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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 CONTENT_BROWSER_ANDROID_OVERSCROLL_GLOW_H_
#define CONTENT_BROWSER_ANDROID_OVERSCROLL_GLOW_H_
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "base/time/time.h"
#include "ui/gfx/geometry/size_f.h"
#include "ui/gfx/geometry/vector2d_f.h"
namespace cc {
class Layer;
}
namespace content {
class EdgeEffectBase;
// Provides lazy, customized EdgeEffect creation.
class OverscrollGlowClient {
public:
virtual ~OverscrollGlowClient() {}
// Called lazily, after the initial overscrolling event.
virtual scoped_ptr<EdgeEffectBase> CreateEdgeEffect() = 0;
};
/* |OverscrollGlow| mirrors its Android counterpart, OverscrollGlow.java.
* Conscious tradeoffs were made to align this as closely as possible with the
* original Android Java version.
*/
class OverscrollGlow {
public:
enum Edge { EDGE_TOP = 0, EDGE_LEFT, EDGE_BOTTOM, EDGE_RIGHT, EDGE_COUNT };
// |client| must be valid for the duration of the effect's lifetime.
// The effect is enabled by default, but will remain dormant until the first
// overscroll event.
explicit OverscrollGlow(OverscrollGlowClient* client);
~OverscrollGlow();
// Called when the root content layer overscrolls.
// |accumulated_overscroll| and |overscroll_delta| are in device pixels, while
// |velocity| is in device pixels / second.
// Returns true if the effect still needs animation ticks.
bool OnOverscrolled(base::TimeTicks current_time,
gfx::Vector2dF accumulated_overscroll,
gfx::Vector2dF overscroll_delta,
gfx::Vector2dF velocity,
gfx::Vector2dF overscroll_location);
// Returns true if the effect still needs animation ticks, with effect layers
// attached to |parent_layer| if necessary.
// Note: The effect will detach itself when no further animation is required.
bool Animate(base::TimeTicks current_time, cc::Layer* parent_layer);
// Update the effect according to the most recent display parameters,
// Note: All dimensions are in device pixels.
void UpdateDisplay(const gfx::SizeF& viewport_size,
const gfx::SizeF& content_size,
const gfx::Vector2dF& content_scroll_offset);
// Reset the effect to its inactive state, clearing any active effects.
void Reset();
// Whether the effect is active, either being pulled or receding.
bool IsActive() const;
private:
enum Axis { AXIS_X, AXIS_Y };
// Returns whether the effect has been properly initialized.
bool InitializeIfNecessary();
bool CheckNeedsAnimate();
void UpdateLayerAttachment(cc::Layer* parent);
void Detach();
void Pull(base::TimeTicks current_time,
const gfx::Vector2dF& overscroll_delta,
const gfx::Vector2dF& overscroll_location);
void Absorb(base::TimeTicks current_time,
const gfx::Vector2dF& velocity,
bool x_overscroll_started,
bool y_overscroll_started);
void Release(base::TimeTicks current_time);
EdgeEffectBase* GetOppositeEdge(int edge_index);
OverscrollGlowClient* const client_;
scoped_ptr<EdgeEffectBase> edge_effects_[EDGE_COUNT];
gfx::SizeF viewport_size_;
float edge_offsets_[EDGE_COUNT];
bool initialized_;
scoped_refptr<cc::Layer> root_layer_;
DISALLOW_COPY_AND_ASSIGN(OverscrollGlow);
};
} // namespace content
#endif // CONTENT_BROWSER_ANDROID_SCROLL_GLOW_H_
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