FlutterScrollableSemanticsObject Class Reference

#import <SemanticsObject.h>

Inheritance diagram for FlutterScrollableSemanticsObject:

Instance Methods
(instancetype)	- initWithBridge:uid: [implementation]
(void)	- dealloc [implementation]
(void)	- accessibilityBridgeDidFinishUpdate [implementation]
(id)	- nativeAccessibility [implementation]
(float)	- scrollExtentMax [implementation]
(float)	- scrollPosition [implementation]
(CGSize)	- contentSizeInternal [implementation]
(CGPoint)	- contentOffsetInternal [implementation]
Instance Methods inherited from SemanticsObject
(BOOL)	- isAccessibilityBridgeAlive
(void)	- setSemanticsNode:
(void)	- replaceChildAtIndex:withChild:
(BOOL)	- nodeWillCauseLayoutChange:
(BOOL)	- nodeWillCauseScroll:
(BOOL)	- nodeShouldTriggerAnnouncement:
(void)	- collectRoutes:
(NSString *)	- routeName
(BOOL)	- onCustomAccessibilityAction:
(void)	- accessibilityBridgeDidFinishUpdate
((unavailable("Use initWithBridge instead")	- __attribute__
(instancetype)	- initWithBridge:uid:
(void)	- dealloc [implementation]
(void)	- setChildren: [implementation]
(void)	- setChildrenInHitTestOrder: [implementation]
(NSAttributedString *)	- createAttributedStringFromString:withAttributes: [implementation]
(void)	- showOnScreen [implementation]
(BOOL)	- isAccessibilityElement [implementation]
(bool)	- isFocusable [implementation]
(NSString *)	- accessibilityIdentifier [implementation]
(NSString *)	- accessibilityLabel [implementation]
(bool)	- containsPoint: [implementation]
(id)	- search: [implementation]
(id)	- _accessibilityHitTest:withEvent: [implementation]
(BOOL)	- accessibilityScrollToVisible [implementation]
(BOOL)	- accessibilityScrollToVisibleWithChild: [implementation]
(NSAttributedString *)	- accessibilityAttributedLabel [implementation]
(NSString *)	- accessibilityHint [implementation]
(NSAttributedString *)	- accessibilityAttributedHint [implementation]
(NSString *)	- accessibilityValue [implementation]
(NSAttributedString *)	- accessibilityAttributedValue [implementation]
(CGRect)	- accessibilityFrame [implementation]
(CGRect)	- globalRect [implementation]
(void)	- setAccessibilityContainer: [implementation]
(id)	- accessibilityContainer [implementation]
(BOOL)	- accessibilityActivate [implementation]
(void)	- accessibilityIncrement [implementation]
(void)	- accessibilityDecrement [implementation]
(BOOL)	- accessibilityScroll: [implementation]
(BOOL)	- accessibilityPerformEscape [implementation]
(void)	- accessibilityElementDidBecomeFocused [implementation]
(void)	- accessibilityElementDidLoseFocus [implementation]

Properties
FlutterSemanticsScrollView *	scrollView [implementation]
Properties inherited from SemanticsObject
int32_t	uid
SemanticsObject *	parent
fml::WeakPtr< flutter::AccessibilityBridgeIos >	bridge
flutter::SemanticsNode	node
BOOL	hasChildren
NSArray< SemanticsObject * > *	children
NSArray< SemanticsObject * > *	childrenInHitTestOrder
id	nativeAccessibility
SemanticsObjectContainer *	container [implementation]

Detailed Description

The semantics object for scrollable. This class creates an UIScrollView to interact with the iOS.

Definition at line 188 of file SemanticsObject.h.

Method Documentation

accessibilityBridgeDidFinishUpdate

- (void) accessibilityBridgeDidFinishUpdate

implementation

Called after accessibility bridge finishes a semantics update.

Subclasses can override this method if they contain states that can only be updated once every node in the accessibility tree has finished updating.

Reimplemented from SemanticsObject.

Definition at line 145 of file SemanticsObject.mm.

