#2: PowerMateVolume: receive reliable notifications when the computer…

… resumes from standby, so device settings can be reset
Aldaviva · Jul 15, 2023 · 74af5bb · 74af5bb
1 parent c200d93
commit 74af5bb
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Showing 7 changed files with 126 additions and 26 deletions.
diff --git a/Demo/Demo.cs b/Demo/Demo.cs
@@ -2,17 +2,32 @@
 
 using IPowerMateClient powerMate = new PowerMateClient();
 
-powerMate.LightBrightness = 255;
+powerMate.LightBrightness = 128;
+// powerMate.LightPulseSpeed = 3;
+// powerMate.LightAnimation  = LightAnimation.Pulsing;
+Console.WriteLine($"Set brightness to {powerMate.LightBrightness}.");
 
 powerMate.IsConnectedChanged += (_, isConnected) => Console.WriteLine(isConnected ? "Connected to PowerMate" : "Disconnected from PowerMate, attempting reconnection");
 
-powerMate.InputReceived += (_, input) => Console.WriteLine($"Received event from PowerMate: {input}");
+// powerMate.InputReceived += (_, input) => Console.WriteLine($"Received event from PowerMate: {input}");
+
+// using Timer               parameterChangeTimer = new(_ => { Console.WriteLine(DateTime.Now); }, null, 0, 10000);
+// using Timer timer2 = new(10000) { AutoReset = true, Enabled = true };
+// timer2.Elapsed += (_, _) => Console.WriteLine(DateTime.Now);
+
+Console.WriteLine(powerMate.IsConnected ? "Listening for PowerMate events" : "Waiting for PowerMate to be connected");
+using Timer setAllFeaturesTimer = new(_ => {
+    try {
+        bool didSetFeatures = powerMate.SetAllFeaturesIfStale();
+        Console.WriteLine($"Features {(didSetFeatures ? "were" : "were not")} reset automatically");
+    } catch (Exception e) {
+        Console.WriteLine("Exception while setting features: " + e);
+    }
+}, null, 0, 3000);
 
 CancellationTokenSource cancellationTokenSource = new();
 Console.CancelKeyPress += (_, eventArgs) => {
     eventArgs.Cancel = true;
     cancellationTokenSource.Cancel();
 };
-
-Console.WriteLine(powerMate.IsConnected ? "Listening for PowerMate events" : "Waiting for PowerMate to be connected");
 cancellationTokenSource.Token.WaitHandle.WaitOne();
diff --git a/PowerMate/IPowerMateClient.cs b/PowerMate/IPowerMateClient.cs
@@ -53,4 +53,6 @@ public interface IPowerMateClient: IHidClient {
     /// </summary>
     int LightPulseSpeed { get; set; }
 
+    bool SetAllFeaturesIfStale();
+
 }
diff --git a/PowerMate/PowerMateClient.cs b/PowerMate/PowerMateClient.cs
@@ -10,6 +10,8 @@ public class PowerMateClient: AbstractHidClient, IPowerMateClient {
 
     private const byte DefaultLightBrightness = 80;
 
+    private static readonly TimeSpan MinFeatureResetInterval = TimeSpan.FromMilliseconds(500);
+
     /// <inheritdoc />
     protected override int VendorId { get; } = 0x077d;
 
@@ -32,7 +34,7 @@ public PowerMateClient(DeviceList deviceList): base(deviceList) { }
 
     /// <inheritdoc />
     protected override void OnConnect() {
-        LightAnimation = LightAnimation; //resend all pulsing and brightness values to device
+        SetAllFeatures();
     }
 
     /// <inheritdoc />
@@ -41,12 +43,8 @@ protected override void OnHidRead(byte[] readBuffer) {
         PowerMateInput input = new(readBuffer);
         EventSynchronizationContext.Post(_ => { InputReceived?.Invoke(this, input); }, null);
 
