Follow a native call into picture-in-picture from the app

supportsPictureInPicture and smallestScreenSize have to be declared here, because a library cannot change a host Activity's manifest entry.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

app/src/main/AndroidManifest.xml

@@ -53,9 +53,10 @@
         -->
         <activity
             android:name=".MainActivity"
-            android:configChanges="orientation|screenSize|screenLayout|keyboardHidden|uiMode"
+            android:configChanges="orientation|screenSize|smallestScreenSize|screenLayout|keyboardHidden|uiMode"
             android:exported="true"
             android:launchMode="singleTask"
+            android:supportsPictureInPicture="true"
             android:theme="@style/Theme.ElementX.Splash"
             android:windowSoftInputMode="adjustResize">
             <intent-filter>

app/src/main/kotlin/io/element/android/x/MainActivity.kt

@@ -70,6 +70,19 @@ class MainActivity : NodeActivity() {
         }
     }
 
+    /**
+     * The pre-Android 12 way into picture-in-picture for a native call.
+     *
+     * Everything else about it is installed where the call is drawn, which knows whose call it is.
+     * This cannot be: an Activity override has no session in scope. From Android 12 the system is told
+     * up front that this Activity would like to shrink, and the call handles it without ever coming
+     * through here.
+     */
+    override fun onUserLeaveHint() {
+        super.onUserLeaveHint()
+        appBindings.nativeCallPip().onUserLeaveHint(this)
+    }
+
     @Composable
     private fun MainContent(appBindings: AppBindings) {
         val migrationState = appBindings.migrationEntryPoint().present()

app/src/main/kotlin/io/element/android/x/di/AppBindings.kt

@@ -12,6 +12,7 @@ import dev.zacsweers.metro.AppScope
 import dev.zacsweers.metro.ContributesTo
 import dev.zacsweers.metro.Multibinds
 import io.element.android.features.api.MigrationEntryPoint
+import io.element.android.features.callnative.api.NativeCallPip
 import io.element.android.features.enterprise.api.AppStartupHook
 import io.element.android.features.enterprise.api.EnterpriseService
 import io.element.android.features.lockscreen.api.LockScreenEntryPoint
@@ -52,6 +53,13 @@ interface AppBindings {
 
     fun buildMeta(): BuildMeta
 
+    /**
+     * For picture-in-picture. Only an Activity is told it is being left, and only the call knows
+     * whether that is worth shrinking for, so `MainActivity` needs this much of the native call and
+     * no more.
+     */
+    fun nativeCallPip(): NativeCallPip
+
     fun sentrySdkDsn(): SentrySdkDsn?
 
     @Multibinds(allowEmpty = true)

appnav/build.gradle.kts

@@ -50,6 +50,7 @@ dependencies {
     implementation(libs.coil)
 
     implementation(projects.features.announcement.api)
+    implementation(projects.features.callnative.api)
     implementation(projects.features.ftue.api)
     implementation(projects.features.linknewdevice.api)
     implementation(projects.features.share.api)

appnav/src/main/kotlin/io/element/android/appnav/LoggedInFlowNode.kt

@@ -48,6 +48,7 @@ import io.element.android.appnav.room.RoomFlowNode
 import io.element.android.appnav.room.RoomNavigationTarget
 import io.element.android.appnav.room.joined.JoinedRoomLoadedFlowNode
 import io.element.android.compound.colors.SemanticColorsLightDark
+import io.element.android.features.callnative.api.NativeCallHost
 import io.element.android.features.createroom.api.CreateRoomEntryPoint
 import io.element.android.features.enterprise.api.EnterpriseService
 import io.element.android.features.enterprise.api.SessionEnterpriseService
@@ -144,6 +145,7 @@ class LoggedInFlowNode(
     private val shareEntryPoint: ShareEntryPoint,
     private val matrixClient: MatrixClient,
     private val sendingQueue: SendQueues,
+    private val nativeCallHost: NativeCallHost,
     private val incomingVerificationEntryPoint: IncomingVerificationEntryPoint,
     private val mediaPreviewConfigMigration: MediaPreviewConfigMigration,
     private val sessionEnterpriseService: SessionEnterpriseService,
@@ -701,15 +703,19 @@ class LoggedInFlowNode(
         ) {
             CompositionLocalProvider(LocalMapTilerConfig provides updatedMapTilerConfig) {
                 val isOnline by syncService.isOnline.collectAsState()
-                ConnectivityIndicatorContainer(
-                    isOnline = isOnline,
-                    modifier = modifier,
-                ) { contentModifier ->
-                    Box(modifier = contentModifier) {
-                        val ftueState by ftueService.state.collectAsState()
-                        BackstackView(transitionHandler = rememberLoggedInFlowTransitionHandler(backstack))
-                        if (ftueState is FtueState.Complete) {
-                            PermanentChild(permanentNavModel = permanentNavModel, navTarget = NavTarget.LoggedInPermanent)
+                // Outside the connectivity indicator so the two strips stack rather than fight: an
+                // offline banner during a call belongs under the call bar, not over it.
+                nativeCallHost.Render(modifier = modifier) { callContentModifier ->
+                    ConnectivityIndicatorContainer(
+                        isOnline = isOnline,
+                        modifier = callContentModifier,
+                    ) { contentModifier ->
+                        Box(modifier = contentModifier) {
+                            val ftueState by ftueService.state.collectAsState()
+                            BackstackView(transitionHandler = rememberLoggedInFlowTransitionHandler(backstack))
+                            if (ftueState is FtueState.Complete) {
+                                PermanentChild(permanentNavModel = permanentNavModel, navTarget = NavTarget.LoggedInPermanent)
+                            }
                         }
                     }
                 }