chromeos: Improve brightness and volume animations.

chrome/browser/chromeos/setting_level_bubble.cc

Index: chrome/browser/chromeos/setting_level_bubble.cc
diff --git a/chrome/browser/chromeos/setting_level_bubble.cc b/chrome/browser/chromeos/setting_level_bubble.cc
index 3f467aec3ef9c2b75a495030a69c7ce1a7238c48..4320ea180bd7c104ae2d8d0375988151fac3e9a8 100644
--- a/chrome/browser/chromeos/setting_level_bubble.cc
+++ b/chrome/browser/chromeos/setting_level_bubble.cc
@@ -4,9 +4,10 @@
 
 #include "chrome/browser/chromeos/setting_level_bubble.h"
 
+#include <algorithm>
+
 #include <gdk/gdk.h>
 
-#include "base/timer.h"
 #include "chrome/browser/chromeos/login/background_view.h"
 #include "chrome/browser/chromeos/login/login_utils.h"
 #include "chrome/browser/chromeos/login/webui_login_display.h"
@@ -19,10 +20,19 @@
 #include "ui/gfx/screen.h"
 #include "views/widget/root_view.h"
 
+using base::TimeDelta;
+using base::TimeTicks;
+using std::max;
+using std::min;
+
 namespace {
 
-const int kBubbleShowTimeoutSec = 2;
-const int kAnimationDurationMs = 200;
+// How long should the bubble be shown onscreen whenever the setting changes?
+const int kBubbleShowTimeoutMs = 1000;
+
+// How long should the level initially take to move up or down when it changes?
+// (The rate adapts to handle keyboard autorepeat.)
+const int64 kInitialAnimationDurationMs = 200;
 
 // Horizontal position of the center of the bubble on the screen: 0 is left
 // edge, 0.5 is center, 1 is right edge.
@@ -31,12 +41,12 @@ const double kBubbleXRatio = 0.5;
 // Vertical gap from the bottom of the screen in pixels.
 const int kBubbleBottomGap = 30;
 
-int LimitPercent(int percent) {
-  if (percent < 0)
-    percent = 0;
-  else if (percent > 100)
-    percent = 100;
-  return percent;
+// Duration between animation frames.
+// Chosen to match ui::SlideAnimation's kDefaultFramerateHz.
+const int kAnimationIntervalMs = 1000 / 50;
+
+double LimitPercent(double percent) {
+  return min(max(percent, 0.0), 100.0);
 }
 
 }  // namespace
@@ -75,30 +85,26 @@ static views::Widget* GetToplevelWidget() {
 SettingLevelBubble::SettingLevelBubble(SkBitmap* increase_icon,
                                        SkBitmap* decrease_icon,
                                        SkBitmap* disabled_icon)
-    : previous_percent_(-1),
-      current_percent_(-1),
+    : current_percent_(-1.0),
+      target_percent_(-1.0),
       increase_icon_(increase_icon),
       decrease_icon_(decrease_icon),
       disabled_icon_(disabled_icon),
       bubble_(NULL),
       view_(NULL),
-      animation_(this) {
-  animation_.SetSlideDuration(kAnimationDurationMs);
-  animation_.SetTweenType(ui::Tween::LINEAR);
+      is_animating_(false) {
 }
 
 SettingLevelBubble::~SettingLevelBubble() {}
 
-void SettingLevelBubble::ShowBubble(int percent, bool enabled) {
-  percent = LimitPercent(percent);
-  if (previous_percent_ == -1)
-    previous_percent_ = percent;
-  current_percent_ = percent;
+void SettingLevelBubble::ShowBubble(double percent, bool enabled) {
+  const double old_target_percent = target_percent_;
+  UpdateTargetPercent(percent);
 
   SkBitmap* icon = increase_icon_;
-  if (!enabled || current_percent_ == 0)
+  if (!enabled || target_percent_ == 0)
     icon = disabled_icon_;
-  else if (current_percent_ < previous_percent_)
+  else if (old_target_percent >= 0 && target_percent_ < old_target_percent)
     icon = decrease_icon_;
 
   if (!bubble_) {
@@ -109,7 +115,7 @@ void SettingLevelBubble::ShowBubble(int percent, bool enabled) {
     }
     DCHECK(view_ == NULL);
     view_ = new SettingLevelBubbleView;
-    view_->Init(icon, previous_percent_, enabled);
+    view_->Init(icon, current_percent_, enabled);
 
     // Calculate the position in screen coordinates that the bubble should
     // "point" at (since we use BubbleBorder::FLOAT, this position actually
@@ -123,29 +129,27 @@ void SettingLevelBubble::ShowBubble(int percent, bool enabled) {
         monitor_area.bottom() - view_size.height() / 2 - kBubbleBottomGap,
         0, 0);
 
-    // ShowFocusless doesn't set ESC accelerator.
     bubble_ = Bubble::ShowFocusless(parent_widget,
                                     position_relative_to,
                                     BubbleBorder::FLOAT,
                                     view_,  // contents
                                     this,   // delegate
                                     true);  // show while screen is locked
-    bubble_->set_fade_away_on_close(true);
+    // TODO(derat): We probably shouldn't be using Bubble.  It'd be nice to call
+    // bubble_->set_fade_away_on_close(true) here, but then, if ShowBubble()
+    // gets called while the bubble is fading away, we end up just adjusting the
+    // value on the disappearing bubble; ideally we'd have a way to cancel the
+    // fade and show the bubble at full opacity for another
+    // kBubbleShowTimeoutMs.
   } else {
     DCHECK(view_);
-    timeout_timer_.Stop();
+    hide_timer_.Stop();
     view_->SetIcon(icon);
+    view_->SetEnabled(enabled);
   }
 
