Revert 98434 - Adding a Views scrollbar implementation.

views/controls/scrollbar/bitmap_scroll_bar.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_SCROLLBAR_BITMAP_SCROLL_BAR_H_
 #define VIEWS_CONTROLS_SCROLLBAR_BITMAP_SCROLL_BAR_H_
 #pragma once
 
-#include "views/controls/scrollbar/base_scroll_bar.h"
+#include "views/context_menu_controller.h"
+#include "views/controls/button/image_button.h"
+#include "views/controls/menu/menu.h"
+#include "views/controls/scrollbar/scroll_bar.h"
+#include "views/repeat_controller.h"
 
 namespace views {
 
 namespace {
 class BitmapScrollBarThumb;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 //
 // BitmapScrollBar
 //
 //  A ScrollBar subclass that implements a scroll bar rendered using bitmaps
 //  that the user provides. There are bitmaps for the up and down buttons, as
 //  well as for the thumb and track. This is intended for creating UIs that
 //  have customized, non-native appearances, like floating HUDs etc.
 //
+//  Maybe TODO(beng): (Cleanup) If we need to, we may want to factor rendering
+//                    out of this altogether and have the user supply
+//                    Background impls for each component, and just use those
+//                    to render, so that for example we get native theme
+//                    rendering.
+//
 ///////////////////////////////////////////////////////////////////////////////
-class VIEWS_EXPORT BitmapScrollBar : public BaseScrollBar,
-                                     public ButtonListener {
+class BitmapScrollBar : public ScrollBar,
+                        public ButtonListener,
+                        public ContextMenuController,
+                        public Menu::Delegate {
  public:
   BitmapScrollBar(bool horizontal, bool show_scroll_buttons);
   virtual ~BitmapScrollBar() { }
 
+  // Get the bounds of the "track" area that the thumb is free to slide within.
+  gfx::Rect GetTrackBounds() const;
+
   // A list of parts that the user may supply bitmaps for.
   enum ScrollBarPart {
     // The button used to represent scrolling up/left by 1 line.
     PREV_BUTTON = 0,
     // The button used to represent scrolling down/right by 1 line.
     // IMPORTANT: The code assumes the prev and next
     // buttons have equal width and equal height.
     NEXT_BUTTON,
     // The top/left segment of the thumb on the scrollbar.
     THUMB_START_CAP,
     // The tiled background image of the thumb.
     THUMB_MIDDLE,
     // The bottom/right segment of the thumb on the scrollbar.
     THUMB_END_CAP,
     // The grippy that is rendered in the center of the thumb.
     THUMB_GRIPPY,
     // The tiled background image of the thumb track.
     THUMB_TRACK,
     PART_COUNT
   };
 
   // Sets the bitmap to be rendered for the specified part and state.
   void SetImage(ScrollBarPart part,
                 CustomButton::ButtonState state,
                 SkBitmap* bitmap);
 
+  // An enumeration of different amounts of incremental scroll, representing
+  // events sent from different parts of the UI/keyboard.
+  enum ScrollAmount {
+    SCROLL_NONE = 0,
+    SCROLL_START,
+    SCROLL_END,
+    SCROLL_PREV_LINE,
+    SCROLL_NEXT_LINE,
+    SCROLL_PREV_PAGE,
+    SCROLL_NEXT_PAGE,
+  };
 
-  gfx::Rect GetTrackBounds() const;
+  // Scroll the contents by the specified type (see ScrollAmount above).
+  void ScrollByAmount(ScrollAmount amount);
 
- protected:
+  // Scroll the contents to the appropriate position given the supplied
+  // position of the thumb (thumb track coordinates). If |scroll_to_middle| is
+  // true, then the conversion assumes |thumb_position| is in the middle of the
+  // thumb rather than the top.
+  void ScrollToThumbPosition(int thumb_position, bool scroll_to_middle);
+
+  // Scroll the contents by the specified offset (contents coordinates).
+  void ScrollByContentsOffset(int contents_offset);
+
   // View overrides:
   virtual gfx::Size GetPreferredSize() OVERRIDE;
   virtual void Layout() OVERRIDE;
-  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
-
-  // ScrollBar overrides:
-  virtual int GetLayoutSize() const OVERRIDE;
+  virtual bool OnMousePressed(const MouseEvent& event) OVERRIDE;
+  virtual void OnMouseReleased(const MouseEvent& event) OVERRIDE;
+  virtual void OnMouseCaptureLost() OVERRIDE;
+  virtual bool OnKeyPressed(const KeyEvent& event) OVERRIDE;
+  virtual bool OnMouseWheel(const MouseWheelEvent& event) OVERRIDE;
 
