GH-583: [api-fix] Power / Battery

DeviceTests/DeviceTests.Shared/Battery_Tests.cs

@@ -42,5 +42,11 @@ public void Charge_Power()
 
             Assert.NotEqual(BatteryPowerSource.Unknown, Battery.PowerSource);
         }
+
+        [Fact]
+        public void App_Is_Not_Lower_Power_mode()
+        {
+            Assert.Equal(EnergySaverStatus.Off, Battery.EnergySaverStatus);
+        }
     }
 }

README.md

@@ -67,7 +67,6 @@ The following cross-platform APIs are available in Xamarin.Essentials:
 * [Open Browser](https://docs.microsoft.com/xamarin/essentials/open-browser)
 * [Orientation Sensor](https://docs.microsoft.com/en-us/xamarin/essentials/orientation-sensor)
 * [Phone Dialer](https://docs.microsoft.com/xamarin/essentials/phone-dialer)
-* [Power](https://docs.microsoft.com/en-us/xamarin/essentials/power)
 * [Preferences](https://docs.microsoft.com/xamarin/essentials/preferences)
 * [Screen Lock](https://docs.microsoft.com/xamarin/essentials/screen-lock)
 * [Secure Storage](https://docs.microsoft.com/xamarin/essentials/secure-storage)

Samples/Samples/ViewModel/BatteryViewModel.cs

@@ -14,20 +14,20 @@ public BatteryViewModel()
 
         public BatteryPowerSource PowerSource => Battery.PowerSource;
 
-        public EnergySaverStatus EnergySaverStatus => Power.EnergySaverStatus;
+        public EnergySaverStatus EnergySaverStatus => Battery.EnergySaverStatus;
 
         public override void OnAppearing()
         {
             base.OnAppearing();
 
             Battery.BatteryChanged += OnBatteryChanged;
-            Power.EnergySaverStatusChanged += OnEnergySaverStatusChanged;
+            Battery.EnergySaverStatusChanged += OnEnergySaverStatusChanged;
         }
 
         public override void OnDisappearing()
         {
             Battery.BatteryChanged -= OnBatteryChanged;
-            Power.EnergySaverStatusChanged -= OnEnergySaverStatusChanged;
+            Battery.EnergySaverStatusChanged -= OnEnergySaverStatusChanged;
 
             base.OnDisappearing();
         }

Xamarin.Essentials/Battery/Battery.android.cs

@@ -1,13 +1,51 @@
 using System;
 using Android.Content;
 using Android.OS;
-using Debug = System.Diagnostics.Debug;
 
 namespace Xamarin.Essentials
 {
     public static partial class Battery
     {
         static BatteryBroadcastReceiver batteryReceiver;
+        static EnergySaverBroadcastReceiver powerReceiver;
+
+        static void StartEnergySaverListeners()
+        {
+            if (!Platform.HasApiLevel(BuildVersionCodes.Lollipop))
+                return;
+
+            powerReceiver = new EnergySaverBroadcastReceiver(OnEnergySaverChanged);
+            Platform.AppContext.RegisterReceiver(powerReceiver, new IntentFilter(PowerManager.ActionPowerSaveModeChanged));
+        }
+
+        static void StopEnergySaverListeners()
+        {
+            if (!Platform.HasApiLevel(BuildVersionCodes.Lollipop))
+                return;
+
+            try
+            {
+                Platform.AppContext.UnregisterReceiver(powerReceiver);
+            }
+            catch (Java.Lang.IllegalArgumentException)
+            {
+                System.Diagnostics.Debug.WriteLine("Energy saver receiver already unregistered. Disposing of it.");
+            }
+            powerReceiver.Dispose();
+            powerReceiver = null;
+        }
+
+        static EnergySaverStatus PlatformEnergySaverStatus
+        {
+            get
+            {
+                var status = false;
+                if (Platform.HasApiLevel(BuildVersionCodes.Lollipop))
+                    status = Platform.PowerManager?.IsPowerSaveMode ?? false;
+
+                return status ? EnergySaverStatus.On : EnergySaverStatus.Off;
+            }
+        }
 
