Refactor the TrayAudio code so that it can be used by other platforms.

ash/system/audio/tray_audio.cc

Index: ash/system/audio/tray_audio.cc
diff --git a/ash/system/audio/tray_audio.cc b/ash/system/audio/tray_audio.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3bc47caed7dfe0666fcafd62af640771a6853e0b
--- /dev/null
+++ b/ash/system/audio/tray_audio.cc
@@ -0,0 +1,143 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.

[James Cook, 2014/02/18 19:34:48]

ditto

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ash/system/audio/tray_audio.h"
+
+#include <cmath>
+
+#include "ash/ash_constants.h"
+#include "ash/ash_switches.h"
+#include "ash/metrics/user_metrics_recorder.h"
+#include "ash/shell.h"
+#include "ash/system/audio/tray_audio_delegate.h"
+#include "ash/system/audio/volume_view.h"
+#include "ash/system/tray/actionable_view.h"
+#include "ash/system/tray/fixed_sized_scroll_view.h"
+#include "ash/system/tray/hover_highlight_view.h"
+#include "ash/system/tray/system_tray.h"
+#include "ash/system/tray/system_tray_delegate.h"
+#include "ash/system/tray/system_tray_notifier.h"
+#include "ash/system/tray/tray_constants.h"
+#include "ash/volume_control_delegate.h"
+#include "base/strings/utf_string_conversions.h"
+#include "grit/ash_resources.h"
+#include "grit/ash_strings.h"
+#include "third_party/skia/include/core/SkCanvas.h"
+#include "third_party/skia/include/core/SkPaint.h"
+#include "third_party/skia/include/core/SkRect.h"
+#include "third_party/skia/include/effects/SkGradientShader.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/base/resource/resource_bundle.h"
+#include "ui/gfx/canvas.h"
+#include "ui/gfx/font_list.h"
+#include "ui/gfx/image/image.h"
+#include "ui/gfx/image/image_skia_operations.h"
+#include "ui/views/controls/button/image_button.h"
+#include "ui/views/controls/image_view.h"
+#include "ui/views/controls/label.h"
+#include "ui/views/controls/slider.h"
+#include "ui/views/layout/box_layout.h"
+#include "ui/views/view.h"
+
+namespace ash {
+namespace internal {
+
+TrayAudio::TrayAudio(SystemTray* system_tray,
+                     system::TrayAudioDelegate* audio_delegate)
+    : TrayImageItem(system_tray, IDR_AURA_UBER_TRAY_VOLUME_MUTE),
+      audio_delegate_(audio_delegate),
+      volume_view_(NULL),
+      pop_up_volume_view_(false) {
+  Shell::GetInstance()->system_tray_notifier()->AddAudioObserver(this);
+}
+
+TrayAudio::~TrayAudio() {
+  Shell::GetInstance()->system_tray_notifier()->RemoveAudioObserver(this);
+}
+
+bool TrayAudio::GetInitialVisibility() {
+  return audio_delegate_->IsOutputAudioMuted();
+}
+
+views::View* TrayAudio::CreateDefaultView(user::LoginStatus status) {
+  volume_view_ = new tray::VolumeView(this, audio_delegate_, true);
+  return volume_view_;
+}
+
+views::View* TrayAudio::CreateDetailedView(user::LoginStatus status) {
+  volume_view_ = new tray::VolumeView(this, audio_delegate_, false);
+  return volume_view_;
+}
+
+void TrayAudio::DestroyDefaultView() {
+  volume_view_ = NULL;
+}
+
+void TrayAudio::DestroyDetailedView() {
+  if (volume_view_) {
+    volume_view_ = NULL;
+    pop_up_volume_view_ = false;
+  }
+}
+
+bool TrayAudio::ShouldHideArrow() const {
+  return true;
+}
+
+bool TrayAudio::ShouldShowShelf() const {
+  return ash::switches::ShowAudioDeviceMenu() && !pop_up_volume_view_;
+}
+
+void TrayAudio::OnOutputVolumeChanged() {
+  float percent =
+      static_cast<float>(audio_delegate_->GetOutputVolumeLevel()) / 100.0f;
+  if (tray_view())
+    tray_view()->SetVisible(GetInitialVisibility());
+
+  if (volume_view_) {
+    volume_view_->SetVolumeLevel(percent);
+    SetDetailedViewCloseDelay(kTrayPopupAutoCloseDelayInSeconds);
+    return;
+  }
+  pop_up_volume_view_ = true;
+  PopupDetailedView(kTrayPopupAutoCloseDelayInSeconds, false);
+}
+
+void TrayAudio::OnOutputMuteChanged() {
+  if (tray_view())
+      tray_view()->SetVisible(GetInitialVisibility());
+
+  if (volume_view_) {
+    volume_view_->Update();
+    SetDetailedViewCloseDelay(kTrayPopupAutoCloseDelayInSeconds);
+  } else {
+    pop_up_volume_view_ = true;
+    PopupDetailedView(kTrayPopupAutoCloseDelayInSeconds, false);
+  }
+}
+
+void TrayAudio::OnAudioNodesChanged() {
+  Update();
+}
+
+void TrayAudio::OnActiveOutputNodeChanged() {
+  Update();
+}
+
+void TrayAudio::OnActiveInputNodeChanged() {
+  Update();
+}
+
+void TrayAudio::Update() {
+  if (tray_view())
+      tray_view()->SetVisible(GetInitialVisibility());
+  if (volume_view_) {
+    volume_view_->SetVolumeLevel(
+        static_cast<float>(audio_delegate_->GetOutputVolumeLevel()) / 100.0f);
+    volume_view_->Update();
+  }
+}
+
+}  // namespace internal
+}  // namespace ash