ui/gfx/animation/animation_container.cc

   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 #include "ui/gfx/animation/animation_container.h"
   6
   7 #include "ui/gfx/animation/animation_container_element.h"
   8 #include "ui/gfx/animation/animation_container_observer.h"
   9 #include "ui/gfx/frame_time.h"
  10
  11 using base::TimeDelta;
  12 using base::TimeTicks;
  13
  14 namespace gfx {
  15
  16 AnimationContainer::AnimationContainer()
  17     : last_tick_time_(gfx::FrameTime::Now()),
  18       observer_(NULL) {
  19 }
  20
  21 AnimationContainer::~AnimationContainer() {
  22   // The animations own us and stop themselves before being deleted. If
  23   // elements_ is not empty, something is wrong.
  24   DCHECK(elements_.empty());
  25 }
  26
  27 void AnimationContainer::Start(AnimationContainerElement* element) {
  28   DCHECK(elements_.count(element) == 0);  // Start should only be invoked if the
  29                                           // element isn't running.
  30
  31   if (elements_.empty()) {
  32     last_tick_time_ = gfx::FrameTime::Now();
  33     SetMinTimerInterval(element->GetTimerInterval());
  34   } else if (element->GetTimerInterval() < min_timer_interval_) {
  35     SetMinTimerInterval(element->GetTimerInterval());
  36   }
  37
  38   element->SetStartTime(last_tick_time_);
  39   elements_.insert(element);
  40 }
  41
  42 void AnimationContainer::Stop(AnimationContainerElement* element) {
  43   DCHECK(elements_.count(element) > 0);  // The element must be running.
  44
  45   elements_.erase(element);
  46
  47   if (elements_.empty()) {
  48     timer_.Stop();
  49     if (observer_)
  50       observer_->AnimationContainerEmpty(this);
  51   } else {
  52     TimeDelta min_timer_interval = GetMinInterval();
  53     if (min_timer_interval > min_timer_interval_)
  54       SetMinTimerInterval(min_timer_interval);
  55   }
  56 }
  57
  58 void AnimationContainer::Run() {
  59   // We notify the observer after updating all the elements. If all the elements
  60   // are deleted as a result of updating then our ref count would go to zero and
  61   // we would be deleted before we notify our observer. We add a reference to
  62   // ourself here to make sure we're still valid after running all the elements.
  63   scoped_refptr<AnimationContainer> this_ref(this);
  64
  65   TimeTicks current_time = gfx::FrameTime::Now();
  66
  67   last_tick_time_ = current_time;
  68
  69   // Make a copy of the elements to iterate over so that if any elements are
  70   // removed as part of invoking Step there aren't any problems.
  71   Elements elements = elements_;
  72
  73   for (Elements::const_iterator i = elements.begin();
  74        i != elements.end(); ++i) {
  75     // Make sure the element is still valid.
  76     if (elements_.find(*i) != elements_.end())
  77       (*i)->Step(current_time);
  78   }
  79
  80   if (observer_)
  81     observer_->AnimationContainerProgressed(this);
  82 }
  83
  84 void AnimationContainer::SetMinTimerInterval(base::TimeDelta delta) {
  85   // This doesn't take into account how far along the current element is, but
  86   // that shouldn't be a problem for uses of Animation/AnimationContainer.
  87   timer_.Stop();
  88   min_timer_interval_ = delta;
  89   timer_.Start(FROM_HERE, min_timer_interval_, this, &AnimationContainer::Run);
  90 }
  91
  92 TimeDelta AnimationContainer::GetMinInterval() {
  93   DCHECK(!elements_.empty());
  94
  95   TimeDelta min;
  96   Elements::const_iterator i = elements_.begin();
  97   min = (*i)->GetTimerInterval();
  98   for (++i; i != elements_.end(); ++i) {
  99     if ((*i)->GetTimerInterval() < min)
 100       min = (*i)->GetTimerInterval();
 101   }
 102   return min;
 103 }
 104
 105 }  // namespace gfx