-        if ((LightAnimation != input.ActualLightAnimation
-                || (LightAnimation != LightAnimation.Pulsing && LightBrightness != input.ActualLightBrightness)
-                || (LightAnimation == LightAnimation.Pulsing && LightPulseSpeed != input.ActualLightPulseSpeed))
-            && _mostRecentFeatureSetTime is not null && DateTime.Now - _mostRecentFeatureSetTime > TimeSpan.FromMilliseconds(500)) {
-            Console.WriteLine("Resetting features...");
-            LightAnimation = LightAnimation;
+        if (!AreDeviceFeaturesUpToDate(input) && EnoughTimeHasPassedThatFeaturesCanBeAutoReset()) {
+            SetAllFeatures();
         }
     }
 
@@ -123,6 +121,30 @@ private void SetFeature(PowerMateFeature feature, params byte[] payload) {
         }
     }
 
+    private bool AreDeviceFeaturesUpToDate(PowerMateInput deviceInput) =>
+        LightAnimation == deviceInput.ActualLightAnimation
+        && (LightAnimation == LightAnimation.Pulsing || LightBrightness == deviceInput.ActualLightBrightness)
+        && (LightAnimation != LightAnimation.Pulsing || LightPulseSpeed == deviceInput.ActualLightPulseSpeed);
+
+    private bool EnoughTimeHasPassedThatFeaturesCanBeAutoReset() => _mostRecentFeatureSetTime is not null && DateTime.Now - _mostRecentFeatureSetTime > MinFeatureResetInterval;
+
+    private void SetAllFeatures() {
+        LightAnimation = LightAnimation;
+    }
+
+    /// <inheritdoc />
+    public bool SetAllFeaturesIfStale() {
+        byte[] featureBuffer = new byte[9];
+        DeviceStream?.GetFeature(featureBuffer);
+
+        bool shouldSetFeatures = DeviceStream is not null && !AreDeviceFeaturesUpToDate(new PowerMateInput(featureBuffer)) && EnoughTimeHasPassedThatFeaturesCanBeAutoReset();
+        if (shouldSetFeatures) {
+            SetAllFeatures();
+        }
+
+        return shouldSetFeatures;
+    }
+
     /// <param name="pulseSpeed">in the range [0, 24]</param>
     /// <returns>two big-endian bytes to send to the PowerMate to set its pulsing speed</returns>
     private static byte[] EncodePulseSpeed(int pulseSpeed) {

diff --git a/PowerMateVolume/PowerMateVolume.cs b/PowerMateVolume/PowerMateVolume.cs
@@ -1,8 +1,7 @@
-using Microsoft.Win32;
-using PowerMate;
+using PowerMate;
 using PowerMateVolume;
 
-// ReSharper disable AccessToDisposedClosure - disposal happens at program shutdown, so access won't happen after that
+// ReSharper disable AccessToDisposedClosure - disposal happens at program shutdown, so access can't happen after that
 
 if (!float.TryParse(Environment.GetCommandLineArgs().ElementAtOrDefault(1), out float volumeIncrement)) {
     volumeIncrement = 0.01f;
@@ -35,12 +34,13 @@
     }
 };
 
-SystemEvents.PowerModeChanged += (_, args) => {
-    if (args.Mode == PowerModes.Resume) {
-        // #1: On Jarnsaxa, waking up from sleep resets the PowerMate's light settings, so set them all again
-        powerMate.LightAnimation = powerMate.LightAnimation;
-    }
-};
+using IStandbyListener standbyListener = new EventLogStandbyListener();
+standbyListener.FatalError += (_, exception) =>
+    MessageBox.Show("Event log subscription is broken, continuing without resume detection: " + exception, "PowerMateVolume", MessageBoxButtons.OK, MessageBoxIcon.Error);
+standbyListener.Resumed += (_, _) => MessageBox.Show(powerMate.SetAllFeaturesIfStale()
+        ? "On resume, PowerMate had wrong settings, so PowerMateVolume reset all the features on the device."
+        : "On resume, PowerMate had right settings, so PowerMateVolume did not reset the features on the device.",
+    "PowerMateVolume", MessageBoxButtons.OK, MessageBoxIcon.Information);
 
