Make the mute button in the Ash system menu keyboard focusable

ash/common/system/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/audio/volume_view.h"
 
 #include "ash/common/ash_constants.h"
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/metrics/user_metrics_action.h"
 #include "ash/common/system/audio/tray_audio.h"
 #include "ash/common/system/audio/tray_audio_delegate.h"
 #include "ash/common/system/tray/system_tray_item.h"
 #include "ash/common/system/tray/tray_constants.h"
 #include "ash/common/system/tray/tray_popup_item_container.h"
 #include "ash/common/wm_shell.h"
 #include "grit/ash_resources.h"
 #include "grit/ash_strings.h"
+#include "ui/accessibility/ax_view_state.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/image/image_skia_operations.h"
 #include "ui/gfx/paint_vector_icon.h"
 #include "ui/gfx/vector_icons_public.h"
 #include "ui/views/background.h"
 #include "ui/views/border.h"
 #include "ui/views/controls/button/image_button.h"
 #include "ui/views/controls/image_view.h"
 #include "ui/views/controls/separator.h"
 #include "ui/views/layout/box_layout.h"
+#include "ui/views/painter.h"
 
 namespace {
 const int kVolumeImageWidth = 25;
 const int kVolumeImageHeight = 25;
 const int kSeparatorSize = 3;
 const int kSeparatorVerticalInset = 8;
 const int kSliderRightPaddingToVolumeViewEdge = 17;
 const int kExtraPaddingBetweenBarAndMore = 10;
 const int kExtraPaddingBetweenIconAndSlider = 8;
 const int kBoxLayoutPadding = 2;
 
 // IDR_AURA_UBER_TRAY_VOLUME_LEVELS contains 5 images,
 // The one for mute is at the 0 index and the other
 // four are used for ascending volume levels.
 const int kVolumeLevels = 4;
 
 }  // namespace
 
 namespace ash {
 namespace tray {
 
 class VolumeButton : public views::ToggleImageButton {
  public:
   VolumeButton(views::ButtonListener* listener,
                system::TrayAudioDelegate* audio_delegate)
       : views::ToggleImageButton(listener),
         audio_delegate_(audio_delegate),
         image_index_(-1) {
+    SetFocusBehavior(FocusBehavior::ALWAYS);
+    SetFocusPainter(views::Painter::CreateSolidFocusPainter(
+        kFocusBorderColor, gfx::Insets(1, 1, 1, 1)));
     SetImageAlignment(ALIGN_CENTER, ALIGN_MIDDLE);
     image_ = ui::ResourceBundle::GetSharedInstance().GetImageNamed(
         IDR_AURA_UBER_TRAY_VOLUME_LEVELS);
     Update();
   }
 
   ~VolumeButton() override {}
 
   void Update() {
     float level =
@@ skipping 15 matching lines @@
   }
 
  private:
   // views::View:
   gfx::Size GetPreferredSize() const override {
     gfx::Size size = views::ToggleImageButton::GetPreferredSize();
     size.set_height(GetTrayConstant(TRAY_POPUP_ITEM_HEIGHT));
     return size;
   }
 
+  void GetAccessibleState(ui::AXViewState* state) override {
+    ui::ResourceBundle& bundle = ui::ResourceBundle::GetSharedInstance();
+    state->name = bundle.GetLocalizedString(IDS_ASH_STATUS_TRAY_VOLUME_MUTE);
+    state->role = ui::AX_ROLE_TOGGLE_BUTTON;
+    if (audio_delegate_->IsOutputAudioMuted())
+      state->AddStateFlag(ui::AX_STATE_PRESSED);
+  }
+
   // views::CustomButton:
   void StateChanged() override {
     if (state() == STATE_HOVERED || state() == STATE_PRESSED) {
       set_background(
           views::Background::CreateSolidBackground(kHoverBackgroundColor));
     } else {
       set_background(nullptr);
     }
   }
 
@@ skipping 188 matching lines @@
   separator_->SetSize(gfx::Size(kSeparatorSize, bounds().height()));
 }
 
 void VolumeView::GetAccessibleState(ui::AXViewState* state) {
   // Intentionally overrides ActionableView, leaving |state| unset. A slider
   // childview exposes accessibility data.
 }
 
 }  // namespace tray
 }  // namespace ash