Fix MainPanelWorkaround to work on dispose order instead of on a loop

Author: devbridie

core/xr/src/main/java/com/android/developers/androidify/xr/MainPanelWorkaround.kt

@@ -16,25 +16,24 @@
 package com.android.developers.androidify.xr
 
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.DisposableEffect
 import androidx.xr.compose.platform.LocalSession
 import androidx.xr.scenecore.scene
-import kotlinx.coroutines.delay
 
 /*
- * A composable that attempts to continually hide the mainPanel.
+ * A composable that hides the mainPanel when it is disposed. When placed outside of an (Application)Subspace,
+ * this composable will be disposed after the Subspace, hiding the mainPanelEntity again.
  *
- * This is a temporary workaround for b/440325404, that causes the mainPanelEntity when an
+ * This is a temporary workaround for b/440325404, that causes the mainPanelEntity to appear when an
  * ApplicationSubspace transitions out of the composition due to a race condition when transitioning
  * the two hierarchies.
  */
 @Composable
 fun MainPanelWorkaround() {
-    val session = LocalSession.current
-    LaunchedEffect(null) {
-        while (true) {
-            delay(100L)
-            session?.scene?.mainPanelEntity?.setEnabled(false)
+    val session = LocalSession.current ?: return
+    DisposableEffect(Unit) {
+        onDispose {
+            session.scene.mainPanelEntity.setEnabled(false)
         }
     }
 }

feature/creation/src/main/java/com/android/developers/androidify/creation/xr/EditScreenSpatial.kt

@@ -75,8 +75,8 @@ fun EditScreenSpatial(
     onDropCallback: (Uri) -> Unit = {},
 ) {
     DisableSharedTransition {
+        MainPanelWorkaround()
         SquiggleBackgroundSubspace(minimumHeight = 600.dp) {
-            MainPanelWorkaround()
             SpatialColumn(SubspaceModifier.fillMaxWidth()) {
                 SpatialPanel(
                     SubspaceModifier.offset(z = 10.dp)

feature/creation/src/main/java/com/android/developers/androidify/creation/xr/LoadingScreenSpatial.kt

@@ -52,12 +52,12 @@ private const val squiggleSafeContentHeight = 0.6f
 fun LoadingScreenSpatial(
     onCancelPress: () -> Unit,
 ) {
+    MainPanelWorkaround()
     BackgroundSubspace(
         aspectRatio = 1.4f,
         minimumHeight = 500.dp,
         drawable = CreationR.drawable.squiggle_light,
     ) {
-        MainPanelWorkaround()
         Orbiter(
             position = ContentEdge.Top,
             offsetType = OrbiterOffsetType.OuterEdge,

feature/home/src/main/java/com/android/developers/androidify/home/xr/AboutScreenSpatial.kt

@@ -33,8 +33,8 @@ import com.android.developers.androidify.xr.SquiggleBackgroundSubspace
 
 @Composable
 fun AboutScreenSpatial(onBackPressed: () -> Unit, bottomButtons: @Composable () -> Unit) {
+    MainPanelWorkaround()
     SquiggleBackgroundSubspace(500.dp) {
-        MainPanelWorkaround()
         SpatialPanel {
             Orbiter(
                 ContentEdge.Top,

feature/home/src/main/java/com/android/developers/androidify/home/xr/HomeScreenSpatial.kt

@@ -69,8 +69,8 @@ fun HomeScreenContentsSpatial(
     onAboutClicked: () -> Unit,
 ) {
     DisableSharedTransition {
+        MainPanelWorkaround()
         SquiggleBackgroundSubspace(minimumHeight = 600.dp) {
-            MainPanelWorkaround()
             Orbiter(
                 position = ContentEdge.Top,
                 offsetType = OrbiterOffsetType.OuterEdge,

feature/results/src/main/java/com/android/developers/androidify/results/xr/ResultsScreenSpatial.kt

@@ -59,9 +59,8 @@ fun ResultsScreenSpatial(
 ) {
     var offsetPose by remember { mutableStateOf(Pose()) }
     DisableSharedTransition {
+        MainPanelWorkaround()
         Subspace {
-            MainPanelWorkaround()
-
             SpatialPanel(
                 SubspaceModifier
                     .offset(z = 5.dp)