Fix Volume slider is captured in screenshot done in touchview mode

chromeos/audio/cras_audio_handler.cc

 // Copyright (c) 2013 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 "chromeos/audio/cras_audio_handler.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 358 matching lines @@
   // Set all active devices to the same volume.
   for (AudioDeviceMap::const_iterator it = audio_devices_.begin();
        it != audio_devices_.end();
        it++) {
     const AudioDevice& device = it->second;
     if (!device.is_input && device.active)
       SetOutputNodeVolumePercent(device.id, volume_percent);
   }
 }
 
+void CrasAudioHandler::SetOutputVolumePercentInternally(int volume_percent) {

[jennyz, 2016/07/28 21:10:05]

Please add a unit test for this new API.

[Qiang(Joe) Xu, 2016/07/28 23:15:57]

Done.

+  volume_internally_changed_ = true;

[jennyz, 2016/07/28 21:02:17]

Will it be possible for SetOutputVolumePercentInternal be called multiple times
consecutively? If so, you may need to track its number. If not, please add some
DCHECK or Error log here.

[Qiang(Joe) Xu, 2016/07/28 23:15:57]

Currently only maximize mode screenshot calls this method. And I think everytime
screenshot is taken, the flag should already be released.

+  // Set all active devices to the same volume.
+  for (AudioDeviceMap::const_iterator it = audio_devices_.begin();
+       it != audio_devices_.end(); it++) {
+    const AudioDevice& device = it->second;
+    if (!device.is_input && device.active)
+      SetOutputNodeVolumePercent(device.id, volume_percent);
+  }

[jennyz, 2016/07/28 21:02:17]

line 381-387 is the same as SetOutputVolumePercent, why not just call
SetOutputVolumePercent?

[Qiang(Joe) Xu, 2016/07/28 23:15:57]

Done.

+}
+
 // TODO: Rename the 'Percent' to something more meaningful.
 void CrasAudioHandler::SetInputGainPercent(int gain_percent) {
   // TODO(jennyz): Should we set all input devices' gain to the same level?
   for (AudioDeviceMap::const_iterator it = audio_devices_.begin();
        it != audio_devices_.end();
        it++) {
     const AudioDevice& device = it->second;
     if (device.is_input && device.active)
       SetInputNodeGainPercent(active_input_node_id_, gain_percent);
   }
@@ skipping 236 matching lines @@
       return;
     } else {
       // Reset the initializing_audio_state_ in case SetOutputNodeVolume request
       // is lost by cras due to cras is not ready when CrasAudioHandler is being
       // initialized.
       initializing_audio_state_ = false;
       init_volume_count_ = 0;
     }
   }
 
+  // Do not notify the observers for the volume changed event if that is
+  // initiated internally, not by users. For example, a volume restoring
+  // comes from maximize mode screenshot volume-down, power down accelerators.
+  if (volume_internally_changed_) {

[jennyz, 2016/07/28 21:02:17]

volume_internally_changed_ is similar to initializing_audio_state_, can you
merge them?

[Qiang(Joe) Xu, 2016/07/28 23:15:57]

I use a mask to merge them.

+    volume_internally_changed_ = false;
+    return;
+  }
+
   FOR_EACH_OBSERVER(AudioObserver, observers_,
                     OnOutputNodeVolumeChanged(node_id, volume));
 }
 
 void CrasAudioHandler::ActiveOutputNodeChanged(uint64_t node_id) {
   if (active_output_node_id_ == node_id)
     return;
 
   // Active audio output device should always be changed by chrome.
   // During system boot, cras may change active input to unknown device 0x1,
@@ skipping 727 matching lines @@
                      hdmi_rediscover_grace_period_duration_in_ms_),
       this, &CrasAudioHandler::UpdateAudioAfterHDMIRediscoverGracePeriod);
 }
 
 void CrasAudioHandler::SetHDMIRediscoverGracePeriodForTesting(
     int duration_in_ms) {
   hdmi_rediscover_grace_period_duration_in_ms_ = duration_in_ms;
 }
 
 }  // namespace chromeos