Source/WebKit/chromium/public/WebWidget.h

/*
 * 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.
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 * 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
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 */

#ifndef WebWidget_h
#define WebWidget_h

#include "WebCanvas.h"
#include "WebCommon.h"
#include "WebCompositionUnderline.h"
#include "WebTextInputType.h"
#include "WebTextDirection.h"

namespace WebKit {

class WebInputEvent;
class WebString;
struct WebPoint;
struct WebRect;
struct WebSize;
template <typename T> class WebVector;

class WebWidget {
public:
    // This method closes and deletes the WebWidget.
    virtual void close() = 0;

    // Returns the current size of the WebWidget.
    virtual WebSize size() = 0;

    // Called to resize the WebWidget.
    virtual void resize(const WebSize&) = 0;

    // Called to update imperative animation state.  This should be called before
    // paint, although the client can rate-limit these calls.
    virtual void animate() = 0;

    // Called to layout the WebWidget.  This MUST be called before Paint,
    // and it may result in calls to WebWidgetClient::didInvalidateRect.
    virtual void layout() = 0;

    // 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) = 0;

    // Triggers compositing of the current layers onto the screen.
    // The finish argument controls whether the compositor will wait for the
    // GPU to finish rendering before returning. You MUST call Layout
    // before calling this method, for the same reasons described in
    // the paint method above.
    virtual void composite(bool finish) = 0;

    // 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() = 0;

    // Called to inform the WebWidget of an input event.  Returns true if
    // the event has been processed, false otherwise.
    virtual bool handleInputEvent(const WebInputEvent&) = 0;

    // Called to inform the WebWidget that mouse capture was lost.
    virtual void mouseCaptureLost() = 0;

    // Called to inform the WebWidget that it has gained or lost keyboard focus.
    virtual void setFocus(bool) = 0;

    // 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) = 0;

    // 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() = 0;

    // 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) = 0;

    // Returns the current text input type of this WebWidget.
    virtual WebTextInputType textInputType() = 0;

    // Returns the current caret bounds of this WebWidget. The selection bounds
    // will be returned if a selection range is available.
    virtual WebRect caretOrSelectionBounds() = 0;

    // Returns the start and end point for the current selection, aligned to the
    // bottom of the selected line.
    virtual bool selectionRange(WebPoint& start, WebPoint& end) const = 0;

    // Changes the text direction of the selected input node.
    virtual void setTextDirection(WebTextDirection) = 0;

    // Returns true if the WebWidget uses GPU accelerated compositing
    // to render its contents.
    virtual bool isAcceleratedCompositingActive() const = 0;

protected:
    ~WebWidget() { }
};

} // namespace WebKit

#endif