-  view_->SetEnabled(enabled);
-
-  if (animation_.is_animating())
-    animation_.End();
-  animation_.Reset();
-  animation_.Show();
-
-  timeout_timer_.Start(base::TimeDelta::FromSeconds(kBubbleShowTimeoutSec),
-                       this, &SettingLevelBubble::OnTimeout);
+  hide_timer_.Start(base::TimeDelta::FromMilliseconds(kBubbleShowTimeoutMs),
+                    this, &SettingLevelBubble::OnHideTimeout);
 }
 
 void SettingLevelBubble::HideBubble() {
@@ -153,36 +157,51 @@ void SettingLevelBubble::HideBubble() {
     bubble_->Close();
 }
 
-void SettingLevelBubble::UpdateWithoutShowingBubble(int percent, bool enabled) {
+void SettingLevelBubble::UpdateWithoutShowingBubble(double percent,
+                                                    bool enabled) {
+  UpdateTargetPercent(percent);
   if (view_)
     view_->SetEnabled(enabled);
+}
 
-  percent = LimitPercent(percent);
+void SettingLevelBubble::OnHideTimeout() {
+  HideBubble();
+}
 
-  previous_percent_ =
-      animation_.is_animating() ?
-      animation_.GetCurrentValue() :
-      current_percent_;
-  if (previous_percent_ < 0)
-    previous_percent_ = percent;
-  current_percent_ = percent;
+void SettingLevelBubble::OnAnimationTimeout() {
+  const TimeTicks now = TimeTicks::Now();
+  const int64 remaining_ms = (target_time_ - now).InMilliseconds();
 
-  if (animation_.is_animating())
-    animation_.End();
-  animation_.Reset();
-  animation_.Show();
-}
+  if (remaining_ms <= 0) {
+    current_percent_ = target_percent_;
+    StopAnimation();
+  } else {
+    // Figure out what fraction of the total time until we want to reach the
+    // target has elapsed since the last update.
+    const double remaining_percent = target_percent_ - current_percent_;
+    const int64 elapsed_ms =
+        (now - last_animation_update_time_).InMilliseconds();
+    current_percent_ +=
+        remaining_percent *
+        (static_cast<double>(elapsed_ms) / (elapsed_ms + remaining_ms));
+  }
+  last_animation_update_time_ = now;
 
-void SettingLevelBubble::OnTimeout() {
-  HideBubble();
+  if (view_)
+    view_->SetLevel(current_percent_);
 }
 
 void SettingLevelBubble::BubbleClosing(Bubble* bubble, bool) {
   DCHECK(bubble == bubble_);
-  timeout_timer_.Stop();
-  animation_.Stop();
+  hide_timer_.Stop();
+  StopAnimation();
   bubble_ = NULL;
   view_ = NULL;
+  current_percent_ = -1.0;
+  target_percent_ = -1.0;
+  target_time_ = TimeTicks();
+  last_animation_update_time_ = TimeTicks();
+  last_target_update_time_ = TimeTicks();
 }
 
 bool SettingLevelBubble::CloseOnEscape() {
@@ -193,17 +212,41 @@ bool SettingLevelBubble::FadeInOnShow() {
   return false;
 }
 
-void SettingLevelBubble::AnimationEnded(const ui::Animation* animation) {
-  previous_percent_ = current_percent_;
-}
+void SettingLevelBubble::UpdateTargetPercent(double percent) {
+  target_percent_ = LimitPercent(percent);
+  const TimeTicks now = TimeTicks::Now();
 
-void SettingLevelBubble::AnimationProgressed(const ui::Animation* animation) {
-  if (view_) {
-    view_->SetLevel(
-        ui::Tween::ValueBetween(animation->GetCurrentValue(),
-                                previous_percent_,
-                                current_percent_));
+  if (current_percent_ < 0.0) {
+    // If we're setting the level for the first time, no need to animate.
+    current_percent_ = target_percent_;
+    if (view_)
+      view_->SetLevel(current_percent_);
+  } else {
+    // Use the time since the last request as a hint for the duration of the
+    // animation.  This makes us automatically adapt to the repeat rate if a key
+    // is being held down to change a setting (which prevents us from lagging
+    // behind when the key is finally released).
+    int64 duration_ms = kInitialAnimationDurationMs;
+    if (!last_target_update_time_.is_null())
+      duration_ms = min(kInitialAnimationDurationMs,
+                        (now - last_target_update_time_).InMilliseconds());
+    target_time_ = now + TimeDelta::FromMilliseconds(duration_ms);
+
+    if (!is_animating_) {
+      animation_timer_.Start(TimeDelta::FromMilliseconds(kAnimationIntervalMs),
+                             this,
+                             &SettingLevelBubble::OnAnimationTimeout);
+      is_animating_ = true;
+      last_animation_update_time_ = now;
+    }
   }
+
+  last_target_update_time_ = now;
+}
+
+void SettingLevelBubble::StopAnimation() {
+  animation_timer_.Stop();
+  is_animating_ = false;
 }
 
 }  // namespace chromeos