addressing comments

Author: chunhtai

shell/platform/darwin/ios/framework/Source/FlutterTextInputPlugin.h

@@ -71,8 +71,7 @@ FLUTTER_DARWIN_EXPORT
 @property(nonatomic, copy) UITextContentType textContentType API_AVAILABLE(ios(10.0));
 
 @property(nonatomic, assign) id<FlutterTextInputDelegate> textInputDelegate;
-@property(class, nonatomic, weak, assign)
-    UIAccessibilityElement* backingTextInputAccessibilityObject;
+@property(nonatomic, assign) UIAccessibilityElement* backingTextInputAccessibilityObject;
 
 @end
 #endif  // SHELL_PLATFORM_IOS_FRAMEWORK_SOURCE_FLUTTERTEXTINPUTPLUGIN_H_

shell/platform/darwin/ios/framework/Source/FlutterTextInputPlugin.mm

@@ -14,7 +14,7 @@
 static const char _kTextAffinityUpstream[] = "TextAffinity.upstream";
 // A delay before enabling the accessibility of FlutterTextInputView after
 // it is activated.
-static constexpr double _kUITextInputAccessibilityEnablingDelaySeconds = 0.5;
+static constexpr double kUITextInputAccessibilityEnablingDelaySeconds = 0.5;
 
 // The "canonical" invalid CGRect, similar to CGRectNull, used to
 // indicate a CGRect involved in firstRectForRange calculation is
@@ -440,8 +440,6 @@ @implementation FlutterTextInputView {
   CGRect _cachedFirstRect;
 }
 
-static UIAccessibilityElement* _backingTextInputAccessibilityObject;
-
 @synthesize tokenizer = _tokenizer;
 
 - (instancetype)init {
@@ -541,14 +539,6 @@ - (void)dealloc {
   [super dealloc];
 }
 
-+ (UIAccessibilityElement*)backingTextInputAccessibilityObject {
-  return _backingTextInputAccessibilityObject;
-}
-
-+ (void)setBackingTextInputAccessibilityObject:(UIAccessibilityElement*)element {
-  _backingTextInputAccessibilityObject = element;
-}
-
 - (void)setTextInputClient:(int)client {
   _textInputClient = client;
 }
@@ -1122,15 +1112,18 @@ - (void)deleteBackward {
     [self replaceRange:_selectedTextRange withText:@""];
 }
 
+- (void)postAccessibilityNotification:(UIAccessibilityNotifications)notification target:(id)target {
+  UIAccessibilityPostNotification(notification, target);
+}
+
 - (void)accessibilityElementDidBecomeFocused {
   if ([self accessibilityElementIsFocused]) {
     // For most of the cases, this flutter text input view should never
     // receive the focus. If we do receive the focus, we make the best effort
     // to send the focus back to the real text field.
-    __strong UIAccessibilityElement* textInput =
-        FlutterTextInputView.backingTextInputAccessibilityObject;
-    FML_DCHECK(textInput);
-    UIAccessibilityPostNotification(UIAccessibilityScreenChangedNotification, textInput);
+    FML_DCHECK(_backingTextInputAccessibilityObject);
+    [self postAccessibilityNotification:UIAccessibilityScreenChangedNotification
+                                 target:_backingTextInputAccessibilityObject];
   }
 }
 
@@ -1182,6 +1175,8 @@ @interface FlutterTextInputPlugin ()
 
 @implementation FlutterTextInputPlugin
 
+NSTimer* _enableFlutterTextInputViewAccessibilityTimer;
+
 @synthesize textInputDelegate = _textInputDelegate;
 
 - (instancetype)init {
@@ -1203,10 +1198,17 @@ - (void)dealloc {
   [_reusableInputView release];
   [_inputHider release];
   [_autofillContext release];
-
+  [self removeEnableFlutterTextInputViewAccessibilityTimer];
   [super dealloc];
 }
 
+- (void)removeEnableFlutterTextInputViewAccessibilityTimer {
+  if (_enableFlutterTextInputViewAccessibilityTimer) {
+    [_enableFlutterTextInputViewAccessibilityTimer invalidate];
+    _enableFlutterTextInputViewAccessibilityTimer = nil;
+  }
+}
+
 - (UIView<UITextInput>*)textInputView {
   return _activeView;
 }
@@ -1267,21 +1269,26 @@ - (void)showTextInput {
   // with a semantics update sent to the engine. The voiceover will focus
   // the newly attached active view while performing accessibility update.
   // This results in accessibility focus stuck at the FlutterTextInputView.
-  [NSTimer scheduledTimerWithTimeInterval:_kUITextInputAccessibilityEnablingDelaySeconds
-                                   target:self
-                                 selector:@selector(enableActiveViewAccessibility:)
-                                 userInfo:nil
-                                  repeats:NO];
+  if (!_enableFlutterTextInputViewAccessibilityTimer) {
+    _enableFlutterTextInputViewAccessibilityTimer =
+        [NSTimer scheduledTimerWithTimeInterval:kUITextInputAccessibilityEnablingDelaySeconds
+                                         target:self
+                                       selector:@selector(enableActiveViewAccessibility:)
+                                       userInfo:nil
+                                        repeats:NO];
+  }
   [_activeView becomeFirstResponder];
 }
 