         static void StartBatteryListeners()
         {
@@ -25,7 +63,7 @@ static void StopBatteryListeners()
             }
             catch (Java.Lang.IllegalArgumentException)
             {
-                Debug.WriteLine("Battery receiver already unregistered. Disposing of it.");
+                System.Diagnostics.Debug.WriteLine("Battery receiver already unregistered. Disposing of it.");
             }
             batteryReceiver.Dispose();
             batteryReceiver = null;
@@ -44,7 +82,7 @@ static double PlatformChargeLevel
                     var scale = battery.GetIntExtra(BatteryManager.ExtraScale, -1);
 
                     if (scale <= 0)
-                        return -1;
+                        return 1.0;
 
                     return (double)level / (double)scale;
                 }
@@ -119,4 +157,20 @@ public BatteryBroadcastReceiver(Action onChanged) =>
         public override void OnReceive(Context context, Intent intent) =>
             onChanged?.Invoke();
     }
+
+    [BroadcastReceiver(Enabled = true, Exported = false, Label = "Essentials Energy Saver Broadcast Receiver")]
+    class EnergySaverBroadcastReceiver : BroadcastReceiver
+    {
+        Action onChanged;
+
+        public EnergySaverBroadcastReceiver()
+        {
+        }
+
+        public EnergySaverBroadcastReceiver(Action onChanged) =>
+            this.onChanged = onChanged;
+
+        public override void OnReceive(Context context, Intent intent) =>
+            onChanged?.Invoke();
+    }
 }

Xamarin.Essentials/Battery/Battery.ios.cs

@@ -7,6 +7,24 @@ public static partial class Battery
     {
         static NSObject levelObserver;
         static NSObject stateObserver;
+        static NSObject saverStatusObserver;
+
+        static void StartEnergySaverListeners()
+        {
+            saverStatusObserver = NSNotificationCenter.DefaultCenter.AddObserver(NSProcessInfo.PowerStateDidChangeNotification, PowerChangedNotification);
+        }
+
+        static void StopEnergySaverListeners()
+        {
+            saverStatusObserver?.Dispose();
+            saverStatusObserver = null;
+        }
+
+        static void PowerChangedNotification(NSNotification notification)
+            => MainThread.BeginInvokeOnMainThread(OnEnergySaverChanged);
+
+        static EnergySaverStatus PlatformEnergySaverStatus =>
+            NSProcessInfo.ProcessInfo?.LowPowerModeEnabled == true ? EnergySaverStatus.On : EnergySaverStatus.Off;
 
         static void StartBatteryListeners()
         {

Xamarin.Essentials/Battery/Battery.netstandard.cs

@@ -16,5 +16,14 @@ static void StopBatteryListeners() =>
 
         static BatteryPowerSource PlatformPowerSource =>
             throw new NotImplementedInReferenceAssemblyException();
+
+        static void StartEnergySaverListeners() =>
+            throw new NotImplementedInReferenceAssemblyException();
+
+        static void StopEnergySaverListeners() =>
+            throw new NotImplementedInReferenceAssemblyException();
+
+        static EnergySaverStatus PlatformEnergySaverStatus =>
+            throw new NotImplementedInReferenceAssemblyException();
     }
 }

Xamarin.Essentials/Battery/Battery.shared.cs

@@ -6,6 +6,8 @@ public static partial class Battery
     {
         static event EventHandler<BatteryChangedEventArgs> BatteryChangedInternal;
 
+        static event EventHandler<EnergySaverStatusChangedEventArgs> EnergySaverStatusChangedInternal;
+
         // a cache so that events aren't fired unnecessarily
         // this is mainly an issue on Android, but we can stiil do this everywhere
         static double currentLevel;
@@ -18,6 +20,8 @@ public static partial class Battery
 
         public static BatteryPowerSource PowerSource => PlatformPowerSource;
 
+        public static EnergySaverStatus EnergySaverStatus => PlatformEnergySaverStatus;
+
         public static event EventHandler<BatteryChangedEventArgs> BatteryChanged
         {
             add
@@ -44,6 +48,29 @@ public static event EventHandler<BatteryChangedEventArgs> BatteryChanged
             }
         }
 
