app/multi_animation.cc

   1 // Copyright (c) 2010 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 "app/multi_animation.h"
   6
   7 // Default interval, in ms.
   8 static const int kDefaultInterval = 20;
   9
  10 static int TotalTime(const MultiAnimation::Parts& parts) {
  11   int time_ms = 0;
  12   for (size_t i = 0; i < parts.size(); ++i)
  13     time_ms += parts[i].time_ms;
  14   return time_ms;
  15 }
  16
  17 MultiAnimation::MultiAnimation(const Parts& parts)
  18     : Animation(base::TimeDelta::FromMilliseconds(kDefaultInterval)),
  19       parts_(parts),
  20       cycle_time_ms_(TotalTime(parts)),
  21       current_value_(0),
  22       current_part_index_(0) {
  23   DCHECK(!parts_.empty());
  24 }
  25
  26 void MultiAnimation::Step(base::TimeTicks time_now) {
  27   double last_value = current_value_;
  28   size_t last_index = current_part_index_;
  29
  30   int delta = static_cast<int>((time_now - start_time()).InMilliseconds() %
  31                                cycle_time_ms_);
  32   const Part& part = GetPart(&delta, &current_part_index_);
  33   double percent = static_cast<double>(delta) /
  34         static_cast<double>(part.time_ms);
  35   current_value_ = Tween::CalculateValue(part.type, percent);
  36
  37   if ((current_value_ != last_value || current_part_index_ != last_index) &&
  38       delegate()) {
  39     delegate()->AnimationProgressed(this);
  40   }
  41 }
  42
  43 const MultiAnimation::Part& MultiAnimation::GetPart(int* time_ms,
  44                                                     size_t* part_index) {
  45   DCHECK(*time_ms < cycle_time_ms_);
  46
  47   for (size_t i = 0; i < parts_.size(); ++i) {
  48     if (*time_ms < parts_[i].time_ms) {
  49       *part_index = i;
  50       return parts_[i];
  51     }
  52
  53     *time_ms -= parts_[i].time_ms;
  54   }
  55   NOTREACHED();
  56   *time_ms = 0;
  57   *part_index = 0;
  58   return parts_[0];
  59 }