 - (void)enableActiveViewAccessibility:(NSTimer*)time {
   if (_activeView.isFirstResponder) {
     _activeView.accessibilityEnabled = YES;
   }
+  _enableFlutterTextInputViewAccessibilityTimer = nil;
 }
 
 - (void)hideTextInput {
+  [self removeEnableFlutterTextInputViewAccessibilityTimer];
   _activeView.accessibilityEnabled = NO;
   [_activeView resignFirstResponder];
   [_activeView removeFromSuperview];

shell/platform/darwin/ios/framework/Source/FlutterTextInputPluginTest.m

@@ -20,6 +20,30 @@ - (void)setTextInputState:(NSDictionary*)state;
 - (void)setMarkedRect:(CGRect)markedRect;
 - (void)updateEditingState;
 - (BOOL)isVisibleToAutofill;
+
+@end
+
+@interface FlutterTextInputViewSpy : FlutterTextInputView
+@property(nonatomic, assign) UIAccessibilityNotifications receivedNotification;
+@property(nonatomic, assign) id receivedNotificationTarget;
+@property(nonatomic, assign) BOOL isAccessibilityFocused;
+
+- (void)postAccessibilityNotification:(UIAccessibilityNotifications)notification target:(id)target;
+
+@end
+
+@implementation FlutterTextInputViewSpy {
+}
+
+- (void)postAccessibilityNotification:(UIAccessibilityNotifications)notification target:(id)target {
+  self.receivedNotification = notification;
+  self.receivedNotificationTarget = target;
+}
+
+- (BOOL)accessibilityElementIsFocused {
+  return _isAccessibilityFocused;
+}
+
 @end
 
 @interface FlutterSecureTextInputView : FlutterTextInputView
@@ -779,4 +803,19 @@ - (void)testUITextInputAccessibilityNotHiddenWhenShowed {
   XCTAssertEqual([inputFields count], 0u);
 }
 
+- (void)testFlutterTextInputViewDirectFocusToBackingTextInput {
+  FlutterTextInputViewSpy* inputView = [[FlutterTextInputViewSpy alloc] init];
+  inputView.textInputDelegate = engine;
+  UIView* container = [[UIView alloc] init];
+  UIAccessibilityElement* backing =
+      [[UIAccessibilityElement alloc] initWithAccessibilityContainer:container];
+  inputView.backingTextInputAccessibilityObject = backing;
+  // Simulate accessibility focus.
+  inputView.isAccessibilityFocused = YES;
+  [inputView accessibilityElementDidBecomeFocused];
+
+  XCTAssertEqual(inputView.receivedNotification, UIAccessibilityScreenChangedNotification);
+  XCTAssertEqual(inputView.receivedNotificationTarget, backing);
+}
+
 @end

shell/platform/darwin/ios/framework/Source/accessibility_text_entry.mm

@@ -198,13 +198,14 @@ - (void)dealloc {
 - (void)setSemanticsNode:(const flutter::SemanticsNode*)node {
   [super setSemanticsNode:node];
   _inactive_text_input.text = @(node->value.data());
+  FlutterTextInputView* textInput = (FlutterTextInputView*)[self bridge]->textInputView();
   if ([self node].HasFlag(flutter::SemanticsFlags::kIsFocused)) {
+    textInput.backingTextInputAccessibilityObject = self;
     // The text input view must have a non-trivial size for the accessibility
     // system to send text editing events.
-    FlutterTextInputView.backingTextInputAccessibilityObject = self;
-    [self bridge]->textInputView().frame = CGRectMake(0.0, 0.0, 1.0, 1.0);
-  } else if (FlutterTextInputView.backingTextInputAccessibilityObject == self) {
-    FlutterTextInputView.backingTextInputAccessibilityObject = nil;
+    textInput.frame = CGRectMake(0.0, 0.0, 1.0, 1.0);
+  } else if (textInput.backingTextInputAccessibilityObject == self) {
+    textInput.backingTextInputAccessibilityObject = nil;
   }
 }