Android: enable immersive fullscreen

apps/android/app/src/main/java/com/steipete/clawdis/node/MainActivity.kt

@@ -11,6 +11,9 @@ import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
 import androidx.compose.ui.Modifier
 import androidx.core.content.ContextCompat
+import androidx.core.view.WindowCompat
+import androidx.core.view.WindowInsetsCompat
+import androidx.core.view.WindowInsetsControllerCompat
 import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.lifecycleScope
 import androidx.lifecycle.repeatOnLifecycle
@@ -22,6 +25,7 @@ class MainActivity : ComponentActivity() {
 
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
+    applyImmersiveMode()
     requestDiscoveryPermissionsIfNeeded()
     requestNotificationPermissionIfNeeded()
     NodeForegroundService.start(this)
@@ -48,6 +52,18 @@ class MainActivity : ComponentActivity() {
     }
   }
 
+  override fun onResume() {
+    super.onResume()
+    applyImmersiveMode()
+  }
+
+  override fun onWindowFocusChanged(hasFocus: Boolean) {
+    super.onWindowFocusChanged(hasFocus)
+    if (hasFocus) {
+      applyImmersiveMode()
+    }
+  }
+
   override fun onStart() {
     super.onStart()
     viewModel.setForeground(true)
@@ -58,6 +74,14 @@ class MainActivity : ComponentActivity() {
     super.onStop()
   }
 
+  private fun applyImmersiveMode() {
+    WindowCompat.setDecorFitsSystemWindows(window, false)
+    val controller = WindowInsetsControllerCompat(window, window.decorView)
+    controller.systemBarsBehavior =
+      WindowInsetsControllerCompat.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE
+    controller.hide(WindowInsetsCompat.Type.systemBars())
+  }
+
   private fun requestDiscoveryPermissionsIfNeeded() {
     if (Build.VERSION.SDK_INT >= 33) {
       val ok =