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flutter::FlutterPlatformNodeDelegate Class Reference

#include <flutter_platform_node_delegate.h>

Inheritance diagram for flutter::FlutterPlatformNodeDelegate:

Classes

class  OwnerBridge
 

Public Member Functions

 FlutterPlatformNodeDelegate ()
 
virtual ~FlutterPlatformNodeDelegate () override
 
const ui::AXUniqueId & GetUniqueId () const override
 
const ui::AXNodeData & GetData () const override
 
bool AccessibilityPerformAction (const ui::AXActionData &data) override
 
gfx::NativeViewAccessible GetParent () override
 
gfx::NativeViewAccessible GetFocus () override
 
int GetChildCount () const override
 
gfx::NativeViewAccessible ChildAtIndex (int index) override
 
gfx::Rect GetBoundsRect (const ui::AXCoordinateSystem coordinate_system, const ui::AXClippingBehavior clipping_behavior, ui::AXOffscreenResult *offscreen_result) const override
 
gfx::NativeViewAccessible GetLowestPlatformAncestor () const override
 
ui::AXNodePosition::AXPositionInstance CreateTextPositionAt (int offset) const override
 
virtual void Init (std::weak_ptr< OwnerBridge > bridge, ui::AXNode *node)
 Called only once, immediately after construction. The constructor doesn't take any arguments because in the Windows subclass we use a special function to construct a COM object. Subclasses must call super. More...
 
ui::AXNode * GetAXNode () const
 Gets the underlying ax node for this platform node delegate. More...
 
std::weak_ptr< OwnerBridgeGetOwnerBridge () const
 Gets the owner of this platform node delegate. This is useful when you want to get the information about surrounding nodes of this platform node delegate, e.g. the global rect of this platform node delegate. This pointer is only safe in the platform thread. More...
 
virtual ui::AXPlatformNode * GetPlatformNode () const
 
virtual ui::AXPlatformNode * GetFromNodeID (int32_t id) override
 
virtual ui::AXPlatformNode * GetFromTreeIDAndNodeID (const ui::AXTreeID &tree_id, int32_t node_id) override
 
virtual const ui::AXTree::Selection GetUnignoredSelection () const override
 

Detailed Description

The platform node delegate to be used in accessibility bridge. This class is responsible for providing native accessibility object with appropriate information, such as accessibility label/value/bounds.

While most methods have default implementations and are ready to be used as-is, the subclasses must override the GetNativeViewAccessible to return native accessibility objects. To do that, subclasses should create and maintain AXPlatformNode[s] which delegate their accessibility attributes to this class.

For desktop platforms, subclasses also need to override the GetBoundsRect to apply window-to-screen transform.

This class transforms bounds assuming the device pixel ratio is 1.0. See the https://github.com/flutter/flutter/issues/74283 for more information.

Definition at line 33 of file flutter_platform_node_delegate.h.

Constructor & Destructor Documentation

◆ FlutterPlatformNodeDelegate()

flutter::FlutterPlatformNodeDelegate::FlutterPlatformNodeDelegate ( )
default

◆ ~FlutterPlatformNodeDelegate()

flutter::FlutterPlatformNodeDelegate::~FlutterPlatformNodeDelegate ( )
overridevirtualdefault

Member Function Documentation

◆ AccessibilityPerformAction()

bool flutter::FlutterPlatformNodeDelegate::AccessibilityPerformAction ( const ui::AXActionData &  data)
override

Definition at line 30 of file flutter_platform_node_delegate.cc.

31  {
32  AccessibilityNodeId target = ax_node_->id();
33  auto bridge_ptr = bridge_.lock();
34  BASE_DCHECK(bridge_ptr);
35  switch (data.action) {
36  case ax::mojom::Action::kDoDefault:
37  bridge_ptr->DispatchAccessibilityAction(
38  target, FlutterSemanticsAction::kFlutterSemanticsActionTap, {});
39  return true;
40  case ax::mojom::Action::kFocus:
41  bridge_ptr->SetLastFocusedId(target);
42  bridge_ptr->DispatchAccessibilityAction(
43  target,
44  FlutterSemanticsAction::
45  kFlutterSemanticsActionDidGainAccessibilityFocus,
46  {});
47  return true;
48  case ax::mojom::Action::kScrollToMakeVisible:
49  bridge_ptr->DispatchAccessibilityAction(
50  target, FlutterSemanticsAction::kFlutterSemanticsActionShowOnScreen,
51  {});
52  return true;
53  // TODO(chunhtai): support more actions.
54  default:
55  return false;
56  }
57  return false;
58 }

References target.

