content/browser/renderer_host/render_widget_host_delegate.h

// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_RENDER_WIDGET_HOST_DELEGATE_H_
#define CONTENT_BROWSER_RENDER_WIDGET_HOST_DELEGATE_H_

#include "base/basictypes.h"
#include "build/build_config.h"
#include "content/common/content_export.h"
#include "ui/gfx/native_widget_types.h"

namespace blink {
class WebMouseWheelEvent;
class WebGestureEvent;
}

namespace content {

class BrowserAccessibilityManager;
class RenderWidgetHostImpl;
struct NativeWebKeyboardEvent;

//
// RenderWidgetHostDelegate
//
//  An interface implemented by an object interested in knowing about the state
//  of the RenderWidgetHost.
class CONTENT_EXPORT RenderWidgetHostDelegate {
 public:
  // The RenderWidgetHost is going to be deleted.
  virtual void RenderWidgetDeleted(RenderWidgetHostImpl* render_widget_host) {}

  // Callback to give the browser a chance to handle the specified keyboard
  // event before sending it to the renderer.
  // Returns true if the |event| was handled. Otherwise, if the |event| would
  // be handled in HandleKeyboardEvent() method as a normal keyboard shortcut,
  // |*is_keyboard_shortcut| should be set to true.
  virtual bool PreHandleKeyboardEvent(const NativeWebKeyboardEvent& event,
                                      bool* is_keyboard_shortcut);

  // Callback to inform the browser that the renderer did not process the
  // specified events. This gives an opportunity to the browser to process the
  // event (used for keyboard shortcuts).
  virtual void HandleKeyboardEvent(const NativeWebKeyboardEvent& event) {}

  // Callback to inform the browser that the renderer did not process the
  // specified mouse wheel event.  Returns true if the browser has handled
  // the event itself.
  virtual bool HandleWheelEvent(const blink::WebMouseWheelEvent& event);

  // Callback to give the browser a chance to handle the specified gesture
  // event before sending it to the renderer.
  // Returns true if the |event| was handled.
  virtual bool PreHandleGestureEvent(const blink::WebGestureEvent& event);

  // Callback to inform the browser that the renderer did not process the
  // specified gesture event.  Returns true if the |event| was handled.
  virtual bool HandleGestureEvent(const blink::WebGestureEvent& event);

  // Notifies that screen rects were sent to renderer process.
  virtual void DidSendScreenRects(RenderWidgetHostImpl* rwh) {}

  // Notifies that RenderWidgetHost will toggle touch emulation.
  virtual void OnTouchEmulationEnabled(bool enabled) {}

  // Get the root BrowserAccessibilityManager for this frame tree.
  virtual BrowserAccessibilityManager* GetRootBrowserAccessibilityManager();

  // Get the root BrowserAccessibilityManager for this frame tree,
  // or create it if it doesn't exist.
  virtual BrowserAccessibilityManager*
      GetOrCreateRootBrowserAccessibilityManager();

#if defined(OS_WIN)
  virtual gfx::NativeViewAccessible GetParentNativeViewAccessible();
#endif

 protected:
  virtual ~RenderWidgetHostDelegate() {}
};

}  // namespace content

#endif  // CONTENT_BROWSER_RENDER_WIDGET_HOST_DELEGATE_H_