scrollBar->lastAnimateTime = current;
  		if (isDown) scrollBar->position += deltaPixels;
  		else scrollBar->position -= deltaPixels;
  		UIElementRefresh(&scrollBar->e);
  		UIElementMessage(scrollBar->e.parent, UI_MSG_SCROLLED, 0, 0);
  	}
  
  	return 0;
  }
  
  int _UIScrollThumbMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UIScrollBar *scrollBar = (UIScrollBar *) element->parent;
  
  	if (message == UI_MSG_PAINT) {
  		UIPainter *painter = (UIPainter *) dp;
  		uint32_t color = element == element->window->pressed ? ui.theme.buttonPressed 
  			: element == element->window->hovered ? ui.theme.buttonHovered : ui.theme.buttonNormal;
  		UIDrawRectangle(painter, element->bounds, color, ui.theme.border, UI_RECT_1(2));
  	} else if (message == UI_MSG_UPDATE) {
  		UIElementRepaint(element, NULL);
  	} else if (message == UI_MSG_MOUSE_DRAG && element->window->pressedButton == 1) {
  		if (!scrollBar->inDrag) {
  			scrollBar->inDrag = true;
  			
  			if (scrollBar->horizontal) {
  				scrollBar->dragOffset = element->bounds.l - scrollBar->e.bounds.l - element->window->cursorX;
  			} else {
  				scrollBar->dragOffset = element->bounds.t - scrollBar->e.bounds.t - element->window->cursorY;
  			}
  		}
  
  		int thumbPosition = (scrollBar->horizontal ? element->window->cursorX : element->window->cursorY) + scrollBar->dragOffset;
  		int size = scrollBar->horizontal ? (UI_RECT_WIDTH(scrollBar->e.bounds) - UI_RECT_WIDTH(element->bounds))
  				: (UI_RECT_HEIGHT(scrollBar->e.bounds) - UI_RECT_HEIGHT(element->bounds));
  		scrollBar->position = (double) thumbPosition / size * (scrollBar->maximum - scrollBar->page);
  		UIElementRefresh(&scrollBar->e);
  		UIElementMessage(scrollBar->e.parent, UI_MSG_SCROLLED, 0, 0);
  	} else if (message == UI_MSG_LEFT_UP) {
  		scrollBar->inDrag = false;
  	}
  
  	return 0;
  }
  
  UIScrollBar *UIScrollBarCreate(UIElement *parent, uint32_t flags) {
  	UIScrollBar *scrollBar = (UIScrollBar *) UIElementCreate(sizeof(UIScrollBar), parent, flags, _UIScrollBarMessage, "Scroll Bar");
  	bool horizontal = scrollBar->horizontal = flags & UI_SCROLL_BAR_HORIZONTAL;
  	UIElementCreate(sizeof(UIElement), &scrollBar->e, flags, _UIScrollUpDownMessage, !horizontal ? "Scroll Up" : "Scroll Left")->cp = (void *) (uintptr_t) 0;
  	UIElementCreate(sizeof(UIElement), &scrollBar->e, flags, _UIScrollThumbMessage, "Scroll Thumb");
  	UIElementCreate(sizeof(UIElement), &scrollBar->e, flags, _UIScrollUpDownMessage, !horizontal ? "Scroll Down" : "Scroll Right")->cp = (void *) (uintptr_t) 1;
  	return scrollBar;
  }
  
  bool _UICharIsAlpha(char c) {
  	return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
  }
  
  bool _UICharIsDigit(char c) {
  	return c >= '0' && c <= '9';
  }
  
  bool _UICharIsAlphaOrDigitOrUnderscore(char c) {
  	return _UICharIsAlpha(c) || _UICharIsDigit(c) || c == '_';
  }
  
  int UICodeHitTest(UICode *code, int x, int y) {
  	x -= code->e.bounds.l;
  
  	if (x < 0 || x >= UI_RECT_WIDTH(code->e.bounds) - UI_SIZE_SCROLL_BAR * code->e.window->scale) {
  		return 0;
  	}
  
  	y -= code->e.bounds.t - code->vScroll->position;
  
  	UIFont *previousFont = UIFontActivate(code->font);
  	int lineHeight = UIMeasureStringHeight();
  	UIFontActivate(previousFont);
  
  	if (y < 0 || y >= lineHeight * code->lineCount) {
  		return 0;
  	}
  
  	int line = y / lineHeight + 1;
  
  	if (x < UI_SIZE_CODE_MARGIN && (~code->e.flags & UI_CODE_NO_MARGIN)) {
  		return -line;
  	} else {
  		return line;
  	}
  }
  
  int UIDrawStringHighlighted(UIPainter *painter, UIRectangle lineBounds, const char *string, ptrdiff_t bytes, int tabSize) {
  	if (bytes == -1) bytes = _UIStringLength(string);
  	if (bytes > 10000) bytes = 10000;
  
  	uint32_t colors[] = {
  		ui.theme.codeDefault,
  		ui.theme.codeComment,
  		ui.theme.codeString,
  		ui.theme.codeNumber,
  		ui.theme.codeOperator,
  		ui.theme.codePreprocessor,
  	};
  
  	int x = lineBounds.l;
  	int y = (lineBounds.t + lineBounds.b - UIMeasureStringHeight()) / 2;
  	int ti = 0;
  	int lexState = 0;
  	bool inComment = false, inIdentifier = false, inChar = false, startedString = false;
  	uint32_t last = 0;
  
  	while (bytes--) {
  		char c = *string++;
  
  		last <<= 8;
  		last |= c;
  
  		if (lexState == 4) {
  			lexState = 0;
  		} else if (lexState == 1) {
  			if ((last & 0xFF0000) == ('*' << 16) && (last & 0xFF00) == ('/' << 8) && inComment) {
  				lexState = 0, inComment = false;
  			}
  		} else if (lexState == 3) {
  			if (!_UICharIsAlpha(c) && !_UICharIsDigit(c)) {
  				lexState = 0;
  			}
  		} else if (lexState == 2) {
  			if (!startedString) {
  				if (!inChar && ((last >> 8) & 0xFF) == '"' && ((last >> 16) & 0xFF) != '\\') {
  					lexState = 0;
  				} else if (inChar && ((last >> 8) & 0xFF) == '\'' && ((last >> 16) & 0xFF) != '\\') {
  					lexState = 0;
  				}
  			}
  
  			startedString = false;
  		}
  
  		if (lexState == 0) {
  			if (c == '#') {
  				lexState = 5;
  			} else if (c == '/' && *string == '/') {
  				lexState = 1;
  			} else if (c == '/' && *string == '*') {
  				lexState = 1, inComment = true;
  			} else if (c == '"') {
  				lexState = 2;
  				inChar = false;
  				startedString = true;
  			} else if (c == '\'') {
  				lexState = 2;
  				inChar = true;
  				startedString = true;
  			} else if (_UICharIsDigit(c) && !inIdentifier) {
  				lexState = 3;
  			} else if (!_UICharIsAlpha(c) && !_UICharIsDigit(c)) {
  				lexState = 4;
  				inIdentifier = false;
  			} else {
  				inIdentifier = true;
  			}
  		}
  
  		if (c == '\t') {
  			x += ui.activeFont->glyphWidth, ti++;
  			while (ti % tabSize) x += ui.activeFont->glyphWidth, ti++;
  		} else {
  			UIDrawGlyph(painter, x, y, c, colors[lexState]);
  			x += ui.activeFont->glyphWidth, ti++;
  		}
  	}
  
  	return x;
  }
  
  int _UICodeMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UICode *code = (UICode *) element;
  	
  	if (message == UI_MSG_LAYOUT) {
  		UIFont *previousFont = UIFontActivate(code->font);
  
  		if (code->moveScrollToFocusNextLayout) {
  			code->vScroll->position = (code->focused + 0.5) * UIMeasureStringHeight() - UI_RECT_HEIGHT(code->e.bounds) / 2;
  		}
  
  		UIRectangle scrollBarBounds = element->bounds;
  		scrollBarBounds.l = scrollBarBounds.r - UI_SIZE_SCROLL_BAR * code->e.window->scale;
  		code->vScroll->maximum = code->lineCount * UIMeasureStringHeight();
  		code->vScroll->page = UI_RECT_HEIGHT(element->bounds);
  		UIFontActivate(previousFont);
  		UIElementMove(&code->vScroll->e, scrollBarBounds, true);
  	} else if (message == UI_MSG_PAINT) {
  		UIFont *previousFont = UIFontActivate(code->font);
  
  		UIPainter *painter = (UIPainter *) dp;
  		UIRectangle lineBounds = element->bounds;
  		lineBounds.r -= UI_SIZE_SCROLL_BAR * code->e.window->scale;
  
  		if (~code->e.flags & UI_CODE_NO_MARGIN) {
  			lineBounds.l += UI_SIZE_CODE_MARGIN + UI_SIZE_CODE_MARGIN_GAP;
  		}
  
  		int lineHeight = UIMeasureStringHeight();
  		lineBounds.t -= (int64_t) code->vScroll->position % lineHeight;
  
  		UIDrawBlock(painter, element->bounds, ui.theme.codeBackground);
  
  		for (int i = code->vScroll->position / lineHeight; i < code->lineCount; i++) {
  			if (lineBounds.t > element->clip.b) {
  				break;
  			}
  
  			lineBounds.b = lineBounds.t + lineHeight;
  
  			if (~code->e.flags & UI_CODE_NO_MARGIN) {
  				char string[16];
  				int p = 16;
  				int lineNumber = i + 1;
  
  				while (lineNumber) {
  					string[--p] = (lineNumber % 10) + '0';
  					lineNumber /= 10;
  				}
  
  				UIRectangle marginBounds = lineBounds;
  				marginBounds.r = marginBounds.l - UI_SIZE_CODE_MARGIN_GAP;
  				marginBounds.l -= UI_SIZE_CODE_MARGIN + UI_SIZE_CODE_MARGIN_GAP;
  
  				uint32_t marginColor = UIElementMessage(element, UI_MSG_CODE_GET_MARGIN_COLOR, i + 1, 0);
  
  				if (marginColor) {
  					UIDrawBlock(painter, marginBounds, marginColor);
  				}
  
  				UIDrawString(painter, marginBounds, string + p, 16 - p, ui.theme.codeDefault, UI_ALIGN_RIGHT, NULL);
  			}
  
  			if (code->focused == i) {
  				UIDrawBlock(painter, lineBounds, ui.theme.codeFocused);
  			}
  
  			int x = UIDrawStringHighlighted(painter, lineBounds, code->content + code->lines[i].offset, code->lines[i].bytes, code->tabSize);
  			int y = (lineBounds.t + lineBounds.b - UIMeasureStringHeight()) / 2;
  
  			UICodeDecorateLine m = { 0 };
  			m.x = x, m.y = y, m.bounds = lineBounds, m.index = i + 1, m.painter = painter;
  			UIElementMessage(element, UI_MSG_CODE_DECORATE_LINE, 0, &m);
  
  			lineBounds.t += lineHeight;
  		}
  
  		UIFontActivate(previousFont);
  	} else if (message == UI_MSG_SCROLLED) {
  		code->moveScrollToFocusNextLayout = false;
  		UIElementRefresh(element);
  	} else if (message == UI_MSG_MOUSE_WHEEL) {
  		return UIElementMessage(&code->vScroll->e, message, di, dp);
  	} else if (message == UI_MSG_GET_CURSOR) {
  		if (UICodeHitTest(code, element->window->cursorX, element->window->cursorY) < 0) {
  			return UI_CURSOR_FLIPPED_ARROW;
  		}
  	} else if (message == UI_MSG_DESTROY) {
  		UI_FREE(code->content);
  		UI_FREE(code->lines);
  	}
  
  	return 0;
  }
  
  void UICodeFocusLine(UICode *code, int index) {
  	code->focused = index - 1;
  	code->moveScrollToFocusNextLayout = true;
  }
  
  void UICodeInsertContent(UICode *code, const char *content, ptrdiff_t byteCount, bool replace) {
  	UIFont *previousFont = UIFontActivate(code->font);
  
  	if (byteCount == -1) {
  		byteCount = _UIStringLength(content);
  	}
  
  	if (byteCount > 1000000000) {
  		byteCount = 1000000000;
  	}
  
  	if (replace) {
  		UI_FREE(code->content);
  		UI_FREE(code->lines);
  		code->content = NULL;
  		code->lines = NULL;
  		code->contentBytes = 0;
  		code->lineCount = 0;
  	}
  
  	code->content = (char *) UI_REALLOC(code->content, code->contentBytes + byteCount);
  
  	if (!byteCount) {
  		return;
  	}
  
  	int lineCount = content[byteCount - 1] != '\n';
  
  	for (int i = 0; i < byteCount; i++) {
  		code->content[i + code->contentBytes] = content[i];
  
  		if (content[i] == '\n') {
  			lineCount++;
  		}
  	}
  
  	code->lines = (UICodeLine *) UI_REALLOC(code->lines, sizeof(UICodeLine) * (code->lineCount + lineCount));
  	int offset = 0, lineIndex = 0;
  
  	for (intptr_t i = 0; i <= byteCount && lineIndex < lineCount; i++) {
  		if (content[i] == '\n' || i == byteCount) {
  			UICodeLine line = { 0 };
  			line.offset = offset + code->contentBytes;
  			line.bytes = i - offset;
  			code->lines[code->lineCount + lineIndex] = line;
  			lineIndex++;
  			offset = i + 1;
  		}
  	}
  
  	code->lineCount += lineCount;
  	code->contentBytes += byteCount;
  
  	if (!replace) {
  		code->vScroll->position = code->lineCount * UIMeasureStringHeight();
  	}
  
  	UIFontActivate(previousFont);
  }
  
  UICode *UICodeCreate(UIElement *parent, uint32_t flags) {
  	UICode *code = (UICode *) UIElementCreate(sizeof(UICode), parent, flags, _UICodeMessage, "Code");
  	code->font = ui.activeFont;
  	code->vScroll = UIScrollBarCreate(&code->e, 0);
  	code->focused = -1;
  	code->tabSize = 4;
  	return code;
  }
  
  int _UIGaugeMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UIGauge *gauge = (UIGauge *) element;
  
  	if (message == UI_MSG_GET_HEIGHT) {
  		return UI_SIZE_GAUGE_HEIGHT * element->window->scale;
  	} else if (message == UI_MSG_GET_WIDTH) {
  		return UI_SIZE_GAUGE_WIDTH * element->window->scale;
  	} else if (message == UI_MSG_PAINT) {
  		UIPainter *painter = (UIPainter *) dp;
  		UIDrawRectangle(painter, element->bounds, ui.theme.buttonNormal, ui.theme.border, UI_RECT_1(1));
  		UIRectangle filled = UIRectangleAdd(element->bounds, UI_RECT_1I(1));
  		filled.r = filled.l + UI_RECT_WIDTH(filled) * gauge->position;
  		UIDrawBlock(painter, filled, ui.theme.selected);
  	}
  
  	return 0;
  }
  
  UIGauge *UIGaugeCreate(UIElement *parent, uint32_t flags) {
  	return (UIGauge *) UIElementCreate(sizeof(UIGauge), parent, flags, _UIGaugeMessage, "Gauge");
  }
  
  int _UISliderMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UISlider *slider = (UISlider *) element;
  
  	if (message == UI_MSG_GET_HEIGHT) {
  		return UI_SIZE_SLIDER_HEIGHT * element->window->scale;
  	} else if (message == UI_MSG_GET_WIDTH) {
  		return UI_SIZE_SLIDER_WIDTH * element->window->scale;
  	} else if (message == UI_MSG_PAINT) {
  		UIPainter *painter = (UIPainter *) dp;
  		UIRectangle bounds = element->bounds;
  		int centerY = (bounds.t + bounds.b) / 2;
  		int trackSize = UI_SIZE_SLIDER_TRACK * element->window->scale;
  		int thumbSize = UI_SIZE_SLIDER_THUMB * element->window->scale;
  		int thumbPosition = (UI_RECT_WIDTH(bounds) - thumbSize) * slider->position;
  		UIRectangle track = UI_RECT_4(bounds.l, bounds.r, centerY - (trackSize + 1) / 2, centerY + trackSize / 2);
  		UIDrawRectangle(painter, track, ui.theme.buttonNormal, ui.theme.border, UI_RECT_1(1));
  		bool pressed = element == element->window->pressed;
  		bool hovered = element == element->window->hovered;
  		bool disabled = element->flags & UI_ELEMENT_DISABLED;
  		uint32_t color = disabled ? ui.theme.buttonDisabled : pressed ? ui.theme.buttonPressed : hovered ? ui.theme.buttonHovered : ui.theme.buttonNormal;
  		UIRectangle thumb = UI_RECT_4(bounds.l + thumbPosition, bounds.l + thumbPosition + thumbSize, centerY - (thumbSize + 1) / 2, centerY + thumbSize / 2);
  		UIDrawRectangle(painter, thumb, color, ui.theme.border, UI_RECT_1(1));
  	} else if (message == UI_MSG_LEFT_DOWN || (message == UI_MSG_MOUSE_DRAG && element->window->pressedButton == 1)) {
  		UIRectangle bounds = element->bounds;
  		int thumbSize = UI_SIZE_SLIDER_THUMB * element->window->scale;
  		slider->position = (float) (element->window->cursorX - thumbSize / 2 - bounds.l) / (UI_RECT_WIDTH(bounds) - thumbSize);
  		if (slider->steps > 1) slider->position = (int) (slider->position * (slider->steps - 1) + 0.5f) / (float) (slider->steps - 1);
  		if (slider->position < 0) slider->position = 0;
  		if (slider->position > 1) slider->position = 1;
  		UIElementMessage(element, UI_MSG_VALUE_CHANGED, 0, 0);
  		UIElementRepaint(element, NULL);
  	} else if (message == UI_MSG_UPDATE) {
  		UIElementRepaint(element, NULL);
  	}
  
  	return 0;
  }
  
  UISlider *UISliderCreate(UIElement *parent, uint32_t flags) {
  	return (UISlider *) UIElementCreate(sizeof(UISlider), parent, flags, _UISliderMessage, "Slider");
  }
  
  int UITableHitTest(UITable *table, int x, int y) {
  	x -= table->e.bounds.l;
  
  	if (x < 0 || x >= UI_RECT_WIDTH(table->e.bounds) - UI_SIZE_SCROLL_BAR * table->e.window->scale) {
  		return -1;
  	}
  
  	y -= (table->e.bounds.t + UI_SIZE_TABLE_HEADER * table->e.window->scale) - table->vScroll->position;
  
  	int rowHeight = UI_SIZE_TABLE_ROW * table->e.window->scale;
  
  	if (y < 0 || y >= rowHeight * table->itemCount) {
  		return -1;
  	}
  
  	return y / rowHeight;
  }
  
  int UITableHeaderHitTest(UITable *table, int x, int y) {
  	if (!table->columnCount) return -1;
  	UIRectangle header = table->e.bounds;
  	header.b = header.t + UI_SIZE_TABLE_HEADER * table->e.window->scale;
  	header.l += UI_SIZE_TABLE_COLUMN_GAP * table->e.window->scale;
  	int position = 0, index = 0;
  
  	while (true) {
  		int end = position;
  		for (; table->columns[end] != '\t' && table->columns[end]; end++);
  		header.r = header.l + table->columnWidths[index];
  		if (UIRectangleContains(header, x, y)) return index;
  		header.l += table->columnWidths[index] + UI_SIZE_TABLE_COLUMN_GAP * table->e.window->scale;
  		if (table->columns[end] != '\t') break;
  		position = end + 1, index++;
  	}
  
  	return -1;
  }
  
  bool UITableEnsureVisible(UITable *table, int index) {
  	int rowHeight = UI_SIZE_TABLE_ROW * table->e.window->scale;
  	int y = index * rowHeight;
  	y -= table->vScroll->position;
  	int height = UI_RECT_HEIGHT(table->e.bounds) - UI_SIZE_TABLE_HEADER * table->e.window->scale - rowHeight;
  
  	if (y < 0) {
  		table->vScroll->position += y;
  		UIElementRefresh(&table->e);
  		return true;
  	} else if (y > height) {
  		table->vScroll->position -= height - y;
  		UIElementRefresh(&table->e);
  		return true;
  	} else {
  		return false;
  	}
  }
  
  void UITableResizeColumns(UITable *table) {
  	int position = 0;
  	int count = 0;
  
  	while (true) {
  		int end = position;
  		for (; table->columns[end] != '\t' && table->columns[end]; end++);
  		count++;
  		if (table->columns[end] == '\t') position = end + 1;
  		else break;
  	}
  
