flutter::AccessibilityBridgeWindows Class Reference

#include <accessibility_bridge_windows.h>

Inheritance diagram for flutter::AccessibilityBridgeWindows:

Public Member Functions
	AccessibilityBridgeWindows (FlutterWindowsView *view)
virtual	~AccessibilityBridgeWindows ()=default
void	DispatchAccessibilityAction (AccessibilityNodeId target, FlutterSemanticsAction action, fml::MallocMapping data) override
	Dispatch accessibility action back to the Flutter framework. These actions are generated in the native accessibility system when users interact with the assistive technologies. For example, a FlutterSemanticsAction::kFlutterSemanticsActionTap is fired when user click or touch the screen. More...
virtual void	DispatchWinAccessibilityEvent (std::shared_ptr< FlutterPlatformNodeDelegateWindows > node_delegate, ax::mojom::Event event_type)
virtual void	SetFocus (std::shared_ptr< FlutterPlatformNodeDelegateWindows > node_delegate)
gfx::NativeViewAccessible	GetChildOfAXFragmentRoot () override
gfx::NativeViewAccessible	GetParentOfAXFragmentRoot () override
bool	IsAXFragmentRootAControlElement () override
Public Member Functions inherited from flutter::AccessibilityBridge
	AccessibilityBridge ()
	Creates a new instance of a accessibility bridge. More...
virtual	~AccessibilityBridge ()
void	AddFlutterSemanticsNodeUpdate (const FlutterSemanticsNode2 &node)
	Adds a semantics node update to the pending semantics update. Calling this method alone will NOT update the semantics tree. To flush the pending updates, call the CommitUpdates(). More...
void	AddFlutterSemanticsCustomActionUpdate (const FlutterSemanticsCustomAction2 &action)
	Adds a custom semantics action update to the pending semantics update. Calling this method alone will NOT update the semantics tree. To flush the pending updates, call the CommitUpdates(). More...
void	CommitUpdates ()
	Flushes the pending updates and applies them to this accessibility bridge. Calling this with no pending updates does nothing, and callers should call this method at the end of an atomic batch to avoid leaving the tree in a unstable state. For example if a node reparents from A to B, callers should only call this method when both removal from A and addition to B are in the pending updates. More...
std::weak_ptr< FlutterPlatformNodeDelegate >	GetFlutterPlatformNodeDelegateFromID (AccessibilityNodeId id) const
	Get the flutter platform node delegate with the given id from this accessibility bridge. Returns expired weak_ptr if the delegate associated with the id does not exist or has been removed from the accessibility tree. More...
const ui::AXTreeData &	GetAXTreeData () const
	Get the ax tree data from this accessibility bridge. The tree data contains information such as the id of the node that has the keyboard focus or the text selection range. More...
const std::vector< ui::AXEventGenerator::TargetedEvent >	GetPendingEvents () const
	Gets all pending accessibility events generated during semantics updates. This is useful when deciding how to handle events in AccessibilityBridgeDelegate::OnAccessibilityEvent in case one may decide to handle an event differently based on all pending events. More...
ui::AXNode *	GetNodeFromTree (const ui::AXTreeID tree_id, const ui::AXNode::AXID node_id) const override
ui::AXNode *	GetNodeFromTree (const ui::AXNode::AXID node_id) const override
ui::AXTreeID	GetTreeID () const override
ui::AXTreeID	GetParentTreeID () const override
ui::AXNode *	GetRootAsAXNode () const override
ui::AXNode *	GetParentNodeFromParentTreeAsAXNode () const override
ui::AXTree *	GetTree () const override
ui::AXPlatformNode *	GetPlatformNodeFromTree (const ui::AXNode::AXID node_id) const override
ui::AXPlatformNode *	GetPlatformNodeFromTree (const ui::AXNode &node) const override
ui::AXPlatformNodeDelegate *	RootDelegate () const override
Public Member Functions inherited from flutter::FlutterPlatformNodeDelegate::OwnerBridge
virtual	~OwnerBridge ()=default

