text: /*
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version 2
   * of the License, or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
   *
   * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
   * All rights reserved.
   */
  
  /** \file
   * \ingroup GHOST
   * %Main interface file for C++ Api with declaration of GHOST_ISystem interface
   * class.
   * Contains the doxygen documentation main page.
   */
  
  #ifndef __GHOST_ISYSTEM_H__
  #define __GHOST_ISYSTEM_H__
  
  #include "GHOST_Types.h"
  #include "GHOST_IContext.h"
  #include "GHOST_ITimerTask.h"
  #include "GHOST_IWindow.h"
  
  class GHOST_IEventConsumer;
  
  /**
   * \page GHOSTPage GHOST
   *
   * \section intro Introduction
   *
   * GHOST is yet another acronym. It stands for "Generic Handy Operating System
   * Toolkit". It has been created to replace the OpenGL utility tool kit
   * <a href="http://www.opengl.org/resources/libraries/glut/">GLUT</a>.
   * GLUT was used in <a href="http://www.blender3d.com">Blender</a> until the
   * point that Blender needed to be ported to Apple's Mac OSX. Blender needed a
   * number of modifications in GLUT to work but the GLUT sources for OSX were
   * unavailable at the time. The decision was made to build our own replacement
   * for GLUT. In those days, NaN Technologies BV was the company that developed
   * Blender.
   * <br><br>
   * Enough history. What does GHOST have to offer?<br>
   * In short: everything that Blender needed from GLUT to run on all it's supported
   * operating systems and some extra's.
   * This includes :
   *
   * - Time(r) management.
   * - Display/window management (windows are only created on the main display).
   * - Event management.
   * - Cursor shape management (no custom cursors for now).
   * - Access to the state of the mouse buttons and the keyboard.
   * - Menus for windows with events generated when they are accessed (this is
   *   work in progress).
   * - Video mode switching.
   * - Copy/Paste buffers.
   * - System paths.
   *
   * Font management has been moved to a separate library.
   *
   * \section platforms Platforms
   *
   * GHOST supports the following platforms:
   *
   * - OSX Cocoa.
   * - Windows.
   * - X11.
   * - SDL2 (experimental).
   * - NULL (headless mode).
   *
   * \section Building GHOST
   *
   * GHOST is not build standalone however there are tests in intern/ghost/test
   *
   * \section interface Interface
   * GHOST has two programming interfaces:
   *
   * - The C-API. For programs written in C.
   * - The C++-API. For programs written in C++.
   *
   * GHOST itself is written in C++ and the C-API is a wrapper around the C++
   * API.
   *
   * \subsection cplusplus_api The C++ API consists of the following files:
   *
   * - GHOST_IEvent.h
   * - GHOST_IEventConsumer.h
   * - GHOST_ISystem.h
   * - GHOST_ITimerTask.h
   * - GHOST_IWindow.h
   * - GHOST_Rect.h
   * - GHOST_Types.h
   *
   * For an example of using the C++-API, have a look at the GHOST_C-Test.cpp
   * program in the ?/ghost/test/gears/ directory.
   *
   * \subsection c_api The C-API
   * To use GHOST in programs written in C, include the file GHOST_C-API.h in
   * your program. This file includes the GHOST_Types.h file for all GHOST types
   * and defines functions that give you access to the same functionality present
   * in the C++ API.<br>
   * For an example of using the C-API, have a look at the GHOST_C-Test.c program
   * in the ?/ghost/test/gears/ directory.
   *
   * \section work Work in progress
   * \todo write WIP section
   */
  