  	UI_FREE(table->columnWidths);
  	table->columnWidths = (int *) UI_MALLOC(count * sizeof(int));
  	table->columnCount = count;
  
  	position = 0;
  
  	char buffer[256];
  	UITableGetItem m = { 0 };
  	m.buffer = buffer;
  	m.bufferBytes = sizeof(buffer);
  
  	while (true) {
  		int end = position;
  		for (; table->columns[end] != '\t' && table->columns[end]; end++);
  
  		int longest = UIMeasureStringWidth(table->columns + position, end - position);
  
  		for (int i = 0; i < table->itemCount; i++) {
  			m.index = i;
  			int bytes = UIElementMessage(&table->e, UI_MSG_TABLE_GET_ITEM, 0, &m);
  			int width = UIMeasureStringWidth(buffer, bytes);
  
  			if (width > longest) {
  				longest = width;
  			}
  		}
  
  		table->columnWidths[m.column] = longest;
  		m.column++;
  		if (table->columns[end] == '\t') position = end + 1;
  		else break;
  	}
  }
  
  int _UITableMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UITable *table = (UITable *) element;
  
  	if (message == UI_MSG_PAINT) {
  		UIPainter *painter = (UIPainter *) dp;
  		UIRectangle bounds = element->bounds;
  		bounds.r -= UI_SIZE_SCROLL_BAR * element->window->scale;
  		UIDrawBlock(painter, bounds, ui.theme.panel2);
  		char buffer[256];
  		UIRectangle row = bounds;
  		int rowHeight = UI_SIZE_TABLE_ROW * element->window->scale;
  		UITableGetItem m = { 0 };
  		m.buffer = buffer;
  		m.bufferBytes = sizeof(buffer);
  		row.t += UI_SIZE_TABLE_HEADER * table->e.window->scale;
  		row.t -= (int64_t) table->vScroll->position % rowHeight;
  		int hovered = UITableHitTest(table, element->window->cursorX, element->window->cursorY);
  
  		for (int i = table->vScroll->position / rowHeight; i < table->itemCount; i++) {
  			if (row.t > element->clip.b) {
  				break;
  			}
  			
  			row.b = row.t + rowHeight;
  			m.index = i;
  			m.isSelected = false;
  			m.column = 0;
  			int bytes = UIElementMessage(element, UI_MSG_TABLE_GET_ITEM, 0, &m);
  			uint32_t textColor = ui.theme.text;
  
  			if (m.isSelected) {
  				UIDrawBlock(painter, row, ui.theme.selected);
  				textColor = ui.theme.textSelected;
  			} else if (hovered == i) {
  				UIDrawBlock(painter, row, ui.theme.buttonHovered);
  			}
  
  			UIRectangle cell = row;
  			cell.l += UI_SIZE_TABLE_COLUMN_GAP * table->e.window->scale;
  
  			for (int j = 0; j < table->columnCount; j++) {
  				if (j) {
  					m.column = j;
  					bytes = UIElementMessage(element, UI_MSG_TABLE_GET_ITEM, 0, &m);
  				}
  
  				cell.r = cell.l + table->columnWidths[j];
  				if ((size_t) bytes > m.bufferBytes && bytes > 0) bytes = m.bufferBytes;
  				UIDrawString(painter, cell, buffer, bytes, textColor, UI_ALIGN_LEFT, NULL);
  				cell.l += table->columnWidths[j] + UI_SIZE_TABLE_COLUMN_GAP * table->e.window->scale;
  			}
  
  			row.t += rowHeight;
  		}
  
  		UIRectangle header = bounds;
  		header.b = header.t + UI_SIZE_TABLE_HEADER * table->e.window->scale;
  		UIDrawRectangle(painter, header, ui.theme.panel1, ui.theme.border, UI_RECT_4(0, 0, 0, 1));
  		header.l += UI_SIZE_TABLE_COLUMN_GAP * table->e.window->scale;
  
  		int position = 0;
  		int index = 0;
  
  		if (table->columnCount) {
  			while (true) {
  				int end = position;
  				for (; table->columns[end] != '\t' && table->columns[end]; end++);
  
  				header.r = header.l + table->columnWidths[index];
  				UIDrawString(painter, header, table->columns + position, end - position, ui.theme.text, UI_ALIGN_LEFT, NULL);
  				if (index == table->columnHighlight) UIDrawInvert(painter, header);
  				header.l += table->columnWidths[index] + UI_SIZE_TABLE_COLUMN_GAP * table->e.window->scale;
  
  				if (table->columns[end] == '\t') {
  					position = end + 1;
  					index++;
  				} else {
  					break;
  				}
  			}
  		}
  	} else if (message == UI_MSG_LAYOUT) {
  		UIRectangle scrollBarBounds = element->bounds;
  		scrollBarBounds.l = scrollBarBounds.r - UI_SIZE_SCROLL_BAR * element->window->scale;
  		table->vScroll->maximum = table->itemCount * UI_SIZE_TABLE_ROW * element->window->scale;
  		table->vScroll->page = UI_RECT_HEIGHT(element->bounds) - UI_SIZE_TABLE_HEADER * table->e.window->scale;
  		UIElementMove(&table->vScroll->e, scrollBarBounds, true);
  	} else if (message == UI_MSG_MOUSE_MOVE || message == UI_MSG_UPDATE) {
  		UIElementRepaint(element, NULL);
  	} else if (message == UI_MSG_SCROLLED) {
  		UIElementRefresh(element);
  	} else if (message == UI_MSG_MOUSE_WHEEL) {
  		return UIElementMessage(&table->vScroll->e, message, di, dp);
  	} else if (message == UI_MSG_DESTROY) {
  		UI_FREE(table->columns);
  		UI_FREE(table->columnWidths);
  	}
  
  	return 0;
  }
  
  UITable *UITableCreate(UIElement *parent, uint32_t flags, const char *columns) {
  	UITable *table = (UITable *) UIElementCreate(sizeof(UITable), parent, flags, _UITableMessage, "Table");
  	table->vScroll = UIScrollBarCreate(&table->e, 0);
  	table->columns = UIStringCopy(columns, -1);
  	table->columnHighlight = -1;
  	return table;
  }
  
  void UITextboxReplace(UITextbox *textbox, const char *text, ptrdiff_t bytes, bool sendChangedMessage) {
  	if (bytes == -1) {
  		bytes = _UIStringLength(text);
  	}
  
  	int deleteFrom = textbox->carets[0], deleteTo = textbox->carets[1];
  
  	if (deleteFrom > deleteTo) {
  		UI_SWAP(int, deleteFrom, deleteTo);
  	}
  
  	for (int i = deleteTo; i < textbox->bytes; i++) {
  		textbox->string[i - deleteTo + deleteFrom] = textbox->string[i];
  	}
  
  	textbox->bytes -= deleteTo - deleteFrom;
  	textbox->carets[0] = textbox->carets[1] = deleteFrom;
  
  	textbox->string = (char *) UI_REALLOC(textbox->string, textbox->bytes + bytes);
  
  	for (int i = textbox->bytes + bytes - 1; i >= textbox->carets[0] + bytes; i--) {
  		textbox->string[i] = textbox->string[i - bytes];
  	}
  
  	for (int i = textbox->carets[0]; i < textbox->carets[0] + bytes; i++) {
  		textbox->string[i] = text[i - textbox->carets[0]];
  	}
  
  	textbox->bytes += bytes;
  	textbox->carets[0] += bytes;
  	textbox->carets[1] = textbox->carets[0];
  
  	if (sendChangedMessage) {
  		UIElementMessage(&textbox->e, UI_MSG_VALUE_CHANGED, 0, 0);
  	}
  
  	textbox->e.window->textboxModifiedFlag = true;
  }
  
  void UITextboxClear(UITextbox *textbox, bool sendChangedMessage) {
  	textbox->carets[1] = 0;
  	textbox->carets[0] = textbox->bytes;
  	UITextboxReplace(textbox, "", 0, sendChangedMessage);
  }
  
  void UITextboxMoveCaret(UITextbox *textbox, bool backward, bool word) {
  	while (true) {
  		if (textbox->carets[0] > 0 && backward) {
  			textbox->carets[0]--;
  		} else if (textbox->carets[0] < textbox->bytes && !backward) {
  			textbox->carets[0]++;
  		} else {
  			return;
  		}
  
  		if (!word) {
  			return;
  		} else if (textbox->carets[0] != textbox->bytes && textbox->carets[0] != 0) {
  			char c1 = textbox->string[textbox->carets[0] - 1];
  			char c2 = textbox->string[textbox->carets[0]];
  
  			if (_UICharIsAlphaOrDigitOrUnderscore(c1) != _UICharIsAlphaOrDigitOrUnderscore(c2)) {
  				return;
  			}
  		}
  	}
  }
  
  int _UITextboxMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UITextbox *textbox = (UITextbox *) element;
  
  	if (message == UI_MSG_GET_HEIGHT) {
  		return UI_SIZE_TEXTBOX_HEIGHT * element->window->scale;
  	} else if (message == UI_MSG_GET_WIDTH) {
  		return UI_SIZE_TEXTBOX_WIDTH * element->window->scale;
  	} else if (message == UI_MSG_PAINT) {
  		int scaledMargin = UI_SIZE_TEXTBOX_MARGIN * element->window->scale;
  		int totalWidth = UIMeasureStringWidth(textbox->string, textbox->bytes) + scaledMargin * 2;
  		UIRectangle textBounds = UIRectangleAdd(element->bounds, UI_RECT_1I(scaledMargin));
  
  		if (textbox->scroll > totalWidth - UI_RECT_WIDTH(textBounds)) {
  			textbox->scroll = totalWidth - UI_RECT_WIDTH(textBounds);
  		}
  
  		if (textbox->scroll < 0) {
  			textbox->scroll = 0;
  		}
  
  		int caretX = UIMeasureStringWidth(textbox->string, textbox->carets[0]) - textbox->scroll;
  
  		if (caretX < 0) {
  			textbox->scroll = caretX + textbox->scroll;
  		} else if (caretX > UI_RECT_WIDTH(textBounds)) {
  			textbox->scroll = caretX - UI_RECT_WIDTH(textBounds) + textbox->scroll + 1;
  		}
  
  		UIPainter *painter = (UIPainter *) dp;
  		bool focused = element->window->focused == element;
  		bool disabled = element->flags & UI_ELEMENT_DISABLED;
  		UIDrawRectangle(painter, element->bounds, 
  			disabled ? ui.theme.buttonDisabled : focused ? ui.theme.textboxFocused : ui.theme.textboxNormal, 
  			ui.theme.border, UI_RECT_1(1));
  #ifdef __cplusplus
  		UIStringSelection selection = {};
  #else
  		UIStringSelection selection = { 0 };
  #endif
  		selection.carets[0] = textbox->carets[0];
  		selection.carets[1] = textbox->carets[1];
  		selection.colorBackground = ui.theme.selected;
  		selection.colorText = ui.theme.textSelected;
  		textBounds.l -= textbox->scroll;
  		UIDrawString(painter, textBounds, textbox->string, textbox->bytes, 
  			disabled ? ui.theme.textDisabled : ui.theme.text, UI_ALIGN_LEFT, focused ? &selection : NULL);
  	} else if (message == UI_MSG_GET_CURSOR) {
  		return UI_CURSOR_TEXT;
  	} else if (message == UI_MSG_LEFT_DOWN) {
  		UIElementFocus(element);
  	} else if (message == UI_MSG_UPDATE) {
  		UIElementRepaint(element, NULL);
  	} else if (message == UI_MSG_DESTROY) {
  		UI_FREE(textbox->string);
  	} else if (message == UI_MSG_KEY_TYPED) {
  		UIKeyTyped *m = (UIKeyTyped *) dp;
  		bool handled = true;
  
  		if (textbox->rejectNextKey) {
  			textbox->rejectNextKey = false;
  			handled = false;
  		} else if (m->code == UI_KEYCODE_BACKSPACE || m->code == UI_KEYCODE_DELETE) {
  			if (textbox->carets[0] == textbox->carets[1]) {
  				UITextboxMoveCaret(textbox, m->code == UI_KEYCODE_BACKSPACE, element->window->ctrl);
  			}
  
  			UITextboxReplace(textbox, NULL, 0, true);
  		} else if (m->code == UI_KEYCODE_LEFT || m->code == UI_KEYCODE_RIGHT) {
  			UITextboxMoveCaret(textbox, m->code == UI_KEYCODE_LEFT, element->window->ctrl);
  
  			if (!element->window->shift) {
  				textbox->carets[1] = textbox->carets[0];
  			}
  		} else if (m->code == UI_KEYCODE_HOME || m->code == UI_KEYCODE_END) {
  			if (m->code == UI_KEYCODE_HOME) {
  				textbox->carets[0] = 0;
  			} else {
  				textbox->carets[0] = textbox->bytes;
  			}
  
  			if (!element->window->shift) {
  				textbox->carets[1] = textbox->carets[0];
  			}
  		} else if (m->code == UI_KEYCODE_LETTER('A') && element->window->ctrl) {
  			textbox->carets[1] = 0;
  			textbox->carets[0] = textbox->bytes;
  		} else if (m->textBytes && !element->window->alt && !element->window->ctrl && m->text[0] >= 0x20) {
  			UITextboxReplace(textbox, m->text, m->textBytes, true);
  		} else {
  			handled = false;
  		}
  
  		if (handled) {
  			UIElementRepaint(element, NULL);
  			return 1;
  		}
  	}
  
  	return 0;
  }
  
  UITextbox *UITextboxCreate(UIElement *parent, uint32_t flags) {
  	return (UITextbox *) UIElementCreate(sizeof(UITextbox), parent, flags | UI_ELEMENT_TAB_STOP, _UITextboxMessage, "Textbox");
  }
  
  int _UIColorCircleMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UIColorPicker *colorPicker = (UIColorPicker *) element->parent;
  
  	if (message == UI_MSG_PAINT) {
  		UIPainter *painter = (UIPainter *) dp;
  
  		int startY = element->bounds.t, endY = element->bounds.b;
  		int startX = element->bounds.l, endX = element->bounds.r;
  		int size = endY - startY;
  
  		for (int i = startY; i < endY; i++) {
  			uint32_t *out = painter->bits + i * painter->width + startX;
  			int j = startX;
  			float y0 = i - startY - size / 2, x0 = -size / 2;
  			float angle = _UIArcTan2Float((i - startY) * 2.0f / size - 1, -1);
  
  			do {
  				float distanceFromCenterSquared = x0 * x0 + y0 * y0;
  				float hue = (angle + 3.14159f) * 0.954929658f;
  				float saturation = _UISquareRootFloat(distanceFromCenterSquared * 4.0f / size / size);
  
  				if (saturation <= 1 && UIRectangleContains(painter->clip, j, i)) {
  					UIColorToRGB(hue, saturation, colorPicker->value, out);
  					*out |= 0xFF000000;
  				}
  
  				out++, j++, x0++;
  
  				if (distanceFromCenterSquared) {
  					angle -= y0 / distanceFromCenterSquared;
  				} else {
  					angle = _UIArcTan2Float((i - startY) * 2.0f / size - 1, 0.01f);
  				}
  			} while (j < endX);
  		}
  
  		float angle = colorPicker->hue / 0.954929658f - 3.14159f;
  		float radius = colorPicker->saturation * size / 2;
  		int cx = (startX + endX) / 2 + radius * _UICosFloat(angle);
  		int cy = (startY + endY) / 2 + radius * _UISinFloat(angle);
  		UIDrawInvert(painter, UI_RECT_4(cx - 1, cx + 1, startY, endY));
  		UIDrawInvert(painter, UI_RECT_4(startX, endX, cy - 1, cy + 1));
  	} else if (message == UI_MSG_GET_CURSOR) {
  		return UI_CURSOR_CROSS_HAIR;
  	} else if (message == UI_MSG_LEFT_DOWN || message == UI_MSG_MOUSE_DRAG) {
  		int startY = element->bounds.t, endY = element->bounds.b, cursorY = element->window->cursorY;
  		int startX = element->bounds.l, endX = element->bounds.r, cursorX = element->window->cursorX;
  		int dx = (startX + endX) / 2, dy = (startY + endY) / 2;
  		int size = endY - startY;
  
  		float angle = _UIArcTan2Float((cursorY - startY) * 2.0f / size - 1, (cursorX - startX) * 2.0f / size - 1);
  		float distanceFromCenterSquared = (cursorX - dx) * (cursorX - dx) + (cursorY - dy) * (cursorY - dy);
  		colorPicker->hue = (angle + 3.14159f) * 0.954929658f;
  		colorPicker->saturation = _UISquareRootFloat(distanceFromCenterSquared * 4.0f / size / size);;
  		if (colorPicker->saturation > 1) colorPicker->saturation = 1;
  
