Add keep screen on feature to FrontendScreen

app/src/main/kotlin/io/homeassistant/companion/android/frontend/FrontendScreen.kt

@@ -40,6 +40,7 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.platform.LocalView
 import androidx.compose.ui.platform.testTag
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.LayoutDirection
@@ -124,6 +125,7 @@ internal fun FrontendScreen(
     val pendingDialog by viewModel.pendingDialog.collectAsStateWithLifecycle()
     val pendingFileChooser by viewModel.pendingFileChooser.collectAsStateWithLifecycle()
     val autoPlayVideoEnabled by viewModel.autoPlayVideoEnabled.collectAsStateWithLifecycle()
+    val keepScreenOnEnabled by viewModel.keepScreenOnEnabled.collectAsStateWithLifecycle()
 
     // The fullscreen View handed over by the WebView is Activity-scoped. Keep it in screen
     // state so it does not leak across configuration changes via the ViewModel.
@@ -173,6 +175,7 @@ internal fun FrontendScreen(
         onGesture = viewModel::onGesture,
         onExoPlayerFullscreenChanged = viewModel::onExoPlayerFullscreenChanged,
         autoPlayVideoEnabled = autoPlayVideoEnabled,
+        keepScreenOnEnabled = keepScreenOnEnabled,
         onPipReadinessChanged = onPipReadinessChanged,
         modifier = modifier,
     )
@@ -198,6 +201,7 @@ internal fun FrontendScreenContent(
     modifier: Modifier = Modifier,
     customView: View? = null,
     autoPlayVideoEnabled: Boolean = false,
+    keepScreenOnEnabled: Boolean = false,
     pendingPermissionRequest: PermissionRequest? = null,
     pendingDialog: FrontendDialog? = null,
     pendingFileChooser: FileChooserRequest? = null,
@@ -232,6 +236,8 @@ internal fun FrontendScreenContent(
         pendingRequest = pendingFileChooser,
     )
 
+    KeepScreenOnEffect(enabled = keepScreenOnEnabled)
+
     Box(modifier = modifier.fillMaxSize()) {
         // Always render WebView at base layer
         SafeHAWebView(
@@ -645,6 +651,24 @@ private fun WebViewEffects(
     }
 }
 
+/**
+ * Toggles `View.keepScreenOn` (mapped by the platform to `WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON`)
+ * based on the user's "Keep screen on" preference while the frontend is composed.
+ *
+ * The flag is always cleared on dispose so it does not leak to other screens that share the
+ * hosting activity window.
+ */
+@Composable
+private fun KeepScreenOnEffect(enabled: Boolean) {
+    val view = LocalView.current
+    DisposableEffect(view, enabled) {
+        view.keepScreenOn = enabled
+        onDispose {
+            view.keepScreenOn = false
+        }
+    }
+}
+
 /**
  * Renders PiP-eligible overlays and reports their combined [PipReadiness] to the host.
  */

app/src/main/kotlin/io/homeassistant/companion/android/frontend/FrontendViewModel.kt

@@ -248,6 +248,17 @@ internal class FrontendViewModel @VisibleForTesting constructor(
         emitAll(prefsRepository.autoPlayVideoFlow())
     }.stateIn(viewModelScope, SharingStarted.Eagerly, initialValue = false)
 
+    /**
+     * The user's "Keep screen on" preference.
+     *
+     * Applied by the screen to the hosting window so the device does not lock while the
+     * WebView is active. Exposed as a [StateFlow] so the screen can read the current value
+     * synchronously when first attaching to the window and react to subsequent changes.
+     */
+    val keepScreenOnEnabled: StateFlow<Boolean> = flow {
+        emitAll(prefsRepository.keepScreenOnFlow())
+    }.stateIn(viewModelScope, SharingStarted.Eagerly, initialValue = false)
+
     init {
         viewModelScope.launch {
             _viewState.collectLatest { state ->

app/src/test/kotlin/io/homeassistant/companion/android/frontend/FrontendViewModelTest.kt