  /** \interface GHOST_ISystem
   * Interface for classes that provide access to the operating system.
   * There should be only one system class in an application.
   * Therefore, the routines to create and dispose the system are static.
   * Provides:
   *  -# Time(r) management.
   *  -# Display/window management (windows are only created on the main display).
   *  -# Event management.
   *  -# Cursor shape management (no custom cursors for now).
   *  -# Access to the state of the mouse buttons and the keyboard.
   *  -# Menus for windows with events generated when they are accessed (this is
   *     work in progress).
   */
  class GHOST_ISystem {
   public:
    /**
     * Creates the one and only system.
     * \return An indication of success.
     */
    static GHOST_TSuccess createSystem();
  
    /**
     * Disposes the one and only system.
     * \return An indication of success.
     */
    static GHOST_TSuccess disposeSystem();
  
    /**
     * Returns a pointer to the one and only system (nil if it hasn't been created).
     * \return A pointer to the system.
     */
    static GHOST_ISystem *getSystem();
  
   protected:
    /**
     * Constructor.
     * Protected default constructor to force use of static createSystem member.
     */
    GHOST_ISystem()
    {
    }
  
    /**
     * Destructor.
     * Protected default constructor to force use of static dispose member.
     */
    virtual ~GHOST_ISystem()
    {
    }
  
   public:
    /***************************************************************************************
     * Time(r) functionality
     ***************************************************************************************/
  
    /**
     * Returns the system time.
     * Returns the number of milliseconds since the start of the system process.
     * Based on ANSI clock() routine.
     * \return The number of milliseconds.
     */
    virtual GHOST_TUns64 getMilliSeconds() const = 0;
  
    /**
     * Installs a timer.
     * Note that, on most operating systems, messages need to be processed in order
     * for the timer callbacks to be invoked.
     * \param delay     The time to wait for the first call to the timerProc (in milliseconds)
     * \param interval  The interval between calls to the timerProc (in milliseconds)
     * \param timerProc The callback invoked when the interval expires,
     * \param userData  Placeholder for user data.
     * \return A timer task (0 if timer task installation failed).
     */
    virtual GHOST_ITimerTask *installTimer(GHOST_TUns64 delay,
                                           GHOST_TUns64 interval,
                                           GHOST_TimerProcPtr timerProc,
                                           GHOST_TUserDataPtr userData = NULL) = 0;
  
    /**
     * Removes a timer.
     * \param timerTask Timer task to be removed.
     * \return Indication of success.
     */
    virtual GHOST_TSuccess removeTimer(GHOST_ITimerTask *timerTask) = 0;
  
    /***************************************************************************************
     * Display/window management functionality
     ***************************************************************************************/
  
    /**
     * Returns the number of displays on this system.
     * \return The number of displays.
     */
    virtual GHOST_TUns8 getNumDisplays() const = 0;
  
    /**
     * Returns the dimensions of the main display on this system.
     * \return The dimension of the main display.
     */
    virtual void getMainDisplayDimensions(GHOST_TUns32 &width, GHOST_TUns32 &height) const = 0;
  
    /**
     * Returns the combine dimensions of all monitors.
     * \return The dimension of the workspace.
     */
    virtual void getAllDisplayDimensions(GHOST_TUns32 &width, GHOST_TUns32 &height) const = 0;
  
    /**
     * Create a new window.
     * The new window is added to the list of windows managed.
     * Never explicitly delete the window, use disposeWindow() instead.
     * \param title: The name of the window
     * (displayed in the title bar of the window if the OS supports it).
     * \param left: The coordinate of the left edge of the window.
     * \param top: The coordinate of the top edge of the window.
     * \param width: The width the window.
     * \param height: The height the window.
     * \param state: The state of the window when opened.
     * \param type: The type of drawing context installed in this window.
     * \param glSettings: Misc OpenGL settings.
     * \param exclusive: Use to show the window on top and ignore others (used full-screen).
     * \param is_dialog: Stay on top of parent window, no icon in taskbar, can't be minimized.
     * \param parentWindow: Parent (embedder) window
     * \return The new window (or 0 if creation failed).
     */
    virtual GHOST_IWindow *createWindow(const STR_String &title,
                                        GHOST_TInt32 left,
                                        GHOST_TInt32 top,
                                        GHOST_TUns32 width,
                                        GHOST_TUns32 height,
                                        GHOST_TWindowState state,
                                        GHOST_TDrawingContextType type,
                                        GHOST_GLSettings glSettings,
                                        const bool exclusive = false,
                                        const bool is_dialog = false,
                                        const GHOST_IWindow *parentWindow = NULL) = 0;
  
