Make Combobox portable

views/controls/combobox/combobox.h

+// Copyright (c) 2006-2008 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_COMBOBOX_COMBOBOX_H_
+#define VIEWS_CONTROLS_COMBOBOX_COMBOBOX_H_
+
+#include "views/view.h"
+
+namespace views {
+
+class NativeComboboxWrapper;
+
+// A non-editable combo-box.
+class Combobox : public View {
+ public:
+  // The combobox's class name.
+  static const char kViewClassName[];
+
+  class Model {
+   public:
+    // Return the number of items in the combo box.
+    virtual int GetItemCount(Combobox* source) = 0;
+
+    // Return the string that should be used to represent a given item.
+    virtual std::wstring GetItemAt(Combobox* source, int index) = 0;
+  };
+
+  class Listener {
+   public:
+    // This is invoked once the selected item changed.
+    virtual void ItemChanged(Combobox* combo_box,
+                             int prev_index,
+                             int new_index) = 0;
+  };
+
+  // |model| is not owned by the combo box.
+  explicit Combobox(Model* model);
+  virtual ~Combobox();
+
+  // Register |listener| for item change events.
+  void set_listener(Listener* listener) {
+    listener_ = listener;
+  }
+
+  // Inform the combo box that its model changed.
+  void ModelChanged();
+
+  // Gets/Sets the selected item.
+  int selected_item() const { return selected_item_; };
+  void SetSelectedItem(int index);
+
+  // Called when the combo box's selection is changed by the user.
+  void SelectionChanged();
+
+  // Accessor for |model_|.
+  Model* model() const { return model_; }
+
+  // Overridden from View:
+  virtual gfx::Size GetPreferredSize();
+  virtual void Layout();
+  virtual void SetEnabled(bool enabled);
+  virtual bool OverrideAccelerator(const Accelerator& accelerator);
+
+ protected:
+  virtual void Focus();
+  virtual void ViewHierarchyChanged(bool is_add, View* parent,
+                                    View* child);
+  virtual std::string GetClassName() const;
+   
+ private:
+  // The object that actually implements the native combobox.
+  NativeComboboxWrapper* native_wrapper_;
+
+  // Our model.
+  Model* model_;
+
+  // Item change listener.
+  Listener* listener_;
+
+  // The current selection.
+  int selected_item_;
+
+  DISALLOW_COPY_AND_ASSIGN(Combobox);
+};
+
+}  // namespace views
+
+#endif  // VIEWS_CONTROLS_COMBOBOX_COMBOBOX_H_