ui/views/controls/scrollbar/native_scroll_bar_wrapper.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef UI_VIEWS_CONTROLS_SCROLLBAR_NATIVE_SCROLL_BAR_WRAPPER_H_
   6 #define UI_VIEWS_CONTROLS_SCROLLBAR_NATIVE_SCROLL_BAR_WRAPPER_H_
   7
   8 #include "ui/views/views_export.h"
   9
  10 namespace ui {
  11 class NativeTheme;
  12 }
  13
  14 namespace views {
  15
  16 class NativeScrollBar;
  17 class View;
  18
  19 // A specialization of NativeControlWrapper that hosts a platform-native
  20 // scroll bar.
  21 class VIEWS_EXPORT NativeScrollBarWrapper {
  22  public:
  23   virtual ~NativeScrollBarWrapper() {}
  24
  25   // Updates the scroll bar appearance given a viewport size, content size and
  26   // current position.
  27   virtual void Update(int viewport_size, int content_size, int current_pos) = 0;
  28
  29   // Retrieves the views::View that hosts the native control.
  30   virtual View* GetView() = 0;
  31
  32   // Returns the position of the scrollbar.
  33   virtual int GetPosition() const = 0;
  34
  35   // Creates an appropriate NativeScrollBarWrapper for the platform.
  36   static NativeScrollBarWrapper* CreateWrapper(NativeScrollBar* button);
  37
  38   // Returns the system sizes of vertical/horizontal scroll bars.
  39   static int GetVerticalScrollBarWidth(const ui::NativeTheme* theme);
  40   static int GetHorizontalScrollBarHeight(const ui::NativeTheme* theme);
  41 };
  42
  43 }  // namespace views
  44
  45 #endif  // UI_VIEWS_CONTROLS_SCROLLBAR_NATIVE_SCROLL_BAR_WRAPPER_H_