android: move overscroll effects to ui/

content/browser/android/overscroll_glow.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 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 "content/browser/android/edge_effect_base.h"
-#include "ui/gfx/geometry/size_f.h"
-#include "ui/gfx/geometry/vector2d_f.h"
-
-namespace cc {
-class Layer;
-}
-
-namespace content {
-
-// 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:
-  // |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.
-  // |overscroll_location| is the coordinate of the causal overscrolling event.
-  // Returns true if the effect still needs animation ticks.
-  bool OnOverscrolled(base::TimeTicks current_time,
-                      const gfx::Vector2dF& accumulated_overscroll,
-                      gfx::Vector2dF overscroll_delta,
-                      gfx::Vector2dF velocity,
-                      const 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 OnFrameUpdated(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;
-
-  // The maximum alpha value (in the range [0,1]) of any animated edge layers.
-  // If the effect is inactive, this will be 0.
-  float GetVisibleAlpha() const;
-
- private:
-  enum Axis { AXIS_X, AXIS_Y };
-  enum { EDGE_COUNT = EdgeEffectBase::EDGE_COUNT };
-
-  // 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_;
-  bool allow_horizontal_overscroll_;
-  bool allow_vertical_overscroll_;
-
-  scoped_refptr<cc::Layer> root_layer_;
-
-  DISALLOW_COPY_AND_ASSIGN(OverscrollGlow);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_ANDROID_OVERSCROLL_GLOW_H_