A11y setting: mono audio UI

chromeos/audio/audio_a11y_controller.cc

Index: chromeos/audio/audio_a11y_controller.cc
diff --git a/chromeos/audio/audio_a11y_controller.cc b/chromeos/audio/audio_a11y_controller.cc
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index 0000000000000000000000000000000000000000..01427cd6f5e285e96ee9092028d866ccdb5618ee
--- /dev/null
+++ b/chromeos/audio/audio_a11y_controller.cc
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+// 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/audio_a11y_controller.h"
+
+#include <vector>
+
+#include "chromeos/dbus/cras_audio_client.h"
+#include "chromeos/dbus/dbus_thread_manager.h"
+
+namespace chromeos {
+namespace {
+static const std::vector<double> kStereoToMono = {0.5, 0.5, 0.5, 0.5};
+static const std::vector<double> kStereoToStereo = {1, 0, 0, 1};
+}  // namespace
+
+AudioA11yController::AudioA11yController() {}
+
+AudioA11yController::~AudioA11yController() {}
+
+void AudioA11yController::SetOutputMono(bool enabled) {
+  if (output_mono_enabled_ == enabled)
+    return;
+  output_mono_enabled_ = enabled;
+
+  if (output_mono_enabled_) {
+    chromeos::DBusThreadManager::Get()->GetCrasAudioClient()->
+        SetGlobalOutputChannelRemix(channels_, kStereoToMono);
+  } else {
+    chromeos::DBusThreadManager::Get()->GetCrasAudioClient()->
+        SetGlobalOutputChannelRemix(channels_, kStereoToStereo);
+  }
+}
+
+bool AudioA11yController::IsOutputMonoEnabled() const {
+  return output_mono_enabled_;
+}
+
+}  // namespace chromeos
+
+
+
+