  		UIElementMessage(&colorPicker->e, UI_MSG_VALUE_CHANGED, 0, 0);
  		UIElementRepaint(&colorPicker->e, NULL);
  	}
  
  	return 0;
  }
  
  int _UIColorSliderMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UIColorPicker *colorPicker = (UIColorPicker *) element->parent;
  	float opacitySlider = element->flags & 1;
  
  	if (message == UI_MSG_PAINT) {
  		UIPainter *painter = (UIPainter *) dp;
  
  		int startY = element->bounds.t, endY = element->bounds.b;
  		int startX = element->bounds.l, endX = element->bounds.r;
  		int size = endY - startY;
  
  		for (int i = startY; i < endY; i++) {
  			if (i < painter->clip.t || i >= painter->clip.b) continue;
  			uint32_t *out = painter->bits + i * painter->width + startX;
  			int j = element->clip.l;
  			uint32_t color;
  			float p = 1.0f - (float) (i - startY) / size;
  
  			if (opacitySlider) {
  				UIColorToRGB(colorPicker->hue, colorPicker->saturation, colorPicker->value, &color);
  				color = UI_COLOR_FROM_FLOAT(p * (UI_COLOR_RED_F(color) - 0.5f) + 0.5f, 
  					p * (UI_COLOR_GREEN_F(color) - 0.5f) + 0.5f, 
  					p * (UI_COLOR_BLUE_F(color) - 0.5f) + 0.5f);
  			} else {
  				UIColorToRGB(colorPicker->hue, colorPicker->saturation, p, &color);
  			}
  
  			color |= 0xFF000000;
  
  			do {
  				*out = color;
  				out++, j++;
  			} while (j < element->clip.r);
  		}
  
  		int cy = (size - 1) * (1 - (opacitySlider ? colorPicker->opacity : colorPicker->value)) + startY;
  		UIDrawInvert(painter, UI_RECT_4(startX, endX, cy - 1, cy + 1));
  	} else if (message == UI_MSG_GET_CURSOR) {
  		return UI_CURSOR_CROSS_HAIR;
  	} else if (message == UI_MSG_LEFT_DOWN || message == UI_MSG_MOUSE_DRAG) {
  		int startY = element->bounds.t, endY = element->bounds.b, cursorY = element->window->cursorY;
  		float *value = opacitySlider ? &colorPicker->opacity : &colorPicker->value;
  		*value = 1 - (float) (cursorY - startY) / (endY - startY);
  		if (*value < 0) *value = 0;
  		if (*value > 1) *value = 1;
  		UIElementMessage(&colorPicker->e, UI_MSG_VALUE_CHANGED, 0, 0);
  		UIElementRepaint(&colorPicker->e, NULL);
  	}
  
  	return 0;
  }
  
  int _UIColorPickerMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	bool hasOpacity = element->flags & UI_COLOR_PICKER_HAS_OPACITY;
  
  	if (message == UI_MSG_GET_WIDTH) {
  		return (hasOpacity ? 280 : 240) * element->window->scale;
  	} else if (message == UI_MSG_GET_HEIGHT) {
  		return 200 * element->window->scale;
  	} else if (message == UI_MSG_LAYOUT) {
  		UIRectangle bounds = element->bounds;
  
  		int sliderSize = 35 * element->window->scale;
  		int gap = 5 * element->window->scale;
  
  		if (hasOpacity) {
  			UIElementMove(element->children, UI_RECT_4(bounds.l, bounds.r - (sliderSize + gap) * 2, bounds.t, bounds.b), false);
  			UIElementMove(element->children->next, UI_RECT_4(bounds.r - sliderSize * 2 - gap, bounds.r - sliderSize - gap, bounds.t, bounds.b), false);
  			UIElementMove(element->children->next->next, UI_RECT_4(bounds.r - sliderSize, bounds.r, bounds.t, bounds.b), false);
  		} else {
  			UIElementMove(element->children, UI_RECT_4(bounds.l, bounds.r - sliderSize - gap, bounds.t, bounds.b), false);
  			UIElementMove(element->children->next, UI_RECT_4(bounds.r - sliderSize, bounds.r, bounds.t, bounds.b), false);
  		}
  	}
  
  	return 0;
  }
  
  UIColorPicker *UIColorPickerCreate(UIElement *parent, uint32_t flags) {
  	UIColorPicker *colorPicker = (UIColorPicker *) UIElementCreate(sizeof(UIColorPicker), parent, flags, _UIColorPickerMessage, "ColorPicker");
  	UIElementCreate(sizeof(UIElement), &colorPicker->e, 0, _UIColorCircleMessage, "ColorCircle");
  	UIElementCreate(sizeof(UIElement), &colorPicker->e, 0, _UIColorSliderMessage, "ColorSlider");
  
  	if (flags & UI_COLOR_PICKER_HAS_OPACITY) {
  		UIElementCreate(sizeof(UIElement), &colorPicker->e, 1, _UIColorSliderMessage, "ColorSlider");
  	}
  
  	return colorPicker;
  }
  
  #define UI_MDI_CHILD_CALCULATE_LAYOUT() \
  	int titleSize = UI_SIZE_MDI_CHILD_TITLE * element->window->scale; \
  	int borderSize = UI_SIZE_MDI_CHILD_BORDER * element->window->scale; \
  	UIRectangle title = UIRectangleAdd(element->bounds, UI_RECT_4(borderSize, -borderSize, 0, 0)); \
  	title.b = title.t + titleSize; \
  	UIRectangle content = UIRectangleAdd(element->bounds, UI_RECT_4(borderSize, -borderSize, titleSize, -borderSize));
  
  int _UIMDIChildHitTest(UIMDIChild *mdiChild, int x, int y) {
  	UIElement *element = &mdiChild->e;
  	UI_MDI_CHILD_CALCULATE_LAYOUT();
  	int cornerSize = UI_SIZE_MDI_CHILD_CORNER * element->window->scale;
  	if (!UIRectangleContains(element->bounds, x, y) || UIRectangleContains(content, x, y)) return -1;
  	else if (x < element->bounds.l + cornerSize && y < element->bounds.t + cornerSize) return 0b1010;
  	else if (x > element->bounds.r - cornerSize && y < element->bounds.t + cornerSize) return 0b0110;
  	else if (x < element->bounds.l + cornerSize && y > element->bounds.b - cornerSize) return 0b1001;
  	else if (x > element->bounds.r - cornerSize && y > element->bounds.b - cornerSize) return 0b0101;
  	else if (x < element->bounds.l + borderSize) return 0b1000;
  	else if (x > element->bounds.r - borderSize) return 0b0100;
  	else if (y < element->bounds.t + borderSize) return 0b0010;
  	else if (y > element->bounds.b - borderSize) return 0b0001;
  	else if (UIRectangleContains(title, x, y)) return 0b1111;
  	else return -1;
  }
  
  void _UIMDIChildCloseButton(void *_child) {
  	UIElement *child = (UIElement *) _child;
  	
  	if (!UIElementMessage(child, UI_MSG_WINDOW_CLOSE, 0, 0)) {
  		UIElementDestroy(child);
  		UIElementRefresh(child->parent);
  	}
  }
  
  int _UIMDIChildMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UIMDIChild *mdiChild = (UIMDIChild *) element;
  
  	if (message == UI_MSG_PAINT) {
  		UI_MDI_CHILD_CALCULATE_LAYOUT();
  		UIPainter *painter = (UIPainter *) dp;
  		UIRectangle borders = UI_RECT_4(borderSize, borderSize, titleSize, borderSize);
  		UIDrawBorder(painter, element->bounds, ui.theme.buttonNormal, borders);
  		UIDrawBorder(painter, element->bounds, ui.theme.border, UI_RECT_1((int) element->window->scale));
  		UIDrawBorder(painter, UIRectangleAdd(content, UI_RECT_1I(-1)), ui.theme.border, UI_RECT_1((int) element->window->scale));
  		UIDrawString(painter, title, mdiChild->title, mdiChild->titleBytes, ui.theme.text, UI_ALIGN_LEFT, NULL);
  	} else if (message == UI_MSG_GET_WIDTH) {
  		UIElement *child = element->children;
  		while (child && child->next) child = child->next;
  		int width = 2 * UI_SIZE_MDI_CHILD_BORDER;
  		width += (child ? UIElementMessage(child, message, di ? (di - UI_SIZE_MDI_CHILD_TITLE + UI_SIZE_MDI_CHILD_BORDER) : 0, dp) : 0);
  		if (width < UI_SIZE_MDI_CHILD_MINIMUM_WIDTH) width = UI_SIZE_MDI_CHILD_MINIMUM_WIDTH;
  		return width;
  	} else if (message == UI_MSG_GET_HEIGHT) {
  		UIElement *child = element->children;
  		while (child && child->next) child = child->next;
  		int height = UI_SIZE_MDI_CHILD_TITLE + UI_SIZE_MDI_CHILD_BORDER;
  		height += (child ? UIElementMessage(child, message, di ? (di - 2 * UI_SIZE_MDI_CHILD_BORDER) : 0, dp) : 0);
  		if (height < UI_SIZE_MDI_CHILD_MINIMUM_HEIGHT) height = UI_SIZE_MDI_CHILD_MINIMUM_HEIGHT;
  		return height;
  	} else if (message == UI_MSG_LAYOUT) {
  		UI_MDI_CHILD_CALCULATE_LAYOUT();
  
  		UIElement *child = element->children;
  		int position = title.r;
  
  		while (child && child->next) {
  			int width = UIElementMessage(child, UI_MSG_GET_WIDTH, 0, 0);
  			UIElementMove(child, UI_RECT_4(position - width, position, title.t, title.b), false);
  			position -= width, child = child->next;
  		}
  
  		if (child) {
  			UIElementMove(child, content, false);
  		}
  	} else if (message == UI_MSG_GET_CURSOR) {
  		int hitTest = _UIMDIChildHitTest(mdiChild, element->window->cursorX, element->window->cursorY);
  		if (hitTest == 0b1000) return UI_CURSOR_RESIZE_LEFT;
  		if (hitTest == 0b0010) return UI_CURSOR_RESIZE_UP;
  		if (hitTest == 0b0110) return UI_CURSOR_RESIZE_UP_RIGHT;
  		if (hitTest == 0b1010) return UI_CURSOR_RESIZE_UP_LEFT;
  		if (hitTest == 0b0100) return UI_CURSOR_RESIZE_RIGHT;
  		if (hitTest == 0b0001) return UI_CURSOR_RESIZE_DOWN;
  		if (hitTest == 0b1001) return UI_CURSOR_RESIZE_DOWN_LEFT;
  		if (hitTest == 0b0101) return UI_CURSOR_RESIZE_DOWN_RIGHT;
  		return UI_CURSOR_ARROW;
  	} else if (message == UI_MSG_LEFT_DOWN) {
  		mdiChild->dragHitTest = _UIMDIChildHitTest(mdiChild, element->window->cursorX, element->window->cursorY);
  		mdiChild->dragOffset = UIRectangleAdd(element->bounds, UI_RECT_2(-element->window->cursorX, -element->window->cursorY));
  	} else if (message == UI_MSG_LEFT_UP) {
  		if (mdiChild->bounds.l < 0) mdiChild->bounds.r -= mdiChild->bounds.l, mdiChild->bounds.l = 0;
  		if (mdiChild->bounds.t < 0) mdiChild->bounds.b -= mdiChild->bounds.t, mdiChild->bounds.t = 0;
  		UIElementRefresh(element->parent);
  	} else if (message == UI_MSG_MOUSE_DRAG) {
  		if (mdiChild->dragHitTest > 0) {
  #define _UI_MDI_CHILD_MOVE_EDGE(bit, edge, cursor, size, opposite, negate, minimum, offset) \
  	if (mdiChild->dragHitTest & bit) mdiChild->bounds.edge = mdiChild->dragOffset.edge + element->window->cursor - element->parent->bounds.offset; \
  	if ((mdiChild->dragHitTest & bit) && size(mdiChild->bounds) < minimum) mdiChild->bounds.edge = mdiChild->bounds.opposite negate minimum;
  			_UI_MDI_CHILD_MOVE_EDGE(0b1000, l, cursorX, UI_RECT_WIDTH, r, -, UI_SIZE_MDI_CHILD_MINIMUM_WIDTH, l);
  			_UI_MDI_CHILD_MOVE_EDGE(0b0100, r, cursorX, UI_RECT_WIDTH, l, +, UI_SIZE_MDI_CHILD_MINIMUM_WIDTH, l);
  			_UI_MDI_CHILD_MOVE_EDGE(0b0010, t, cursorY, UI_RECT_HEIGHT, b, -, UI_SIZE_MDI_CHILD_MINIMUM_HEIGHT, t);
  			_UI_MDI_CHILD_MOVE_EDGE(0b0001, b, cursorY, UI_RECT_HEIGHT, t, +, UI_SIZE_MDI_CHILD_MINIMUM_HEIGHT, t);
  			UIElementRefresh(element->parent);
  		}
  	} else if (message == UI_MSG_DESTROY) {
  		UI_FREE(mdiChild->title);
  		UIMDIClient *client = (UIMDIClient *) element->parent;
  		if (client->e.children == element) client->e.children = element->next;
  		if (mdiChild->previous) mdiChild->previous->e.next = element->next;
  		if (element->next) ((UIMDIChild *) element->next)->previous = mdiChild->previous;
  		if (client->active == mdiChild) client->active = mdiChild->previous;
  	}
  
  	return 0;
  }
  
  int _UIMDIClientMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UIMDIClient *client = (UIMDIClient *) element;
  
  	if (message == UI_MSG_PAINT) {
  		UIDrawBlock((UIPainter *) dp, element->bounds, (element->flags & UI_MDI_CLIENT_TRANSPARENT) ? 0 : ui.theme.panel2);
  	} else if (message == UI_MSG_LAYOUT) {
  		UIElement *child = element->children;
  
  		while (child) {
  			UI_ASSERT(child->messageClass == _UIMDIChildMessage);
  
  			UIMDIChild *mdiChild = (UIMDIChild *) child;
  
  			if (UIRectangleEquals(mdiChild->bounds, UI_RECT_1(0))) {
  				int width = UIElementMessage(&mdiChild->e, UI_MSG_GET_WIDTH, 0, 0);
  				int height = UIElementMessage(&mdiChild->e, UI_MSG_GET_HEIGHT, width, 0);
  				if (client->cascade + width > element->bounds.r || client->cascade + height > element->bounds.b) client->cascade = 0;
  				mdiChild->bounds = UI_RECT_4(client->cascade, client->cascade + width, client->cascade, client->cascade + height);
  				client->cascade += UI_SIZE_MDI_CASCADE * element->window->scale;
  			}
  
  			UIRectangle bounds = UIRectangleAdd(mdiChild->bounds, UI_RECT_2(element->bounds.l, element->bounds.t));
  			UIElementMove(child, bounds, false);
  			child = child->next;
  		}
  	} else if (message == UI_MSG_FIND_BY_POINT) {
  		UIFindByPoint *m = (UIFindByPoint *) dp;
  		UIMDIChild *child = client->active;
  
  		while (child) {
  			if (UIRectangleContains(child->e.bounds, m->x, m->y)) {
  				m->result = UIElementFindByPoint(&child->e, m->x, m->y);
  				return 1;
  			}
  
  			child = child->previous;
  		}
  
  		return 1;
  	} else if (message == UI_MSG_PRESSED_DESCENDENT) {
  		UIMDIChild *child = (UIMDIChild *) dp;
  
  		if (child && child != client->active) {
  			if (client->e.children == &child->e) client->e.children = child->e.next;
  			if (child->previous) child->previous->e.next = child->e.next;
  			if (child->e.next) ((UIMDIChild *) child->e.next)->previous = child->previous;
  			if (client->active) client->active->e.next = &child->e;
  			child->previous = client->active;
  			child->e.next = NULL;
  			client->active = child;
  			((UIMDIChild *) client->e.children)->previous = NULL;
  			UIElementRefresh(element);
  		}
  	}
  
  	return 0;
  }
  
  UIMDIChild *UIMDIChildCreate(UIElement *parent, uint32_t flags, UIRectangle initialBounds, const char *title, ptrdiff_t titleBytes) {
  	UI_ASSERT(parent->messageClass == _UIMDIClientMessage);
  
  	UIMDIChild *mdiChild = (UIMDIChild *) UIElementCreate(sizeof(UIMDIChild), parent, flags, _UIMDIChildMessage, "MDIChild");
  	UIMDIClient *mdiClient = (UIMDIClient *) parent;
  
  	mdiChild->bounds = initialBounds;
  	mdiChild->title = UIStringCopy(title, (mdiChild->titleBytes = titleBytes));
  	mdiChild->previous = mdiClient->active;
  	mdiClient->active = mdiChild;
  
  	if (flags & UI_MDI_CHILD_CLOSE_BUTTON) {
  		UIButton *closeButton = UIButtonCreate(&mdiChild->e, UI_BUTTON_SMALL | UI_ELEMENT_NON_CLIENT, "X", 1);
  		closeButton->invoke = _UIMDIChildCloseButton;
  		closeButton->e.cp = mdiChild;
  	}
  
  	return mdiChild;
  }
  
  UIMDIClient *UIMDIClientCreate(UIElement *parent, uint32_t flags) {
  	return (UIMDIClient *) UIElementCreate(sizeof(UIMDIClient), parent, flags, _UIMDIClientMessage, "MDIClient");
  }
  
  int _UIExpandPaneMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UIExpandPane *pane = (UIExpandPane *) element;
  	
  	if (message == UI_MSG_GET_HEIGHT) {
  		int height = UIElementMessage(&pane->button->e, message, di, dp);
  
  		if (pane->expanded) {
  			height += UIElementMessage(&pane->panel->e, message, di, dp);
  		}
  
  		return height;
  	} else if (message == UI_MSG_LAYOUT) {
  		UIRectangle bounds = pane->e.bounds;
  		int buttonHeight = UIElementMessage(&pane->button->e, UI_MSG_GET_HEIGHT, UI_RECT_WIDTH(bounds), NULL);
  		UIElementMove(&pane->button->e, UI_RECT_4(bounds.l, bounds.r, bounds.t, bounds.t + buttonHeight), false);
  
  		if (pane->expanded) {
  			pane->panel->e.flags &= ~UI_ELEMENT_HIDE;
  			UIElementMove(&pane->panel->e, UI_RECT_4(bounds.l, bounds.r, bounds.t + buttonHeight, bounds.b), false);
  		} else {
  			pane->panel->e.flags |= UI_ELEMENT_HIDE;
  		}
  	} else if (message == UI_MSG_CLIENT_PARENT) {
  		*(UIElement **) dp = &pane->panel->e;
  	}
  
  	return 0;
  }
  
  void _UIExpandPaneButtonInvoke(void *cp) {
  	UIExpandPane *pane = (UIExpandPane *) cp;
  	pane->expanded = !pane->expanded;
  	if (pane->expanded) pane->button->e.flags |= UI_BUTTON_CHECKED;
  	else pane->button->e.flags &= ~UI_BUTTON_CHECKED;
  
