public/web/WebWidgetClient.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.
 *     * 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,
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef WebWidgetClient_h
#define WebWidgetClient_h

#include "WebNavigationPolicy.h"
#include "public/platform/WebCommon.h"
#include "public/platform/WebLayerTreeView.h"
#include "public/platform/WebPoint.h"
#include "public/platform/WebRect.h"
#include "public/platform/WebScreenInfo.h"
#include "public/web/WebTouchAction.h"

namespace blink {

class WebGestureEvent;
class WebNode;
class WebString;
class WebWidget;
struct WebCursorInfo;
struct WebFloatPoint;
struct WebFloatSize;
struct WebSize;

class WebWidgetClient {
public:
    // Called when a region of the WebWidget needs to be re-painted.
    virtual void didInvalidateRect(const WebRect&) { }

    // Called when the Widget has changed size as a result of an auto-resize.
    virtual void didAutoResize(const WebSize& newSize) { }

    // Called when the Widget has a new layout size. As a result of
    // setting the new layout size, the frame for this widget has possibly
    // been marked as needing layout. Widgets must mark their containers
    // for layout when the plguin container controls widget layout, otherwise
    // the frame layout will not occur.
    virtual void didUpdateLayoutSize(const WebSize& newSize) { }

    // Attempt to initialize compositing for this widget. If this is successful,
    // layerTreeView() will return a valid WebLayerTreeView.
    virtual void initializeLayerTreeView() { }

    // Return a compositing view used for this widget. This is owned by the
    // WebWidgetClient.
    virtual WebLayerTreeView* layerTreeView() { return 0; }
    // FIXME: Remove all overrides of this and change layerTreeView() above to ASSERT_NOT_REACHED.
    virtual bool allowsBrokenNullLayerTreeView() const { return false; }

    // Called when a call to WebWidget::animate is required
    virtual void scheduleAnimation() { }

    // Called when one of the following things were involved during the layout:
    // * > 200 text characters
    // * > 1024 image pixels
    // * a plugin
    // * a canvas
    // An approximation for first layout that resulted in pixels on screen.
    // Not the best heuristic, and we should replace it with something better.
    virtual void didFirstVisuallyNonEmptyLayout() { }

    // The frame's document first layout immediately after the parsing finished.
    // Another way to put it: first frame produced after DOMContentLoaded was dispatched.
    virtual void didFirstLayoutAfterFinishedParsing() { }

    // Called when the widget acquires or loses focus, respectively.
    virtual void didFocus() { }
    virtual void didBlur() { }

    // Called when the cursor for the widget changes.
    virtual void didChangeCursor(const WebCursorInfo&) { }

    // Called when the widget should be closed.  WebWidget::close() should
    // be called asynchronously as a result of this notification.
    virtual void closeWidgetSoon() { }

    // Called to show the widget according to the given policy.
    virtual void show(WebNavigationPolicy) { }

    // Called to get/set the position of the widget in screen coordinates.
    virtual WebRect windowRect() { return WebRect(); }
    virtual void setWindowRect(const WebRect&) { }

    // Called when a tooltip should be shown at the current cursor position.
    virtual void setToolTipText(const WebString&, WebTextDirection hint) { }

    // Called to get the position of the resizer rect in window coordinates.
    virtual WebRect windowResizerRect() { return WebRect(); }

    // Called to get the position of the root window containing the widget
    // in screen coordinates.
    virtual WebRect rootWindowRect() { return WebRect(); }

    // Called to query information about the screen where this widget is
    // displayed.
    virtual WebScreenInfo screenInfo() { return WebScreenInfo(); }

    // Called to get the scale factor of the display.
    virtual float deviceScaleFactor() { return 1; }

    // When this method gets called, WebWidgetClient implementation should
    // reset the input method by cancelling any ongoing composition.
    virtual void resetInputMethod() { }

    // Requests to lock the mouse cursor. If true is returned, the success
    // result will be asynchronously returned via a single call to
    // WebWidget::didAcquirePointerLock() or
    // WebWidget::didNotAcquirePointerLock().
    // If false, the request has been denied synchronously.
    virtual bool requestPointerLock() { return false; }

    // Cause the pointer lock to be released. This may be called at any time,
    // including when a lock is pending but not yet acquired.
    // WebWidget::didLosePointerLock() is called when unlock is complete.
    virtual void requestPointerUnlock() { }

    // Returns true iff the pointer is locked to this widget.
    virtual bool isPointerLocked() { return false; }

    // Called when a gesture event is handled.
    virtual void didHandleGestureEvent(const WebGestureEvent& event, bool eventCancelled) { }

    // Called when overscrolled on main thread.
    virtual void didOverscroll(const WebFloatSize& unusedDelta, const WebFloatSize& accumulatedRootOverScroll, const WebFloatPoint& position, const WebFloatSize& velocity) { }

    // Called to update if touch events should be sent.
    virtual void hasTouchEventHandlers(bool) { }

    // Called during WebWidget::HandleInputEvent for a TouchStart event to inform the embedder
    // of the touch actions that are permitted for this touch.
    virtual void setTouchAction(WebTouchAction touchAction) { }

    // Called when value of focused text field gets dirty, e.g. value is
    // modified by script, not by user input.
    virtual void didUpdateTextOfFocusedElementByNonUserInput() { }

    // Request the browser to show the IME for current input type.
    virtual void showImeIfNeeded() { }

    // Request that the browser show a UI for an unhandled tap, if needed.
    // Invoked during the handling of a GestureTap input event whenever the
    // event is not consumed.
    // |tappedPosition| is the point where the mouseDown occurred in client
    // coordinates.
    // |tappedNode| is the node that the mouseDown event hit, provided so the
    // UI can be shown only on certain kinds of nodes in specific locations.
    // |pageChanged| is true if and only if the DOM tree or style was
    // modified during the dispatch of the mouse*, or click events associated
    // with the tap.
    // This provides a heuristic to help identify when a page is doing
    // something as a result of a tap without explicitly consuming the event.
    virtual void showUnhandledTapUIIfNeeded(const WebPoint& tappedPosition,
        const WebNode& tappedNode, bool pageChanged) { }

    // Called immediately after a mousedown event is dispatched due to a mouse
    // press or gesture tap.
    // Note: This is called even when the mouse down event is prevent default.
    virtual void onMouseDown(const WebNode& mouseDownNode) { }
protected:
    ~WebWidgetClient() { }
};

} // namespace blink

#endif