It is time.

ui/views/controls/scrollbar/base_scroll_bar.h

-// Copyright (c) 2012 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 UI_VIEWS_CONTROLS_SCROLLBAR_BASE_SCROLL_BAR_H_
-#define UI_VIEWS_CONTROLS_SCROLLBAR_BASE_SCROLL_BAR_H_
-
-#include "base/gtest_prod_util.h"
-#include "ui/views/animation/scroll_animator.h"
-#include "ui/views/context_menu_controller.h"
-#include "ui/views/controls/button/image_button.h"
-#include "ui/views/controls/menu/menu_delegate.h"
-#include "ui/views/controls/scrollbar/scroll_bar.h"
-#include "ui/views/repeat_controller.h"
-
-namespace views {
-
-class BaseScrollBarThumb;
-class MenuRunner;
-
-///////////////////////////////////////////////////////////////////////////////
-//
-// BaseScrollBar
-//
-///////////////////////////////////////////////////////////////////////////////
-class VIEWS_EXPORT BaseScrollBar : public ScrollBar,
-                                   public ScrollDelegate,
-                                   public ContextMenuController,
-                                   public MenuDelegate {
- public:
-  BaseScrollBar(bool horizontal, BaseScrollBarThumb* thumb);
-  virtual ~BaseScrollBar();
-
-  // Get the bounds of the "track" area that the thumb is free to slide within.
-  virtual gfx::Rect GetTrackBounds() const = 0;
-
-  // 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,
-  };
-
-  // Scroll the contents by the specified type (see ScrollAmount above).
-  void ScrollByAmount(ScrollAmount amount);
-
-  // 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).
-  bool ScrollByContentsOffset(int contents_offset);
-
-  // Called when the thumb state has been changed from |old_state| to
-  // |new_state|.
-  void OnThumbStateChanged(CustomButton::ButtonState old_state,
-                           CustomButton::ButtonState new_state);
-
-  // View overrides:
-  virtual gfx::Size GetPreferredSize() const override = 0;
-  virtual void Layout() override = 0;
-  virtual bool OnMousePressed(const ui::MouseEvent& event) override;
-  virtual void OnMouseReleased(const ui::MouseEvent& event) override;
-  virtual void OnMouseCaptureLost() override;
-  virtual void OnMouseEntered(const ui::MouseEvent& event) override;
-  virtual void OnMouseExited(const ui::MouseEvent& event) override;
-  virtual bool OnKeyPressed(const ui::KeyEvent& event) override;
-  virtual bool OnMouseWheel(const ui::MouseWheelEvent& event) override;
-
-  // ui::EventHandler overrides:
-  virtual void OnGestureEvent(ui::GestureEvent* event) override;
-
-  // ScrollBar overrides:
-  virtual void Update(int viewport_size,
-                      int content_size,
-                      int contents_scroll_offset) override;
-  virtual int GetLayoutSize() const override = 0;
-  virtual int GetPosition() const override;
-
-  // ScrollDelegate overrides:
-  virtual bool OnScroll(float dx, float dy) override;
-
-  // ContextMenuController overrides:
-  virtual void ShowContextMenuForView(View* source,
-                                      const gfx::Point& point,
-                                      ui::MenuSourceType source_type) override;
-
-  // Menu::Delegate overrides:
-  virtual base::string16 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 = 0;
-
-  BaseScrollBarThumb* GetThumb() const;
-  CustomButton::ButtonState GetThumbTrackState() const;
-
-  // Wrapper functions that calls the controller. We need this since native
-  // scrollbars wrap around a different scrollbar. When calling the controller
-  // we need to pass in the appropriate scrollbar. For normal scrollbars it's
-  // the |this| scrollbar, for native scrollbars it's the native scrollbar used
-  // to create this.
-  virtual void ScrollToPosition(int position);
-  virtual int GetScrollIncrement(bool is_page, bool is_positive);
-
- private:
-  FRIEND_TEST_ALL_PREFIXES(NativeScrollBarTest, ScrollBarFitsToBottom);
-  int GetThumbSizeForTest();
-
-  // Changes to 'pushed' state and starts a timer to scroll repeatedly.
-  void ProcessPressEvent(const ui::LocatedEvent& event);
-
-  // Sets state to |state| and stops the repeater.
-  void SetState(CustomButton::ButtonState state);
-
-  // 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);
-
-  BaseScrollBarThumb* thumb_;
-
-  // 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_;
-
-  // The current size of the view port, in pixels.
-  int viewport_size_;
-
-  // 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_;
-
-  scoped_ptr<MenuRunner> menu_runner_;
-  scoped_ptr<ScrollAnimator> scroll_animator_;
-
-  // Difference between current position and cumulative deltas obtained from
-  // scroll update events.
-  // TODO(tdresser): This should be removed when raw pixel scrolling for views
-  // is enabled. See crbug.com/329354.
-  gfx::Vector2dF roundoff_error_;
-
-  DISALLOW_COPY_AND_ASSIGN(BaseScrollBar);
-};
-
-}  // namespace views
-
-#endif  // UI_VIEWS_CONTROLS_SCROLLBAR_BASE_SCROLL_BAR_H_