    /**
     * Dispose a window.
     * \param   window Pointer to the window to be disposed.
     * \return  Indication of success.
     */
    virtual GHOST_TSuccess disposeWindow(GHOST_IWindow *window) = 0;
  
    /**
     * Create a new offscreen context.
     * Never explicitly delete the context, use disposeContext() instead.
     * \return  The new context (or 0 if creation failed).
     */
    virtual GHOST_IContext *createOffscreenContext() = 0;
  
    /**
     * Dispose of a context.
     * \param   context Pointer to the context to be disposed.
     * \return  Indication of success.
     */
    virtual GHOST_TSuccess disposeContext(GHOST_IContext *context) = 0;
  
    /**
     * Returns whether a window is valid.
     * \param   window Pointer to the window to be checked.
     * \return  Indication of validity.
     */
    virtual bool validWindow(GHOST_IWindow *window) = 0;
  
    /**
     * Begins full screen mode.
     * \param setting   The new setting of the display.
     * \param window    Window displayed in full screen.
     *                  This window is invalid after full screen has been ended.
     * \return  Indication of success.
     */
    virtual GHOST_TSuccess beginFullScreen(const GHOST_DisplaySetting &setting,
                                           GHOST_IWindow **window,
                                           const bool stereoVisual,
                                           const bool alphaBackground = 0) = 0;
  
    /**
     * Updates the resolution while in fullscreen mode.
     * \param setting   The new setting of the display.
     * \param window    Window displayed in full screen.
     *
     * \return  Indication of success.
     */
    virtual GHOST_TSuccess updateFullScreen(const GHOST_DisplaySetting &setting,
                                            GHOST_IWindow **window) = 0;
  
    /**
     * Ends full screen mode.
     * \return  Indication of success.
     */
    virtual GHOST_TSuccess endFullScreen(void) = 0;
  
    /**
     * Returns current full screen mode status.
     * \return The current status.
     */
    virtual bool getFullScreen(void) = 0;
  
    /**
     * Native pixel size support (MacBook 'retina').
     */
    virtual bool useNativePixel(void) = 0;
  
    /**
     * Focus window after opening, or put them in the background.
     */
    virtual void useWindowFocus(const bool use_focus) = 0;
  
    /***************************************************************************************
     * Event management functionality
     ***************************************************************************************/
  
    /**
     * Retrieves events from the system and stores them in the queue.
     * \param waitForEvent Flag to wait for an event (or return immediately).
     * \return Indication of the presence of events.
     */
    virtual bool processEvents(bool waitForEvent) = 0;
  
    /**
     * Retrieves events from the queue and send them to the event consumers.
     */
    virtual void dispatchEvents() = 0;
  
    /**
     * Adds the given event consumer to our list.
     * \param consumer The event consumer to add.
     * \return Indication of success.
     */
    virtual GHOST_TSuccess addEventConsumer(GHOST_IEventConsumer *consumer) = 0;
  
    /**
     * Removes the given event consumer to our list.
     * \param consumer The event consumer to remove.
     * \return Indication of success.
     */
    virtual GHOST_TSuccess removeEventConsumer(GHOST_IEventConsumer *consumer) = 0;
  
    /***************************************************************************************
     * Cursor management functionality
     ***************************************************************************************/
  
    /**
     * Returns the current location of the cursor (location in screen coordinates)
     * \param x         The x-coordinate of the cursor.
     * \param y         The y-coordinate of the cursor.
     * \return          Indication of success.
     */
    virtual GHOST_TSuccess getCursorPosition(GHOST_TInt32 &x, GHOST_TInt32 &y) const = 0;
  
