ui/gfx/animation/animation_container.h

   1 // Copyright (c) 2011 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 UI_GFX_ANIMATION_ANIMATION_CONTAINER_H_
   6 #define UI_GFX_ANIMATION_ANIMATION_CONTAINER_H_
   7
   8 #include <set>
   9
  10 #include "base/memory/ref_counted.h"
  11 #include "base/time/time.h"
  12 #include "base/timer/timer.h"
  13 #include "ui/gfx/gfx_export.h"
  14
  15 namespace gfx {
  16
  17 class AnimationContainerElement;
  18 class AnimationContainerObserver;
  19
  20 // AnimationContainer is used by Animation to manage the underlying timer.
  21 // Internally each Animation creates a single AnimationContainer. You can
  22 // group a set of Animations into the same AnimationContainer by way of
  23 // Animation::SetContainer. Grouping a set of Animations into the same
  24 // AnimationContainer ensures they all update and start at the same time.
  25 //
  26 // AnimationContainer is ref counted. Each Animation contained within the
  27 // AnimationContainer own it.
  28 class GFX_EXPORT AnimationContainer
  29     : public base::RefCounted<AnimationContainer> {
  30  public:
  31   AnimationContainer();
  32
  33   // Invoked by Animation when it needs to start. Starts the timer if necessary.
  34   // NOTE: This is invoked by Animation for you, you shouldn't invoke this
  35   // directly.
  36   void Start(AnimationContainerElement* animation);
  37
  38   // Invoked by Animation when it needs to stop. If there are no more animations
  39   // running the timer stops.
  40   // NOTE: This is invoked by Animation for you, you shouldn't invoke this
  41   // directly.
  42   void Stop(AnimationContainerElement* animation);
  43
  44   void set_observer(AnimationContainerObserver* observer) {
  45     observer_ = observer;
  46   }
  47
  48   // The time the last animation ran at.
  49   base::TimeTicks last_tick_time() const { return last_tick_time_; }
  50
  51   // Are there any timers running?
  52   bool is_running() const { return !elements_.empty(); }
  53
  54  private:
  55   friend class base::RefCounted<AnimationContainer>;
  56
  57   typedef std::set<AnimationContainerElement*> Elements;
  58
  59   ~AnimationContainer();
  60
  61   // Timer callback method.
  62   void Run();
  63
  64   // Sets min_timer_interval_ and restarts the timer.
  65   void SetMinTimerInterval(base::TimeDelta delta);
  66
  67   // Returns the min timer interval of all the timers.
  68   base::TimeDelta GetMinInterval();
  69
  70   // Represents one of two possible values:
  71   // . If only a single animation has been started and the timer hasn't yet
  72   //   fired this is the time the animation was added.
  73   // . The time the last animation ran at (::Run was invoked).
  74   base::TimeTicks last_tick_time_;
  75
  76   // Set of elements (animations) being managed.
  77   Elements elements_;
  78
  79   // Minimum interval the timers run at.
  80   base::TimeDelta min_timer_interval_;
  81
  82   base::RepeatingTimer<AnimationContainer> timer_;
  83
  84   AnimationContainerObserver* observer_;
  85
  86   DISALLOW_COPY_AND_ASSIGN(AnimationContainer);
  87 };
  88
  89 }  // namespace gfx
  90
  91 #endif  // UI_GFX_ANIMATION_ANIMATION_CONTAINER_H_