                                           {
  // In order to make iOS think this UIScrollView is scrollable, the following
  // requirements must be true.
  // 1. contentSize must be bigger than the frame size.
  // 2. The scrollable isAccessibilityElement must return YES
  //
  // Once the requirements are met, the iOS uses contentOffset to determine
  // what scroll actions are available. e.g. If the view scrolls vertically and
  // contentOffset is 0.0, only the scroll down action is available.
  self.scrollView.frame = self.accessibilityFrame;
  self.scrollView.contentSize = [self contentSizeInternal];
  [self.scrollView setContentOffset:[self contentOffsetInternal] animated:NO];
}

contentOffsetInternal

- (CGPoint) contentOffsetInternal

implementation

Definition at line 145 of file SemanticsObject.mm.

                                 {
  CGPoint result;
  CGPoint origin = self.scrollView.frame.origin;
  const SkRect& rect = self.node.rect;
  if (self.node.actions & flutter::kVerticalScrollSemanticsActions) {
    result = ConvertPointToGlobal(self, CGPointMake(rect.x(), rect.y() + [self scrollPosition]));
  } else if (self.node.actions & flutter::kHorizontalScrollSemanticsActions) {
    result = ConvertPointToGlobal(self, CGPointMake(rect.x() + [self scrollPosition], rect.y()));
  } else {
    result = origin;
  }
  return CGPointMake(result.x - origin.x, result.y - origin.y);
}

contentSizeInternal

- (CGSize) contentSizeInternal

implementation

Definition at line 145 of file SemanticsObject.mm.

                              {
  CGRect result;
  const SkRect& rect = self.node.rect;
 
  if (self.node.actions & flutter::kVerticalScrollSemanticsActions) {
    result = CGRectMake(rect.x(), rect.y(), rect.width(), rect.height() + [self scrollExtentMax]);
  } else if (self.node.actions & flutter::kHorizontalScrollSemanticsActions) {
    result = CGRectMake(rect.x(), rect.y(), rect.width() + [self scrollExtentMax], rect.height());
  } else {
    result = CGRectMake(rect.x(), rect.y(), rect.width(), rect.height());
  }
  return ConvertRectToGlobal(self, result).size;
}

dealloc

- (void) dealloc

implementation

Reimplemented from SemanticsObject.

Definition at line 145 of file SemanticsObject.mm.

                {
  [_scrollView removeFromSuperview];
}

initWithBridge:uid:

- (instancetype) initWithBridge: (fml::WeakPtr<flutter::AccessibilityBridgeIos>)  bridge uid: (int32_t)  uid

implementation

Reimplemented from SemanticsObject.

Definition at line 145 of file SemanticsObject.mm.

                              :(fml::WeakPtr<flutter::AccessibilityBridgeIos>)bridge
                           uid:(int32_t)uid {
  self = [super initWithBridge:bridge uid:uid];
  if (self) {
    _scrollView = [[FlutterSemanticsScrollView alloc] initWithSemanticsObject:self];
    [_scrollView setShowsHorizontalScrollIndicator:NO];
    [_scrollView setShowsVerticalScrollIndicator:NO];
    [self.bridge->view() addSubview:_scrollView];
  }
  return self;
}

nativeAccessibility

- (id) nativeAccessibility

implementation

Definition at line 145 of file SemanticsObject.mm.

                          {
  return self.scrollView;
}

scrollExtentMax

- (float) scrollExtentMax

implementation

Definition at line 145 of file SemanticsObject.mm.

                         {
  if (![self isAccessibilityBridgeAlive]) {
    return 0.0f;
  }
  float scrollExtentMax = self.node.scrollExtentMax;
  if (isnan(scrollExtentMax)) {
    scrollExtentMax = 0.0f;
  } else if (!isfinite(scrollExtentMax)) {
    scrollExtentMax = kScrollExtentMaxForInf + [self scrollPosition];
  }
  return scrollExtentMax;
}

scrollPosition

- (float) scrollPosition

implementation

Definition at line 145 of file SemanticsObject.mm.

                        {
  if (![self isAccessibilityBridgeAlive]) {
    return 0.0f;
  }
  float scrollPosition = self.node.scrollPosition;
  if (isnan(scrollPosition)) {
    scrollPosition = 0.0f;
  }
  NSCAssert(isfinite(scrollPosition), @"The scrollPosition must not be infinity");
  return scrollPosition;
}

Property Documentation

scrollView

- (FlutterSemanticsScrollView*) scrollView

readwritenonatomicassignimplementation

Definition at line 145 of file SemanticsObject.mm.

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The documentation for this class was generated from the following files:

• shell/platform/darwin/ios/framework/Source/SemanticsObject.h
• shell/platform/darwin/ios/framework/Source/SemanticsObject.mm