update

Author: chunhtai

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

@@ -761,14 +761,20 @@ - (void)showAutocorrectionPromptRectForStart:(NSUInteger)start
                               arguments:@[ @(client), @(start), @(end) ]];
 }
 
-#pragma mark - Screenshot Delegate
+#pragma mark - FlutterViewEngineDelegate
 
 - (flutter::Rasterizer::Screenshot)takeScreenshot:(flutter::Rasterizer::ScreenshotType)type
                                   asBase64Encoded:(BOOL)base64Encode {
   FML_DCHECK(_shell) << "Cannot takeScreenshot without a shell";
   return _shell->Screenshot(type, base64Encode);
 }
 
+- (void)futterViewAccessibilityDidCall {
+  if (self.viewController.view.accessibilityElements == nil) {
+    [self ensureSemanticsEnabled];
+  }
+}
+
 - (NSObject<FlutterBinaryMessenger>*)binaryMessenger {
   return _binaryMessenger;
 }

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

@@ -21,7 +21,16 @@
                                   asBase64Encoded:(BOOL)base64Encode;
 
 - (std::shared_ptr<flutter::FlutterPlatformViewsController>&)platformViewsController;
-- (void)ensureSemanticsEnabled;
+
+/**
+ * A callback that is called when iOS queries accessibility information of the Flutter view.
+ *
+ * This is useful to predict the current iOS accessibility status. For example, there is
+ * no API to listen whether voice control is turned on or off. The Flutter engine uses
+ * this callback to enable semantics in order to catch the case that voice control is
+ * on.
+ */
+- (void)futterViewAccessibilityDidCall;
 @end
 
 @interface FlutterView : UIView

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

@@ -139,9 +139,10 @@ - (BOOL)isAccessibilityElement {
   // TODO(chunhtai): Remove this workaround once iOS provides an
   // API to query whether voice control is enabled.
   // https://github.com/flutter/flutter/issues/76808.
-  if (self.accessibilityElements == nil) {
-    [_delegate ensureSemanticsEnabled];
-  }
+  [_delegate futterViewAccessibilityDidCall];
+  // if (self.accessibilityElements == nil) {
+  //   [_delegate futterViewAccessibilityDidCall];
+  // }
   return NO;
 }
 

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

@@ -4,33 +4,19 @@
 
 #import <XCTest/XCTest.h>
 
+#import "flutter/shell/platform/darwin/ios/framework/Source/FlutterEngine_Internal.h"
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterView.h"
 
-@interface FakeDelegate : NSObject<FlutterViewEngineDelegate>
+@interface FakeDelegate : FlutterEngine
 @property(nonatomic) BOOL ensureSemanticsEnabledCalled;
 @end
 
-@implementation FakeDelegate {
-  std::shared_ptr<flutter::FlutterPlatformViewsController> _platformViewsController;
-}
-
-- (instancetype)init{
-  _ensureSemanticsEnabledCalled = NO;
-  _platformViewsController = std::shared_ptr<flutter::FlutterPlatformViewsController>(nullptr);
-  return self;
-}
+@implementation FakeDelegate
 
-- (flutter::Rasterizer::Screenshot)takeScreenshot:(flutter::Rasterizer::ScreenshotType)type
-                                  asBase64Encoded:(BOOL)base64Encode {
-  return {};
-}
-
-- (std::shared_ptr<flutter::FlutterPlatformViewsController>&)platformViewsController {
-  return _platformViewsController;
-}
 - (void)ensureSemanticsEnabled {
   _ensureSemanticsEnabledCalled = YES;
 }
+
 @end
 
 @interface FlutterViewTest : XCTestCase
@@ -39,9 +25,8 @@ @interface FlutterViewTest : XCTestCase
 @implementation FlutterViewTest
 
 - (void)testFlutterViewEnableSemanticsWhenIsAccessibilityElementIsCalled {
-  FakeDelegate* delegate = [[FakeDelegate alloc] init];
-  FlutterView* view = [[FlutterView alloc] initWithDelegate:delegate
-                                                      opaque:NO];
+  FakeDelegate* delegate = [[FakeDelegate alloc] initWithName:@"foobar"];
+  FlutterView* view = [[FlutterView alloc] initWithDelegate:delegate opaque:NO];
   delegate.ensureSemanticsEnabledCalled = NO;
   XCTAssertFalse(view.isAccessibilityElement);
   XCTAssertTrue(delegate.ensureSemanticsEnabledCalled);