 Console.WriteLine("Listening for PowerMate events");
 cancellationTokenSource.Token.WaitHandle.WaitOne();
diff --git a/PowerMateVolume/PowerMateVolume.csproj b/PowerMateVolume/PowerMateVolume.csproj
@@ -12,7 +12,7 @@
         <Authors>Ben Hutchison</Authors>
         <Copyright>© 2023 $(Authors)</Copyright>
         <AssemblyTitle>PowerMate Volume</AssemblyTitle> <!-- File description -->
-        <Version>1.0.1</Version> <!-- Product version -->
+        <Version>1.0.2</Version> <!-- Product version -->
         <Product>$(AssemblyTitle)</Product> <!-- Product name -->
         <FileVersion>$(Version)</FileVersion> <!-- File version -->
         <ApplicationManifest>app.manifest</ApplicationManifest>
@@ -23,7 +23,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-      <Content Include="powermate.ico" />
+        <Content Include="powermate.ico" />
     </ItemGroup>
 
     <ItemGroup>

diff --git a/PowerMateVolume/StandbyEventEmitter.cs b/PowerMateVolume/StandbyEventEmitter.cs
@@ -0,0 +1,61 @@
+using System.Diagnostics.Eventing.Reader;
+
+namespace PowerMateVolume;
+
+public interface IStandbyListener: IDisposable {
+
+    event EventHandler StandingBy;
+    event EventHandler Resumed;
+    event EventHandler<Exception> FatalError;
+
+}
+
+public class EventLogStandbyListener: IStandbyListener {
+
+    public event EventHandler? StandingBy;
+    public event EventHandler? Resumed;
+    public event EventHandler<Exception>? FatalError;
+
+    private readonly EventLogWatcher _logWatcher;
+
+    /// <exception cref="EventLogNotFoundException">if the given event log or file was not found</exception>
+    /// <exception cref="UnauthorizedAccessException">if the log did not already exist and this program is not running elevated</exception>
+    public EventLogStandbyListener() {
+        _logWatcher = new EventLogWatcher(new EventLogQuery("System", PathType.LogName, "*[System[Provider/@Name=\"Microsoft-Windows-Kernel-Power\" and (EventID=42 or EventID=107)]]"));
+
+        _logWatcher.EventRecordWritten += onEventRecord;
+
+        try {
+            _logWatcher.Enabled = true;
+        } catch (EventLogNotFoundException) {
+            _logWatcher.Dispose();
+            throw;
+        } catch (UnauthorizedAccessException) {
+            _logWatcher.Dispose();
+            throw;
+        }
+    }
+
+    private void onEventRecord(object? sender, EventRecordWrittenEventArgs e) {
+        if (e.EventException is { } exception) {
+            FatalError?.Invoke(this, exception);
+            Dispose();
+        } else {
+            using EventRecord? record = e.EventRecord;
+            switch (record?.Id) {
+                case 42:
+                    StandingBy?.Invoke(this, EventArgs.Empty);
+                    break;
+                case 107:
+                    Resumed?.Invoke(this, EventArgs.Empty);
+                    break;
+            }
+        }
+    }
+
+    public void Dispose() {
+        _logWatcher.Dispose();
+        GC.SuppressFinalize(this);
+    }
+
+}
diff --git a/Tests/Tests.csproj b/Tests/Tests.csproj
@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
         <TargetFramework>net7.0</TargetFramework>
@@ -11,9 +11,9 @@
     <ItemGroup>
         <PackageReference Include="FakeItEasy" Version="7.4.0" />
         <PackageReference Include="FluentAssertions" Version="6.11.0" />
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.6.2" />
-        <PackageReference Include="xunit" Version="2.4.2" />
-        <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.6.3" />
+        <PackageReference Include="xunit" Version="2.5.0" />
+        <PackageReference Include="xunit.runner.visualstudio" Version="2.5.0">
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
             <PrivateAssets>all</PrivateAssets>
         </PackageReference>