prevent sleep on Windows when playing

backend/app.go

@@ -127,6 +127,16 @@ func StartupApp(appName, displayAppName, appVersionTag, latestReleaseURL string)
 		_, _ = a.ImageManager.GetCoverThumbnail(coverID)
 	})
 
+	a.PlaybackManager.OnPlaying(func() {
+		SetSystemSleepDisabled(true)
+	})
+	a.PlaybackManager.OnPaused(func() {
+		SetSystemSleepDisabled(false)
+	})
+	a.PlaybackManager.OnStopped(func() {
+		SetSystemSleepDisabled(false)
+	})
+
 	// Start IPC server if another not already running in a different instance
 	if cli == nil {
 		ipc.DestroyConn() // cleanup socket possibly orphaned by crashed process

backend/nosleep_unsupported.go

@@ -0,0 +1,7 @@
+//go:build !windows
+
+package backend
+
+func SetSystemSleepDisabled(disable bool) {
+	// no-op
+}

backend/nosleep_windows.go

@@ -0,0 +1,22 @@
+//go:build windows
+
+package backend
+
+import "syscall"
+
+const (
+	ES_CONTINUOUS      uint = 0x80000000
+	ES_SYSTEM_REQUIRED uint = 0x00000001
+)
+
+func SetSystemSleepDisabled(disable bool) {
+	kernel32 := syscall.NewLazyDLL("kernel32.dll")
+	executionState := kernel32.NewProc("SetThreadExecutionState")
+
+	uType := ES_CONTINUOUS
+	if disable {
+		uType |= ES_SYSTEM_REQUIRED
+	}
+
+	syscall.SyscallN(executionState.Addr(), 1, uintptr(uType), 0, 0)
+}