cc/input/top_controls_manager.h

   1 // Copyright 2013 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 CC_INPUT_TOP_CONTROLS_MANAGER_H_
   6 #define CC_INPUT_TOP_CONTROLS_MANAGER_H_
   7
   8 #include "base/memory/scoped_ptr.h"
   9 #include "base/memory/weak_ptr.h"
  10 #include "cc/input/top_controls_state.h"
  11 #include "cc/layers/layer_impl.h"
  12 #include "ui/gfx/size.h"
  13 #include "ui/gfx/vector2d_f.h"
  14
  15 namespace base {
  16 class TimeTicks;
  17 }
  18
  19 namespace cc {
  20
  21 class KeyframedFloatAnimationCurve;
  22 class LayerTreeImpl;
  23 class TopControlsManagerClient;
  24
  25 // Manages the position of the top controls.
  26 class CC_EXPORT TopControlsManager
  27     : public base::SupportsWeakPtr<TopControlsManager> {
  28  public:
  29   enum AnimationDirection {
  30     NO_ANIMATION,
  31     SHOWING_CONTROLS,
  32     HIDING_CONTROLS
  33   };
  34
  35   static scoped_ptr<TopControlsManager> Create(
  36       TopControlsManagerClient* client,
  37       float top_controls_height,
  38       float top_controls_show_threshold,
  39       float top_controls_hide_threshold);
  40   virtual ~TopControlsManager();
  41
  42   float controls_top_offset() { return controls_top_offset_; }
  43   float content_top_offset() {
  44     return controls_top_offset_ + top_controls_height_;
  45   }
  46   KeyframedFloatAnimationCurve* animation() {
  47     return top_controls_animation_.get();
  48   }
  49   AnimationDirection animation_direction() { return animation_direction_; }
  50
  51   void UpdateTopControlsState(TopControlsState constraints,
  52                               TopControlsState current,
  53                               bool animate);
  54
  55   void ScrollBegin();
  56   gfx::Vector2dF ScrollBy(const gfx::Vector2dF pending_delta);
  57   void ScrollEnd();
  58
  59   gfx::Vector2dF Animate(base::TimeTicks monotonic_time);
  60
  61  protected:
  62   TopControlsManager(TopControlsManagerClient* client,
  63                      float top_controls_height,
  64                      float top_controls_show_threshold,
  65                      float top_controls_hide_threshold);
  66
  67  private:
  68   void SetControlsTopOffset(float offset);
  69   void ResetAnimations();
  70   void SetupAnimation(AnimationDirection direction);
  71   void StartAnimationIfNecessary();
  72   bool IsAnimationCompleteAtTime(base::TimeTicks time);
  73
  74   TopControlsManagerClient* client_;  // The client manages the lifecycle of
  75                                       // this.
  76
  77   scoped_ptr<KeyframedFloatAnimationCurve> top_controls_animation_;
  78   AnimationDirection animation_direction_;
  79   TopControlsState permitted_state_;
  80   float controls_top_offset_;
  81   float top_controls_height_;
  82
  83   float current_scroll_delta_;
  84   float controls_scroll_begin_offset_;
  85
  86   // The height of the visible top control such that it must be shown when
  87   // the user stops the scroll.
  88   float top_controls_show_height_;
  89
  90   // The height of the visible top control such that it must be hidden when
  91   // the user stops the scroll.
  92   float top_controls_hide_height_;
  93
  94   DISALLOW_COPY_AND_ASSIGN(TopControlsManager);
  95 };
  96
  97 }  // namespace cc
  98
  99 #endif  // CC_INPUT_TOP_CONTROLS_MANAGER_H_