Protected Member Functions
void	OnAccessibilityEvent (ui::AXEventGenerator::TargetedEvent targeted_event) override
	Handle accessibility events generated due to accessibility tree changes. These events are needed to be sent to native accessibility system. See ui::AXEventGenerator::Event for possible events. More...
std::shared_ptr< FlutterPlatformNodeDelegate >	CreateFlutterPlatformNodeDelegate () override
	Creates a platform specific FlutterPlatformNodeDelegate. Ownership passes to the caller. This method will be called whenever a new AXNode is created in AXTree. Each platform needs to implement this method in order to inject its subclass into the accessibility bridge. More...
virtual std::weak_ptr< FlutterPlatformNodeDelegate >	GetFocusedNode ()

Detailed Description

AccessibilityBridgeWindows must be created as a shared_ptr, since some methods acquires its weak_ptr.

Definition at line 27 of file accessibility_bridge_windows.h.

Constructor & Destructor Documentation

AccessibilityBridgeWindows()

flutter::AccessibilityBridgeWindows::AccessibilityBridgeWindows

(

FlutterWindowsView *

view

)

Definition at line 13 of file accessibility_bridge_windows.cc.

    : view_(view) {
  FML_DCHECK(view_);
}

~AccessibilityBridgeWindows()

virtual flutter::AccessibilityBridgeWindows::~AccessibilityBridgeWindows ( )

virtualdefault

Member Function Documentation

CreateFlutterPlatformNodeDelegate()

std::shared_ptr< FlutterPlatformNodeDelegate > flutter::AccessibilityBridgeWindows::CreateFlutterPlatformNodeDelegate ( )

overrideprotectedvirtual

Creates a platform specific FlutterPlatformNodeDelegate. Ownership passes to the caller. This method will be called whenever a new AXNode is created in AXTree. Each platform needs to implement this method in order to inject its subclass into the accessibility bridge.

Implements flutter::AccessibilityBridge.

Definition at line 170 of file accessibility_bridge_windows.cc.

                                                              {
  return std::make_shared<FlutterPlatformNodeDelegateWindows>(
      shared_from_this(), view_);
}

DispatchAccessibilityAction()

void flutter::AccessibilityBridgeWindows::DispatchAccessibilityAction ( AccessibilityNodeId  target, FlutterSemanticsAction  action, fml::MallocMapping  data  )

overridevirtual

Dispatch accessibility action back to the Flutter framework. These actions are generated in the native accessibility system when users interact with the assistive technologies. For example, a FlutterSemanticsAction::kFlutterSemanticsActionTap is fired when user click or touch the screen.

Parameters

[in]	target	The semantics node id of the action target.
[in]	action	The generated flutter semantics action.
[in]	data	Additional data associated with the action.

Implements flutter::FlutterPlatformNodeDelegate::OwnerBridge.

Definition at line 162 of file accessibility_bridge_windows.cc.

                           {
  view_->GetEngine()->DispatchSemanticsAction(target, action, std::move(data));
}

References action, flutter::FlutterWindowsEngine::DispatchSemanticsAction(), and flutter::FlutterWindowsView::GetEngine().

Referenced by flutter::testing::TEST().

DispatchWinAccessibilityEvent()

void flutter::AccessibilityBridgeWindows::DispatchWinAccessibilityEvent ( std::shared_ptr< FlutterPlatformNodeDelegateWindows >  node_delegate, ax::mojom::Event  event_type  )

virtual

Definition at line 175 of file accessibility_bridge_windows.cc.

                             {
  node_delegate->DispatchWinAccessibilityEvent(event_type);
}

References event_type, and node_delegate.

Referenced by OnAccessibilityEvent().