◆ ChildAtIndex()

gfx::NativeViewAccessible flutter::FlutterPlatformNodeDelegate::ChildAtIndex ( int  index)
override

Definition at line 87 of file flutter_platform_node_delegate.cc.

87  {
88  auto bridge_ptr = bridge_.lock();
89  BASE_DCHECK(bridge_ptr);
90  AccessibilityNodeId child = ax_node_->GetUnignoredChildAtIndex(index)->id();
91  return bridge_ptr->GetNativeAccessibleFromId(child);
92 }

◆ CreateTextPositionAt()

ui::AXNodePosition::AXPositionInstance flutter::FlutterPlatformNodeDelegate::CreateTextPositionAt ( int  offset) const
override

Definition at line 136 of file flutter_platform_node_delegate.cc.

136  {
137  return ui::AXNodePosition::CreatePosition(*ax_node_, offset);
138 }

◆ GetAXNode()

ui::AXNode * flutter::FlutterPlatformNodeDelegate::GetAXNode ( ) const

Gets the underlying ax node for this platform node delegate.

Definition at line 26 of file flutter_platform_node_delegate.cc.

26  {
27  return ax_node_;
28 }

◆ GetBoundsRect()

gfx::Rect flutter::FlutterPlatformNodeDelegate::GetBoundsRect ( const ui::AXCoordinateSystem  coordinate_system,
const ui::AXClippingBehavior  clipping_behavior,
ui::AXOffscreenResult *  offscreen_result 
) const
override

Definition at line 94 of file flutter_platform_node_delegate.cc.

97  {
98  auto bridge_ptr = bridge_.lock();
99  BASE_DCHECK(bridge_ptr);
100  // TODO(chunhtai): We need to apply screen dpr in here.
101  // https://github.com/flutter/flutter/issues/74283
102  const bool clip_bounds =
103  clipping_behavior == ui::AXClippingBehavior::kClipped;
104  bool offscreen = false;
105  gfx::RectF bounds =
106  bridge_ptr->RelativeToGlobalBounds(ax_node_, offscreen, clip_bounds);
107  if (offscreen_result != nullptr) {
108  *offscreen_result = offscreen ? ui::AXOffscreenResult::kOffscreen
109  : ui::AXOffscreenResult::kOnscreen;
110  }
111  return gfx::ToEnclosingRect(bounds);
112 }

◆ GetChildCount()

int flutter::FlutterPlatformNodeDelegate::GetChildCount ( ) const
override

Definition at line 83 of file flutter_platform_node_delegate.cc.

83  {
84  return static_cast<int>(ax_node_->GetUnignoredChildCount());
85 }

◆ GetData()

const ui::AXNodeData & flutter::FlutterPlatformNodeDelegate::GetData ( ) const
override

Definition at line 60 of file flutter_platform_node_delegate.cc.

60  {
61  return ax_node_->data();
62 }

◆ GetFocus()

gfx::NativeViewAccessible flutter::FlutterPlatformNodeDelegate::GetFocus ( )
override

Definition at line 73 of file flutter_platform_node_delegate.cc.

73  {
74  auto bridge_ptr = bridge_.lock();
75  BASE_DCHECK(bridge_ptr);
76  AccessibilityNodeId last_focused = bridge_ptr->GetLastFocusedId();
77  if (last_focused == ui::AXNode::kInvalidAXID) {
78  return nullptr;
79  }
80  return bridge_ptr->GetNativeAccessibleFromId(last_focused);
81 }

◆ GetFromNodeID()

ui::AXPlatformNode * flutter::FlutterPlatformNodeDelegate::GetFromNodeID ( int32_t  id)
overridevirtual

Definition at line 140 of file flutter_platform_node_delegate.cc.

141  {
142  ui::AXTreeManager* tree_manager =
143  ui::AXTreeManagerMap::GetInstance().GetManager(
144  ax_node_->tree()->GetAXTreeID());
145  AccessibilityBridge* platform_manager =
146  static_cast<AccessibilityBridge*>(tree_manager);
147  return platform_manager->GetPlatformNodeFromTree(node_id);
148 }

References flutter::AccessibilityBridge::GetPlatformNodeFromTree().