  	UIElement *ancestor = &pane->e;
  
  	while (ancestor) {
  		UIElementRefresh(ancestor);
  
  		if ((ancestor->messageClass == _UIPanelMessage && (ancestor->flags & UI_PANEL_SCROLL)) 
  				|| (ancestor->messageClass == _UIMDIChildMessage)
  				|| (ancestor->flags & UI_ELEMENT_V_FILL)) {
  			break;
  		}
  
  		ancestor = ancestor->parent;
  	}
  }
  
  UIExpandPane *UIExpandPaneCreate(UIElement *parent, uint32_t flags, const char *label, ptrdiff_t labelBytes, uint32_t panelFlags) {
  	UIExpandPane *pane = (UIExpandPane *) UIElementCreate(sizeof(UIExpandPane), parent, flags, _UIExpandPaneMessage, "ExpandPane");
  	pane->button = UIButtonCreate(parent, UI_ELEMENT_NON_CLIENT, label, labelBytes);
  	pane->button->e.cp = pane;
  	pane->button->invoke = _UIExpandPaneButtonInvoke;
  	pane->panel = UIPanelCreate(parent, UI_ELEMENT_NON_CLIENT | panelFlags);
  	return pane;
  }
  
  void _UIImageDisplayUpdateViewport(UIImageDisplay *display) {
  	UIRectangle bounds = display->e.bounds;
  	bounds.r -= bounds.l, bounds.b -= bounds.t;
  	
  	float minimumZoomX = 1, minimumZoomY = 1;
  	if (display->width  > bounds.r) minimumZoomX = (float) bounds.r / display->width;
  	if (display->height > bounds.b) minimumZoomY = (float) bounds.b / display->height;
  	float minimumZoom = minimumZoomX < minimumZoomY ? minimumZoomX : minimumZoomY;
  	
  	if (display->zoom < minimumZoom || (display->e.flags & _UI_IMAGE_DISPLAY_ZOOM_FIT)) {
  		display->zoom = minimumZoom;
  		display->e.flags |= _UI_IMAGE_DISPLAY_ZOOM_FIT;
  	}
  	
  	if (display->panX < 0) display->panX = 0;
  	if (display->panY < 0) display->panY = 0;
  	if (display->panX > display->width  - bounds.r / display->zoom) display->panX = display->width  - bounds.r / display->zoom;
  	if (display->panY > display->height - bounds.b / display->zoom) display->panY = display->height - bounds.b / display->zoom;
  	
  	if (bounds.r && display->width  * display->zoom <= bounds.r) display->panX = display->width  / 2 - bounds.r / display->zoom / 2;
  	if (bounds.b && display->height * display->zoom <= bounds.b) display->panY = display->height / 2 - bounds.b / display->zoom / 2;
  }
  
  int _UIImageDisplayMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UIImageDisplay *display = (UIImageDisplay *) element;
  	
  	if (message == UI_MSG_GET_HEIGHT) {
  		return display->height;
  	} else if (message == UI_MSG_GET_WIDTH) {
  		return display->width;
  	} else if (message == UI_MSG_DESTROY) {
  		UI_FREE(display->bits);
  	} else if (message == UI_MSG_PAINT) {
  		UIPainter *painter = (UIPainter *) dp;
  		
  		int w = UI_RECT_WIDTH(element->bounds), h = UI_RECT_HEIGHT(element->bounds);
  		int x = _UILinearMap(0, display->panX, display->panX + w / display->zoom, 0, w) + element->bounds.l;
  		int y = _UILinearMap(0, display->panY, display->panY + h / display->zoom, 0, h) + element->bounds.t;
  		
  		UIRectangle image = UI_RECT_4(x, x + (int) (display->width * display->zoom), y, (int) (y + display->height * display->zoom));
  		UIRectangle bounds = UIRectangleIntersection(painter->clip, UIRectangleIntersection(display->e.bounds, image));
  		if (!UI_RECT_VALID(bounds)) return 0;
  		
  		if (display->zoom == 1) {
  			uint32_t *lineStart = (uint32_t *) painter->bits + bounds.t * painter->width + bounds.l;
  			uint32_t *sourceLineStart = display->bits + (bounds.l - image.l) + display->width * (bounds.t - image.t);
  	
  			for (int i = 0; i < bounds.b - bounds.t; i++, lineStart += painter->width, sourceLineStart += display->width) {
  				uint32_t *destination = lineStart;
  				uint32_t *source = sourceLineStart;
  				int j = bounds.r - bounds.l;
  	
  				do {
  					*destination = *source;
  					destination++;
  					source++;
  				} while (--j);
  			}
  		} else {
  			float zr = 1.0f / display->zoom;
  			uint32_t *destination = (uint32_t *) painter->bits;
  			
  			for (int i = bounds.t; i < bounds.b; i++) {
  				int ty = (i - image.t) * zr;
  				
  				for (int j = bounds.l; j < bounds.r; j++) {
  					int tx = (j - image.l) * zr;
  					destination[i * painter->width + j] = display->bits[ty * display->width + tx];
  				}
  			}
  		}
  	} else if (message == UI_MSG_MOUSE_WHEEL && (element->flags & UI_IMAGE_DISPLAY_INTERACTIVE)) {
  		display->e.flags &= ~_UI_IMAGE_DISPLAY_ZOOM_FIT;
  		int divisions = -di / 72;
  		float factor = 1;
  		float perDivision = element->window->ctrl ? 2.0f : element->window->alt ? 1.01f : 1.2f;
  		while (divisions > 0) factor *= perDivision, divisions--;
  		while (divisions < 0) factor /= perDivision, divisions++;
  		if (display->zoom * factor > 64) factor = 64 / display->zoom;
  		int mx = element->window->cursorX - element->bounds.l;
  		int my = element->window->cursorY - element->bounds.t;
  		display->zoom *= factor;
  		display->panX -= mx / display->zoom * (1 - factor);
  		display->panY -= my / display->zoom * (1 - factor);
  		_UIImageDisplayUpdateViewport(display);
  		UIElementRepaint(&display->e, NULL);
  	} else if (message == UI_MSG_LAYOUT && (element->flags & UI_IMAGE_DISPLAY_INTERACTIVE)) {
  		UIRectangle bounds = display->e.bounds;
  		bounds.r -= bounds.l, bounds.b -= bounds.t;
  		display->panX -= (bounds.r - display->previousWidth ) / 2 / display->zoom;
  		display->panY -= (bounds.b - display->previousHeight) / 2 / display->zoom;
  		display->previousWidth = bounds.r, display->previousHeight = bounds.b;
  		_UIImageDisplayUpdateViewport(display);
  	} else if (message == UI_MSG_GET_CURSOR && (element->flags & UI_IMAGE_DISPLAY_INTERACTIVE)
  			&& (UI_RECT_WIDTH(element->bounds) < display->width * display->zoom 
  				|| UI_RECT_HEIGHT(element->bounds) < display->height * display->zoom)) {
  		return UI_CURSOR_HAND;
  	} else if (message == UI_MSG_MOUSE_DRAG) {
  		display->panX -= (element->window->cursorX - display->previousPanPointX) / display->zoom;
  		display->panY -= (element->window->cursorY - display->previousPanPointY) / display->zoom;
  		_UIImageDisplayUpdateViewport(display);
  		display->previousPanPointX = element->window->cursorX;
  		display->previousPanPointY = element->window->cursorY;
  		UIElementRepaint(element, NULL);
  	} else if (message == UI_MSG_LEFT_DOWN) {           
  		display->e.flags &= ~_UI_IMAGE_DISPLAY_ZOOM_FIT;  
  		display->previousPanPointX = element->window->cursorX;
  		display->previousPanPointY = element->window->cursorY;
  	}
  
  	return 0;
  }
  
  void UIImageDisplaySetContent(UIImageDisplay *display, uint32_t *bits, size_t width, size_t height, size_t stride) {
  	UI_FREE(display->bits);
  
  	display->bits = (uint32_t *) UI_MALLOC(width * height * 4);
  	display->width = width;
  	display->height = height;
  
  	uint32_t *destination = display->bits;
  	uint32_t *source = bits;
  
  	for (uintptr_t row = 0; row < height; row++, source += stride / 4) {
  		for (uintptr_t i = 0; i < width; i++) {
  			*destination++ = source[i];
  		}
  	}
  }
  
  UIImageDisplay *UIImageDisplayCreate(UIElement *parent, uint32_t flags, uint32_t *bits, size_t width, size_t height, size_t stride) {
  	UIImageDisplay *display = (UIImageDisplay *) UIElementCreate(sizeof(UIImageDisplay), parent, flags, _UIImageDisplayMessage, "ImageDisplay");
  	display->zoom = 1.0f;
  	UIImageDisplaySetContent(display, bits, width, height, stride);
  	return display;
  }
  
  int _UIDialogWrapperMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	if (message == UI_MSG_LAYOUT) {
  		int width = UIElementMessage(element->children, UI_MSG_GET_WIDTH, 0, 0);
  		int height = UIElementMessage(element->children, UI_MSG_GET_HEIGHT, width, 0);
  		int cx = (element->bounds.l + element->bounds.r) / 2;
  		int cy = (element->bounds.t + element->bounds.b) / 2;
  		UIRectangle bounds = UI_RECT_4(cx - (width + 1) / 2, cx + width / 2, cy - (height + 1) / 2, cy + height / 2);
  		UIElementMove(element->children, bounds, false);
  		UIElementRepaint(element, NULL);
  	} else if (message == UI_MSG_PAINT) {
  		UIRectangle bounds = UIRectangleAdd(element->children->bounds, UI_RECT_1I(-1));
  		UIDrawBorder((UIPainter *) dp, bounds, ui.theme.border, UI_RECT_1(1));
  		UIDrawBorder((UIPainter *) dp, UIRectangleAdd(bounds, UI_RECT_1(1)), ui.theme.border, UI_RECT_1(1));
  	} else if (message == UI_MSG_KEY_TYPED) {
  		UIKeyTyped *typed = (UIKeyTyped *) dp;
  
  		if (element->window->ctrl) return 0;
  		if (element->window->shift) return 0;
  
  		char c0 = 0, c1 = 0;
  
  		if (typed->textBytes == 1 && typed->text[0] >= 'a' && typed->text[0] <= 'z') {
  			c0 = typed->text[0], c1 = typed->text[0] - 'a' + 'A';
  		} else {
  			return 0;
  		}
  
  		UIElement *row = element->children->children;
  		UIElement *target = NULL;
  		bool duplicate = false;
  
  		while (row) {
  			UIElement *item = row->children;
  
  			while (item) {
  				if (item->messageClass == _UIButtonMessage) {
  					UIButton *button = (UIButton *) item;
  
  					if (button->label && button->labelBytes && (button->label[0] == c0 || button->label[0] == c1)) {
  						if (!target) {
  							target = &button->e;
  						} else {
  							duplicate = true;
  						}
  					}
  				}
  
  				item = item->next;
  			}
  
  			row = row->next;
  		}
  
  		if (target) {
  			if (duplicate) {
  				UIElementFocus(target);
  			} else {
  				UIElementMessage(target, UI_MSG_CLICKED, 0, 0);
  			}
  
  			return 1;
  		}
  	}
  
  	return 0;
  }
  
  void _UIDialogButtonInvoke(void *cp) {
  	ui.dialogResult = (const char *) cp;
  }
  
  int _UIDialogTextboxMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	if (message == UI_MSG_VALUE_CHANGED) {
  		UITextbox *textbox = (UITextbox *) element;
  		char **buffer = (char **) element->cp;
  		*buffer = (char *) UI_REALLOC(*buffer, textbox->bytes + 1);
  		(*buffer)[textbox->bytes] = 0;
  
  		for (ptrdiff_t i = 0; i < textbox->bytes; i++) {
  			(*buffer)[i] = textbox->string[i];
  		}
  	}
  
  	return 0;
  }
  
  const char *UIDialogShow(UIWindow *window, uint32_t flags, const char *format, ...) {
  	// TODO Enter and escape.
  
  	// Create the dialog wrapper and panel.
  
  	UI_ASSERT(!window->dialog);
  	window->dialog = UIElementCreate(sizeof(UIElement), &window->e, 0, _UIDialogWrapperMessage, "DialogWrapper");
  	UIPanel *panel = UIPanelCreate(window->dialog, UI_PANEL_MEDIUM_SPACING | UI_PANEL_GRAY | UI_PANEL_EXPAND);
  	panel->border = UI_RECT_1(UI_SIZE_PANE_MEDIUM_BORDER * 2);
  	window->e.children->flags |= UI_ELEMENT_DISABLED;
  
  	// Create the dialog contents.
  
  	va_list arguments;
  	va_start(arguments, format);
  	UIPanel *row = NULL;
  	UIElement *focus = NULL;
  
  	for (int i = 0; format[i]; i++) {
  		if (i == 0 || format[i - 1] == '\n') {
  			row = UIPanelCreate(&panel->e, UI_PANEL_HORIZONTAL);
  			row->gap = UI_SIZE_PANE_SMALL_GAP;
  		}
  
  		if (format[i] == ' ' || format[i] == '\n') {
  		} else if (format[i] == '%') {
  			i++;
  
  			if (format[i] == 'b' /* button */) {
  				const char *label = va_arg(arguments, const char *);
  				UIButton *button = UIButtonCreate(&row->e, 0, label, -1);
  				if (!focus) focus = &button->e;
  				button->invoke = _UIDialogButtonInvoke;
  				button->e.cp = (void *) label;
  			} else if (format[i] == 's' /* label from string */) {
  				const char *label = va_arg(arguments, const char *);
  				UILabelCreate(&row->e, 0, label, -1);
  			} else if (format[i] == 't' /* textbox */) {
  				char **buffer = va_arg(arguments, char **);
  				UITextbox *textbox = UITextboxCreate(&row->e, UI_ELEMENT_H_FILL);
  				if (!focus) focus = &textbox->e;
  				if (*buffer) UITextboxReplace(textbox, *buffer, _UIStringLength(*buffer), false);
  				textbox->e.cp = buffer;
  				textbox->e.messageUser = _UIDialogTextboxMessage;
  			} else if (format[i] == 'f' /* horizontal fill */) {
  				UISpacerCreate(&row->e, UI_ELEMENT_H_FILL, 0, 0);
  			} else if (format[i] == 'l' /* horizontal line */) {
  				UISpacerCreate(&row->e, UI_SPACER_LINE | UI_ELEMENT_H_FILL, 0, 1);
  			} else if (format[i] == 'u' /* user */) {
  				void (*callback)(UIElement *) = va_arg(arguments, void (*)(UIElement *));
  				callback(&row->e);
  			}
  		} else {
  			int j = i;
  			while (format[j] && format[j] != '%' && format[j] != '\n') j++;
  			UILabelCreate(&row->e, 0, format + i, j - i);
  			i = j - 1;
  		}
  	}
  
  	va_end(arguments);
  
  	window->dialogOldFocus = window->focused;
  	UIElementFocus(focus ? focus : window->dialog);
  
  	// Run the modal message loop.
  
  	int result;
  	ui.dialogResult = NULL;
  	for (int i = 1; i <= 3; i++) _UIWindowSetPressed(window, NULL, i);
  	UIElementRefresh(&window->e);
  	_UIUpdate();
  	while (!ui.dialogResult && _UIMessageLoopSingle(&result));
  	ui.quit = !ui.dialogResult;
  
  	// Destroy the dialog.
  
  	window->e.children->flags &= ~UI_ELEMENT_DISABLED;
  	UIElementDestroy(window->dialog);
  	window->dialog = NULL;
  	UIElementRefresh(&window->e);
  	if (window->dialogOldFocus) UIElementFocus(window->dialogOldFocus);
  	return ui.dialogResult ? ui.dialogResult : "";
  }
  
  bool _UIMenusClose() {
  	UIWindow *window = ui.windows;
  	bool anyClosed = false;
  
  	while (window) {
  		if (window->e.flags & UI_WINDOW_MENU) {
  			UIElementDestroy(&window->e);
  			anyClosed = true;
  		}
  
  		window = window->next;
  	}
  
  	return anyClosed;
  }
  
  #ifndef UI_ESSENCE
  int _UIMenuItemMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	if (message == UI_MSG_CLICKED) {
  		_UIMenusClose();
  	}
  
  	return 0;
  }
  
  int _UIMenuMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	UIMenu *menu = (UIMenu *) element;
  
  	if (message == UI_MSG_GET_WIDTH) {
  		UIElement *child = element->children;
  		int width = 0;
  
  		while (child) {
  			if (~child->flags & UI_ELEMENT_NON_CLIENT) {
  				int w = UIElementMessage(child, UI_MSG_GET_WIDTH, 0, 0);
  				if (w > width) width = w;
  			}
  
  			child = child->next;
  		}
  
  		return width + 4 + UI_SIZE_SCROLL_BAR;
  	} else if (message == UI_MSG_GET_HEIGHT) {
  		UIElement *child = element->children;
  		int height = 0;
  
  		while (child) {
  			if (~child->flags & UI_ELEMENT_NON_CLIENT) {
  				height += UIElementMessage(child, UI_MSG_GET_HEIGHT, 0, 0);
  			}
  
  			child = child->next;
  		}
  
  		return height + 4;
  	} else if (message == UI_MSG_PAINT) {
  		UIDrawBlock((UIPainter *) dp, element->bounds, ui.theme.border);
  	} else if (message == UI_MSG_LAYOUT) {
  		UIElement *child = element->children;
  		int position = element->bounds.t + 2 - menu->vScroll->position;
  		int totalHeight = 0;
  		int scrollBarSize = (menu->e.flags & UI_MENU_NO_SCROLL) ? 0 : UI_SIZE_SCROLL_BAR;
  
  		while (child) {
  			if (~child->flags & UI_ELEMENT_NON_CLIENT) {
  				int height = UIElementMessage(child, UI_MSG_GET_HEIGHT, 0, 0);
  				UIElementMove(child, UI_RECT_4(element->bounds.l + 2, element->bounds.r - scrollBarSize - 2, 
  							position, position + height), false);
  				position += height;
  				totalHeight += height;
  			}
  
  			child = child->next;
  		}
  
  		UIRectangle scrollBarBounds = element->bounds;
  		scrollBarBounds.l = scrollBarBounds.r - scrollBarSize * element->window->scale;
  		menu->vScroll->maximum = totalHeight;
  		menu->vScroll->page = UI_RECT_HEIGHT(element->bounds);
  		UIElementMove(&menu->vScroll->e, scrollBarBounds, true);
  	} else if (message == UI_MSG_KEY_TYPED) {
  		UIKeyTyped *m = (UIKeyTyped *) dp;
  
  		if (m->code == UI_KEYCODE_ESCAPE) {
  			_UIMenusClose();
  			return 1;
  		}
  	} else if (message == UI_MSG_MOUSE_WHEEL) {
  		return UIElementMessage(&menu->vScroll->e, message, di, dp);
  	} else if (message == UI_MSG_SCROLLED) {
  		UIElementRefresh(element);
  	}
  
  	return 0;
  }
  
  void UIMenuAddItem(UIMenu *menu, uint32_t flags, const char *label, ptrdiff_t labelBytes, void (*invoke)(void *cp), void *cp) {
  	UIButton *button = UIButtonCreate(&menu->e, flags | UI_BUTTON_MENU_ITEM, label, labelBytes);
  	button->invoke = invoke;
  	button->e.messageUser = _UIMenuItemMessage;
  	button->e.cp = cp;
  }
  
  void _UIMenuPrepare(UIMenu *menu, int *width, int *height) {
  	*width = UIElementMessage(&menu->e, UI_MSG_GET_WIDTH, 0, 0);
  	*height = UIElementMessage(&menu->e, UI_MSG_GET_HEIGHT, 0, 0);
  
  	if (menu->e.flags & UI_MENU_PLACE_ABOVE) {
  		menu->pointY -= *height;
  	}
  }
  
  UIMenu *UIMenuCreate(UIElement *parent, uint32_t flags) {
  	UIWindow *window = UIWindowCreate(parent->window, UI_WINDOW_MENU, 0, 0, 0);
  	UIMenu *menu = (UIMenu *) UIElementCreate(sizeof(UIMenu), &window->e, flags, _UIMenuMessage, "Menu");
  	menu->vScroll = UIScrollBarCreate(&menu->e, UI_ELEMENT_NON_CLIENT);
  
  	if (parent->parent) {
  		UIRectangle screenBounds = UIElementScreenBounds(parent);
  		menu->pointX = screenBounds.l;
  		menu->pointY = (flags & UI_MENU_PLACE_ABOVE) ? (screenBounds.t + 1) : (screenBounds.b - 1);
  	} else {
  		int x = 0, y = 0;
  		_UIWindowGetScreenPosition(parent->window, &x, &y);
  
  		menu->pointX = parent->window->cursorX + x;
  		menu->pointY = parent->window->cursorY + y;
  	}
  
  	return menu;
  }
  #endif
  
  UIRectangle UIElementScreenBounds(UIElement *element) {
  	int x = 0, y = 0;
  	_UIWindowGetScreenPosition(element->window, &x, &y);
  	return UIRectangleAdd(element->bounds, UI_RECT_2(x, y));
  }
  
  void UIWindowRegisterShortcut(UIWindow *window, UIShortcut shortcut) {
  	if (window->shortcutCount + 1 > window->shortcutAllocated) {
  		window->shortcutAllocated = (window->shortcutCount + 1) * 2;
  		window->shortcuts = (UIShortcut *) UI_REALLOC(window->shortcuts, window->shortcutAllocated * sizeof(UIShortcut));
  	}
  
  	window->shortcuts[window->shortcutCount++] = shortcut;
  }
  
  void _UIElementPaint(UIElement *element, UIPainter *painter) {
  	if (element->flags & UI_ELEMENT_HIDE) {
  		return;
  	}
  
