Add ALSA support to volume keys

chrome/browser/chromeos/audio_handler.h

Index: chrome/browser/chromeos/audio_handler.h
diff --git a/chrome/browser/chromeos/audio_handler.h b/chrome/browser/chromeos/audio_handler.h
index ca1a83b2c27e8e26f8369af37e203bb2affeaaf1..9290bc628fc1b73cea82af130877cbff8da967ca 100644
--- a/chrome/browser/chromeos/audio_handler.h
+++ b/chrome/browser/chromeos/audio_handler.h
@@ -8,12 +8,13 @@
 
 #include "base/basictypes.h"
 #include "base/scoped_ptr.h"
+#include "base/thread.h"
 
 template <typename T> struct DefaultSingletonTraits;
 
 namespace chromeos {
 
-class PulseAudioMixer;
+class AudioMixerBase;
 
 class AudioHandler {
  public:
@@ -30,7 +31,7 @@ class AudioHandler {
   // as the percentage gets lower, and then switches to silence at 0%.
   void SetVolumePercent(double volume_percent);
 
-  // Adust volume up (positive percentage) or down (negative percentage),
+  // Adjust volume up (positive percentage) or down (negative percentage),
   // capping at 100%.  GetVolumePercent() will be accurate after this
   // blocking call.
   void AdjustVolumeByPercent(double adjust_by_percent);
@@ -47,6 +48,9 @@ class AudioHandler {
   // and constructor/destructor private as recommended for Singletons.
   friend struct DefaultSingletonTraits<AudioHandler>;
 
+  // Connect to the current using_mixer_.
+  bool TryToConnect(bool async);
+
   void OnMixerInitialized(bool success);
 
   AudioHandler();
@@ -54,17 +58,28 @@ class AudioHandler {
   bool VerifyMixerConnection();
 
   // Conversion between our internal scaling (0-100%) and decibels.
-  static double VolumeDbToPercent(double volume_db);
-  static double PercentToVolumeDb(double volume_percent);
+  double VolumeDbToPercent(double volume_db) const;
+  double PercentToVolumeDb(double volume_percent) const;
+
+  scoped_ptr<AudioMixerBase> mixer_;
 
-  scoped_ptr<PulseAudioMixer> mixer_;
   bool connected_;
   int reconnect_tries_;
 
+  // The min and max volume in decibels, limited to the maximum range of the
+  // audio system being used.
+  double max_volume_db_;
+  double min_volume_db_;
+
+  // Which mixer is being used, PulseAudio or ALSA
+  int using_mixer_;

[Daniel Erat, 2010/12/20 22:01:12]

use an enum instead, e.g. MixerType with MIXER_TYPE_PULSE_AUDIO and
MIXER_TYPE_ALSA values

[davejcool, 2010/12/21 02:00:21]

Funny, I went back and forth on that one... but it will make things clearer,
even if it does create more lines than just doing "++using_mixer".

+
   DISALLOW_COPY_AND_ASSIGN(AudioHandler);
 };
 
 }  // namespace chromeos
 
+DISABLE_RUNNABLE_METHOD_REFCOUNT(chromeos::AudioHandler);
+
 #endif  // CHROME_BROWSER_CHROMEOS_AUDIO_HANDLER_H_