Add stylus battery status behind feature flag

This CL adds a feature flag for stylus battery
status in the stylus tools menu.
Also adds skeleton code to set up the UI to be
hooked up with backend CL in a subsequent CL.

Bug: 1158537
Change-Id: I873c1dac4827a64e0f66a18aa63a4df1e0c44036
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2590366
Commit-Queue: Ahmed Mehfooz <amehfooz@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#837886}

ash/BUILD.gn

@@ -1171,6 +1171,8 @@ component("ash") {
     "system/palette/palette_utils.h",
     "system/palette/palette_welcome_bubble.cc",
     "system/palette/palette_welcome_bubble.h",
+    "system/palette/stylus_battery_delegate.cc",
+    "system/palette/stylus_battery_delegate.h",
     "system/palette/tools/capture_region_mode.cc",
     "system/palette/tools/capture_region_mode.h",
     "system/palette/tools/capture_screen_action.cc",

ash/ash_strings.grd

@@ -1209,6 +1209,15 @@ This file contains the strings for ash.
         Silence phone is not available on work profile
       </message>
       
+      <message name="IDS_ASH_STYLUS_BATTERY_LOW_LABEL">
+        Low
+      </message>
+      <message name="IDS_ASH_STYLUS_BATTERY_MED_LABEL">
+        Med
+      </message>
+      <message name="IDS_ASH_STYLUS_BATTERY_HI_LABEL">
+        Hi
+      </message>
       <message name="IDS_ASH_STYLUS_TOOLS_CAPTURE_REGION_ACTION" desc="Title of the capture region action in the stylus tools (a pop-up panel next to the status tray). This causes a partial screenshot to be taken (the user selects an area of the screen to take a screenshot of).">
         Capture region
       </message>

ash/ash_strings_grd/IDS_ASH_STYLUS_BATTERY_HI_LABEL.png.sha1

+f9dfa5adb30c929b0694cbf46ed7893fee05d1fb
\ No newline at end of file

ash/ash_strings_grd/IDS_ASH_STYLUS_BATTERY_LOW_LABEL.png.sha1

+8491abd1aa9f1928d8d1b968e215718da80f9304
\ No newline at end of file

ash/ash_strings_grd/IDS_ASH_STYLUS_BATTERY_MED_LABEL.png.sha1

+a2bda703b9e32c023a76e2845d05b1c17718630e
\ No newline at end of file

ash/public/cpp/ash_features.cc

@@ -131,6 +131,9 @@ const base::Feature kReverseScrollGestures{"EnableReverseScrollGestures",
 const base::Feature kFullscreenAlertBubble{"EnableFullscreenBubble",
                                            base::FEATURE_DISABLED_BY_DEFAULT};
 
+const base::Feature kStylusBatteryStatus{"StylusBatteryStatus",
+                                         base::FEATURE_DISABLED_BY_DEFAULT};
+
 const base::Feature kSystemTrayMicGainSetting{"SystemTrayMicGainSetting",
                                               base::FEATURE_ENABLED_BY_DEFAULT};
 
@@ -290,6 +293,10 @@ bool AreContextualNudgesEnabled() {
   return base::FeatureList::IsEnabled(kContextualNudges);
 }
 
+bool IsStylusBatteryStatusEnabled() {
+  return base::FeatureList::IsEnabled(kStylusBatteryStatus);
+}
+
 bool IsSystemTrayMicGainSettingEnabled() {
   return base::FeatureList::IsEnabled(kSystemTrayMicGainSetting);
 }

ash/public/cpp/ash_features.h

@@ -178,6 +178,9 @@ ASH_PUBLIC_EXPORT extern const base::Feature kReverseScrollGestures;
 // TODO(https://crbug.com/1107185): Remove this after the feature is launched.
 ASH_PUBLIC_EXPORT extern const base::Feature kFullscreenAlertBubble;
 
+// Enables battery indicator for styluses in the palette tray
+ASH_PUBLIC_EXPORT extern const base::Feature kStylusBatteryStatus;
+
 // Enables sliders for setting mic gain levels in the more audio settings
 // section in the system tray.
 ASH_PUBLIC_EXPORT extern const base::Feature kSystemTrayMicGainSetting;
@@ -267,6 +270,8 @@ ASH_PUBLIC_EXPORT bool AreContextualNudgesEnabled();
 
