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// 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_SLIDER_H_
#define UI_VIEWS_CONTROLS_SLIDER_H_
#include "base/macros.h"
#include "ui/gfx/animation/animation_delegate.h"
#include "ui/gfx/animation/slide_animation.h"
#include "ui/views/view.h"
#include "ui/views/views_export.h"
typedef unsigned int SkColor;
namespace views {
namespace test {
class SliderTestApi;
}
class Slider;
enum SliderChangeReason {
VALUE_CHANGED_BY_USER, // value was changed by the user (by clicking, e.g.)
VALUE_CHANGED_BY_API, // value was changed by a call to SetValue.
};
class VIEWS_EXPORT SliderListener {
public:
virtual void SliderValueChanged(Slider* sender,
float value,
float old_value,
SliderChangeReason reason) = 0;
// Invoked when a drag starts or ends (more specifically, when the mouse
// button is pressed or released).
virtual void SliderDragStarted(Slider* sender) {}
virtual void SliderDragEnded(Slider* sender) {}
protected:
virtual ~SliderListener() {}
};
class VIEWS_EXPORT Slider : public View, public gfx::AnimationDelegate {
public:
// Internal class name.
static const char kViewClassName[];
explicit Slider(SliderListener* listener);
~Slider() override;
float value() const { return value_; }
void SetValue(float value);
void set_enable_accessibility_events(bool enabled) {
accessibility_events_enabled_ = enabled;
}
// Update UI based on control on/off state.
void UpdateState(bool control_on);
protected:
// Returns the current position of the thumb on the slider.
float GetAnimatingValue() const;
// Shows or hides the highlight on the slider thumb. The default
// implementation does nothing.
void SetHighlighted(bool is_highlighted);
// gfx::AnimationDelegate:
void AnimationProgressed(const gfx::Animation* animation) override;
void AnimationEnded(const gfx::Animation* animation) override;
private:
friend class test::SliderTestApi;
void SetValueInternal(float value, SliderChangeReason reason);
// Should be called on the Mouse Down event. Used to calculate relative
// position of the mouse cursor (or the touch point) on the button to
// accurately move the button using the MoveButtonTo() method.
void PrepareForMove(const int new_x);
// Moves the button to the specified point and updates the value accordingly.
void MoveButtonTo(const gfx::Point& point);
// Notify the listener_, if not NULL, that dragging started.
void OnSliderDragStarted();
// Notify the listener_, if not NULL, that dragging ended.
void OnSliderDragEnded();
// views::View:
const char* GetClassName() const override;
gfx::Size CalculatePreferredSize() const override;
bool OnMousePressed(const ui::MouseEvent& event) override;
bool OnMouseDragged(const ui::MouseEvent& event) override;
void OnMouseReleased(const ui::MouseEvent& event) override;
bool OnKeyPressed(const ui::KeyEvent& event) override;
void GetAccessibleNodeData(ui::AXNodeData* node_data) override;
void OnPaint(gfx::Canvas* canvas) override;
void OnFocus() override;
void OnBlur() override;
void VisibilityChanged(View* starting_from, bool is_visible) override;
void AddedToWidget() override;
// ui::EventHandler:
void OnGestureEvent(ui::GestureEvent* event) override;
void set_listener(SliderListener* listener) {
listener_ = listener;
}
void NotifyPendingAccessibilityValueChanged();
SliderListener* listener_;
std::unique_ptr<gfx::SlideAnimation> move_animation_;
float value_ = 0.f;
float keyboard_increment_ = 0.1f;
float initial_animating_value_ = 0.f;
bool value_is_valid_ = false;
bool accessibility_events_enabled_ = true;
// Relative position of the mouse cursor (or the touch point) on the slider's
// button.
int initial_button_offset_ = 0;
// Record whether the slider is in the active state or the disabled state.
bool is_active_ = true;
// Animating value of the current radius of the thumb's highlight.
float thumb_highlight_radius_ = 0.f;
gfx::SlideAnimation highlight_animation_;
bool pending_accessibility_value_change_;
DISALLOW_COPY_AND_ASSIGN(Slider);
};
} // namespace views
#endif // UI_VIEWS_CONTROLS_SLIDER_H_
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