chrome/browser/ui/panels/panel_bounds_animation.cc

   1 // Copyright (c) 2012 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/panels/panel_bounds_animation.h"
   6
   7 #include "chrome/browser/ui/panels/panel.h"
   8 #include "chrome/browser/ui/panels/panel_manager.h"
   9
  10 namespace {
  11
  12 // These values are experimental and subjective.
  13 const int kDefaultFramerateHz = 50;
  14 const int kSetBoundsAnimationMs = 180;
  15 const int kSetBoundsAnimationBigMinimizeMs = 1500;
  16
  17 }
  18
  19 PanelBoundsAnimation::PanelBoundsAnimation(gfx::AnimationDelegate* target,
  20                                            Panel* panel,
  21                                            const gfx::Rect& initial_bounds,
  22                                            const gfx::Rect& final_bounds)
  23     : gfx::LinearAnimation(kDefaultFramerateHz, target),
  24       panel_(panel),
  25       for_big_minimize_(false),
  26       animation_stop_to_show_titlebar_(0) {
  27   // Detect animation that happens when expansion state is set to MINIMIZED
  28   // and there is relatively big portion of the panel to hide from view.
  29   // Initialize animation differently in this case, using fast-pause-slow
  30   // method, see below for more details.
  31   int duration = kSetBoundsAnimationMs;
  32   if (initial_bounds.height() > final_bounds.height() &&
  33       panel_->expansion_state() == Panel::MINIMIZED) {
  34     double hidden_title_height =
  35         panel_->TitleOnlyHeight() - final_bounds.height();
  36     double distance_y = initial_bounds.height() - final_bounds.height();
  37     animation_stop_to_show_titlebar_ = 1.0 - hidden_title_height / distance_y;
  38     if (animation_stop_to_show_titlebar_ > 0.7) {  // Relatively big movement.
  39       for_big_minimize_ = true;
  40       duration = kSetBoundsAnimationBigMinimizeMs;
  41     }
  42   }
  43   SetDuration(PanelManager::AdjustTimeInterval(duration));
  44 }
  45
  46 PanelBoundsAnimation::~PanelBoundsAnimation() {
  47 }
  48
  49 double PanelBoundsAnimation::GetCurrentValue() const {
  50   return ComputeAnimationValue(gfx::LinearAnimation::GetCurrentValue(),
  51                                for_big_minimize_,
  52                                animation_stop_to_show_titlebar_);
  53 }
  54
  55 double PanelBoundsAnimation::ComputeAnimationValue(double progress,
  56     bool for_big_minimize, double animation_stop_to_show_titlebar) {
  57   if (!for_big_minimize) {
  58     // Cubic easing out.
  59     double value = 1.0 - progress;
  60     return 1.0 - value * value * value;
  61   }
  62
  63   // Minimize animation is done in 3 steps:
  64   // 1. Quickly (0 -> 0.15) make only titlebar visible.
  65   // 2. Freeze for a little bit (0.15->0.6), just showing titlebar.
  66   // 3. Slowly minimize to thin strip (0.6->1.0)
  67   const double kProgressAtFreezeStart = 0.15;
  68   const double kProgressAtFreezeEnd = 0.6;
  69   double value;
  70   if (progress <= kProgressAtFreezeStart) {
  71     value = animation_stop_to_show_titlebar *
  72         (progress / kProgressAtFreezeStart);
  73   } else if (progress <= kProgressAtFreezeEnd) {
  74     value = animation_stop_to_show_titlebar;
  75   } else {
  76     value = animation_stop_to_show_titlebar +
  77         (1.0 - animation_stop_to_show_titlebar) *
  78         ((progress - kProgressAtFreezeEnd) / (1.0 - kProgressAtFreezeEnd));
  79   }
  80   return value;
  81 }