GetChildOfAXFragmentRoot()

gfx::NativeViewAccessible flutter::AccessibilityBridgeWindows::GetChildOfAXFragmentRoot ( )

override

Definition at line 187 of file accessibility_bridge_windows.cc.

                                                     {
  ui::AXPlatformNodeDelegate* root_delegate = RootDelegate();
  if (!root_delegate) {
    return nullptr;
  }
 
  return root_delegate->GetNativeViewAccessible();
}

References flutter::AccessibilityBridge::RootDelegate().

GetFocusedNode()

std::weak_ptr< FlutterPlatformNodeDelegate > flutter::AccessibilityBridgeWindows::GetFocusedNode ( )

protectedvirtual

Definition at line 206 of file accessibility_bridge_windows.cc.

                                           {
  ui::AXNode::AXID focus_id = GetAXTreeData().sel_focus_object_id;
  return GetFlutterPlatformNodeDelegateFromID(focus_id);
}

References flutter::AccessibilityBridge::GetAXTreeData(), and flutter::AccessibilityBridge::GetFlutterPlatformNodeDelegateFromID().

Referenced by OnAccessibilityEvent().

GetParentOfAXFragmentRoot()

gfx::NativeViewAccessible flutter::AccessibilityBridgeWindows::GetParentOfAXFragmentRoot ( )

override

Definition at line 197 of file accessibility_bridge_windows.cc.

                                                      {
  return nullptr;
}

IsAXFragmentRootAControlElement()

bool flutter::AccessibilityBridgeWindows::IsAXFragmentRootAControlElement ( )

override

Definition at line 201 of file accessibility_bridge_windows.cc.

                                                                 {
  return true;
}

OnAccessibilityEvent()

void flutter::AccessibilityBridgeWindows::OnAccessibilityEvent ( ui::AXEventGenerator::TargetedEvent  targeted_event )

overrideprotectedvirtual

Handle accessibility events generated due to accessibility tree changes. These events are needed to be sent to native accessibility system. See ui::AXEventGenerator::Event for possible events.

Parameters

[in]

targeted_event

The object that contains both the generated event and the event target.

Implements flutter::AccessibilityBridge.

Definition at line 18 of file accessibility_bridge_windows.cc.

                                                    {
  ui::AXNode* ax_node = targeted_event.node;
  ui::AXEventGenerator::Event event_type = targeted_event.event_params.event;
 
  auto node_delegate =
      GetFlutterPlatformNodeDelegateFromID(ax_node->id()).lock();
  FML_DCHECK(node_delegate)
      << "No FlutterPlatformNodeDelegate found for node ID " << ax_node->id();
  std::shared_ptr<FlutterPlatformNodeDelegateWindows> win_delegate =
      std::static_pointer_cast<FlutterPlatformNodeDelegateWindows>(
          node_delegate);
 
