text: /*
   * Copyright (C) 2009 Google Inc. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are
   * met:
   *
   *     * Redistributions of source code must retain the above copyright
   * notice, this list of conditions and the following disclaimer.
   *     * Redistributions in binary form must reproduce the above
   * copyright notice, this list of conditions and the following disclaimer
   * in the documentation and/or other materials provided with the
   * distribution.
   *     * Neither the name of Google Inc. nor the names of its
   * contributors may be used to endorse or promote products derived from
   * this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #ifndef WebWidget_h
  #define WebWidget_h
  
  #include "../platform/WebCanvas.h"
  #include "../platform/WebCommon.h"
  #include "../platform/WebPoint.h"
  #include "../platform/WebRect.h"
  #include "../platform/WebSize.h"
  #include "WebBeginFrameArgs.h"
  #include "WebCompositionUnderline.h"
  #include "WebTextDirection.h"
  #include "WebTextInputInfo.h"
  
  namespace blink {
  
  class WebCompositeAndReadbackAsyncCallback;
  class WebInputEvent;
  class WebLayerTreeView;
  class WebMouseEvent;
  class WebPagePopup;
  class WebString;
  class WebWidgetClient;
  struct WebPoint;
  struct WebRenderingStats;
  template <typename T> class WebVector;
  
  class WebWidget {
  public:
      // This method closes and deletes the WebWidget.
      virtual void close() { }
  
      // Returns the current size of the WebWidget.
      virtual WebSize size() { return WebSize(); }
  
      // Used to group a series of resize events. For example, if the user
      // drags a resizer then willStartLiveResize will be called, followed by a
      // sequence of resize events, ending with willEndLiveResize when the user
      // lets go of the resizer.
      virtual void willStartLiveResize() { }
  
      // Called to resize the WebWidget.
      virtual void resize(const WebSize&) { }
  
      // Resizes the unscaled pinch viewport. Normally the unscaled pinch
      // viewport is the same size as the main frame. The passed size becomes the
      // size of the viewport when unscaled (i.e. scale = 1). This is used to
      // shrink the visible viewport to allow things like the ChromeOS virtual
      // keyboard to overlay over content but allow scrolling it into view.
      virtual void resizePinchViewport(const WebSize&) { }
  
      // Ends a group of resize events that was started with a call to
      // willStartLiveResize.
      virtual void willEndLiveResize() { }
  
      // Called to notify the WebWidget of entering/exiting fullscreen mode. The
      // resize method may be called between will{Enter,Exit}FullScreen and
      // did{Enter,Exit}FullScreen.
      virtual void willEnterFullScreen() { }
      virtual void didEnterFullScreen() { }
      virtual void willExitFullScreen() { }
      virtual void didExitFullScreen() { }
  
      // Called to update imperative animation state. This should be called before
      // paint, although the client can rate-limit these calls.
      // FIXME: Remove this function once Chrome side patch lands.
      void animate(double monotonicFrameBeginTime)
      {
          beginFrame(WebBeginFrameArgs(monotonicFrameBeginTime));
      }
      virtual void beginFrame(const WebBeginFrameArgs& frameTime) { }
  
      // Called to notify that a previously begun frame was finished and
      // committed to the compositor. This is used to schedule lower priority
      // work after tasks such as input processing and painting.
      virtual void didCommitFrameToCompositor() { }
  
      // Called to layout the WebWidget. This MUST be called before Paint,
      // and it may result in calls to WebWidgetClient::didInvalidateRect.
      virtual void layout() { }
  
      // Called to paint the rectangular region within the WebWidget
      // onto the specified canvas at (viewPort.x,viewPort.y). You MUST call
      // Layout before calling this method. It is okay to call paint
      // multiple times once layout has been called, assuming no other
      // changes are made to the WebWidget (e.g., once events are
      // processed, it should be assumed that another call to layout is
      // warranted before painting again).
      virtual void paint(WebCanvas*, const WebRect& viewPort) { }
  
      virtual void paintCompositedDeprecated(WebCanvas*, const WebRect&) { }
  
      // The caller is responsible for keeping the WebCompositeAndReadbackAsyncCallback
      // object alive until it is called. This should only be called when
      // isAcceleratedCompositingActive() is true.
      virtual void compositeAndReadbackAsync(WebCompositeAndReadbackAsyncCallback*) { }
  
      // Returns true if we've started tracking repaint rectangles.
      virtual bool isTrackingRepaints() const { return false; }
  
      // Indicates that the compositing surface associated with this WebWidget is
      // ready to use.
      virtual void setCompositorSurfaceReady() { }
  
      // Called to inform the WebWidget of a change in theme.
      // Implementors that cache rendered copies of widgets need to re-render
      // on receiving this message
      virtual void themeChanged() { }
  
      // Called to inform the WebWidget of an input event. Returns true if
      // the event has been processed, false otherwise.
      virtual bool handleInputEvent(const WebInputEvent&) { return false; }
  
      // Called to inform the WebWidget of the mouse cursor's visibility.
      virtual void setCursorVisibilityState(bool isVisible) { }
  
      // Check whether the given point hits any registered touch event handlers.
      virtual bool hasTouchEventHandlersAt(const WebPoint&) { return true; }
  
      // Applies viewport related properties during a commit from the compositor
      // thread.
      virtual void applyViewportDeltas(
          const WebSize& scrollDelta,
          float scaleFactor,
          float topControlsDelta) { }
  
