Use input method to control visibility of virtual keyboard

views/ime/input_method.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 VIEWS_IME_INPUT_METHOD_H_
 #define VIEWS_IME_INPUT_METHOD_H_
 #pragma once
 
 #include <string>
+#include <vector>
 
 #include "base/basictypes.h"
 #include "base/i18n/rtl.h"
 #include "ui/base/ime/text_input_type.h"
 
 namespace views {
 
 namespace internal {
 class InputMethodDelegate;
 }  // namespace internal
 
 class KeyEvent;
 class TextInputClient;
 class View;
 class Widget;
 
+class TextInputTypeChangedListener {
+ public:
+  virtual void TextInputTypeChanged(View* view, ui::TextInputType type) = 0;
+
+ protected:
+  virtual ~TextInputTypeChangedListener() {}
+};
+
 // An interface implemented by an object that encapsulates a native input method
 // service provided by the underlying operation system.
 // Because on most systems, the system input method service is bound to
 // individual native window. On Windows, its HWND, on Linux/Gtk, its GdkWindow.
 // And in Views control system, only the top-level NativeWidget has a native
 // window that can get keyboard focus. So this API is designed to be bound to
 // the top-level NativeWidget.
 class InputMethod {
  public:
   virtual ~InputMethod() {}
@@ skipping 58 matching lines @@
 
   // Gets the focused text input client. Returns NULL if the Widget is not
   // focused, or there is no focused View or the focused View doesn't support
   // text input.
   virtual TextInputClient* GetTextInputClient() const = 0;
 
   // Gets the text input type of the focused text input client. Returns
   // ui::TEXT_INPUT_TYPE_NONE if there is no focused text input client.
   virtual ui::TextInputType GetTextInputType() const = 0;
 
+  // Adds/Removes text input type changed listener
+  void AddTextInputTypeChangedListener(TextInputTypeChangedListener* listener);
+
+  void RemoveTextInputTypeChangedListener(
+      TextInputTypeChangedListener* listener);
+
+ protected:
+  // Notifies all listeners that the text input type is changed.
+  void TextInputTypeChanged(View* view);
+
+ private:
+  // The list of registered TextInputTypeChanged listeners.
+  typedef std::vector<TextInputTypeChangedListener*>
+      TextInputTypeChangedListenerList;
+  TextInputTypeChangedListenerList text_input_type_changed_listeners_;
+
   // TODO(suzhe): Support mouse/touch event.
 };
 
 }  // namespace views
 
 #endif  // VIEWS_IME_INPUT_METHOD_H_