  	// Clip painting to the element's clip.
  
  	painter->clip = UIRectangleIntersection(element->clip, painter->clip);
  
  	if (!UI_RECT_VALID(painter->clip)) {
  		return;
  	}
  
  	// Paint the element.
  
  	UIElementMessage(element, UI_MSG_PAINT, 0, painter);
  
  	// Paint its children.
  
  	UIElement *child = element->children;
  	UIRectangle previousClip = painter->clip;
  
  	while (child) {
  		painter->clip = previousClip;
  		_UIElementPaint(child, painter);
  		child = child->next;
  	}
  }
  
  void UIElementFocus(UIElement *element) {
  	UIElement *previous = element->window->focused;
  	if (previous == element) return;
  	element->window->focused = element;
  	if (previous) UIElementMessage(previous, UI_MSG_UPDATE, UI_UPDATE_FOCUSED, 0);
  	if (element) UIElementMessage(element, UI_MSG_UPDATE, UI_UPDATE_FOCUSED, 0);
  
  #ifdef UI_DEBUG
  	_UIInspectorRefresh();
  #endif
  }
  
  void _UIWindowSetPressed(UIWindow *window, UIElement *element, int button) {
  	UIElement *previous = window->pressed;
  	window->pressed = element;
  	window->pressedButton = button;
  	if (previous) UIElementMessage(previous, UI_MSG_UPDATE, UI_UPDATE_PRESSED, 0);
  	if (element) UIElementMessage(element, UI_MSG_UPDATE, UI_UPDATE_PRESSED, 0);
  
  	UIElement *ancestor = element;
  	UIElement *child = NULL;
  
  	while (ancestor) {
  		UIElementMessage(ancestor, UI_MSG_PRESSED_DESCENDENT, 0, child);
  		child = ancestor;
  		ancestor = ancestor->parent;
  	}
  }
  
  bool _UIDestroy(UIElement *element) {
  	if (element->flags & UI_ELEMENT_DESTROY_DESCENDENT) {
  		element->flags &= ~UI_ELEMENT_DESTROY_DESCENDENT;
  
  		UIElement *child = element->children;
  		UIElement **link = &element->children;
  
  		while (child) {
  			UIElement *next = child->next;
  
  			if (_UIDestroy(child)) {
  				*link = next;
  			} else {
  				link = &child->next;
  			}
  
  			child = next;
  		}
  	}
  
  	if (element->flags & UI_ELEMENT_DESTROY) {
  		UIElementMessage(element, UI_MSG_DESTROY, 0, 0);
  
  		if (element->window->pressed == element) {
  			_UIWindowSetPressed(element->window, NULL, 0);
  		}
  
  		if (element->window->hovered == element) {
  			element->window->hovered = &element->window->e;
  		}
  
  		if (element->window->focused == element) {
  			element->window->focused = NULL;
  		}
  
  		if (element->window->dialogOldFocus == element) {
  			element->window->dialogOldFocus = NULL;
  		}
  
  		if (ui.animating == element) {
  			ui.animating = NULL;
  		}
  
  		UI_FREE(element);
  		return true;
  	} else {
  		return false;
  	}
  }
  
  void _UIUpdate() {
  	UIWindow *window = ui.windows;
  	UIWindow **link = &ui.windows;
  
  	while (window) {
  		UIWindow *next = window->next;
  
  		if (_UIDestroy(&window->e)) {
  			*link = next;
  		} else {
  			link = &window->next;
  
  			if (UI_RECT_VALID(window->updateRegion)) {
  #ifdef __cplusplus
  				UIPainter painter = {};
  #else
  				UIPainter painter = { 0 };
  #endif
  				painter.bits = window->bits;
  				painter.width = window->width;
  				painter.height = window->height;
  				painter.clip = UIRectangleIntersection(UI_RECT_2S(window->width, window->height), window->updateRegion);
  				_UIElementPaint(&window->e, &painter);
  				_UIWindowEndPaint(window, &painter);
  				window->updateRegion = UI_RECT_1(0);
  
  #ifdef UI_DEBUG
  				window->lastFullFillCount = (float) painter.fillCount / (UI_RECT_WIDTH(window->updateRegion) * UI_RECT_HEIGHT(window->updateRegion));
  #endif
  			}
  		}
  
  		window = next;
  	}
  }
  
  UIElement *UIElementFindByPoint(UIElement *element, int x, int y) {
  	UIFindByPoint m = { 0 };
  	m.x = x, m.y = y;
  
  	if (UIElementMessage(element, UI_MSG_FIND_BY_POINT, 0, &m)) {
  		return m.result ? m.result : element;
  	}
  
  	UIElement *child = element->children;
  
  	while (child) {
  		if ((~child->flags & UI_ELEMENT_HIDE) && UIRectangleContains(child->clip, x, y)) {
  			return UIElementFindByPoint(child, x, y);
  		}
  
  		child = child->next;
  	}
  
  	return element;
  }
  
  void _UIProcessAnimations() {
  	if (ui.animating) {
  		UIElementMessage(ui.animating, UI_MSG_ANIMATE, 0, 0);
  		_UIUpdate();
  	}
  }
  
  bool _UIMenusOpen() {
  	UIWindow *window = ui.windows;
  
  	while (window) {
  		if (window->e.flags & UI_WINDOW_MENU) {
  			return true;
  		}
  
  		window = window->next;
  	}
  
  	return false;
  }
  
  void _UIWindowDestroyCommon(UIWindow *window) {
  	UI_FREE(window->bits);
  	UI_FREE(window->shortcuts);
  }
  
  UIElement *_UIElementLastChild(UIElement *element) {
  	if (!element->children) {
  		return NULL;
  	}
  
  	UIElement *child = element->children;
  
  	while (child->next) {
  		child = child->next;
  	}
  
  	return child;
  }
  
  UIElement *_UIElementPreviousSibling(UIElement *element) {
  	if (!element->parent) {
  		return NULL;
  	}
  
  	UIElement *sibling = element->parent->children;
  
  	if (sibling == element) {
  		return NULL;
  	}
  
  	while (sibling->next != element) {
  		sibling = sibling->next;
  		UI_ASSERT(sibling);
  	}
  	
  	return sibling;
  }
  
  bool _UIWindowInputEvent(UIWindow *window, UIMessage message, int di, void *dp) {
  	bool handled = true;
  
  	if (window->pressed) {
  		if (message == UI_MSG_MOUSE_MOVE) {
  			UIElementMessage(window->pressed, UI_MSG_MOUSE_DRAG, di, dp);
  		} else if (message == UI_MSG_LEFT_UP && window->pressedButton == 1) {
  			if (window->hovered == window->pressed) {
  				UIElementMessage(window->pressed, UI_MSG_CLICKED, di, dp);
  				if (ui.quit || ui.dialogResult) goto end;
  			}
  
  			if (window->pressed) {
  				UIElementMessage(window->pressed, UI_MSG_LEFT_UP, di, dp);
  				if (ui.quit || ui.dialogResult) goto end;
  				_UIWindowSetPressed(window, NULL, 1);
  			}
  		} else if (message == UI_MSG_MIDDLE_UP && window->pressedButton == 2) {
  			UIElementMessage(window->pressed, UI_MSG_MIDDLE_UP, di, dp);
  			if (ui.quit || ui.dialogResult) goto end;
  			_UIWindowSetPressed(window, NULL, 2);
  		} else if (message == UI_MSG_RIGHT_UP && window->pressedButton == 3) {
  			UIElementMessage(window->pressed, UI_MSG_RIGHT_UP, di, dp);
  			if (ui.quit || ui.dialogResult) goto end;
  			_UIWindowSetPressed(window, NULL, 3);
  		}
  	}
  
  	if (window->pressed) {
  		bool inside = UIRectangleContains(window->pressed->clip, window->cursorX, window->cursorY);
  
  		if (inside && window->hovered == &window->e) {
  			window->hovered = window->pressed;
  			UIElementMessage(window->pressed, UI_MSG_UPDATE, UI_UPDATE_HOVERED, 0);
  		} else if (!inside && window->hovered == window->pressed) {
  			window->hovered = &window->e;
  			UIElementMessage(window->pressed, UI_MSG_UPDATE, UI_UPDATE_HOVERED, 0);
  		}
  
  		if (ui.quit || ui.dialogResult) goto end;
  	}
  
  	if (!window->pressed) {
  		UIElement *hovered = UIElementFindByPoint(&window->e, window->cursorX, window->cursorY);
  
  		if (message == UI_MSG_MOUSE_MOVE) {
  			UIElementMessage(hovered, UI_MSG_MOUSE_MOVE, di, dp);
  
  			int cursor = UIElementMessage(window->hovered, UI_MSG_GET_CURSOR, di, dp);
  
  			if (cursor != window->cursorStyle) {
  				window->cursorStyle = cursor;
  				_UIWindowSetCursor(window, cursor);
  			}
  		} else if (message == UI_MSG_LEFT_DOWN) {
  			if ((window->e.flags & UI_WINDOW_MENU) || !_UIMenusClose()) {
  				_UIWindowSetPressed(window, hovered, 1);
  				UIElementMessage(hovered, UI_MSG_LEFT_DOWN, di, dp);
  			}
  		} else if (message == UI_MSG_MIDDLE_DOWN) {
  			if ((window->e.flags & UI_WINDOW_MENU) || !_UIMenusClose()) {
  				_UIWindowSetPressed(window, hovered, 2);
  				UIElementMessage(hovered, UI_MSG_MIDDLE_DOWN, di, dp);
  			}
  		} else if (message == UI_MSG_RIGHT_DOWN) {
  			if ((window->e.flags & UI_WINDOW_MENU) || !_UIMenusClose()) {
  				_UIWindowSetPressed(window, hovered, 3);
  				UIElementMessage(hovered, UI_MSG_RIGHT_DOWN, di, dp);
  			}
  		} else if (message == UI_MSG_MOUSE_WHEEL) {
  			UIElement *element = hovered;
  
  			while (element) {
  				if (UIElementMessage(element, UI_MSG_MOUSE_WHEEL, di, dp)) {
  					break;
  				}
  
  				element = element->parent;
  			}
  		} else if (message == UI_MSG_KEY_TYPED) {
  			handled = false;
  
  			if (window->focused) {
  				UIElement *element = window->focused;
  
  				while (element) {
  					if (UIElementMessage(element, UI_MSG_KEY_TYPED, di, dp)) {
  						handled = true;
  						break;
  					}
  
  					element = element->parent;
  				}
  			} else {
  				if (UIElementMessage(&window->e, UI_MSG_KEY_TYPED, di, dp)) {
  					handled = true;
  				}
  			}
  
  			if (!handled && !_UIMenusOpen()) {
  				UIKeyTyped *m = (UIKeyTyped *) dp;
  
  				if (m->code == UI_KEYCODE_TAB && !window->ctrl && !window->alt) {
  					UIElement *start = window->focused ? window->focused : &window->e;
  					UIElement *element = start;
  
  					do {
  						if (element->children && !(element->flags & (UI_ELEMENT_HIDE | UI_ELEMENT_DISABLED))) {
  							element = window->shift ? _UIElementLastChild(element) : element->children;
  							continue;
  						} 
  
  						while (element) {
  							if (window->shift ? (element->parent && element->parent->children != element) : !!element->next) {
  								element = window->shift ? _UIElementPreviousSibling(element) : element->next;
  								break;
  							} else {
  								element = element->parent;
  							}
  						}
  
  						if (!element) {
  							element = &window->e;
  						}
  					} while (element != start && ((~element->flags & UI_ELEMENT_TAB_STOP) 
  						|| (element->flags & (UI_ELEMENT_HIDE | UI_ELEMENT_DISABLED))));
  
  					if (~element->flags & UI_ELEMENT_WINDOW) {
  						UIElementFocus(element);
  					}
  
  					handled = true;
  				} else if (!window->dialog) {
  					for (intptr_t i = window->shortcutCount - 1; i >= 0; i--) {
  						UIShortcut *shortcut = window->shortcuts + i;
  
  						if (shortcut->code == m->code && shortcut->ctrl == window->ctrl 
  								&& shortcut->shift == window->shift && shortcut->alt == window->alt) {
  							shortcut->invoke(shortcut->cp);
  							handled = true;
  							break;
  						}
  					}
  				}
  			}
  		}
  
  		if (ui.quit || ui.dialogResult) goto end;
  
  		if (hovered != window->hovered) {
  			UIElement *previous = window->hovered;
  			window->hovered = hovered;
  			UIElementMessage(previous, UI_MSG_UPDATE, UI_UPDATE_HOVERED, 0);
  			UIElementMessage(window->hovered, UI_MSG_UPDATE, UI_UPDATE_HOVERED, 0);
  		}
  	}
  
  	end: _UIUpdate();
  	return handled;
  }
  
  UIFont *UIFontCreate(const char *cPath, uint32_t size) {
  	UIFont *font = (UIFont *) UI_CALLOC(sizeof(UIFont));
  
  #ifdef UI_FREETYPE
  	if (cPath) {
  		if (!FT_New_Face(ui.ft, cPath, 0, &font->font)) {
  			FT_Set_Char_Size(font->font, 0, size * 64, 100, 100);
  			FT_Load_Char(font->font, 'a', FT_LOAD_DEFAULT);
  			font->glyphWidth = font->font->glyph->advance.x / 64;
  			font->glyphHeight = (font->font->size->metrics.ascender - font->font->size->metrics.descender) / 64;
  			font->isFreeType = true;
  			return font;
  		}
  	}
  #endif
  	
  	font->glyphWidth = 9;
  	font->glyphHeight = 16;
  	return font;
  }
  
  UIFont *UIFontActivate(UIFont *font) {
  	UIFont *previous = ui.activeFont;
  	ui.activeFont = font;
  	return previous;
  }
  
  void _UIInitialiseCommon() {
  #ifdef UI_FREETYPE
  	FT_Init_FreeType(&ui.ft);
  #endif
  
  	ui.theme = _uiThemeDark;
  	UIFontActivate(UIFontCreate(0, 0));
  }
  
  void _UIWindowAdd(UIWindow *window) {
  	window->scale = 1.0f;
  	window->e.window = window;
  	window->hovered = &window->e;
  	window->next = ui.windows;
  	ui.windows = window;
  }
  
  int _UIWindowMessageCommon(UIElement *element, UIMessage message, int di, void *dp) {
  	if (message == UI_MSG_LAYOUT && element->children) {
  		UIElementMove(element->children, element->bounds, false);
  		if (element->window->dialog) UIElementMove(element->window->dialog, element->bounds, false);
  		UIElementRepaint(element, NULL);
  	} else if (message == UI_MSG_FIND_BY_POINT) {
  		UIFindByPoint *m = (UIFindByPoint *) dp;
  		if (element->window->dialog) m->result = UIElementFindByPoint(element->window->dialog, m->x, m->y);
  		else if (!element->children) m->result = NULL;
  		else m->result = UIElementFindByPoint(element->children, m->x, m->y);
  		return 1;
  	}
  
  	return 0;
  }
  
  #ifdef UI_DEBUG
  
  void UIInspectorLog(const char *cFormat, ...) {
  	va_list arguments;
  	va_start(arguments, cFormat);
  	char buffer[4096];
  	vsnprintf(buffer, sizeof(buffer), cFormat, arguments);
  	UICodeInsertContent(ui.inspectorLog, buffer, -1, false);
  	va_end(arguments);
  	UIElementRefresh(&ui.inspectorLog->e);
  }
  
  UIElement *_UIInspectorFindNthElement(UIElement *element, int *index, int *depth) {
  	if (*index == 0) {
  		return element;
  	}
  
  	*index = *index - 1;
  	
