src/ui/gfx/animation/linear_animation.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/linear_animation.h"
   6
   7 #include <math.h>
   8
   9 #include "ui/gfx/animation/animation_container.h"
  10 #include "ui/gfx/animation/animation_delegate.h"
  11
  12 using base::Time;
  13 using base::TimeDelta;
  14
  15 namespace gfx {
  16
  17 static TimeDelta CalculateInterval(int frame_rate) {
  18   int timer_interval = 1000000 / frame_rate;
  19   if (timer_interval < 10000)
  20     timer_interval = 10000;
  21   return TimeDelta::FromMicroseconds(timer_interval);
  22 }
  23
  24 LinearAnimation::LinearAnimation(int frame_rate,
  25                                  AnimationDelegate* delegate)
  26     : Animation(CalculateInterval(frame_rate)),
  27       state_(0.0),
  28       in_end_(false) {
  29   set_delegate(delegate);
  30 }
  31
  32 LinearAnimation::LinearAnimation(int duration,
  33                                  int frame_rate,
  34                                  AnimationDelegate* delegate)
  35     : Animation(CalculateInterval(frame_rate)),
  36       duration_(TimeDelta::FromMilliseconds(duration)),
  37       state_(0.0),
  38       in_end_(false) {
  39   set_delegate(delegate);
  40   SetDuration(duration);
  41 }
  42
  43 double LinearAnimation::GetCurrentValue() const {
  44   // Default is linear relationship, subclass to adapt.
  45   return state_;
  46 }
  47
  48 void LinearAnimation::SetCurrentValue(double new_value) {
  49   new_value = std::max(0.0, std::min(1.0, new_value));
  50   base::TimeDelta time_delta = base::TimeDelta::FromMicroseconds(
  51       duration_.InMicroseconds() * (new_value - state_));
  52   SetStartTime(start_time() - time_delta);
  53   state_ = new_value;
  54 }
  55
  56 void LinearAnimation::End() {
  57   if (!is_animating())
  58     return;
  59
  60   // NOTE: We don't use AutoReset here as Stop may end up deleting us (by way
  61   // of the delegate).
  62   in_end_ = true;
  63   Stop();
  64 }
  65
  66 void LinearAnimation::SetDuration(int duration) {
  67   duration_ = TimeDelta::FromMilliseconds(duration);
  68   if (duration_ < timer_interval())
  69     duration_ = timer_interval();
  70   if (is_animating())
  71     SetStartTime(container()->last_tick_time());
  72 }
  73
  74 void LinearAnimation::Step(base::TimeTicks time_now) {
  75   TimeDelta elapsed_time = time_now - start_time();
  76   state_ = static_cast<double>(elapsed_time.InMicroseconds()) /
  77            static_cast<double>(duration_.InMicroseconds());
  78   if (state_ >= 1.0)
  79     state_ = 1.0;
  80
  81   AnimateToState(state_);
  82
  83   if (delegate())
  84     delegate()->AnimationProgressed(this);
  85
  86   if (state_ == 1.0)
  87     Stop();
  88 }
  89
  90 void LinearAnimation::AnimationStarted() {
  91   state_ = 0.0;
  92 }
  93
  94 void LinearAnimation::AnimationStopped() {
  95   if (!in_end_)
  96     return;
  97
  98   in_end_ = false;
  99   // Set state_ to ensure we send ended to delegate and not canceled.
 100   state_ = 1;
 101   AnimateToState(1.0);
 102 }
 103
 104 bool LinearAnimation::ShouldSendCanceledFromStop() {
 105   return state_ != 1;
 106 }
 107
 108 }  // namespace gfx