  switch (event_type) {
    case ui::AXEventGenerator::Event::ALERT:
      DispatchWinAccessibilityEvent(win_delegate, ax::mojom::Event::kAlert);
      break;
    case ui::AXEventGenerator::Event::CHECKED_STATE_CHANGED:
      DispatchWinAccessibilityEvent(win_delegate,
                                    ax::mojom::Event::kValueChanged);
      break;
    case ui::AXEventGenerator::Event::CHILDREN_CHANGED:
      DispatchWinAccessibilityEvent(win_delegate,
                                    ax::mojom::Event::kChildrenChanged);
      break;
    case ui::AXEventGenerator::Event::DOCUMENT_SELECTION_CHANGED: {
      // An event indicating a change in document selection should be fired
      // only for the focused node whose selection has changed. If a valid
      // caret and selection exist in the app tree, they must both be within
      // the focus node.
      auto focus_delegate = GetFocusedNode().lock();
      if (focus_delegate) {
        win_delegate =
            std::static_pointer_cast<FlutterPlatformNodeDelegateWindows>(
                focus_delegate);
      }
      DispatchWinAccessibilityEvent(
          win_delegate, ax::mojom::Event::kDocumentSelectionChanged);
      break;
    }
    case ui::AXEventGenerator::Event::FOCUS_CHANGED:
      DispatchWinAccessibilityEvent(win_delegate, ax::mojom::Event::kFocus);
      SetFocus(win_delegate);
      break;
    case ui::AXEventGenerator::Event::IGNORED_CHANGED:
      if (ax_node->IsIgnored()) {
        DispatchWinAccessibilityEvent(win_delegate, ax::mojom::Event::kHide);
      }
      break;
    case ui::AXEventGenerator::Event::IMAGE_ANNOTATION_CHANGED:
      DispatchWinAccessibilityEvent(win_delegate,
                                    ax::mojom::Event::kTextChanged);
      break;
    case ui::AXEventGenerator::Event::LIVE_REGION_CHANGED:
      DispatchWinAccessibilityEvent(win_delegate,
                                    ax::mojom::Event::kLiveRegionChanged);
      break;
    case ui::AXEventGenerator::Event::NAME_CHANGED:
      DispatchWinAccessibilityEvent(win_delegate,
                                    ax::mojom::Event::kTextChanged);
      break;
    case ui::AXEventGenerator::Event::SCROLL_HORIZONTAL_POSITION_CHANGED:
      DispatchWinAccessibilityEvent(win_delegate,
                                    ax::mojom::Event::kScrollPositionChanged);
      break;
    case ui::AXEventGenerator::Event::SCROLL_VERTICAL_POSITION_CHANGED:
      DispatchWinAccessibilityEvent(win_delegate,
                                    ax::mojom::Event::kScrollPositionChanged);
      break;
    case ui::AXEventGenerator::Event::SELECTED_CHANGED:
      DispatchWinAccessibilityEvent(win_delegate,
                                    ax::mojom::Event::kValueChanged);
      break;
    case ui::AXEventGenerator::Event::SELECTED_CHILDREN_CHANGED:
      DispatchWinAccessibilityEvent(win_delegate,
                                    ax::mojom::Event::kSelectedChildrenChanged);
      break;
    case ui::AXEventGenerator::Event::SUBTREE_CREATED:
      DispatchWinAccessibilityEvent(win_delegate, ax::mojom::Event::kShow);
      break;
    case ui::AXEventGenerator::Event::VALUE_CHANGED:
      DispatchWinAccessibilityEvent(win_delegate,
                                    ax::mojom::Event::kValueChanged);
      break;
    case ui::AXEventGenerator::Event::WIN_IACCESSIBLE_STATE_CHANGED:
      DispatchWinAccessibilityEvent(win_delegate,
                                    ax::mojom::Event::kStateChanged);
      break;
    case ui::AXEventGenerator::Event::ACCESS_KEY_CHANGED:
    case ui::AXEventGenerator::Event::ACTIVE_DESCENDANT_CHANGED:
