content/browser/web_contents/aura/overscroll_window_animation.h

   1 // Copyright 2015 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 CONTENT_BROWSER_WEB_CONTENTS_AURA_OVERSCROLL_WINDOW_ANIMATION_H_
   6 #define CONTENT_BROWSER_WEB_CONTENTS_AURA_OVERSCROLL_WINDOW_ANIMATION_H_
   7
   8 #include "base/gtest_prod_util.h"
   9 #include "content/browser/renderer_host/overscroll_controller_delegate.h"
  10 #include "content/common/content_export.h"
  11 #include "ui/compositor/layer_animation_observer.h"
  12
  13 namespace aura {
  14 class Window;
  15 }
  16
  17 namespace ui {
  18 class Layer;
  19 class LayerAnimator;
  20 }
  21
  22 namespace content {
  23
  24 class ShadowLayerDelegate;
  25 class WebContentsImpl;
  26
  27 // Manages the animation of a window sliding on top or behind another one. The
  28 // main window, which is the one displayed before the animation starts, is not
  29 // owned by OverscrollWindowAnimation, while the slide window, created at the
  30 // start of the animation, is owned by us for its duration.
  31 class CONTENT_EXPORT OverscrollWindowAnimation
  32     : public OverscrollControllerDelegate,
  33       ui::ImplicitAnimationObserver {
  34  public:
  35   // The direction of this animation. SLIDE_FRONT indicates that the slide
  36   // window moves on top of the main window, entering the screen from the right.
  37   // SLIDE_BACK means that the main window is animated to the right, revealing
  38   // the slide window in the back. SLIDE_NONE means we are not animating yet.
  39   // Both windows are animated at the same time but at different speeds,
  40   // creating a parallax scrolling effect. Left and right are reversed for RTL
  41   // languages, but stack order remains unchanged.
  42   enum Direction { SLIDE_FRONT, SLIDE_BACK, SLIDE_NONE };
  43
  44   // Delegate class that interfaces with the window animation.
  45   class CONTENT_EXPORT Delegate {
  46    public:
  47     virtual ~Delegate() {}
  48
  49     // Create a slide window with the given |bounds| relative to its parent.
  50     virtual scoped_ptr<aura::Window> CreateFrontWindow(
  51         const gfx::Rect& bounds) = 0;
  52     virtual scoped_ptr<aura::Window> CreateBackWindow(
  53         const gfx::Rect& bounds) = 0;
  54
  55     // Returns the main window that participates in the animation. The delegate
  56     // does not own this window.
  57     virtual aura::Window* GetMainWindow() const = 0;
  58
  59     // Called when we know the animation is going to complete successfully, but
  60     // before it actually completes.
  61     virtual void OnOverscrollCompleting() = 0;
  62
  63     // Called when the animation has been completed. The slide window is
  64     // transferred to the delegate.
  65     virtual void OnOverscrollCompleted(scoped_ptr<aura::Window> window) = 0;
  66
  67     // Called when the overscroll gesture has been cancelled, after the cancel
  68     // animation finishes.
  69     virtual void OnOverscrollCancelled() = 0;
  70   };
  71
  72   explicit OverscrollWindowAnimation(Delegate* delegate);
  73
  74   ~OverscrollWindowAnimation() override;
  75
  76   // Returns true if we are currently animating.
  77   bool is_active() const { return !!slide_window_; }
  78
  79   // OverscrollControllerDelegate:
  80   gfx::Rect GetVisibleBounds() const override;
  81   bool OnOverscrollUpdate(float delta_x, float delta_y) override;
  82   void OnOverscrollComplete(OverscrollMode overscroll_mode) override;
  83   void OnOverscrollModeChange(OverscrollMode old_mode,
  84                               OverscrollMode new_mode) override;
  85
  86  private:
  87   // Cancels the slide, animating the front and back window to their original
  88   // positions.
  89   void CancelSlide();
  90
  91   // Returns a translation on the x axis for the given overscroll.
  92   float GetTranslationForOverscroll(float delta_x);
  93
  94   // Animates a translation of the given |layer|. If |listen_for_completion| is
  95   // true, adds |this| as observer of the animation.
  96   void AnimateTranslation(ui::Layer* layer,
  97                           float translate_x,
  98                           bool listen_for_completion);
  99
 100   // Return the front/back layer that is involved in the animation. The caller
 101   // does not own it.
 102   ui::Layer* GetFrontLayer() const;
 103   ui::Layer* GetBackLayer() const;
 104
 105   // ui::ImplicitAnimationObserver:
 106   void OnImplicitAnimationsCompleted() override;
 107
 108   // We own the window created for the animation.
 109   scoped_ptr<aura::Window> slide_window_;
 110
 111   // Shadow shown under the animated layer.
 112   scoped_ptr<ShadowLayerDelegate> shadow_;
 113
 114   // Delegate that provides the animation target and is notified of the
 115   // animation state.
 116   Delegate* delegate_;
 117
 118   // The current animation direction.
 119   Direction direction_;
 120
 121   // Indicates if the current slide has been cancelled. True while the cancel
 122   // animation is in progress.
 123   bool overscroll_cancelled_;
 124
 125   DISALLOW_COPY_AND_ASSIGN(OverscrollWindowAnimation);
 126 };
 127
 128 }  // namespace content
 129
 130 #endif  // CONTENT_BROWSER_WEB_CONTENTS_AURA_OVERSCROLL_WINDOW_ANIMATION_H_