[Mac] Implement the system dictionary popup by implementing NSTextInput methods.

chrome/renderer/text_input_client_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_TEXT_INPUT_CLIENT_OBSERVER_H_
+#define CHROME_RENDERER_TEXT_INPUT_CLIENT_OBSERVER_H_
+
+#include "base/basictypes.h"
+#include "build/build_config.h"
+#include "chrome/renderer/render_view_observer.h"
+#include "ui/gfx/point.h"
+
+namespace WebKit {
+class WebView;
+}
+
+// This is the renderer-side message filter that generates the replies for the
+// messages sent by the TextInputClientMac. See
+// chrome/browser/renderer_host/text_input_client_mac.h for more information.
+class TextInputClientObserver : public RenderViewObserver {
+ public:
+  explicit TextInputClientObserver(RenderView* render_view);
+  virtual ~TextInputClientObserver();
+
+  // RenderViewObserver overrides:
+  bool OnMessageReceived(const IPC::Message& message);
+
+ private:
+  // Returns the WebView of the RenderView.
+  WebKit::WebView* webview();
+
+  // IPC Message handlers:
+  void OnCharacterIndexForPoint(gfx::Point point);
+  void OnFirstRectForCharacterRange(uint location, uint length);
+  void OnStringForRange(uint location, uint length);
+
+  DISALLOW_COPY_AND_ASSIGN(TextInputClientObserver);
+};
+
+#endif  // CHROME_RENDERER_TEXT_INPUT_CLIENT_OBSERVER_H_