+        public static event EventHandler<EnergySaverStatusChangedEventArgs> EnergySaverStatusChanged
+        {
+            add
+            {
+                var wasRunning = EnergySaverStatusChangedInternal != null;
+
+                EnergySaverStatusChangedInternal += value;
+
+                if (!wasRunning && EnergySaverStatusChangedInternal != null)
+                    StartEnergySaverListeners();
+            }
+
+            remove
+            {
+                var wasRunning = EnergySaverStatusChangedInternal != null;
+
+                EnergySaverStatusChangedInternal -= value;
+
+                if (wasRunning && EnergySaverStatusChangedInternal == null)
+                    StopEnergySaverListeners();
+            }
+        }
+
         static void SetCurrent()
         {
             currentLevel = Battery.ChargeLevel;
@@ -65,6 +92,15 @@ static void OnBatteryChanged(BatteryChangedEventArgs e)
                 BatteryChangedInternal?.Invoke(null, e);
             }
         }
+
+        static void OnEnergySaverChanged()
+            => OnEnergySaverChanged(EnergySaverStatus);
+
+        static void OnEnergySaverChanged(EnergySaverStatus saverStatus)
+            => OnEnergySaverChanged(new EnergySaverStatusChangedEventArgs(saverStatus));
+
+        static void OnEnergySaverChanged(EnergySaverStatusChangedEventArgs e)
+            => EnergySaverStatusChangedInternal?.Invoke(null, e);
     }
 
     public enum BatteryState
@@ -86,6 +122,13 @@ public enum BatteryPowerSource
         Wireless
     }
 
+    public enum EnergySaverStatus
+    {
+        Unknown,
+        On,
+        Off
+    }
+
     public class BatteryChangedEventArgs : EventArgs
     {
         internal BatteryChangedEventArgs(double level, BatteryState state, BatteryPowerSource source)
@@ -106,4 +149,17 @@ public override string ToString() =>
             $"{nameof(State)}: {State}, " +
             $"{nameof(PowerSource)}: {PowerSource}";
     }
+
+    public class EnergySaverStatusChangedEventArgs : EventArgs
+    {
+        internal EnergySaverStatusChangedEventArgs(EnergySaverStatus saverStatus)
+        {
+            EnergySaverStatus = saverStatus;
+        }
+
+        public EnergySaverStatus EnergySaverStatus { get; }
+
+        public override string ToString() =>
+            $"{nameof(EnergySaverStatus)}: {EnergySaverStatus}";
+    }
 }

Xamarin.Essentials/Battery/Battery.uwp.cs

@@ -1,7 +1,18 @@
-namespace Xamarin.Essentials
+using Windows.System.Power;
+
+namespace Xamarin.Essentials
 {
     public static partial class Battery
     {
+        static void StartEnergySaverListeners() =>
+            PowerManager.EnergySaverStatusChanged += ReportEnergySaverUpdated;
+
+        static void StopEnergySaverListeners() =>
+            PowerManager.EnergySaverStatusChanged -= ReportEnergySaverUpdated;
+
+        static void ReportEnergySaverUpdated(object sender, object e)
+            => MainThread.BeginInvokeOnMainThread(OnEnergySaverChanged);
+
         static void StartBatteryListeners() =>
             DefaultBattery.ReportUpdated += ReportUpdated;
 
@@ -19,7 +30,7 @@ static double PlatformChargeLevel
             get
             {
                 var finalReport = DefaultBattery.GetReport();
-                var finalPercent = -1.0;
+                var finalPercent = 1.0;
 
                 var remaining = finalReport.RemainingCapacityInMilliwattHours;
                 var full = finalReport.FullChargeCapacityInMilliwattHours;
@@ -39,15 +50,15 @@ static BatteryState PlatformState
 
                 switch (report.Status)
                 {
-                    case Windows.System.Power.BatteryStatus.Charging:
+                    case BatteryStatus.Charging:
                         return BatteryState.Charging;
-                    case Windows.System.Power.BatteryStatus.Discharging:
+                    case BatteryStatus.Discharging:
                         return BatteryState.Discharging;
-                    case Windows.System.Power.BatteryStatus.Idle:
+                    case BatteryStatus.Idle:
                         if (ChargeLevel >= 1.0)
                             return BatteryState.Full;
                         return BatteryState.NotCharging;
-                    case Windows.System.Power.BatteryStatus.NotPresent:
+                    case BatteryStatus.NotPresent:
                         return BatteryState.NotPresent;
                 }
 
@@ -75,5 +86,8 @@ static BatteryPowerSource PlatformPowerSource
                 }
             }
         }
+
+        static EnergySaverStatus PlatformEnergySaverStatus =>
+            PowerManager.EnergySaverStatus == Windows.System.Power.EnergySaverStatus.On ? EnergySaverStatus.On : EnergySaverStatus.Off;
     }
 }