 ASH_PUBLIC_EXPORT bool IsSystemTrayMicGainSettingEnabled();
 
+ASH_PUBLIC_EXPORT bool IsStylusBatteryStatusEnabled();
+
 ASH_PUBLIC_EXPORT bool IsDisplayIdentificationEnabled();
 
 ASH_PUBLIC_EXPORT bool IsWebUITabStripTabDragIntegrationEnabled();

ash/system/palette/palette_tray.cc

@@ -7,6 +7,7 @@
 #include <memory>
 
 #include "ash/accessibility/accessibility_controller_impl.h"
+#include "ash/public/cpp/ash_features.h"
 #include "ash/public/cpp/ash_pref_names.h"
 #include "ash/public/cpp/shelf_config.h"
 #include "ash/public/cpp/stylus_utils.h"
@@ -21,6 +22,7 @@
 #include "ash/system/palette/palette_tool_manager.h"
 #include "ash/system/palette/palette_utils.h"
 #include "ash/system/palette/palette_welcome_bubble.h"
+#include "ash/system/palette/stylus_battery_delegate.h"
 #include "ash/system/tray/tray_background_view.h"
 #include "ash/system/tray/tray_bubble_wrapper.h"
 #include "ash/system/tray/tray_container.h"
@@ -87,6 +89,26 @@ bool ShouldShowOnDisplay(PaletteTray* palette_tray) {
   return display.IsInternal();
 }
 
+class BatteryView : public views::View {
+ public:
+  explicit BatteryView(StylusBatteryDelegate* delegate) {
+    SetLayoutManager(std::make_unique<views::BoxLayout>(
+        views::BoxLayout::Orientation::kHorizontal, gfx::Insets(), 4));
+
+    icon_ = AddChildView(std::make_unique<views::ImageView>());
+    icon_->SetImage(delegate->GetBatteryImage());
+    label_ = AddChildView(std::make_unique<views::Label>(
+        l10n_util::GetStringUTF16(delegate->GetLabelIdForBatteryLevel())));
+    label_->SetEnabledColor(delegate->GetColorForBatteryLevel());
+    TrayPopupUtils::SetLabelFontList(label_,
+                                     TrayPopupUtils::FontStyle::kSmallTitle);
+  }
+
+ private:
+  views::ImageView* icon_ = nullptr;
+  views::Label* label_ = nullptr;
+};
+
 class TitleView : public views::View {
  public:
   explicit TitleView(PaletteTray* palette_tray) : palette_tray_(palette_tray) {
@@ -107,6 +129,17 @@ class TitleView : public views::View {
     TrayPopupUtils::SetLabelFontList(title_label,
                                      TrayPopupUtils::FontStyle::kPodMenuHeader);
     layout_ptr->SetFlexForView(title_label, 1);
+
+    if (ash::features::IsStylusBatteryStatusEnabled()) {
+      AddChildView(std::make_unique<BatteryView>(
+          palette_tray->stylus_battery_delegate()));
+
+      auto* separator = AddChildView(std::make_unique<views::Separator>());
+      separator->SetPreferredHeight(GetPreferredSize().height());
+      separator->SetColor(AshColorProvider::Get()->GetContentLayerColor(
+          AshColorProvider::ContentLayerType::kSeparatorColor));
+    }
+
     help_button_ = AddChildView(std::make_unique<TopShortcutButton>(
         base::BindRepeating(
             &TitleView::ButtonPressed, base::Unretained(this),

ash/system/palette/palette_tray.h

@@ -11,6 +11,7 @@
 #include "ash/public/cpp/session/session_observer.h"
 #include "ash/shell_observer.h"
 #include "ash/system/palette/palette_tool_manager.h"
+#include "ash/system/palette/stylus_battery_delegate.h"
 #include "ash/system/tray/tray_background_view.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
@@ -91,6 +92,10 @@ class ASH_EXPORT PaletteTray : public TrayBackgroundView,
                                  PaletteInvocationMethod method) override;
   void RecordPaletteModeCancellation(PaletteModeCancelType type) override;
 
