chrome/browser/ui/autofill/loading_animation.cc

   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 #include "chrome/browser/ui/autofill/loading_animation.h"
   6
   7 #include "base/logging.h"
   8 #include "ui/gfx/animation/tween.h"
   9
  10 namespace autofill {
  11
  12 // Duration of one cycle of the animation.
  13 static const int kDurationMs = 1800;
  14
  15 // The frame rate of the animation.
  16 static const int kHertz = 60;
  17
  18 LoadingAnimation::LoadingAnimation(gfx::AnimationDelegate* delegate,
  19                                    int font_height)
  20     : LinearAnimation(kDurationMs, kHertz, delegate),
  21       first_cycle_(true),
  22       font_height_(font_height) {}
  23
  24 LoadingAnimation::~LoadingAnimation() {}
  25
  26 void LoadingAnimation::Step(base::TimeTicks time_now) {
  27   LinearAnimation::Step(time_now);
  28
  29   if (!is_animating()) {
  30     first_cycle_ = false;
  31     Start();
  32   }
  33 }
  34
  35 double LoadingAnimation::GetCurrentValueForDot(size_t dot_i) const {
  36   double base_value = gfx::LinearAnimation::GetCurrentValue();
  37
  38   const double kSecondDotDelayMs = 100.0;
  39   const double kThirdDotDelayMs = 300.0;
  40   if (dot_i == 1)
  41     base_value -= kSecondDotDelayMs / kDurationMs;
  42   else if (dot_i == 2)
  43     base_value -= kThirdDotDelayMs / kDurationMs;
  44
  45   if (base_value < 0.0)
  46     base_value = first_cycle_ ? 0.0 : base_value + 1.0;
  47
  48   double value = gfx::Tween::CalculateValue(gfx::Tween::EASE_OUT, base_value);
  49
  50   static AnimationFrame kAnimationFrames[] = {
  51     { 0.0, 0.0 },
  52     { 0.55, 0.0 },
  53     { 0.6, -1.0 },
  54     { 0.8, 0.3 },
  55     { 0.9, -0.2 },
  56     { 0.95, 0.1 },
  57     { 1.0, 0.0 },
  58   };
  59
  60   for (size_t i = 0; i < arraysize(kAnimationFrames); ++i) {
  61     if (value > kAnimationFrames[i].value)
  62       continue;
  63
  64     double position;
  65     if (i == 0) {
  66       position = kAnimationFrames[i].position;
  67     } else {
  68       double inter_frame_value =
  69           (value - kAnimationFrames[i - 1].value) /
  70           (kAnimationFrames[i].value - kAnimationFrames[i - 1].value);
  71       position = gfx::Tween::FloatValueBetween(inter_frame_value,
  72                                                kAnimationFrames[i - 1].position,
  73                                                kAnimationFrames[i].position);
  74     }
  75     return position * font_height_ / 2.0;
  76   }
  77
  78   NOTREACHED();
  79   return 0.0;
  80 }
  81
  82 void LoadingAnimation::Reset() {
  83   Stop();
  84   first_cycle_ = true;
  85 }
  86
  87 }  // namespace autofill