views: Moves TextfieldController/TextRange into their own headers.

views/controls/textfield/textfield_controller.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_CONTROLS_TEXTFIELD_TEXTFIELD_CONTROLLER_H_
+#define VIEWS_CONTROLS_TEXTFIELD_TEXTFIELD_CONTROLLER_H_
+#pragma once
+
+#include "base/string16.h"
+
+namespace views {
+
+class KeyEvent;
+class Textfield;
+
+// This defines the callback interface for other code to be notified of changes
+// in the state of a text field.
+class TextfieldController {
+ public:
+  // This method is called whenever the text in the field changes.
+  virtual void ContentsChanged(Textfield* sender,
+                               const string16& new_contents) = 0;
+
+  // This method is called to get notified about keystrokes in the edit.
+  // Returns true if the message was handled and should not be processed
+  // further. If it returns false the processing continues.
+  virtual bool HandleKeyEvent(Textfield* sender,
+                              const KeyEvent& key_event) = 0;
+};
+
+}  // namespace views
+
+#endif  // VIEWS_CONTROLS_TEXTFIELD_TEXTFIELD_CONTROLLER_H_