  	UIElement *child = element->children;
  
  	while (child) {
  		if (!(child->flags & (UI_ELEMENT_DESTROY | UI_ELEMENT_HIDE))) {
  			UIElement *result = _UIInspectorFindNthElement(child, index, depth);
  
  			if (result) {
  				if (depth) {
  					*depth = *depth + 1;
  				}
  
  				return result;
  			}
  		}
  
  		child = child->next;
  	}
  
  	return NULL;
  }
  
  int _UIInspectorTableMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	if (!ui.inspectorTarget) {
  		return 0;
  	}
  
  	if (message == UI_MSG_TABLE_GET_ITEM) {
  		UITableGetItem *m = (UITableGetItem *) dp;
  		int index = m->index;
  		int depth = 0;
  		UIElement *element = _UIInspectorFindNthElement(&ui.inspectorTarget->e, &index, &depth);
  		if (!element) return 0;
  
  		if (m->column == 0) {
  			return snprintf(m->buffer, m->bufferBytes, "%.*s%s", depth * 2, "                ", element->cClassName);
  		} else if (m->column == 1) {
  			return snprintf(m->buffer, m->bufferBytes, "%d:%d, %d:%d", UI_RECT_ALL(element->bounds));
  		} else if (m->column == 2) {
  			return snprintf(m->buffer, m->bufferBytes, "%d%c", element->id, element->window->focused == element ? '*' : ' ');
  		}
  	} else if (message == UI_MSG_MOUSE_MOVE) {
  		int index = UITableHitTest(ui.inspectorTable, element->window->cursorX, element->window->cursorY);
  		UIElement *element = NULL;
  		if (index >= 0) element = _UIInspectorFindNthElement(&ui.inspectorTarget->e, &index, NULL);
  		UIWindow *window = ui.inspectorTarget;
  		UIPainter painter = { 0 };
  		window->updateRegion = window->e.bounds;
  		painter.bits = window->bits;
  		painter.width = window->width;
  		painter.height = window->height;
  		painter.clip = UI_RECT_2S(window->width, window->height);
  
  		for (int i = 0; i < window->width * window->height; i++) {
  			window->bits[i] = 0xFF00FF;
  		}
  
  		_UIElementPaint(&window->e, &painter);
  		painter.clip = UI_RECT_2S(window->width, window->height);
  
  		if (element) {
  			UIDrawInvert(&painter, element->bounds);
  			UIDrawInvert(&painter, UIRectangleAdd(element->bounds, UI_RECT_1I(4)));
  		}
  
  		_UIWindowEndPaint(window, &painter);
  	}
  
  	return 0;
  }
  
  void _UIInspectorCreate() {
  	ui.inspector = UIWindowCreate(0, UI_WINDOW_INSPECTOR, "Inspector", 0, 0);
  	UISplitPane *splitPane = UISplitPaneCreate(&ui.inspector->e, 0, 0.5f);
  	ui.inspectorTable = UITableCreate(&splitPane->e, 0, "Class\tBounds\tID");
  	ui.inspectorTable->e.messageUser = _UIInspectorTableMessage;
  	ui.inspectorLog = UICodeCreate(&splitPane->e, 0);
  }
  
  int _UIInspectorCountElements(UIElement *element) {
  	UIElement *child = element->children;
  	int count = 1;
  
  	while (child) {
  		if (!(child->flags & (UI_ELEMENT_DESTROY | UI_ELEMENT_HIDE))) {
  			count += _UIInspectorCountElements(child);
  		}
  
  		child = child->next;
  	}
  
  	return count;
  }
  
  void _UIInspectorRefresh() {
  	if (!ui.inspectorTarget || !ui.inspector || !ui.inspectorTable) return;
  	ui.inspectorTable->itemCount = _UIInspectorCountElements(&ui.inspectorTarget->e);
  	UITableResizeColumns(ui.inspectorTable);
  	UIElementRefresh(&ui.inspectorTable->e);
  }
  
  void _UIInspectorSetFocusedWindow(UIWindow *window) {
  	if (!ui.inspector || !ui.inspectorTable) return;
  
  	if (window->e.flags & UI_WINDOW_INSPECTOR) {
  		return;
  	}
  
  	if (ui.inspectorTarget != window) {
  		ui.inspectorTarget = window;
  		_UIInspectorRefresh();
  	}
  }
  
  #else
  
  void _UIInspectorCreate() {}
  void _UIInspectorSetFocusedWindow(UIWindow *window) {}
  void _UIInspectorRefresh() {}
  
  #endif
  
  int UIMessageLoop() {
  	_UIInspectorCreate();
  	_UIUpdate();
  	int result = 0;
  	while (!ui.quit && _UIMessageLoopSingle(&result)) ui.dialogResult = NULL;
  	return result;
  }
  
  #ifdef UI_LINUX
  
  const int UI_KEYCODE_A = XK_a;
  const int UI_KEYCODE_BACKSPACE = XK_BackSpace;
  const int UI_KEYCODE_DELETE = XK_Delete;
  const int UI_KEYCODE_DOWN = XK_Down;
  const int UI_KEYCODE_END = XK_End;
  const int UI_KEYCODE_ENTER = XK_Return;
  const int UI_KEYCODE_ESCAPE = XK_Escape;
  const int UI_KEYCODE_F1 = XK_F1;
  const int UI_KEYCODE_HOME = XK_Home;
  const int UI_KEYCODE_LEFT = XK_Left;
  const int UI_KEYCODE_RIGHT = XK_Right;
  const int UI_KEYCODE_SPACE = XK_space;
  const int UI_KEYCODE_TAB = XK_Tab;
  const int UI_KEYCODE_UP = XK_Up;
  const int UI_KEYCODE_0 = XK_0;
  
  int _UIWindowMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	if (message == UI_MSG_DESTROY) {
  		UIWindow *window = (UIWindow *) element;
  		_UIWindowDestroyCommon(window);
  		window->image->data = NULL;
  		XDestroyImage(window->image);
  		XDestroyIC(window->xic);
  		XDestroyWindow(ui.display, ((UIWindow *) element)->window);
  	}
  
  	return _UIWindowMessageCommon(element, message, di, dp);
  }
  
  UIWindow *UIWindowCreate(UIWindow *owner, uint32_t flags, const char *cTitle, int _width, int _height) {
  	_UIMenusClose();
  
  	UIWindow *window = (UIWindow *) UIElementCreate(sizeof(UIWindow), NULL, flags | UI_ELEMENT_WINDOW, _UIWindowMessage, "Window");
  	_UIWindowAdd(window);
  	if (owner) window->scale = owner->scale;
  
  	int width = (flags & UI_WINDOW_MENU) ? 1 : _width ? _width : 800;
  	int height = (flags & UI_WINDOW_MENU) ? 1 : _height ? _height : 600;
  
  	XSetWindowAttributes attributes = {};
  	attributes.override_redirect = flags & UI_WINDOW_MENU;
  
  	window->window = XCreateWindow(ui.display, DefaultRootWindow(ui.display), 0, 0, width, height, 0, 0, 
  		InputOutput, CopyFromParent, CWOverrideRedirect, &attributes);
  	if (cTitle) XStoreName(ui.display, window->window, cTitle);
  	XSelectInput(ui.display, window->window, SubstructureNotifyMask | ExposureMask | PointerMotionMask 
  		| ButtonPressMask | ButtonReleaseMask | KeyPressMask | KeyReleaseMask | StructureNotifyMask
  		| EnterWindowMask | LeaveWindowMask | ButtonMotionMask | KeymapStateMask | FocusChangeMask);
  
  	if (flags & UI_WINDOW_MAXIMIZE) {
  		Atom atoms[2] = { XInternAtom(ui.display, "_NET_WM_STATE_MAXIMIZED_HORZ", 0), XInternAtom(ui.display, "_NET_WM_STATE_MAXIMIZED_VERT", 0) };
  		XChangeProperty(ui.display, window->window, XInternAtom(ui.display, "_NET_WM_STATE", 0), XA_ATOM, 32, PropModeReplace, (unsigned char *) atoms, 2);
  	}
  
  	if (~flags & UI_WINDOW_MENU) {
  		XMapRaised(ui.display, window->window);
  	}
  
  	if (flags & UI_WINDOW_CENTER_IN_OWNER) {
  		int x = 0, y = 0;
  		_UIWindowGetScreenPosition(owner, &x, &y);
  		XMoveResizeWindow(ui.display, window->window, x + owner->width / 2 - width / 2, y + owner->height / 2 - height / 2, width, height);
  	}
  
  	XSetWMProtocols(ui.display, window->window, &ui.windowClosedID, 1);
  	window->image = XCreateImage(ui.display, ui.visual, 24, ZPixmap, 0, NULL, 10, 10, 32, 0);
  
  	window->xic = XCreateIC(ui.xim, XNInputStyle, XIMPreeditNothing | XIMStatusNothing, XNClientWindow, window->window, XNFocusWindow, window->window, NULL);
  
  	int dndVersion = 4;
  	XChangeProperty(ui.display, window->window, ui.dndAwareID, XA_ATOM, 32 /* bits */, PropModeReplace, (uint8_t *) &dndVersion, 1);
  
  	return window;
  }
  
  Display *_UIX11GetDisplay() {
  	return ui.display;
  }
  
  void UIInitialise() {
  	_UIInitialiseCommon();
  
  	XInitThreads();
  
  	ui.display = XOpenDisplay(NULL);
  	ui.visual = XDefaultVisual(ui.display, 0);
  
  	ui.windowClosedID = XInternAtom(ui.display, "WM_DELETE_WINDOW", 0);
  	ui.primaryID = XInternAtom(ui.display, "PRIMARY", 0);
  	ui.dndEnterID = XInternAtom(ui.display, "XdndEnter", 0);
  	ui.dndPositionID = XInternAtom(ui.display, "XdndPosition", 0);
  	ui.dndStatusID = XInternAtom(ui.display, "XdndStatus", 0);
  	ui.dndActionCopyID = XInternAtom(ui.display, "XdndActionCopy", 0);
  	ui.dndDropID = XInternAtom(ui.display, "XdndDrop", 0);
  	ui.dndSelectionID = XInternAtom(ui.display, "XdndSelection", 0);
  	ui.dndFinishedID = XInternAtom(ui.display, "XdndFinished", 0);
  	ui.dndAwareID = XInternAtom(ui.display, "XdndAware", 0);
  	ui.uriListID = XInternAtom(ui.display, "text/uri-list", 0);
  	ui.plainTextID = XInternAtom(ui.display, "text/plain", 0);
  
  	ui.cursors[UI_CURSOR_ARROW] = XCreateFontCursor(ui.display, XC_left_ptr);
  	ui.cursors[UI_CURSOR_TEXT] = XCreateFontCursor(ui.display, XC_xterm);
  	ui.cursors[UI_CURSOR_SPLIT_V] = XCreateFontCursor(ui.display, XC_sb_v_double_arrow);
  	ui.cursors[UI_CURSOR_SPLIT_H] = XCreateFontCursor(ui.display, XC_sb_h_double_arrow);
  	ui.cursors[UI_CURSOR_FLIPPED_ARROW] = XCreateFontCursor(ui.display, XC_right_ptr);
  	ui.cursors[UI_CURSOR_CROSS_HAIR] = XCreateFontCursor(ui.display, XC_crosshair);
  	ui.cursors[UI_CURSOR_HAND] = XCreateFontCursor(ui.display, XC_hand1);
  	ui.cursors[UI_CURSOR_RESIZE_UP] = XCreateFontCursor(ui.display, XC_top_side);
  	ui.cursors[UI_CURSOR_RESIZE_LEFT] = XCreateFontCursor(ui.display, XC_left_side);
  	ui.cursors[UI_CURSOR_RESIZE_UP_RIGHT] = XCreateFontCursor(ui.display, XC_top_right_corner);
  	ui.cursors[UI_CURSOR_RESIZE_UP_LEFT] = XCreateFontCursor(ui.display, XC_top_left_corner);
  	ui.cursors[UI_CURSOR_RESIZE_DOWN] = XCreateFontCursor(ui.display, XC_bottom_side);
  	ui.cursors[UI_CURSOR_RESIZE_RIGHT] = XCreateFontCursor(ui.display, XC_right_side);
  	ui.cursors[UI_CURSOR_RESIZE_DOWN_LEFT] = XCreateFontCursor(ui.display, XC_bottom_left_corner);
  	ui.cursors[UI_CURSOR_RESIZE_DOWN_RIGHT] = XCreateFontCursor(ui.display, XC_bottom_right_corner);
  
  	XSetLocaleModifiers("");
  
  	ui.xim = XOpenIM(ui.display, 0, 0, 0);
  
  	if(!ui.xim){
  		XSetLocaleModifiers("@im=none");
  		ui.xim = XOpenIM(ui.display, 0, 0, 0);
  	}
  }
  
  UIWindow *_UIFindWindow(Window window) {
  	UIWindow *w = ui.windows;
  
  	while (w) {
  		if (w->window == window) {
  			return w;
  		}
  
  		w = w->next;
  	}
  
  	return NULL;
  }
  
  void _UIWindowSetCursor(UIWindow *window, int cursor) {
  	XDefineCursor(ui.display, window->window, ui.cursors[cursor]);
  }
  
  void _UIX11ResetCursor(UIWindow *window) {
  	XDefineCursor(ui.display, window->window, ui.cursors[UI_CURSOR_ARROW]);
  }
  
  void _UIWindowEndPaint(UIWindow *window, UIPainter *painter) {
  	(void) painter;
  
  	XPutImage(ui.display, window->window, DefaultGC(ui.display, 0), window->image, 
  		UI_RECT_TOP_LEFT(window->updateRegion), UI_RECT_TOP_LEFT(window->updateRegion),
  		UI_RECT_SIZE(window->updateRegion));
  }
  
  void _UIWindowGetScreenPosition(UIWindow *window, int *_x, int *_y) {
  	Window child;
  	XTranslateCoordinates(ui.display, window->window, DefaultRootWindow(ui.display), 0, 0, _x, _y, &child);
  }
  
  void UIMenuShow(UIMenu *menu) {
  	int width, height;
  	_UIMenuPrepare(menu, &width, &height);
  
  	for (int i = 0; i < ScreenCount(ui.display); i++) {
  		Screen *screen = ScreenOfDisplay(ui.display, i);
  
  		int x, y;
  		Window child;
  		XTranslateCoordinates(ui.display, screen->root, DefaultRootWindow(ui.display), 0, 0, &x, &y, &child);
  
  		if (menu->pointX >= x && menu->pointX < x + screen->width 
  				&& menu->pointY >= y && menu->pointY < y + screen->height) {
  			if (menu->pointX + width > x + screen->width) menu->pointX = x + screen->width - width;
  			if (menu->pointY + height > y + screen->height) menu->pointY = y + screen->height - height;
  			if (menu->pointX < x) menu->pointX = x;
  			if (menu->pointY < y) menu->pointY = y;
  			if (menu->pointX + width > x + screen->width) width = x + screen->width - menu->pointX;
  			if (menu->pointY + height > y + screen->height) height = y + screen->height - menu->pointY;
  			break;
  		}
  	}
  
  	Atom properties[] = {
  		XInternAtom(ui.display, "_NET_WM_WINDOW_TYPE", true),
  		XInternAtom(ui.display, "_NET_WM_WINDOW_TYPE_DROPDOWN_MENU", true),
  		XInternAtom(ui.display, "_MOTIF_WM_HINTS", true),
  	};
  
  	XChangeProperty(ui.display, menu->e.window->window, properties[0], XA_ATOM, 32, PropModeReplace, (uint8_t *) properties, 2);
  	XSetTransientForHint(ui.display, menu->e.window->window, DefaultRootWindow(ui.display));
  
  	struct Hints {
  		int flags;
  		int functions;
  		int decorations;
  		int inputMode;
  		int status;
  	};
  
  	struct Hints hints = { 0 };
  	hints.flags = 2;
  	XChangeProperty(ui.display, menu->e.window->window, properties[2], properties[2], 32, PropModeReplace, (uint8_t *) &hints, 5);
  
  	XMapWindow(ui.display, menu->e.window->window);
  	XMoveResizeWindow(ui.display, menu->e.window->window, menu->pointX, menu->pointY, width, height);
  }
  
  void UIWindowPack(UIWindow *window, int _width) {
  	int width = _width ? _width : UIElementMessage(window->e.children, UI_MSG_GET_WIDTH, 0, 0);
  	int height = UIElementMessage(window->e.children, UI_MSG_GET_HEIGHT, width, 0);
  	XResizeWindow(ui.display, window->window, width, height);
  }
  
  bool _UIProcessEvent(XEvent *event) {
  	if (event->type == ClientMessage && (Atom) event->xclient.data.l[0] == ui.windowClosedID) {
  		UIWindow *window = _UIFindWindow(event->xclient.window);
  		if (!window) return false;
  		bool exit = !UIElementMessage(&window->e, UI_MSG_WINDOW_CLOSE, 0, 0);
  		if (exit) return true;
  		_UIUpdate();
  		return false;
  	} else if (event->type == Expose) {
  		UIWindow *window = _UIFindWindow(event->xexpose.window);
  		if (!window) return false;
  		XPutImage(ui.display, window->window, DefaultGC(ui.display, 0), window->image, 0, 0, 0, 0, window->width, window->height);
  	} else if (event->type == ConfigureNotify) {
  		UIWindow *window = _UIFindWindow(event->xconfigure.window);
  		if (!window) return false;
  
  		if (window->width != event->xconfigure.width || window->height != event->xconfigure.height) {
  			window->width = event->xconfigure.width;
  			window->height = event->xconfigure.height;
  			window->bits = (uint32_t *) UI_REALLOC(window->bits, window->width * window->height * 4);
  			window->image->width = window->width;
  			window->image->height = window->height;
  			window->image->bytes_per_line = window->width * 4;
  			window->image->data = (char *) window->bits;
  			window->e.bounds = UI_RECT_2S(window->width, window->height);
  			window->e.clip = UI_RECT_2S(window->width, window->height);
  #ifdef UI_DEBUG
  			for (int i = 0; i < window->width * window->height; i++) window->bits[i] = 0xFF00FF;
  #endif
  			UIElementMessage(&window->e, UI_MSG_LAYOUT, 0, 0);
  			_UIUpdate();
  		}
  	} else if (event->type == MotionNotify) {
  		UIWindow *window = _UIFindWindow(event->xmotion.window);
  		if (!window) return false;
  		window->cursorX = event->xmotion.x;
  		window->cursorY = event->xmotion.y;
  		_UIWindowInputEvent(window, UI_MSG_MOUSE_MOVE, 0, 0);
  	} else if (event->type == LeaveNotify) {
  		UIWindow *window = _UIFindWindow(event->xcrossing.window);
  		if (!window) return false;
  
  		if (!window->pressed) {
  			window->cursorX = -1;
  			window->cursorY = -1;
  		}
  
  		_UIWindowInputEvent(window, UI_MSG_MOUSE_MOVE, 0, 0);
  	} else if (event->type == ButtonPress || event->type == ButtonRelease) {
  		UIWindow *window = _UIFindWindow(event->xbutton.window);
  		if (!window) return false;
  		window->cursorX = event->xbutton.x;
  		window->cursorY = event->xbutton.y;
  
  		if (event->xbutton.button >= 1 && event->xbutton.button <= 3) {
  			_UIWindowInputEvent(window, (UIMessage) ((event->type == ButtonPress ? UI_MSG_LEFT_DOWN : UI_MSG_LEFT_UP) 
  				+ event->xbutton.button * 2 - 2), 0, 0);
  		} else if (event->xbutton.button == 4) {
  			_UIWindowInputEvent(window, UI_MSG_MOUSE_WHEEL, -72, 0);
  		} else if (event->xbutton.button == 5) {
  			_UIWindowInputEvent(window, UI_MSG_MOUSE_WHEEL, 72, 0);
  		}
  