   // BaseButton::ButtonListener overrides:
   virtual void ButtonPressed(Button* sender,
                              const views::Event& event) OVERRIDE;
 
+  // ScrollBar overrides:
+  virtual void Update(int viewport_size,
+                      int content_size,
+                      int contents_scroll_offset) OVERRIDE;
+  virtual int GetLayoutSize() const OVERRIDE;
+  virtual int GetPosition() const OVERRIDE;
+
+  // ContextMenuController overrides.
+  virtual void ShowContextMenuForView(View* source,
+                                      const gfx::Point& p,
+                                      bool is_mouse_gesture) OVERRIDE;
+
+  // Menu::Delegate overrides:
+  virtual std::wstring GetLabel(int id) const OVERRIDE;
+  virtual bool IsCommandEnabled(int id) const OVERRIDE;
+  virtual void ExecuteCommand(int id) OVERRIDE;
+
+ protected:
+  // View overrides:
+  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
+
  private:
-  // Up/Down/Left/Right buttons.
-  ImageButton* prev_button_;
-  ImageButton* next_button_;
+  // Called when the mouse is pressed down in the track area.
+  void TrackClicked();
+
+  // Responsible for scrolling the contents and also updating the UI to the
+  // current value of the Scroll Offset.
+  void ScrollContentsToOffset();
+
+  // Returns the size (width or height) of the track area of the ScrollBar.
+  int GetTrackSize() const;
+
+  // Calculate the position of the thumb within the track based on the
+  // specified scroll offset of the contents.
+  int CalculateThumbPosition(int contents_scroll_offset) const;
+
+  // Calculates the current value of the contents offset (contents coordinates)
+  // based on the current thumb position (thumb track coordinates). See
+  // |ScrollToThumbPosition| for an explanation of |scroll_to_middle|.
+  int CalculateContentsOffset(int thumb_position,
+                              bool scroll_to_middle) const;
+
+  // Called when the state of the thumb track changes (e.g. by the user
+  // pressing the mouse button down in it).
+  void SetThumbTrackState(CustomButton::ButtonState state);
 
   // The thumb needs to be able to access the part images.
   friend BitmapScrollBarThumb;
   SkBitmap* images_[PART_COUNT][CustomButton::BS_COUNT];
 
+  // The size of the scrolled contents, in pixels.
+  int contents_size_;
+
+  // The current amount the contents is offset by in the viewport.
+  int contents_scroll_offset_;
+
+  // Up/Down/Left/Right buttons and the Thumb.
+  ImageButton* prev_button_;
+  ImageButton* next_button_;
+  BitmapScrollBarThumb* thumb_;
+
+  // The state of the scrollbar track. Typically, the track will highlight when
+  // the user presses the mouse on them (during page scrolling).
+  CustomButton::ButtonState thumb_track_state_;
+
+  // The last amount of incremental scroll that this scrollbar performed. This
+  // is accessed by the callbacks for the auto-repeat up/down buttons to know
+  // what direction to repeatedly scroll in.
+  ScrollAmount last_scroll_amount_;
+
+  // An instance of a RepeatController which scrolls the scrollbar continuously
+  // as the user presses the mouse button down on the up/down buttons or the
+  // track.
+  RepeatController repeater_;
+
+  // The position of the mouse within the scroll bar when the context menu
+  // was invoked.
+  int context_menu_mouse_position_;
+
   // True if the scroll buttons at each end of the scroll bar should be shown.
   bool show_scroll_buttons_;
 
   DISALLOW_COPY_AND_ASSIGN(BitmapScrollBar);
 };
 
 }  // namespace views
 
 #endif  // VIEWS_CONTROLS_SCROLLBAR_BITMAP_SCROLL_BAR_H_