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   enum Orientation {
  51     HORIZONTAL,
  52     VERTICAL
  53   };
  54
  55   Slider(SliderListener* listener, Orientation orientation);
  56   virtual ~Slider();
  57
  58   float value() const { return value_; }
  59   void SetValue(float value);
  60
  61   // Set the delta used for changing the value via keyboard.
  62   void SetKeyboardIncrement(float increment);
  63
  64   void SetAccessibleName(const base::string16& name);
  65
  66   void set_enable_accessibility_events(bool enabled) {
  67     accessibility_events_enabled_ = enabled;
  68   }
  69
  70   void set_focus_border_color(SkColor color) { focus_border_color_ = color; }
  71
  72   // Update UI based on control on/off state.
  73   void UpdateState(bool control_on);
  74
  75  private:
  76   friend class test::SliderTestApi;
  77
  78   void SetValueInternal(float value, SliderChangeReason reason);
  79
  80   // Should be called on the Mouse Down event. Used to calculate relative
  81   // position of the mouse cursor (or the touch point) on the button to
  82   // accurately move the button using the MoveButtonTo() method.
  83   void PrepareForMove(const gfx::Point& point);
  84
  85   // Moves the button to the specified point and updates the value accordingly.
  86   void MoveButtonTo(const gfx::Point& point);
  87
  88   void OnPaintFocus(gfx::Canvas* canvas);
  89
  90   // Notify the listener_, if not NULL, that dragging started.
  91   void OnSliderDragStarted();
  92
  93   // Notify the listener_, if not NULL, that dragging ended.
  94   void OnSliderDragEnded();
  95
  96   // views::View overrides:
  97   virtual gfx::Size GetPreferredSize() const OVERRIDE;
  98   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
  99   virtual bool OnMousePressed(const ui::MouseEvent& event) OVERRIDE;
 100   virtual bool OnMouseDragged(const ui::MouseEvent& event) OVERRIDE;
 101   virtual void OnMouseReleased(const ui::MouseEvent& event) OVERRIDE;
 102   virtual bool OnKeyPressed(const ui::KeyEvent& event) OVERRIDE;
 103   virtual void GetAccessibleState(ui::AXViewState* state) OVERRIDE;
 104   virtual void OnFocus() OVERRIDE;
 105   virtual void OnBlur() OVERRIDE;
 106
 107   // ui::EventHandler overrides:
 108   virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE;
 109
 110   // gfx::AnimationDelegate overrides:
 111   virtual void AnimationProgressed(const gfx::Animation* animation) OVERRIDE;
 112
 113   void set_listener(SliderListener* listener) {
 114     listener_ = listener;
 115   }
 116
 117   SliderListener* listener_;
 118   Orientation orientation_;
 119
 120   scoped_ptr<gfx::SlideAnimation> move_animation_;
 121
 122   float value_;
 123   float keyboard_increment_;
 124   float animating_value_;
 125   bool value_is_valid_;
 126   base::string16 accessible_name_;
 127   bool accessibility_events_enabled_;
 128   SkColor focus_border_color_;
 129
 130   // Relative position of the mouse cursor (or the touch point) on the slider's
 131   // button.
 132   gfx::Point initial_button_offset_;
 133
 134   const int* bar_active_images_;
 135   const int* bar_disabled_images_;
 136   const gfx::ImageSkia* thumb_;
 137   const gfx::ImageSkia* images_[4];
 138   int bar_height_;
 139
 140   DISALLOW_COPY_AND_ASSIGN(Slider);
 141 };
 142
 143 }  // namespace views
 144
 145 #endif  // UI_VIEWS_CONTROLS_SLIDER_H_