Pause viewers in the background and keep visible playback awake

tools/chatgui-android/app/src/main/java/com/utun/chat/ui/screens/StreamScreen.kt

@@ -19,10 +19,13 @@ import androidx.compose.runtime.*
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.platform.LocalLifecycleOwner
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.viewinterop.AndroidView
 import androidx.core.content.ContextCompat
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.LifecycleEventObserver
 import com.utun.chat.R
 import com.utun.chat.data.LogManager
 import com.utun.chat.data.NativeLib
@@ -131,6 +134,21 @@ fun StreamScreen(channelId: String, channelName: String, onBack: () -> Unit) {
 
 @Composable
 private fun LiveStreamView(group: Long, source: Long, localPreview: Boolean) {
+    val owner = LocalLifecycleOwner.current
+    var visible by remember(owner) { mutableStateOf(owner.lifecycle.currentState.isAtLeast(Lifecycle.State.STARTED)) }
+    DisposableEffect(owner) {
+        val observer = LifecycleEventObserver { _, event ->
+            if (event == Lifecycle.Event.ON_START) visible = true
+            if (event == Lifecycle.Event.ON_STOP) visible = false
+        }
+        owner.lifecycle.addObserver(observer)
+        onDispose { owner.lifecycle.removeObserver(observer) }
+    }
+    if (visible) LiveStreamSurface(group, source, localPreview)
+}
+
+@Composable
+private fun LiveStreamSurface(group: Long, source: Long, localPreview: Boolean) {
     val engine = remember(group, source, localPreview) { StreamPlayerEngine(group, source, localPreview) }
     val aspect by engine.aspect.collectAsState()
     val status by engine.status.collectAsState()
@@ -140,21 +158,22 @@ private fun LiveStreamView(group: Long, source: Long, localPreview: Boolean) {
         Text(stringResource(status))
         Box(Modifier.weight(1f).fillMaxWidth(), contentAlignment = Alignment.Center) {
             AndroidView(factory = { context ->
-        TextureView(context).apply {
-            surfaceTextureListener = object : TextureView.SurfaceTextureListener {
-                override fun onSurfaceTextureAvailable(texture: SurfaceTexture, width: Int, height: Int) {
-                    surface = Surface(texture); engine.start(surface!!)
-                }
-                override fun onSurfaceTextureSizeChanged(texture: SurfaceTexture, width: Int, height: Int) {}
-                override fun onSurfaceTextureDestroyed(texture: SurfaceTexture): Boolean {
-                    engine.stop(); surface?.release(); surface = null; return true
+                TextureView(context).apply {
+                    keepScreenOn = true
+                    surfaceTextureListener = object : TextureView.SurfaceTextureListener {
+                        override fun onSurfaceTextureAvailable(texture: SurfaceTexture, width: Int, height: Int) {
+                            surface = Surface(texture); engine.start(surface!!)
+                        }
+                        override fun onSurfaceTextureSizeChanged(texture: SurfaceTexture, width: Int, height: Int) {}
+                        override fun onSurfaceTextureDestroyed(texture: SurfaceTexture): Boolean {
+                            engine.stop(); surface?.release(); surface = null; return true
+                        }
+                        override fun onSurfaceTextureUpdated(texture: SurfaceTexture) {}
+                    }
                 }
-                override fun onSurfaceTextureUpdated(texture: SurfaceTexture) {}
-            }
-        }
-    }, modifier = Modifier.aspectRatio(aspect, matchHeightConstraintsFirst = true), onRelease = { view ->
-        engine.stop(); view.surfaceTextureListener = null; surface?.release(); surface = null
-    })
+            }, modifier = Modifier.aspectRatio(aspect, matchHeightConstraintsFirst = true), onRelease = { view ->
+                engine.stop(); view.surfaceTextureListener = null; surface?.release(); surface = null
+            })
         }
     }
 }