  		_UIInspectorSetFocusedWindow(window);
  	} else if (event->type == KeyPress) {
  		UIWindow *window = _UIFindWindow(event->xkey.window);
  		if (!window) return false;
  
  		if (event->xkey.x == 0x7123 && event->xkey.y == 0x7456) {
  			// HACK! See UIWindowPostMessage.
  			UIElementMessage(&window->e, (UIMessage) event->xkey.state, 0, 
  				(void *) (((uintptr_t) (event->xkey.time & 0xFFFFFFFF) << 32) 
  					| ((uintptr_t) (event->xkey.x_root & 0xFFFF) << 0) 
  					| ((uintptr_t) (event->xkey.y_root & 0xFFFF) << 16)));
  			_UIUpdate();
  		} else {
  			char text[32];
  			KeySym symbol = NoSymbol;
  			Status status;
  			// printf("%ld, %s\n", symbol, text);
  			UIKeyTyped m = { 0 };
  			m.textBytes = Xutf8LookupString(window->xic, &event->xkey, text, sizeof(text) - 1, &symbol, &status); 
  			m.text = text;
  			m.code = XLookupKeysym(&event->xkey, 0);
  
  			if (symbol == XK_Control_L || symbol == XK_Control_R) {
  				window->ctrl = true;
  				window->ctrlCode = event->xkey.keycode;
  				_UIWindowInputEvent(window, UI_MSG_MOUSE_MOVE, 0, 0);
  			} else if (symbol == XK_Shift_L || symbol == XK_Shift_R) {
  				window->shift = true;
  				window->shiftCode = event->xkey.keycode;
  				_UIWindowInputEvent(window, UI_MSG_MOUSE_MOVE, 0, 0);
  			} else if (symbol == XK_Alt_L || symbol == XK_Alt_R) {
  				window->alt = true;
  				window->altCode = event->xkey.keycode;
  				_UIWindowInputEvent(window, UI_MSG_MOUSE_MOVE, 0, 0);
  			} else if (symbol == XK_KP_Left) {
  				m.code = UI_KEYCODE_LEFT;
  			} else if (symbol == XK_KP_Right) {
  				m.code = UI_KEYCODE_RIGHT;
  			} else if (symbol == XK_KP_Up) {
  				m.code = UI_KEYCODE_UP;
  			} else if (symbol == XK_KP_Down) {
  				m.code = UI_KEYCODE_DOWN;
  			} else if (symbol == XK_KP_Home) {
  				m.code = UI_KEYCODE_HOME;
  			} else if (symbol == XK_KP_End) {
  				m.code = UI_KEYCODE_END;
  			} else if (symbol == XK_KP_Enter) {
  				m.code = UI_KEYCODE_ENTER;
  			} else if (symbol == XK_KP_Delete) {
  				m.code = UI_KEYCODE_DELETE;
  			}
  
  			_UIWindowInputEvent(window, UI_MSG_KEY_TYPED, 0, &m);
  		}
  	} else if (event->type == KeyRelease) {
  		UIWindow *window = _UIFindWindow(event->xkey.window);
  		if (!window) return false;
  
  		if (event->xkey.keycode == window->ctrlCode) {
  			window->ctrl = false;
  			_UIWindowInputEvent(window, UI_MSG_MOUSE_MOVE, 0, 0);
  		} else if (event->xkey.keycode == window->shiftCode) {
  			window->shift = false;
  			_UIWindowInputEvent(window, UI_MSG_MOUSE_MOVE, 0, 0);
  		} else if (event->xkey.keycode == window->altCode) {
  			window->alt = false;
  			_UIWindowInputEvent(window, UI_MSG_MOUSE_MOVE, 0, 0);
  		}
  	} else if (event->type == FocusIn) {
  		UIWindow *window = _UIFindWindow(event->xfocus.window);
  		if (!window) return false;
  		window->ctrl = window->shift = window->alt = false;
  		UIElementMessage(&window->e, UI_MSG_WINDOW_ACTIVATE, 0, 0);
  	} else if (event->type == ClientMessage && event->xclient.message_type == ui.dndEnterID) {
  		UIWindow *window = _UIFindWindow(event->xclient.window);
  		if (!window) return false;
  		window->dragSource = (Window) event->xclient.data.l[0];
  	} else if (event->type == ClientMessage && event->xclient.message_type == ui.dndPositionID) {
  		UIWindow *window = _UIFindWindow(event->xclient.window);
  		if (!window) return false;
  		XClientMessageEvent m = { 0 };
  		m.type = ClientMessage;
  		m.display = event->xclient.display;
  		m.window = (Window) event->xclient.data.l[0];
  		m.message_type = ui.dndStatusID;
  		m.format = 32;
  		m.data.l[0] = window->window;
  		m.data.l[1] = true;
  		m.data.l[4] = ui.dndActionCopyID;
  		XSendEvent(ui.display, m.window, False, NoEventMask, (XEvent *) &m);
  		XFlush(ui.display);
  	} else if (event->type == ClientMessage && event->xclient.message_type == ui.dndDropID) {
  		UIWindow *window = _UIFindWindow(event->xclient.window);
  		if (!window) return false;
  
  		// TODO Dropping text.
  
  		if (!XConvertSelection(ui.display, ui.dndSelectionID, ui.uriListID, ui.primaryID, window->window, event->xclient.data.l[2])) {
  			XClientMessageEvent m = { 0 };
  			m.type = ClientMessage;
  			m.display = ui.display;
  			m.window = window->dragSource;
  			m.message_type = ui.dndFinishedID;
  			m.format = 32;
  			m.data.l[0] = window->window;
  			m.data.l[1] = 0;
  			m.data.l[2] = ui.dndActionCopyID;
  			XSendEvent(ui.display, m.window, False, NoEventMask, (XEvent *) &m);
  			XFlush(ui.display);
  		}
  	} else if (event->type == SelectionNotify) {
  		UIWindow *window = _UIFindWindow(event->xselection.requestor);
  		if (!window) return false;
  		if (!window->dragSource) return false;
  
  		Atom type = None;
  		int format = 0;
  		uint64_t count = 0, bytesLeft = 0;
  		uint8_t *data = NULL;
  		XGetWindowProperty(ui.display, window->window, ui.primaryID, 0, 65536, False, AnyPropertyType, &type, &format, &count, &bytesLeft, &data);
  
  		if (format == 8 /* bits per character */) {
  			if (event->xselection.target == ui.uriListID) {
  				char *copy = (char *) UI_MALLOC(count);
  				int fileCount = 0;
  
  				for (int i = 0; i < (int) count; i++) {
  					copy[i] = data[i];
  
  					if (i && data[i - 1] == '\r' && data[i] == '\n') {
  						fileCount++;
  					}
  				}
  
  				char **files = (char **) UI_MALLOC(sizeof(char *) * fileCount);
  				fileCount = 0;
  
  				for (int i = 0; i < (int) count; i++) {
  					char *s = copy + i;
  					while (!(i && data[i - 1] == '\r' && data[i] == '\n' && i < (int) count)) i++;
  					copy[i - 1] = 0;
  
  					for (int j = 0; s[j]; j++) {
  						if (s[j] == '%' && s[j + 1] && s[j + 2]) {
  							char n[3];
  							n[0] = s[j + 1], n[1] = s[j + 2], n[2] = 0;
  							s[j] = strtol(n, NULL, 16);
  							if (!s[j]) break;
  							memmove(s + j + 1, s + j + 3, strlen(s) - j - 2);
  						}
  					}
  
  					if (s[0] == 'f' && s[1] == 'i' && s[2] == 'l' && s[3] == 'e' && s[4] == ':' && s[5] == '/' && s[6] == '/') {
  						files[fileCount++] = s + 7;
  					}
  				}
  
  				UIElementMessage(&window->e, UI_MSG_WINDOW_DROP_FILES, fileCount, files);
  
  				UI_FREE(files);
  				UI_FREE(copy);
  			} else if (event->xselection.target == ui.plainTextID) {
  				// TODO.
  			}
  		}
  
  		XFree(data);
  
  		XClientMessageEvent m = { 0 };
  		m.type = ClientMessage;
  		m.display = ui.display;
  		m.window = window->dragSource;
  		m.message_type = ui.dndFinishedID;
  		m.format = 32;
  		m.data.l[0] = window->window;
  		m.data.l[1] = true;
  		m.data.l[2] = ui.dndActionCopyID;
  		XSendEvent(ui.display, m.window, False, NoEventMask, (XEvent *) &m);
  		XFlush(ui.display);
  
  		window->dragSource = 0; // Drag complete.
  		_UIUpdate();
  	}
  
  	return false;
  }
  
  bool _UIMessageLoopSingle(int *result) {
  	XEvent events[64];
  
  	if (ui.animating) {
  		if (XPending(ui.display)) {
  			XNextEvent(ui.display, events + 0);
  		} else {
  			_UIProcessAnimations();
  			return true;
  		}
  	} else {
  		XNextEvent(ui.display, events + 0);
  	}
  
  	int p = 1;
  
  	int configureIndex = -1, motionIndex = -1, exposeIndex = -1;
  
  	while (p < 64 && XPending(ui.display)) {
  		XNextEvent(ui.display, events + p);
  
  #define _UI_MERGE_EVENTS(a, b) \
  	if (events[p].type == a) { \
  		if (b != -1) events[b].type = 0; \
  		b = p; \
  	}
  
  		_UI_MERGE_EVENTS(ConfigureNotify, configureIndex);
  		_UI_MERGE_EVENTS(MotionNotify, motionIndex);
  		_UI_MERGE_EVENTS(Expose, exposeIndex);
  
  		p++;
  	}
  
  	for (int i = 0; i < p; i++) {
  		if (!events[i].type) {
  			continue;
  		}
  
  		if (_UIProcessEvent(events + i)) {
  			return false;
  		}
  	}
  
  	return true;
  }
  
  void UIWindowPostMessage(UIWindow *window, UIMessage message, void *_dp) {
  	// HACK! Xlib doesn't seem to have a nice way to do this,
  	// so send a specially crafted key press event instead.
  	// TODO Maybe ClientMessage is what this should use?
  	uintptr_t dp = (uintptr_t) _dp;
  	XKeyEvent event = { 0 };
  	event.display = ui.display;
  	event.window = window->window;
  	event.root = DefaultRootWindow(ui.display);
  	event.subwindow = None;
  	event.time = dp >> 32;
  	event.x = 0x7123;
  	event.y = 0x7456;
  	event.x_root = (dp >> 0) & 0xFFFF;
  	event.y_root = (dp >> 16) & 0xFFFF;
  	event.same_screen = True;
  	event.keycode = 1;
  	event.state = message;
  	event.type = KeyPress;
  	XSendEvent(ui.display, window->window, True, KeyPressMask, (XEvent *) &event);
  	XFlush(ui.display);
  }
  
  #endif
  
  #ifdef UI_WINDOWS
  
  const int UI_KEYCODE_A = 'A';
  const int UI_KEYCODE_0 = '0';
  const int UI_KEYCODE_BACKSPACE = VK_BACK;
  const int UI_KEYCODE_DELETE = VK_DELETE;
  const int UI_KEYCODE_DOWN = VK_DOWN;
  const int UI_KEYCODE_END = VK_END;
  const int UI_KEYCODE_ENTER = VK_RETURN;
  const int UI_KEYCODE_ESCAPE = VK_ESCAPE;
  const int UI_KEYCODE_F1 = VK_F1;
  const int UI_KEYCODE_HOME = VK_HOME;
  const int UI_KEYCODE_LEFT = VK_LEFT;
  const int UI_KEYCODE_RIGHT = VK_RIGHT;
  const int UI_KEYCODE_SPACE = VK_SPACE;
  const int UI_KEYCODE_TAB = VK_TAB;
  const int UI_KEYCODE_UP = VK_UP;
  
  int _UIWindowMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	if (message == UI_MSG_DESTROY) {
  		UIWindow *window = (UIWindow *) element;
  		_UIWindowDestroyCommon(window);
  		SetWindowLongPtr(window->hwnd, GWLP_USERDATA, 0);
  		DestroyWindow(window->hwnd);
  	}
  
  	return _UIWindowMessageCommon(element, message, di, dp);
  }
  
  LRESULT CALLBACK _UIWindowProcedure(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) {
  	UIWindow *window = (UIWindow *) GetWindowLongPtr(hwnd, GWLP_USERDATA);
  
  	if (!window || ui.assertionFailure) {
  		return DefWindowProc(hwnd, message, wParam, lParam);
  	}
  
  	if (message == WM_CLOSE) {
  		if (UIElementMessage(&window->e, UI_MSG_WINDOW_CLOSE, 0, 0)) {
  			_UIUpdate();
  			return 0;
  		} else {
  			PostQuitMessage(0);
  		}
  	} else if (message == WM_SIZE) {
  		RECT client;
  		GetClientRect(hwnd, &client);
  		window->width = client.right;
  		window->height = client.bottom;
  		window->bits = (uint32_t *) UI_REALLOC(window->bits, window->width * window->height * 4);
  		window->e.bounds = UI_RECT_2S(window->width, window->height);
  		window->e.clip = UI_RECT_2S(window->width, window->height);
  		UIElementMessage(&window->e, UI_MSG_LAYOUT, 0, 0);
  		_UIUpdate();
  	} else if (message == WM_MOUSEMOVE) {
  		if (!window->trackingLeave) {
  			window->trackingLeave = true;
  			TRACKMOUSEEVENT leave = { 0 };
  			leave.cbSize = sizeof(TRACKMOUSEEVENT);
  			leave.dwFlags = TME_LEAVE;
  			leave.hwndTrack = hwnd;
  			TrackMouseEvent(&leave);
  		}
  
  		POINT cursor;
  		GetCursorPos(&cursor);
  		ScreenToClient(hwnd, &cursor);
  		window->cursorX = cursor.x;
  		window->cursorY = cursor.y;
  		_UIWindowInputEvent(window, UI_MSG_MOUSE_MOVE, 0, 0);
  	} else if (message == WM_MOUSELEAVE) {
  		window->trackingLeave = false;
  
  		if (!window->pressed) {
  			window->cursorX = -1;
  			window->cursorY = -1;
  		}
  
  		_UIWindowInputEvent(window, UI_MSG_MOUSE_MOVE, 0, 0);
  	} else if (message == WM_LBUTTONDOWN) {
  		SetCapture(hwnd);
  		_UIWindowInputEvent(window, UI_MSG_LEFT_DOWN, 0, 0);
  	} else if (message == WM_LBUTTONUP) {
  		if (window->pressedButton == 1) ReleaseCapture();
  		_UIWindowInputEvent(window, UI_MSG_LEFT_UP, 0, 0);
  	} else if (message == WM_MBUTTONDOWN) {
  		SetCapture(hwnd);
  		_UIWindowInputEvent(window, UI_MSG_MIDDLE_DOWN, 0, 0);
  	} else if (message == WM_MBUTTONUP) {
  		if (window->pressedButton == 2) ReleaseCapture();
  		_UIWindowInputEvent(window, UI_MSG_MIDDLE_UP, 0, 0);
  	} else if (message == WM_RBUTTONDOWN) {
  		SetCapture(hwnd);
  		_UIWindowInputEvent(window, UI_MSG_RIGHT_DOWN, 0, 0);
  	} else if (message == WM_RBUTTONUP) {
  		if (window->pressedButton == 3) ReleaseCapture();
  		_UIWindowInputEvent(window, UI_MSG_RIGHT_UP, 0, 0);
  	} else if (message == WM_MOUSEWHEEL) {
  		int delta = (int) wParam >> 16;
  		_UIWindowInputEvent(window, UI_MSG_MOUSE_WHEEL, -delta, 0);
  	} else if (message == WM_KEYDOWN) {
  		window->ctrl = GetKeyState(VK_CONTROL) & 0x8000;
  		window->shift = GetKeyState(VK_SHIFT) & 0x8000;
  		window->alt = GetKeyState(VK_MENU) & 0x8000;
  
  		UIKeyTyped m = { 0 };
  		m.code = wParam;
  		_UIWindowInputEvent(window, UI_MSG_KEY_TYPED, 0, &m);
  	} else if (message == WM_CHAR) {
  		UIKeyTyped m = { 0 };
  		char c = wParam;
  		m.text = &c;
  		m.textBytes = 1;
  		_UIWindowInputEvent(window, UI_MSG_KEY_TYPED, 0, &m);
  	} else if (message == WM_PAINT) {
  		PAINTSTRUCT paint;
  		HDC dc = BeginPaint(hwnd, &paint);
  		BITMAPINFOHEADER info = { 0 };
  		info.biSize = sizeof(info);
  		info.biWidth = window->width, info.biHeight = -window->height;
  		info.biPlanes = 1, info.biBitCount = 32;
  		StretchDIBits(dc, 0, 0, UI_RECT_SIZE(window->e.bounds), 0, 0, UI_RECT_SIZE(window->e.bounds),
  			window->bits, (BITMAPINFO *) &info, DIB_RGB_COLORS, SRCCOPY);
  		EndPaint(hwnd, &paint);
  	} else if (message == WM_SETCURSOR && LOWORD(lParam) == HTCLIENT) {
  		SetCursor(ui.cursors[window->cursorStyle]);
  		return 1;
  	} else if (message == WM_SETFOCUS || message == WM_KILLFOCUS) {
  		_UIMenusClose();
  
  		if (message == WM_SETFOCUS) {
  			_UIInspectorSetFocusedWindow(window);
  			UIElementMessage(&window->e, UI_MSG_WINDOW_ACTIVATE, 0, 0);
  		}
  	} else if (message == WM_MOUSEACTIVATE && (window->e.flags & UI_WINDOW_MENU)) {
  		return MA_NOACTIVATE;
  	} else if (message == WM_DROPFILES) {
  		HDROP drop = (HDROP) wParam;
  		int count = DragQueryFile(drop, 0xFFFFFFFF, NULL, 0);
  		char **files = (char **) UI_MALLOC(sizeof(char *) * count);
  		
  		for (int i = 0; i < count; i++) {
  			int length = DragQueryFile(drop, i, NULL, 0);
  			files[i] = (char *) UI_MALLOC(length + 1);
  			files[i][length] = 0;
  			DragQueryFile(drop, i, files[i], length + 1);
  		}
  		