    case ui::AXEventGenerator::Event::ATK_TEXT_OBJECT_ATTRIBUTE_CHANGED:
    case ui::AXEventGenerator::Event::ATOMIC_CHANGED:
    case ui::AXEventGenerator::Event::AUTO_COMPLETE_CHANGED:
    case ui::AXEventGenerator::Event::BUSY_CHANGED:
    case ui::AXEventGenerator::Event::CLASS_NAME_CHANGED:
    case ui::AXEventGenerator::Event::COLLAPSED:
    case ui::AXEventGenerator::Event::CONTROLS_CHANGED:
    case ui::AXEventGenerator::Event::DESCRIBED_BY_CHANGED:
    case ui::AXEventGenerator::Event::DESCRIPTION_CHANGED:
    case ui::AXEventGenerator::Event::DOCUMENT_TITLE_CHANGED:
    case ui::AXEventGenerator::Event::DROPEFFECT_CHANGED:
    case ui::AXEventGenerator::Event::ENABLED_CHANGED:
    case ui::AXEventGenerator::Event::EXPANDED:
    case ui::AXEventGenerator::Event::FLOW_FROM_CHANGED:
    case ui::AXEventGenerator::Event::FLOW_TO_CHANGED:
    case ui::AXEventGenerator::Event::GRABBED_CHANGED:
    case ui::AXEventGenerator::Event::HASPOPUP_CHANGED:
    case ui::AXEventGenerator::Event::HIERARCHICAL_LEVEL_CHANGED:
    case ui::AXEventGenerator::Event::INVALID_STATUS_CHANGED:
    case ui::AXEventGenerator::Event::KEY_SHORTCUTS_CHANGED:
    case ui::AXEventGenerator::Event::LABELED_BY_CHANGED:
    case ui::AXEventGenerator::Event::LANGUAGE_CHANGED:
    case ui::AXEventGenerator::Event::LAYOUT_INVALIDATED:
    case ui::AXEventGenerator::Event::LIVE_REGION_CREATED:
    case ui::AXEventGenerator::Event::LIVE_REGION_NODE_CHANGED:
    case ui::AXEventGenerator::Event::LIVE_RELEVANT_CHANGED:
    case ui::AXEventGenerator::Event::LIVE_STATUS_CHANGED:
    case ui::AXEventGenerator::Event::LOAD_COMPLETE:
    case ui::AXEventGenerator::Event::LOAD_START:
    case ui::AXEventGenerator::Event::MENU_ITEM_SELECTED:
    case ui::AXEventGenerator::Event::MULTILINE_STATE_CHANGED:
    case ui::AXEventGenerator::Event::MULTISELECTABLE_STATE_CHANGED:
    case ui::AXEventGenerator::Event::OBJECT_ATTRIBUTE_CHANGED:
    case ui::AXEventGenerator::Event::OTHER_ATTRIBUTE_CHANGED:
    case ui::AXEventGenerator::Event::PLACEHOLDER_CHANGED:
    case ui::AXEventGenerator::Event::PORTAL_ACTIVATED:
    case ui::AXEventGenerator::Event::POSITION_IN_SET_CHANGED:
    case ui::AXEventGenerator::Event::READONLY_CHANGED:
    case ui::AXEventGenerator::Event::RELATED_NODE_CHANGED:
    case ui::AXEventGenerator::Event::REQUIRED_STATE_CHANGED:
    case ui::AXEventGenerator::Event::ROLE_CHANGED:
    case ui::AXEventGenerator::Event::ROW_COUNT_CHANGED:
    case ui::AXEventGenerator::Event::SET_SIZE_CHANGED:
    case ui::AXEventGenerator::Event::SORT_CHANGED:
    case ui::AXEventGenerator::Event::STATE_CHANGED:
    case ui::AXEventGenerator::Event::TEXT_ATTRIBUTE_CHANGED:
    case ui::AXEventGenerator::Event::VALUE_MAX_CHANGED:
    case ui::AXEventGenerator::Event::VALUE_MIN_CHANGED:
    case ui::AXEventGenerator::Event::VALUE_STEP_CHANGED:
      // Unhandled event type.
      break;
  }
}

References DispatchWinAccessibilityEvent(), event_type, flutter::AccessibilityBridge::GetFlutterPlatformNodeDelegateFromID(), GetFocusedNode(), node_delegate, and SetFocus().

SetFocus()

void flutter::AccessibilityBridgeWindows::SetFocus ( std::shared_ptr< FlutterPlatformNodeDelegateWindows >  node_delegate )

virtual

Definition at line 181 of file accessibility_bridge_windows.cc.

                                                                     {
  node_delegate->SetFocus();
}

References node_delegate.

Referenced by OnAccessibilityEvent().

---

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

• shell/platform/windows/accessibility_bridge_windows.h
• shell/platform/windows/accessibility_bridge_windows.cc