◆ GetFromTreeIDAndNodeID()

ui::AXPlatformNode * flutter::FlutterPlatformNodeDelegate::GetFromTreeIDAndNodeID ( const ui::AXTreeID &  tree_id,
int32_t  node_id 
)
overridevirtual

Definition at line 150 of file flutter_platform_node_delegate.cc.

152  {
153  ui::AXTreeManager* tree_manager =
154  ui::AXTreeManagerMap::GetInstance().GetManager(tree_id);
155  AccessibilityBridge* platform_manager =
156  static_cast<AccessibilityBridge*>(tree_manager);
157  return platform_manager->GetPlatformNodeFromTree(node_id);
158 }

References flutter::AccessibilityBridge::GetPlatformNodeFromTree().

◆ GetLowestPlatformAncestor()

gfx::NativeViewAccessible flutter::FlutterPlatformNodeDelegate::GetLowestPlatformAncestor ( ) const
override

Definition at line 124 of file flutter_platform_node_delegate.cc.

124  {
125  auto bridge_ptr = bridge_.lock();
126  BASE_DCHECK(bridge_ptr);
127  auto lowest_platform_ancestor = ax_node_->GetLowestPlatformAncestor();
128  if (lowest_platform_ancestor) {
129  return bridge_ptr->GetNativeAccessibleFromId(
130  ax_node_->GetLowestPlatformAncestor()->id());
131  }
132  return nullptr;
133 }

◆ GetOwnerBridge()

std::weak_ptr< FlutterPlatformNodeDelegate::OwnerBridge > flutter::FlutterPlatformNodeDelegate::GetOwnerBridge ( ) const

Gets the owner of this platform node delegate. This is useful when you want to get the information about surrounding nodes of this platform node delegate, e.g. the global rect of this platform node delegate. This pointer is only safe in the platform thread.

Definition at line 115 of file flutter_platform_node_delegate.cc.

115  {
116  return bridge_;
117 }

◆ GetParent()

gfx::NativeViewAccessible flutter::FlutterPlatformNodeDelegate::GetParent ( )
override

Definition at line 64 of file flutter_platform_node_delegate.cc.

64  {
65  if (!ax_node_->parent()) {
66  return nullptr;
67  }
68  auto bridge_ptr = bridge_.lock();
69  BASE_DCHECK(bridge_ptr);
70  return bridge_ptr->GetNativeAccessibleFromId(ax_node_->parent()->id());
71 }

◆ GetPlatformNode()

ui::AXPlatformNode * flutter::FlutterPlatformNodeDelegate::GetPlatformNode ( ) const
virtual

Definition at line 119 of file flutter_platform_node_delegate.cc.

119  {
120  return nullptr;
121 }

◆ GetUnignoredSelection()

const ui::AXTree::Selection flutter::FlutterPlatformNodeDelegate::GetUnignoredSelection ( ) const
overridevirtual

Definition at line 160 of file flutter_platform_node_delegate.cc.

161  {
162  return ax_node_->GetUnignoredSelection();
163 }

◆ GetUniqueId()

const ui::AXUniqueId& flutter::FlutterPlatformNodeDelegate::GetUniqueId ( ) const
inlineoverride

Definition at line 102 of file flutter_platform_node_delegate.h.

102 { return unique_id_; }

◆ Init()

void flutter::FlutterPlatformNodeDelegate::Init ( std::weak_ptr< OwnerBridge bridge,
ui::AXNode *  node 
)
virtual

Called only once, immediately after construction. The constructor doesn't take any arguments because in the Windows subclass we use a special function to construct a COM object. Subclasses must call super.

Definition at line 20 of file flutter_platform_node_delegate.cc.

21  {
22  bridge_ = std::move(bridge);
23  ax_node_ = node;
24 }

References node.


The documentation for this class was generated from the following files:
flutter::AccessibilityNodeId
ui::AXNode::AXID AccessibilityNodeId
Definition: flutter_platform_node_delegate.h:15
target
uint32_t * target
Definition: fl_texture_registrar_test.cc:40
node
G_BEGIN_DECLS const FlutterSemanticsNode * node
Definition: fl_view_accessible.h:40