      // Applies viewport related properties during a commit from the compositor
      // thread.
      virtual void applyViewportDeltas(
          const WebSize& pinchViewportDelta,
          const WebSize& mainFrameDelta,
          float scaleFactor,
          float topControlsDelta) { }
  
      // Called to inform the WebWidget that mouse capture was lost.
      virtual void mouseCaptureLost() { }
  
      // Called to inform the WebWidget that it has gained or lost keyboard focus.
      virtual void setFocus(bool) { }
  
      // Called to inform the WebWidget of a new composition text.
      // If selectionStart and selectionEnd has the same value, then it indicates
      // the input caret position. If the text is empty, then the existing
      // composition text will be cancelled.
      // Returns true if the composition text was set successfully.
      virtual bool setComposition(
          const WebString& text,
          const WebVector<WebCompositionUnderline>& underlines,
          int selectionStart,
          int selectionEnd) { return false; }
  
      enum ConfirmCompositionBehavior {
          DoNotKeepSelection,
          KeepSelection,
      };
  
      // Called to inform the WebWidget to confirm an ongoing composition.
      // This method is same as confirmComposition(WebString());
      // Returns true if there is an ongoing composition.
      virtual bool confirmComposition() { return false; } // Deprecated
      virtual bool confirmComposition(ConfirmCompositionBehavior selectionBehavior) { return false; }
  
      // Called to inform the WebWidget to confirm an ongoing composition with a
      // new composition text. If the text is empty then the current composition
      // text is confirmed. If there is no ongoing composition, then deletes the
      // current selection and inserts the text. This method has no effect if
      // there is no ongoing composition and the text is empty.
      // Returns true if there is an ongoing composition or the text is inserted.
      virtual bool confirmComposition(const WebString& text) { return false; }
  
      // Fetches the character range of the current composition, also called the
      // "marked range." Returns true and fills the out-paramters on success;
      // returns false on failure.
      virtual bool compositionRange(size_t* location, size_t* length) { return false; }
  
      // Returns information about the current text input of this WebWidget.
      virtual WebTextInputInfo textInputInfo() { return WebTextInputInfo(); }
  
      // Returns the anchor and focus bounds of the current selection.
      // If the selection range is empty, it returns the caret bounds.
      virtual bool selectionBounds(WebRect& anchor, WebRect& focus) const { return false; }
  
      // Called to notify that IME candidate window has changed its visibility or
      // its appearance. These calls correspond to trigger
      // candidatewindow{show,update,hide} events defined in W3C IME API.
      virtual void didShowCandidateWindow() { }
      virtual void didUpdateCandidateWindow() { }
      virtual void didHideCandidateWindow() { }
  
      // Returns the text direction at the start and end bounds of the current selection.
      // If the selection range is empty, it returns false.
      virtual bool selectionTextDirection(WebTextDirection& start, WebTextDirection& end) const { return false; }
  
      // Returns true if the selection range is nonempty and its anchor is first
      // (i.e its anchor is its start).
      virtual bool isSelectionAnchorFirst() const { return false; }
  
      // Fetch the current selection range of this WebWidget. If there is no
      // selection, it will output a 0-length range with the location at the
      // caret. Returns true and fills the out-paramters on success; returns false
      // on failure.
      virtual bool caretOrSelectionRange(size_t* location, size_t* length) { return false; }
  
      // Changes the text direction of the selected input node.
      virtual void setTextDirection(WebTextDirection) { }
  
      // Returns true if the WebWidget uses GPU accelerated compositing
      // to render its contents.
      virtual bool isAcceleratedCompositingActive() const { return false; }
  
      // Returns true if the WebWidget created is of type WebPagePopup.
      virtual bool isPagePopup() const { return false; }
      // Returns true if the WebWidget created is of type WebPopupMenu.
      virtual bool isPopupMenu() const { return false; }
  
      // The WebLayerTreeView initialized on this WebWidgetClient will be going away and
      // is no longer safe to access.
      virtual void willCloseLayerTreeView() { }
  
      // Calling WebWidgetClient::requestPointerLock() will result in one
      // return call to didAcquirePointerLock() or didNotAcquirePointerLock().
      virtual void didAcquirePointerLock() { }
      virtual void didNotAcquirePointerLock() { }
  
      // Pointer lock was held, but has been lost. This may be due to a
      // request via WebWidgetClient::requestPointerUnlock(), or for other
      // reasons such as the user exiting lock, window focus changing, etc.
      virtual void didLosePointerLock() { }
  
      // Informs the WebWidget that the resizer rect changed. Happens for example
      // on mac, when a widget appears below the WebWidget without changing the
      // WebWidget's size (WebWidget::resize() automatically checks the resizer
      // rect.)
      virtual void didChangeWindowResizerRect() { }
  
      // The page background color. Can be used for filling in areas without
      // content.
      virtual WebColor backgroundColor() const { return 0xFFFFFFFF; /* SK_ColorWHITE */ }
  
      // The currently open page popup, which are calendar and datalist pickers
      // but not the select popup.
      virtual WebPagePopup* pagePopup() const { return 0; }
  
      // Sets the height subtracted from the Widget to accomodate the top controls.
      virtual void setTopControlsLayoutHeight(float) { }
  
  protected:
      ~WebWidget() { }
  };
  
  } // namespace blink
  
  #endif
  