  		UIElementMessage(&window->e, UI_MSG_WINDOW_DROP_FILES, count, files);
  		for (int i = 0; i < count; i++) UI_FREE(files[i]);		
  		UI_FREE(files);
  		DragFinish(drop);
  		_UIUpdate();
  	} else if (message == WM_APP + 1) {
  		UIElementMessage(&window->e, (UIMessage) wParam, 0, (void *) lParam);
  		_UIUpdate();
  	} else {
  		if (message == WM_NCLBUTTONDOWN || message == WM_NCMBUTTONDOWN || message == WM_NCRBUTTONDOWN) {
  			if (~window->e.flags & UI_WINDOW_MENU) {
  				_UIMenusClose();
  				_UIUpdate();
  			}
  		}
  
  		return DefWindowProc(hwnd, message, wParam, lParam);
  	}
  
  	return 0;
  }
  
  void UIInitialise() {
  	_UIInitialiseCommon();
  
  	ui.cursors[UI_CURSOR_ARROW] = LoadCursor(NULL, IDC_ARROW);
  	ui.cursors[UI_CURSOR_TEXT] = LoadCursor(NULL, IDC_IBEAM);
  	ui.cursors[UI_CURSOR_SPLIT_V] = LoadCursor(NULL, IDC_SIZENS);
  	ui.cursors[UI_CURSOR_SPLIT_H] = LoadCursor(NULL, IDC_SIZEWE);
  	ui.cursors[UI_CURSOR_FLIPPED_ARROW] = LoadCursor(NULL, IDC_ARROW);
  	ui.cursors[UI_CURSOR_CROSS_HAIR] = LoadCursor(NULL, IDC_CROSS);
  	ui.cursors[UI_CURSOR_HAND] = LoadCursor(NULL, IDC_HAND);
  	ui.cursors[UI_CURSOR_RESIZE_UP] = LoadCursor(NULL, IDC_SIZENS);
  	ui.cursors[UI_CURSOR_RESIZE_LEFT] = LoadCursor(NULL, IDC_SIZEWE);
  	ui.cursors[UI_CURSOR_RESIZE_UP_RIGHT] = LoadCursor(NULL, IDC_SIZENESW);
  	ui.cursors[UI_CURSOR_RESIZE_UP_LEFT] = LoadCursor(NULL, IDC_SIZENWSE);
  	ui.cursors[UI_CURSOR_RESIZE_DOWN] = LoadCursor(NULL, IDC_SIZENS);
  	ui.cursors[UI_CURSOR_RESIZE_RIGHT] = LoadCursor(NULL, IDC_SIZEWE);
  	ui.cursors[UI_CURSOR_RESIZE_DOWN_LEFT] = LoadCursor(NULL, IDC_SIZENESW);
  	ui.cursors[UI_CURSOR_RESIZE_DOWN_RIGHT] = LoadCursor(NULL, IDC_SIZENWSE);
  
  	ui.heap = GetProcessHeap();
  
  	WNDCLASS windowClass = { 0 };
  	windowClass.lpfnWndProc = _UIWindowProcedure;
  	windowClass.lpszClassName = "normal";
  	RegisterClass(&windowClass);
  	windowClass.style |= CS_DROPSHADOW;
  	windowClass.lpszClassName = "shadow";
  	RegisterClass(&windowClass);
  }
  
  bool _UIMessageLoopSingle(int *result) {
  	MSG message = { 0 };
  
  	if (ui.animating) {
  		if (PeekMessage(&message, NULL, 0, 0, PM_REMOVE)) {
  			if (message.message == WM_QUIT) {
  				*result = message.wParam;
  				return false;
  			}
  
  			TranslateMessage(&message);
  			DispatchMessage(&message);
  		} else {
  			_UIProcessAnimations();
  		}
  	} else {
  		if (!GetMessage(&message, NULL, 0, 0)) {
  			*result = message.wParam;
  			return false;
  		}
  
  		TranslateMessage(&message);
  		DispatchMessage(&message);
  	}
  
  	return true;
  }
  
  void UIMenuShow(UIMenu *menu) {
  	int width, height;
  	_UIMenuPrepare(menu, &width, &height);
  	MoveWindow(menu->e.window->hwnd, menu->pointX, menu->pointY, width, height, FALSE);
  	ShowWindow(menu->e.window->hwnd, SW_SHOWNOACTIVATE);
  }
  
  UIWindow *UIWindowCreate(UIWindow *owner, uint32_t flags, const char *cTitle, int width, int height) {
  	_UIMenusClose();
  
  	UIWindow *window = (UIWindow *) UIElementCreate(sizeof(UIWindow), NULL, flags | UI_ELEMENT_WINDOW, _UIWindowMessage, "Window");
  	_UIWindowAdd(window);
  	if (owner) window->scale = owner->scale;
  
  	if (flags & UI_WINDOW_MENU) {
  		UI_ASSERT(owner);
  
  		window->hwnd = CreateWindowEx(WS_EX_TOPMOST | WS_EX_NOACTIVATE, "shadow", 0, WS_POPUP, 
  			0, 0, 0, 0, owner->hwnd, NULL, NULL, NULL);
  	} else {
  		window->hwnd = CreateWindowEx(WS_EX_ACCEPTFILES, "normal", cTitle, WS_OVERLAPPEDWINDOW, 
  			CW_USEDEFAULT, CW_USEDEFAULT, width ? width : CW_USEDEFAULT, height ? height : CW_USEDEFAULT,
  			owner ? owner->hwnd : NULL, NULL, NULL, NULL);
  	}
  
  	SetWindowLongPtr(window->hwnd, GWLP_USERDATA, (LONG_PTR) window);
  
  	if (~flags & UI_WINDOW_MENU) {
  		ShowWindow(window->hwnd, SW_SHOW);
  		PostMessage(window->hwnd, WM_SIZE, 0, 0);
  	}
  
  	return window;
  }
  
  void _UIWindowEndPaint(UIWindow *window, UIPainter *painter) {
  	HDC dc = GetDC(window->hwnd);
  	BITMAPINFOHEADER info = { 0 };
  	info.biSize = sizeof(info);
  	info.biWidth = window->width, info.biHeight = window->height;
  	info.biPlanes = 1, info.biBitCount = 32;
  	StretchDIBits(dc, 
  		UI_RECT_TOP_LEFT(window->updateRegion), UI_RECT_SIZE(window->updateRegion), 
  		window->updateRegion.l, window->updateRegion.b + 1, 
  		UI_RECT_WIDTH(window->updateRegion), -UI_RECT_HEIGHT(window->updateRegion),
  		window->bits, (BITMAPINFO *) &info, DIB_RGB_COLORS, SRCCOPY);
  	ReleaseDC(window->hwnd, dc);
  }
  
  void _UIWindowSetCursor(UIWindow *window, int cursor) {
  	SetCursor(ui.cursors[cursor]);
  }
  
  void _UIWindowGetScreenPosition(UIWindow *window, int *_x, int *_y) {
  	POINT p;
  	p.x = 0;
  	p.y = 0;
  	ClientToScreen(window->hwnd, &p);
  	*_x = p.x;
  	*_y = p.y;
  }
  
  void UIWindowPostMessage(UIWindow *window, UIMessage message, void *_dp) {
  	PostMessage(window->hwnd, WM_APP + 1, (WPARAM) message, (LPARAM) _dp);
  }
  
  void *_UIHeapReAlloc(void *pointer, size_t size) {
  	if (pointer) {
  		if (size) {
  			return HeapReAlloc(ui.heap, 0, pointer, size);
  		} else {
  			UI_FREE(pointer);
  			return NULL;
  		}
  	} else {
  		if (size) {
  			return UI_MALLOC(size);
  		} else {
  			return NULL;
  		}
  	}
  }
  
  #endif
  
  #ifdef UI_ESSENCE
  
  const int UI_KEYCODE_A = ES_SCANCODE_A;
  const int UI_KEYCODE_0 = ES_SCANCODE_0;
  const int UI_KEYCODE_BACKSPACE = ES_SCANCODE_BACKSPACE;
  const int UI_KEYCODE_DELETE = ES_SCANCODE_DELETE;
  const int UI_KEYCODE_DOWN = ES_SCANCODE_DOWN_ARROW;
  const int UI_KEYCODE_END = ES_SCANCODE_END;
  const int UI_KEYCODE_ENTER = ES_SCANCODE_ENTER;
  const int UI_KEYCODE_ESCAPE = ES_SCANCODE_ESCAPE;
  const int UI_KEYCODE_F1 = ES_SCANCODE_F1;
  const int UI_KEYCODE_HOME = ES_SCANCODE_HOME;
  const int UI_KEYCODE_LEFT = ES_SCANCODE_LEFT_ARROW;
  const int UI_KEYCODE_RIGHT = ES_SCANCODE_RIGHT_ARROW;
  const int UI_KEYCODE_SPACE = ES_SCANCODE_SPACE;
  const int UI_KEYCODE_TAB = ES_SCANCODE_TAB;
  const int UI_KEYCODE_UP = ES_SCANCODE_UP_ARROW;
  
  int _UIWindowMessage(UIElement *element, UIMessage message, int di, void *dp) {
  	if (message == UI_MSG_DESTROY) {
  		// TODO Non-main windows.
  		element->window = NULL;
  		EsInstanceDestroy(ui.instance);
  	}
  
  	return _UIWindowMessageCommon(element, message, di, dp);
  }
  
  void UIInitialise() {
  	_UIInitialiseCommon();
  
  	while (true) {
  		EsMessage *message = EsMessageReceive();
  
  		if (message->type == ES_MSG_INSTANCE_CREATE) {
  			ui.instance = EsInstanceCreate(message, NULL, 0);
  			break;
  		}
  	}
  }
  
  bool _UIMessageLoopSingle(int *result) {
  	if (ui.animating) {
  		// TODO.
  	} else {
  		_UIMessageProcess(EsMessageReceive());
  	}
  
  	return true;
  }
  
  UIMenu *UIMenuCreate(UIElement *parent, uint32_t flags) {
  	ui.menuIndex = 0;
  	return EsMenuCreate(parent->window->window, ES_MENU_AT_CURSOR);
  }
  
  void _UIMenuItemCallback(EsMenu *menu, EsGeneric context) {
  	((void (*)(void *)) ui.menuData[context.u * 2 + 0])(ui.menuData[context.u * 2 + 1]);
  }
  
  void UIMenuAddItem(UIMenu *menu, uint32_t flags, const char *label, ptrdiff_t labelBytes, void (*invoke)(void *cp), void *cp) {
  	EsAssert(ui.menuIndex < 128);
  	ui.menuData[ui.menuIndex * 2 + 0] = (void *) invoke;
  	ui.menuData[ui.menuIndex * 2 + 1] = cp;
  	EsMenuAddItem(menu, (flags & UI_BUTTON_CHECKED) ? ES_MENU_ITEM_CHECKED : ES_FLAGS_DEFAULT, 
  			label, labelBytes, _UIMenuItemCallback, ui.menuIndex);
  	ui.menuIndex++;
  }
  
  void UIMenuShow(UIMenu *menu) {
  	EsMenuShow(menu);
  }
  
  int _UIWindowCanvasMessage(EsElement *element, EsMessage *message) {
  	UIWindow *window = (UIWindow *) element->window->userData.p;
  
  	if (!window) {
  		return 0;
  	} else if (message->type == ES_MSG_PAINT) {
  		EsRectangle bounds = ES_RECT_4PD(message->painter->offsetX, message->painter->offsetY, window->width, window->height);
  		EsDrawBitmap(message->painter, bounds, window->bits, window->width * 4, 0xFFFF);
  	} else if (message->type == ES_MSG_LAYOUT) {
  		EsElementGetSize(element, &window->width, &window->height);
  		window->bits = (uint32_t *) UI_REALLOC(window->bits, window->width * window->height * 4);
  		window->e.bounds = UI_RECT_2S(window->width, window->height);
  		window->e.clip = UI_RECT_2S(window->width, window->height);
  		UIElementMessage(&window->e, UI_MSG_LAYOUT, 0, 0);
  		_UIUpdate();
  	} else if (message->type == ES_MSG_SCROLL_WHEEL) {
  		_UIWindowInputEvent(window, UI_MSG_MOUSE_WHEEL, -message->scrollWheel.dy, 0);
  	} else if (message->type == ES_MSG_MOUSE_MOVED || message->type == ES_MSG_HOVERED_END
  			|| message->type == ES_MSG_MOUSE_LEFT_DRAG || message->type == ES_MSG_MOUSE_RIGHT_DRAG || message->type == ES_MSG_MOUSE_MIDDLE_DRAG) {
  		EsPoint point = EsMouseGetPosition(element); 
  		window->cursorX = point.x, window->cursorY = point.y;
  		_UIWindowInputEvent(window, UI_MSG_MOUSE_MOVE, 0, 0);
  	} else if (message->type == ES_MSG_KEY_UP) {
  		window->ctrl = EsKeyboardIsCtrlHeld();
  		window->shift = EsKeyboardIsShiftHeld();
  		window->alt = EsKeyboardIsAltHeld();
  	} else if (message->type == ES_MSG_KEY_DOWN) {
  		window->ctrl = EsKeyboardIsCtrlHeld();
  		window->shift = EsKeyboardIsShiftHeld();
  		window->alt = EsKeyboardIsAltHeld();
  		UIKeyTyped m = { 0 };
  		char c[64];
  		m.text = c;
  		m.textBytes = EsMessageGetInputText(message, c);
  		m.code = message->keyboard.scancode;
  		return _UIWindowInputEvent(window, UI_MSG_KEY_TYPED, 0, &m) ? ES_HANDLED : 0;
  	} else if (message->type == ES_MSG_MOUSE_LEFT_CLICK) {
  		_UIInspectorSetFocusedWindow(window);
  	} else if (message->type == ES_MSG_USER_START) {
  		UIElementMessage(&window->e, (UIMessage) message->user.context1.u, 0, (void *) message->user.context2.p);
  		_UIUpdate();
  	} else if (message->type == ES_MSG_GET_CURSOR) {
  		message->cursorStyle = ES_CURSOR_NORMAL;
  		if (window->cursor == UI_CURSOR_TEXT)              message->cursorStyle = ES_CURSOR_TEXT;
  		if (window->cursor == UI_CURSOR_SPLIT_V)           message->cursorStyle = ES_CURSOR_SPLIT_VERTICAL;
  		if (window->cursor == UI_CURSOR_SPLIT_H)           message->cursorStyle = ES_CURSOR_SPLIT_HORIZONTAL;
  		if (window->cursor == UI_CURSOR_FLIPPED_ARROW)     message->cursorStyle = ES_CURSOR_SELECT_LINES;
  		if (window->cursor == UI_CURSOR_CROSS_HAIR)        message->cursorStyle = ES_CURSOR_CROSS_HAIR_PICK;
  		if (window->cursor == UI_CURSOR_HAND)              message->cursorStyle = ES_CURSOR_HAND_HOVER;
  		if (window->cursor == UI_CURSOR_RESIZE_UP)         message->cursorStyle = ES_CURSOR_RESIZE_VERTICAL;
  		if (window->cursor == UI_CURSOR_RESIZE_LEFT)       message->cursorStyle = ES_CURSOR_RESIZE_HORIZONTAL;
  		if (window->cursor == UI_CURSOR_RESIZE_UP_RIGHT)   message->cursorStyle = ES_CURSOR_RESIZE_DIAGONAL_1;
  		if (window->cursor == UI_CURSOR_RESIZE_UP_LEFT)    message->cursorStyle = ES_CURSOR_RESIZE_DIAGONAL_2;
  		if (window->cursor == UI_CURSOR_RESIZE_DOWN)       message->cursorStyle = ES_CURSOR_RESIZE_VERTICAL;
  		if (window->cursor == UI_CURSOR_RESIZE_RIGHT)      message->cursorStyle = ES_CURSOR_RESIZE_HORIZONTAL;
  		if (window->cursor == UI_CURSOR_RESIZE_DOWN_RIGHT) message->cursorStyle = ES_CURSOR_RESIZE_DIAGONAL_1;
  		if (window->cursor == UI_CURSOR_RESIZE_DOWN_LEFT)  message->cursorStyle = ES_CURSOR_RESIZE_DIAGONAL_2;
  	}
  	
  	else if (message->type == ES_MSG_MOUSE_LEFT_DOWN)   _UIWindowInputEvent(window, UI_MSG_LEFT_DOWN, 0, 0);
  	else if (message->type == ES_MSG_MOUSE_LEFT_UP)     _UIWindowInputEvent(window, UI_MSG_LEFT_UP, 0, 0);
  	else if (message->type == ES_MSG_MOUSE_MIDDLE_DOWN) _UIWindowInputEvent(window, UI_MSG_MIDDLE_DOWN, 0, 0);
  	else if (message->type == ES_MSG_MOUSE_MIDDLE_UP)   _UIWindowInputEvent(window, UI_MSG_MIDDLE_UP, 0, 0);
  	else if (message->type == ES_MSG_MOUSE_RIGHT_DOWN)  _UIWindowInputEvent(window, UI_MSG_RIGHT_DOWN, 0, 0);
  	else if (message->type == ES_MSG_MOUSE_RIGHT_UP)    _UIWindowInputEvent(window, UI_MSG_RIGHT_UP, 0, 0);
  
  	else return 0;
  
  	return ES_HANDLED;
  }
  
  UIWindow *UIWindowCreate(UIWindow *owner, uint32_t flags, const char *cTitle, int width, int height) {
  	_UIMenusClose();
  
  	UIWindow *window = (UIWindow *) UIElementCreate(sizeof(UIWindow), NULL, flags | UI_ELEMENT_WINDOW, _UIWindowMessage, "Window");
  	_UIWindowAdd(window);
  	if (owner) window->scale = owner->scale;
  
  	if (flags & UI_WINDOW_MENU) {
  		// TODO.
  	} else {
  		// TODO Non-main windows.
  		window->window = ui.instance->window;
  		window->window->userData = window;
  		window->canvas = EsCustomElementCreate(window->window, ES_CELL_FILL | ES_ELEMENT_FOCUSABLE);
  		window->canvas->messageUser = _UIWindowCanvasMessage;
  		EsWindowSetTitle(window->window, cTitle, -1);
  		EsElementFocus(window->canvas);
  	}
  
  	return window;
  }
  
  void _UIWindowEndPaint(UIWindow *window, UIPainter *painter) {
  	EsElementRepaint(window->canvas, &window->updateRegion);
  }
  
  void _UIWindowSetCursor(UIWindow *window, int cursor) {
  	window->cursor = cursor;
  }
  
  void _UIWindowGetScreenPosition(UIWindow *window, int *_x, int *_y) {
  	EsRectangle r = EsElementGetScreenBounds(window->window);
  	*_x = r.l, *_y = r.t;
  }
  
  void UIWindowPostMessage(UIWindow *window, UIMessage message, void *_dp) {
  	EsMessage m = {};
  	m.type = ES_MSG_USER_START;
  	m.user.context1.u = message;
  	m.user.context2.p = _dp;
  	EsMessagePost(window->canvas, &m);
  }
  
  #endif
  
  #endif
  