Introduce RenderView::Observer interface so that RenderView doesn't have to k...

chrome/renderer/render_view_observer.h

+// Copyright (c) 2011 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 CHROME_RENDERER_RENDER_VIEW_OBSERVER_H_
+#define CHROME_RENDERER_RENDER_VIEW_OBSERVER_H_
+#pragma once
+
+#include "base/basictypes.h"
+#include "ipc/ipc_channel.h"
+
+class RenderView;
+
+namespace WebKit {
+class WebFrame;
+class WebMouseEvent;
+}
+
+// Base class for objects that want to filter incoming IPCs, and also get
+// notified of changes to the frame.
+class RenderViewObserver : public IPC::Channel::Listener,
+                           public IPC::Message::Sender {
+ public:
+  // By default, observers will be deleted when the RenderView goes away.  If
+  // they want to outlive it, they can override this function.
+  virtual void OnDestruct();
+
+  // These match the WebKit API notifications.
+  virtual void DidFinishDocumentLoad(WebKit::WebFrame* frame) {}
+  virtual void DidFinishLoad(WebKit::WebFrame* frame) {}
+  virtual void FrameDetached(WebKit::WebFrame* frame) {}
+  virtual void FrameWillClose(WebKit::WebFrame* frame) {}
+
+  // These match the RenderView methods below.
+  virtual void FrameTranslated(WebKit::WebFrame* frame) {}
+  virtual void DidHandleMouseEvent(const WebKit::WebMouseEvent& event) {}
+
+ protected:
+  RenderViewObserver(RenderView* render_view);
+  virtual ~RenderViewObserver();
+
+  // IPC::Channel::Listener implementation.
+  virtual bool OnMessageReceived(const IPC::Message& message);
+
+  // IPC::Message::Sender implementation.
+  virtual bool Send(IPC::Message* message);
+
+  RenderView* render_view() { return render_view_; }
+  int routing_id() { return routing_id_; }
+
+ private:
+  friend class RenderView;
+
+  void set_render_view(RenderView* rv) { render_view_ = rv; }
+
+  RenderView* render_view_;
+  // The routing ID of the associated RenderView.
+  int routing_id_;
+
+  DISALLOW_COPY_AND_ASSIGN(RenderViewObserver);
+};
+
+#endif  // CHROME_RENDERER_RENDER_VIEW_OBSERVER_H_