@@ -64,6 +64,7 @@ import kotlinx.coroutines.test.advanceUntilIdle
 import kotlinx.coroutines.test.runTest
 import kotlinx.serialization.json.JsonObject
 import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertFalse
 import org.junit.jupiter.api.Assertions.assertInstanceOf
 import org.junit.jupiter.api.Assertions.assertNotNull
 import org.junit.jupiter.api.Assertions.assertNull
@@ -94,9 +95,11 @@ class FrontendViewModelTest {
     private val gestureHandler: FrontendGestureHandler = mockk(relaxed = true)
     private val zoomSettingsFlow = MutableStateFlow(ZoomSettings())
     private val autoPlayVideoFlow = MutableStateFlow(false)
+    private val keepScreenOnFlow = MutableStateFlow(false)
     private val prefsRepository: PrefsRepository = mockk(relaxed = true) {
         coEvery { this@mockk.zoomSettingsFlow() } returns this@FrontendViewModelTest.zoomSettingsFlow
         coEvery { this@mockk.autoPlayVideoFlow() } returns this@FrontendViewModelTest.autoPlayVideoFlow
+        coEvery { this@mockk.keepScreenOnFlow() } returns this@FrontendViewModelTest.keepScreenOnFlow
     }
 
     private val serverId = 1
@@ -1739,4 +1742,34 @@ class FrontendViewModelTest {
             assertEquals(value, viewModel.autoPlayVideoEnabled.value)
         }
     }
+
+    @Nested
+    inner class KeepScreenOnSetting {
+
+        @Test
+        fun `Given pref flow emits new value when collected then exposed StateFlow reflects it`() = runTest {
+            val viewModel = createViewModel()
+            advanceUntilIdle()
+
+            assertFalse(viewModel.keepScreenOnEnabled.value)
+
+            keepScreenOnFlow.value = true
+            advanceUntilIdle()
+
+            assertTrue(viewModel.keepScreenOnEnabled.value)
+        }
+
+        @ParameterizedTest
+        @ValueSource(booleans = [true, false])
+        fun `Given pref flow seeded with value when ViewModel constructed then exposed StateFlow has that value`(
+            value: Boolean,
+        ) = runTest {
+            keepScreenOnFlow.value = value
+
+            val viewModel = createViewModel()
+            advanceUntilIdle()
+
+            assertEquals(value, viewModel.keepScreenOnEnabled.value)
+        }
+    }
 }

common/src/main/kotlin/io/homeassistant/companion/android/common/data/prefs/PrefsRepository.kt

@@ -82,6 +82,9 @@ interface PrefsRepository {
 
     suspend fun setKeepScreenOnEnabled(enabled: Boolean)
 
+    /** Emits the current "Keep screen on" preference immediately on collection, then on every change. */
+    suspend fun keepScreenOnFlow(): Flow<Boolean>
+
     suspend fun getScreenOrientation(): String?
 
     suspend fun saveScreenOrientation(orientation: String?)

common/src/main/kotlin/io/homeassistant/companion/android/common/data/prefs/PrefsRepositoryImpl.kt

@@ -219,6 +219,12 @@ internal class PrefsRepositoryImpl @Inject constructor(
         localStorage().putBoolean(PREF_KEEP_SCREEN_ON_ENABLED, enabled)
     }
 
+    override suspend fun keepScreenOnFlow(): Flow<Boolean> {
+        return localStorage().observeChanges(PREF_KEEP_SCREEN_ON_ENABLED) {
+            isKeepScreenOnEnabled()
+        }
+    }
+
     override suspend fun getPageZoomLevel(): Int {
         return localStorage().getInt(PREF_PAGE_ZOOM_LEVEL) ?: 100
     }

common/src/test/kotlin/io/homeassistant/companion/android/common/data/prefs/PrefsRepositoryImplTest.kt

@@ -171,6 +171,21 @@ class PrefsRepositoryImplTest {
         }
     }
 
+    @Test
+    fun `Given collecting flow when keep screen on changes then updated keep screen on enabled is emitted`() = runTest {
+        coEvery { localStorage.getBoolean("keep_screen_on_enabled") } returns false
+
+        repository.keepScreenOnFlow().test {
+            assertFalse(awaitItem())
+
+            coEvery { localStorage.getBoolean("keep_screen_on_enabled") } returns true
+            keyChangesFlow.emit("keep_screen_on_enabled")
+
+            assertTrue(awaitItem())
+            cancelAndIgnoreRemainingEvents()
+        }
+    }
+
     @Nested
     inner class ZoomSettingsFlow {