+  StylusBatteryDelegate* stylus_battery_delegate() {
+    return &stylus_battery_delegate_;
+  }
+
  private:
   friend class PaletteTrayTestApi;
 
@@ -155,6 +160,8 @@ class ASH_EXPORT PaletteTray : public TrayBackgroundView,
   // Number of actions in pen palette bubble.
   int num_actions_in_bubble_ = 0;
 
+  StylusBatteryDelegate stylus_battery_delegate_;
+
   ScopedSessionObserver scoped_session_observer_;
 
   base::WeakPtrFactory<PaletteTray> weak_factory_{this};

ash/system/palette/stylus_battery_delegate.cc

+// Copyright 2020 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/palette/stylus_battery_delegate.h"
+
+#include "ash/shell.h"
+#include "ash/strings/grit/ash_strings.h"
+#include "ash/style/ash_color_provider.h"
+#include "ash/system/power/power_status.h"
+#include "ash/system/tray/tray_constants.h"
+#include "base/strings/string16.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/gfx/color_palette.h"
+
+namespace ash {
+namespace {
+// Battery percentage thresholds to used to label the battery level
+// as Hi, Med or Low.
+constexpr int kStylusLowBatteryThreshold = 24;
+constexpr int kStylusMediumBatteryThreshold = 71;
+}  // namespace
+
+StylusBatteryDelegate::StylusBatteryDelegate() = default;
+
+SkColor StylusBatteryDelegate::GetColorForBatteryLevel() const {
+  if (battery_level_ <= kStylusLowBatteryThreshold) {
+    return AshColorProvider::Get()->GetContentLayerColor(
+        AshColorProvider::ContentLayerType::kIconColorAlert);
+  }
+  return AshColorProvider::Get()->GetContentLayerColor(
+      AshColorProvider::ContentLayerType::kIconColorPositive);
+}
+
+int StylusBatteryDelegate::GetLabelIdForBatteryLevel() const {
+  if (battery_level_ <= kStylusLowBatteryThreshold) {
+    return IDS_ASH_STYLUS_BATTERY_LOW_LABEL;
+  }
+  if (battery_level_ <= kStylusMediumBatteryThreshold) {
+    return IDS_ASH_STYLUS_BATTERY_MED_LABEL;
+  }
+  return IDS_ASH_STYLUS_BATTERY_HI_LABEL;
+}
+
+gfx::ImageSkia StylusBatteryDelegate::GetBatteryImage() const {
+  PowerStatus::BatteryImageInfo info;
+  info.charge_percent = battery_level_.value_or(0);
+
+  const SkColor icon_fg_color = GetColorForBatteryLevel();
+  const SkColor icon_bg_color = AshColorProvider::Get()->GetBackgroundColor();
+
+  return PowerStatus::GetBatteryImage(info, kUnifiedTrayIconSize, icon_bg_color,
+                                      icon_fg_color);
+}
+
+}  // namespace ash

ash/system/palette/stylus_battery_delegate.h

+// Copyright 2020 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.
+
+#ifndef ASH_SYSTEM_PALETTE_STYLUS_BATTERY_DELEGATE_H_
+#define ASH_SYSTEM_PALETTE_STYLUS_BATTERY_DELEGATE_H_
+
+#include "ash/ash_export.h"
+#include "base/scoped_observer.h"
+#include "base/strings/string16.h"
+#include "ui/gfx/image/image_skia.h"
+
+namespace ash {
+
+class ASH_EXPORT StylusBatteryDelegate {
+ public:
+  StylusBatteryDelegate();
+  StylusBatteryDelegate(const StylusBatteryDelegate& other) = delete;
+  StylusBatteryDelegate& operator=(const StylusBatteryDelegate& other) = delete;
+
+  SkColor GetColorForBatteryLevel() const;
+  int GetLabelIdForBatteryLevel() const;
+  gfx::ImageSkia GetBatteryImage() const;
+
+  base::Optional<uint8_t> battery_level() const { return battery_level_; }
+
+ private:
+  base::Optional<uint8_t> battery_level_;
+
+  // Peripheral battery observer to be added here.
+};
+
+}  // namespace ash
+
+#endif  // ASH_SYSTEM_PALETTE_STYLUS_BATTERY_DELEGATE_H_