    /**
     * Updates the location of the cursor (location in screen coordinates).
     * Not all operating systems allow the cursor to be moved (without the input device being moved).
     * \param x         The x-coordinate of the cursor.
     * \param y         The y-coordinate of the cursor.
     * \return          Indication of success.
     */
    virtual GHOST_TSuccess setCursorPosition(GHOST_TInt32 x, GHOST_TInt32 y) = 0;
  
    /***************************************************************************************
     * Access to mouse button and keyboard states.
     ***************************************************************************************/
  
    /**
     * Returns the state of a modifier key (ouside the message queue).
     * \param mask      The modifier key state to retrieve.
     * \param isDown    The state of a modifier key (true == pressed).
     * \return          Indication of success.
     */
    virtual GHOST_TSuccess getModifierKeyState(GHOST_TModifierKeyMask mask, bool &isDown) const = 0;
  
    /**
     * Returns the state of a mouse button (ouside the message queue).
     * \param mask      The button state to retrieve.
     * \param isDown    Button state.
     * \return          Indication of success.
     */
    virtual GHOST_TSuccess getButtonState(GHOST_TButtonMask mask, bool &isDown) const = 0;
  
    /**
     * Set which tablet API to use. Only affects Windows, other platforms have a single API.
     * \param api Enum indicating which API to use.
     */
    virtual void setTabletAPI(GHOST_TTabletAPI api) = 0;
  
  #ifdef WITH_INPUT_NDOF
    /**
     * Sets 3D mouse deadzone
     * \param deadzone: Dead-zone of the 3D mouse (both for rotation and pan) relative to full range
     */
    virtual void setNDOFDeadZone(float deadzone) = 0;
  #endif
  
    /**
     * Toggles console
     * \param action
     * - 0: Hides
     * - 1: Shows
     * - 2: Toggles
     * - 3: Hides if it runs not from  command line
     * - *: Does nothing
     * \return current status (1 -visible, 0 - hidden)
     */
    virtual int toggleConsole(int action) = 0;
  
    /***************************************************************************************
     * Access to clipboard.
     ***************************************************************************************/
  
    /**
     * Returns the selection buffer
     * \return "unsigned char" from X11 XA_CUT_BUFFER0 buffer
     *
     */
    virtual GHOST_TUns8 *getClipboard(bool selection) const = 0;
  
    /**
     * Put data to the Clipboard
     */
    virtual void putClipboard(GHOST_TInt8 *buffer, bool selection) const = 0;
  
    /***************************************************************************************
     * System Message Box.
     ***************************************************************************************/
  
    /**
     * Show a system message box
     *
     * \param title                   The title of the message box
     * \param message                 The message to display
     * \param help_label              Help button label
     * \param continue_label          Continue button label
     * \param link                    An optional hyperlink
     * \param dialog_options Options  how to display the message
     */
    virtual GHOST_TSuccess showMessageBox(const char * /*title*/,
                                          const char * /*message*/,
                                          const char * /*help_label*/,
                                          const char * /*continue_label*/,
                                          const char * /*link*/,
                                          GHOST_DialogOptions /*dialog_options*/) const = 0;
  
   protected:
    /**
     * Initialize the system.
     * \return Indication of success.
     */
    virtual GHOST_TSuccess init() = 0;
  
    /**
     * Shut the system down.
     * \return Indication of success.
     */
    virtual GHOST_TSuccess exit() = 0;
  
    /** The one and only system */
    static GHOST_ISystem *m_system;
  
  #ifdef WITH_CXX_GUARDEDALLOC
    MEM_CXX_CLASS_ALLOC_FUNCS("GHOST:GHOST_ISystem")
  #endif
  };
  
  #endif  // __GHOST_ISYSTEM_H__
  