ui/views/controls/slider.h

   1 // Copyright (c) 2012 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_SLIDER_H_
   6 #define UI_VIEWS_CONTROLS_SLIDER_H_
   7
   8 #include "ui/gfx/animation/animation_delegate.h"
   9 #include "ui/views/view.h"
  10 #include "ui/views/views_export.h"
  11
  12 typedef unsigned int SkColor;
  13
  14 namespace gfx {
  15 class ImageSkia;
  16 class SlideAnimation;
  17 }
  18
  19 namespace views {
  20
  21 namespace test {
  22 class SliderTestApi;
  23 }
  24
  25 class Slider;
  26
  27 enum SliderChangeReason {
  28   VALUE_CHANGED_BY_USER,  // value was changed by the user (by clicking, e.g.)
  29   VALUE_CHANGED_BY_API,   // value was changed by a call to SetValue.
  30 };
  31
  32 class VIEWS_EXPORT SliderListener {
  33  public:
  34   virtual void SliderValueChanged(Slider* sender,
  35                                   float value,
  36                                   float old_value,
  37                                   SliderChangeReason reason) = 0;
  38
  39   // Invoked when a drag starts or ends (more specifically, when the mouse
  40   // button is pressed or released).
  41   virtual void SliderDragStarted(Slider* sender) {}
  42   virtual void SliderDragEnded(Slider* sender) {}
  43
  44  protected:
  45   virtual ~SliderListener() {}
  46 };
  47
  48 class VIEWS_EXPORT Slider : public View, public gfx::AnimationDelegate {
  49  public:
  50   // Internal class name.
  51   static const char kViewClassName[];
  52
  53   enum Orientation {
  54     HORIZONTAL,
  55     VERTICAL
  56   };
  57
  58   Slider(SliderListener* listener, Orientation orientation);
  59   ~Slider() override;
  60
  61   float value() const { return value_; }
  62   void SetValue(float value);
  63
  64   // Set the delta used for changing the value via keyboard.
  65   void SetKeyboardIncrement(float increment);
  66
  67   void SetAccessibleName(const base::string16& name);
  68
  69   void set_enable_accessibility_events(bool enabled) {
  70     accessibility_events_enabled_ = enabled;
  71   }
  72
  73   void set_focus_border_color(SkColor color) { focus_border_color_ = color; }
  74
  75   // Update UI based on control on/off state.
  76   void UpdateState(bool control_on);
  77
  78  private:
  79   friend class test::SliderTestApi;
  80
  81   void SetValueInternal(float value, SliderChangeReason reason);
  82
  83   // Should be called on the Mouse Down event. Used to calculate relative
  84   // position of the mouse cursor (or the touch point) on the button to
  85   // accurately move the button using the MoveButtonTo() method.
  86   void PrepareForMove(const gfx::Point& point);
  87
  88   // Moves the button to the specified point and updates the value accordingly.
  89   void MoveButtonTo(const gfx::Point& point);
  90
  91   void OnPaintFocus(gfx::Canvas* canvas);
  92
  93   // Notify the listener_, if not NULL, that dragging started.
  94   void OnSliderDragStarted();
  95
  96   // Notify the listener_, if not NULL, that dragging ended.
  97   void OnSliderDragEnded();
  98
  99   // views::View overrides:
 100   const char* GetClassName() const override;
 101   gfx::Size GetPreferredSize() const override;
 102   void OnPaint(gfx::Canvas* canvas) override;
 103   bool OnMousePressed(const ui::MouseEvent& event) override;
 104   bool OnMouseDragged(const ui::MouseEvent& event) override;
 105   void OnMouseReleased(const ui::MouseEvent& event) override;
 106   bool OnKeyPressed(const ui::KeyEvent& event) override;
 107   void GetAccessibleState(ui::AXViewState* state) override;
 108   void OnFocus() override;
 109   void OnBlur() override;
 110
 111   // ui::EventHandler overrides:
 112   void OnGestureEvent(ui::GestureEvent* event) override;
 113
 114   // gfx::AnimationDelegate overrides:
 115   void AnimationProgressed(const gfx::Animation* animation) override;
 116
 117   void set_listener(SliderListener* listener) {
 118     listener_ = listener;
 119   }
 120
 121   SliderListener* listener_;
 122   Orientation orientation_;
 123
 124   scoped_ptr<gfx::SlideAnimation> move_animation_;
 125
 126   float value_;
 127   float keyboard_increment_;
 128   float animating_value_;
 129   bool value_is_valid_;
 130   base::string16 accessible_name_;
 131   bool accessibility_events_enabled_;
 132   SkColor focus_border_color_;
 133
 134   // Relative position of the mouse cursor (or the touch point) on the slider's
 135   // button.
 136   gfx::Point initial_button_offset_;
 137
 138   const int* bar_active_images_;
 139   const int* bar_disabled_images_;
 140   const gfx::ImageSkia* thumb_;
 141   const gfx::ImageSkia* images_[4];
 142   int bar_height_;
 143
 144   DISALLOW_COPY_AND_ASSIGN(Slider);
 145 };
 146
 147 }  // namespace views
 148
 149 #endif  // UI_VIEWS_CONTROLS_SLIDER_H_