Fix the volume strength icon to reflect the volume control clicks

ash/common/system/chromeos/audio/volume_view.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/common/system/chromeos/audio/volume_view.h"
 
 #include <algorithm>
 
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/metrics/user_metrics_action.h"
@@ skipping 209 matching lines @@
 VolumeView::~VolumeView() {}
 
 void VolumeView::Update() {
   icon_->Update();
   slider_->UpdateState(!audio_delegate_->IsOutputAudioMuted());
   UpdateDeviceTypeAndMore();
   Layout();
 }
 
 void VolumeView::SetVolumeLevel(float percent) {
+  // Update volume level to the current audio level.
+  Update();
+
   // Slider's value is in finer granularity than audio volume level(0.01),
   // there will be a small discrepancy between slider's value and volume level
   // on audio side. To avoid the jittering in slider UI, do not set change
   // slider value if the change is less than 1%.
   if (std::abs(percent - slider_->value()) < 0.01)
     return;
   slider_->SetValue(percent);
   // It is possible that the volume was (un)muted, but the actual volume level
   // did not change. In that case, setting the value of the slider won't
   // trigger an update. So explicitly trigger an update.
@@ skipping 21 matching lines @@
     int device_icon = audio_delegate_->GetActiveOutputDeviceIconId();
     if (device_icon != system::TrayAudioDelegate::kNoAudioDeviceIcon) {
       device_type_->SetImage(ui::ResourceBundle::GetSharedInstance()
                                  .GetImageNamed(device_icon)
                                  .ToImageSkia());
       device_type_->SetVisible(true);
     }
   }
 }
 
-void VolumeView::HandleVolumeUp(float level) {
+void VolumeView::HandleVolumeUp(int level) {
   audio_delegate_->SetOutputVolumeLevel(level);
   if (audio_delegate_->IsOutputAudioMuted() &&
       level > audio_delegate_->GetOutputDefaultVolumeMuteLevel()) {
     audio_delegate_->SetOutputAudioIsMuted(false);
   }
 }
 
-void VolumeView::HandleVolumeDown(float level) {
+void VolumeView::HandleVolumeDown(int level) {
   audio_delegate_->SetOutputVolumeLevel(level);
   if (!audio_delegate_->IsOutputAudioMuted() &&
       level <= audio_delegate_->GetOutputDefaultVolumeMuteLevel()) {
     audio_delegate_->SetOutputAudioIsMuted(true);
   } else if (audio_delegate_->IsOutputAudioMuted() &&
              level > audio_delegate_->GetOutputDefaultVolumeMuteLevel()) {
     audio_delegate_->SetOutputAudioIsMuted(false);
   }
 }
 
 void VolumeView::ButtonPressed(views::Button* sender, const ui::Event& event) {
   if (sender == icon_) {
     bool mute_on = !audio_delegate_->IsOutputAudioMuted();
     audio_delegate_->SetOutputAudioIsMuted(mute_on);
     if (!mute_on)
       audio_delegate_->AdjustOutputVolumeToAudibleLevel();
     icon_->Update();
   } else if (sender == more_button_) {
     owner_->TransitionDetailedView();
   } else {
     NOTREACHED() << "Unexpected sender=" << sender->GetClassName() << ".";
   }
 }
 
 void VolumeView::SliderValueChanged(views::Slider* sender,
                                     float value,
                                     float old_value,
                                     views::SliderChangeReason reason) {
   if (reason == views::VALUE_CHANGED_BY_USER) {
-    float new_volume = value * 100.0f;
-    float current_volume = audio_delegate_->GetOutputVolumeLevel();
+    int new_volume = value * 100;

[James Cook, 2016/11/11 22:21:15]

Aside: I'm a little surprised that this doesn't generate a compiler warning
about potential integer range problems.

[yiyix, 2016/11/11 22:27:54]

Do you think adding a comment here would help the reader to understand?

+    int current_volume = audio_delegate_->GetOutputVolumeLevel();
     // Do not call change audio volume if the difference is less than
     // 1%, which is beyond cras audio api's granularity for output volume.
-    if (std::abs(new_volume - current_volume) < 1.0f)
+    if (std::abs(new_volume - current_volume) < 1)

[tdanderson, 2016/11/11 19:48:35]

if both values are now ints, the only way this can be true is if they are equal.
It seems you could simplify this to if (new_volume == current_volume) return;

If you do this then I don't think the comment on line 314-5 would add any value
so I suggest removing it.

[yiyix, 2016/11/11 22:27:54]

You are right. Done

       return;
     WmShell::Get()->RecordUserMetricsAction(
         is_default_view_ ? UMA_STATUS_AREA_CHANGED_VOLUME_MENU
                          : UMA_STATUS_AREA_CHANGED_VOLUME_POPUP);
     if (new_volume > current_volume)
       HandleVolumeUp(new_volume);
     else
       HandleVolumeDown(new_volume);
   }
   icon_->Update();
@@ skipping 12 matching lines @@
 void VolumeView::OnBoundsChanged(const gfx::Rect& previous_bounds) {
   // Separator's prefered size is based on set bounds. When an empty bounds is
   // set on first layout this causes BoxLayout to ignore the separator. Reset
   // its height on each bounds change so that it is laid out properly.
   if (separator_)
     separator_->SetSize(gfx::Size(kSeparatorSize, bounds().height()));
 }
 
 }  // namespace tray
 }  // namespace ash