[Snackbar] Set the accessibility pane title right before the Snackbar's appearance to resolve an event stream issue

PiperOrigin-RevId: 664967701

Author: Material Design Team

lib/java/com/google/android/material/snackbar/BaseTransientBottomBar.java

@@ -388,8 +388,6 @@ protected BaseTransientBottomBar(
 
     view.setAccessibilityLiveRegion(View.ACCESSIBILITY_LIVE_REGION_POLITE);
     view.setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_YES);
-    ViewCompat.setAccessibilityPaneTitle(
-        view, getContext().getString(R.string.snackbar_accessibility_pane_title));
 
     // Make sure that we fit system windows and have a listener to apply any insets
     view.setFitsSystemWindows(true);
@@ -831,6 +829,10 @@ void onLayoutChange() {
   }
 
   private void showViewImpl() {
+    if (ViewCompat.getAccessibilityPaneTitle(view) == null) {
+      ViewCompat.setAccessibilityPaneTitle(
+          view, getContext().getString(R.string.snackbar_accessibility_pane_title));
+    }
     if (shouldAnimate()) {
       // If animations are enabled, animate it in
       animateViewIn();

tests/javatests/com/google/android/material/snackbar/SnackbarTest.java

@@ -405,6 +405,7 @@ public void testAccessibilityPaneTitle() throws Throwable {
     final Snackbar snackbar =
         Snackbar.make(coordinatorLayout, MESSAGE_TEXT, Snackbar.LENGTH_INDEFINITE)
             .setAction(ACTION_TEXT, mock(View.OnClickListener.class));
+    SnackbarUtils.showTransientBottomBarAndWaitUntilFullyShown(snackbar);
     assertEquals(
         snackbar.getContext().getString(R.string.snackbar_accessibility_pane_title),
         ViewCompat.getAccessibilityPaneTitle(snackbar.getView()).toString());