Make all snackbars with actions persist until explicitly dismissed

PiperOrigin-RevId: 598973358

components/Snackbar/src/MDCSnackbarManager.m

@@ -385,11 +385,15 @@ - (BOOL)isVoiceOverRunning {
 }
 
 - (BOOL)isSnackbarTransient:(MDCSnackbarMessageView *)snackbarView {
-  if ([self isVoiceOverRunning]) {
+  if (snackbarView.message.usesLegacyDismissalBehavior) {
+    if ([self isVoiceOverRunning]) {
+      return ![snackbarView shouldWaitForDismissalDuringVoiceover];
+    } else {
+      return YES;
+    }
+  } else {
     return ![snackbarView shouldWaitForDismissalDuringVoiceover];
   }
-
-  return YES;
 }
 
 #pragma mark - Overlay Activation

components/Snackbar/src/MDCSnackbarMessage.h

@@ -238,8 +238,8 @@ extern NSString *__nonnull const MDCSnackbarMessageBoldAttributeName;
  Whether the Snackbar message is transient and automatically dismisses after the provided @c
  duration time or is not transient and will not dismiss automatically.
 
- @note: If VoiceOver is turned on, a snackbar will not automatically dismiss if the snackbar has an
- action, regardless of this property.
+ @note: If the snackbar has an action, it will not dismiss automatically, regardless of the value of
+ this property, unless @c usesLegacyDismissalBehavior is enabled.
 
  Defaults to YES.
  */

components/Snackbar/tests/unit/MDCSnackbarMessageViewTests.m

@@ -258,9 +258,8 @@ - (void)testSnackbarAccessibiltyViewIsModalDefaultsToNoWithNoActions {
   XCTAssertFalse(self.manager.internalManager.overlayView.accessibilityViewIsModal);
 }
 
-- (void)testWhenSnackbarAccessibiltyViewIsModalIsYesWithActions {
+- (void)testSnackbarAccessibilityViewIsModalIsYesWithActions {
   // Given
-  self.manager.internalManager.isVoiceOverRunningOverride = YES;
   MDCSnackbarMessageAction *action = [[MDCSnackbarMessageAction alloc] init];
   action.title = @"Tap Me";
   self.message.action = action;
@@ -278,11 +277,9 @@ - (void)testWhenSnackbarAccessibiltyViewIsModalIsYesWithActions {
   XCTAssertTrue(self.manager.internalManager.overlayView.accessibilityViewIsModal);
 }
 
-- (void)testWhenSnackbarAccessibiltyViewIsModalIsYesWithActionsAndWithoutVoiceOver {
+- (void)testSnackbarAccessibiltyViewIsModalIsNoWithoutActions {
   // Given
-  MDCSnackbarMessageAction *action = [[MDCSnackbarMessageAction alloc] init];
-  action.title = @"Tap Me";
-  self.message.action = action;
+  self.manager.internalManager.isVoiceOverRunningOverride = YES;
   self.manager.shouldEnableAccessibilityViewIsModal = YES;
 
   // When
@@ -297,9 +294,13 @@ - (void)testWhenSnackbarAccessibiltyViewIsModalIsYesWithActionsAndWithoutVoiceOv
   XCTAssertFalse(self.manager.internalManager.overlayView.accessibilityViewIsModal);
 }
 
-- (void)testWhenSnackbarAccessibiltyViewIsModalIsYesWhenWithNoActions {
+- (void)testSnackbarAccessibilityViewIsModalIsNoWithoutVoiceOverWithLegacyBehavior {
   // Given
-  self.manager.internalManager.isVoiceOverRunningOverride = YES;
+  MDCSnackbarMessageAction *action = [[MDCSnackbarMessageAction alloc] init];
+  action.title = @"Tap Me";
+  self.message.action = action;
+  self.message.usesLegacyDismissalBehavior = YES;
+  self.manager.internalManager.isVoiceOverRunningOverride = NO;
   self.manager.shouldEnableAccessibilityViewIsModal = YES;
 
   // When

components/Snackbar/tests/unit/MDCSnackbarShowMessageErrorTests.m

@@ -67,9 +67,6 @@ - (void)setUp {
 
   self.message = [[MDCSnackbarMessage alloc] init];
   self.message.text = @"Snackbar Message";
-  MDCSnackbarMessageAction *action = [[MDCSnackbarMessageAction alloc] init];
-  action.title = @"Tap Me";
-  self.message.action = action;
 
   self.fakeMessage = [[MDCFakeSnackbarMessage alloc] init];
   self.fakeMessage.text = @"Fake Snackbar Message";