Use correct theme for the off icon of NightLight, fix tooltip and a11y

ash/system/tiles/tiles_default_view.cc

 // Copyright 2016 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/system/tiles/tiles_default_view.h"
 
 #include "ash/metrics/user_metrics_action.h"
 #include "ash/resources/vector_icons/vector_icons.h"
 #include "ash/session/session_controller.h"
 #include "ash/shell.h"
 #include "ash/shell_port.h"
 #include "ash/shutdown_controller.h"
 #include "ash/strings/grit/ash_strings.h"
 #include "ash/system/night_light/night_light_controller.h"
 #include "ash/system/tray/system_menu_button.h"
 #include "ash/system/tray/system_tray.h"
 #include "ash/system/tray/system_tray_controller.h"
 #include "ash/system/tray/system_tray_item.h"
 #include "ash/system/tray/tray_constants.h"
+#include "ash/system/tray/tray_popup_item_style.h"
 #include "ash/system/tray/tray_popup_utils.h"
 #include "ash/wm/lock_state_controller.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/session_manager_client.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/geometry/insets.h"
+#include "ui/gfx/paint_vector_icon.h"
 #include "ui/views/border.h"
 #include "ui/views/controls/button/custom_button.h"
 #include "ui/views/controls/separator.h"
 #include "ui/views/layout/box_layout.h"
 
 namespace ash {
 
 namespace {
 
 // The ISO-639 code for the Hebrew locale. The help icon asset is a '?' which is
 // not mirrored in this locale.
 const char kHebrewLocale[] = "he";
 
-const gfx::VectorIcon& GetNightLightButtonIcon() {
-  return Shell::Get()->night_light_controller()->GetEnabled()
-             ? kSystemMenuNightLightOnIcon
-             : kSystemMenuNightLightOffIcon;
+// Updates the icon and its style of the NightLight toggle button based on the
+// status of NightLight.
+void UpdateNightLightButtonStyle(SystemMenuButton* night_light_button) {
+  // Use the same icon theme used for inactive items in the tray when
+  // NightLight is not active.
+  SkColor normal_color = TrayPopupItemStyle::GetIconColor(
+      TrayPopupItemStyle::ColorStyle::INACTIVE);
+  const gfx::VectorIcon* icon = &kSystemMenuNightLightOffIcon;
+
+  if (Shell::Get()->night_light_controller()->GetEnabled()) {
+    normal_color = kMenuIconColor;
+    icon = &kSystemMenuNightLightOnIcon;
+  }
+
+  night_light_button->SetImage(views::Button::STATE_NORMAL,
+                               gfx::CreateVectorIcon(*icon, normal_color));
+  night_light_button->SetImage(
+      views::Button::STATE_DISABLED,
+      gfx::CreateVectorIcon(*icon, kMenuIconColorDisabled));

[James Cook, 2017/05/25 02:08:45]

I'm finding this hard to follow. How about creating the 3 icons you need
(apparently normal-state enabled, normal-state disabled, disabled-state
disabled) once TilesDefaultView once and providing 1 or 2 utility functions that
returns the one you need?
 
That might avoid the strange "make it in the off state then fix it" trick below.

[afakhry, 2017/05/25 03:17:54]

Please take a look at the new code. I created a class for the NightLight button
so that I can change its accessibility settings.

I think we might also consider adding another constructor to SystemMenuButton
that doesn't require a VectorIcon.

 }
 
 }  // namespace
 
 TilesDefaultView::TilesDefaultView(SystemTrayItem* owner)
     : owner_(owner),
       settings_button_(nullptr),
       help_button_(nullptr),
       night_light_button_(nullptr),
       lock_button_(nullptr),
@@ skipping 31 matching lines @@
       base::i18n::GetConfiguredLocale() == kHebrewLocale) {
     // The asset for the help button is a question mark '?'. Normally this asset
     // is flipped in RTL locales, however Hebrew uses the LTR '?'. So the
     // flipping must be disabled. (crbug.com/475237)
     help_button_->EnableCanvasFlippingForRTLUI(false);
   }
   help_button_->SetEnabled(can_show_web_ui);
   AddChildView(help_button_);
   AddChildView(TrayPopupUtils::CreateVerticalSeparator());
 
+  // Temporarily create the button with the "Off" icon. Calling
+  // UpdateNightLightButtonStyle() below will set the correct icon and its theme
+  // based on the current status of NightLight.
   night_light_button_ = new SystemMenuButton(
-      this, TrayPopupInkDropStyle::HOST_CENTERED, GetNightLightButtonIcon(),
+      this, TrayPopupInkDropStyle::HOST_CENTERED, kSystemMenuNightLightOffIcon,
       IDS_ASH_STATUS_TRAY_NIGHT_LIGHT);
+  UpdateNightLightButtonStyle(night_light_button_);
   night_light_button_->SetEnabled(can_show_web_ui);
   AddChildView(night_light_button_);
   AddChildView(TrayPopupUtils::CreateVerticalSeparator());
 
   lock_button_ =
       new SystemMenuButton(this, TrayPopupInkDropStyle::HOST_CENTERED,
                            kSystemMenuLockIcon, IDS_ASH_STATUS_TRAY_LOCK);
   lock_button_->SetEnabled(can_show_web_ui &&
                            Shell::Get()->session_controller()->CanLockScreen());
 
@@ skipping 16 matching lines @@
   DCHECK(sender);
   if (sender == settings_button_) {
     ShellPort::Get()->RecordUserMetricsAction(UMA_TRAY_SETTINGS);
     Shell::Get()->system_tray_controller()->ShowSettings();
   } else if (sender == help_button_) {
     ShellPort::Get()->RecordUserMetricsAction(UMA_TRAY_HELP);
     Shell::Get()->system_tray_controller()->ShowHelp();
   } else if (sender == night_light_button_) {
     ShellPort::Get()->RecordUserMetricsAction(UMA_TRAY_NIGHT_LIGHT);
     Shell::Get()->night_light_controller()->Toggle();
-    night_light_button_->SetVectorIcon(GetNightLightButtonIcon());
+    UpdateNightLightButtonStyle(night_light_button_);
   } else if (sender == lock_button_) {
     ShellPort::Get()->RecordUserMetricsAction(UMA_TRAY_LOCK_SCREEN);
     chromeos::DBusThreadManager::Get()
         ->GetSessionManagerClient()
         ->RequestLockScreen();
   } else if (sender == power_button_) {
     ShellPort::Get()->RecordUserMetricsAction(UMA_TRAY_SHUT_DOWN);
     Shell::Get()->lock_state_controller()->RequestShutdown();
   }
 }
 
 views::View* TilesDefaultView::GetHelpButtonView() const {
   return help_button_;
 }
 
 const views::CustomButton* TilesDefaultView::GetShutdownButtonViewForTest()
     const {
   return power_button_;
 }
 
 }  // namespace ash