Flutter Windows Embedder
accessibility_bridge.cc
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1 // Copyright 2013 The Flutter Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #include "accessibility_bridge.h"
6 
7 #include <functional>
8 #include <utility>
9 
10 #include "flutter/third_party/accessibility/ax/ax_tree_manager_map.h"
11 #include "flutter/third_party/accessibility/ax/ax_tree_update.h"
12 #include "flutter/third_party/accessibility/base/logging.h"
13 
14 namespace flutter { // namespace
15 
16 constexpr int kHasScrollingAction =
17  FlutterSemanticsAction::kFlutterSemanticsActionScrollLeft |
18  FlutterSemanticsAction::kFlutterSemanticsActionScrollRight |
19  FlutterSemanticsAction::kFlutterSemanticsActionScrollUp |
20  FlutterSemanticsAction::kFlutterSemanticsActionScrollDown;
21 
22 // AccessibilityBridge
24  : tree_(std::make_unique<ui::AXTree>()) {
25  event_generator_.SetTree(tree_.get());
26  tree_->AddObserver(static_cast<ui::AXTreeObserver*>(this));
27  ui::AXTreeData data = tree_->data();
28  data.tree_id = ui::AXTreeID::CreateNewAXTreeID();
29  tree_->UpdateData(data);
30  ui::AXTreeManagerMap::GetInstance().AddTreeManager(tree_->GetAXTreeID(),
31  this);
32 }
33 
35  event_generator_.ReleaseTree();
36  tree_->RemoveObserver(static_cast<ui::AXTreeObserver*>(this));
37 }
38 
40  const FlutterSemanticsNode2& node) {
41  pending_semantics_node_updates_[node.id] = FromFlutterSemanticsNode(node);
42 }
43 
45  const FlutterSemanticsCustomAction2& action) {
46  pending_semantics_custom_action_updates_[action.id] =
47  FromFlutterSemanticsCustomAction(action);
48 }
49 
51  // AXTree cannot move a node in a single update.
52  // This must be split across two updates:
53  //
54  // * Update 1: remove nodes from their old parents.
55  // * Update 2: re-add nodes (including their children) to their new parents.
56  //
57  // First, start by removing nodes if necessary.
58  std::optional<ui::AXTreeUpdate> remove_reparented =
59  CreateRemoveReparentedNodesUpdate();
60  if (remove_reparented.has_value()) {
61  tree_->Unserialize(remove_reparented.value());
62 
63  std::string error = tree_->error();
64  if (!error.empty()) {
65  FML_LOG(ERROR) << "Failed to update ui::AXTree, error: " << error;
66  assert(false);
67  return;
68  }
69  }
70 
71  // Second, apply the pending node updates. This also moves reparented nodes to
72  // their new parents if needed.
73  ui::AXTreeUpdate update{.tree_data = tree_->data()};
74 
75  // Figure out update order, ui::AXTree only accepts update in tree order,
76  // where parent node must come before the child node in
77  // ui::AXTreeUpdate.nodes. We start with picking a random node and turn the
78  // entire subtree into a list. We pick another node from the remaining update,
79  // and keep doing so until the update map is empty. We then concatenate the
80  // lists in the reversed order, this guarantees parent updates always come
81  // before child updates. If the root is in the update, it is guaranteed to
82  // be the first node of the last list.
83  std::vector<std::vector<SemanticsNode>> results;
84  while (!pending_semantics_node_updates_.empty()) {
85  auto begin = pending_semantics_node_updates_.begin();
86  SemanticsNode target = begin->second;
87  std::vector<SemanticsNode> sub_tree_list;
88  GetSubTreeList(target, sub_tree_list);
89  results.push_back(sub_tree_list);
90  pending_semantics_node_updates_.erase(begin);
91  }
92 
93  for (size_t i = results.size(); i > 0; i--) {
94  for (const SemanticsNode& node : results[i - 1]) {
95  ConvertFlutterUpdate(node, update);
96  }
97  }
98 
99  // The first update must set the tree's root, which is guaranteed to be the
100  // last list's first node. A tree's root node never changes, though it can be
101  // modified.
102  if (!results.empty() && GetRootAsAXNode()->id() == ui::AXNode::kInvalidAXID) {
103  FML_DCHECK(!results.back().empty());
104 
105  update.root_id = results.back().front().id;
106  }
107 
108  tree_->Unserialize(update);
109  pending_semantics_node_updates_.clear();
110  pending_semantics_custom_action_updates_.clear();
111 
112  std::string error = tree_->error();
113  if (!error.empty()) {
114  FML_LOG(ERROR) << "Failed to update ui::AXTree, error: " << error;
115  return;
116  }
117  // Handles accessibility events as the result of the semantics update.
118  for (const auto& targeted_event : event_generator_) {
119  auto event_target =
120  GetFlutterPlatformNodeDelegateFromID(targeted_event.node->id());
121  if (event_target.expired()) {
122  continue;
123  }
124 
125  OnAccessibilityEvent(targeted_event);
126  }
127  event_generator_.ClearEvents();
128 }
129 
130 std::weak_ptr<FlutterPlatformNodeDelegate>
132  AccessibilityNodeId id) const {
133  const auto iter = id_wrapper_map_.find(id);
134  if (iter != id_wrapper_map_.end()) {
135  return iter->second;
136  }
137 
138  return std::weak_ptr<FlutterPlatformNodeDelegate>();
139 }
140 
141 const ui::AXTreeData& AccessibilityBridge::GetAXTreeData() const {
142  return tree_->data();
143 }
144 
145 const std::vector<ui::AXEventGenerator::TargetedEvent>
147  std::vector<ui::AXEventGenerator::TargetedEvent> result(
148  event_generator_.begin(), event_generator_.end());
149  return result;
150 }
151 
152 void AccessibilityBridge::OnNodeWillBeDeleted(ui::AXTree* tree,
153  ui::AXNode* node) {}
154 
155 void AccessibilityBridge::OnSubtreeWillBeDeleted(ui::AXTree* tree,
156  ui::AXNode* node) {}
157 
158 void AccessibilityBridge::OnNodeReparented(ui::AXTree* tree, ui::AXNode* node) {
159 }
160 
161 void AccessibilityBridge::OnRoleChanged(ui::AXTree* tree,
162  ui::AXNode* node,
163  ax::mojom::Role old_role,
164  ax::mojom::Role new_role) {}
165 
166 void AccessibilityBridge::OnNodeCreated(ui::AXTree* tree, ui::AXNode* node) {
167  BASE_DCHECK(node);
168  id_wrapper_map_[node->id()] = CreateFlutterPlatformNodeDelegate();
169  id_wrapper_map_[node->id()]->Init(
170  std::static_pointer_cast<FlutterPlatformNodeDelegate::OwnerBridge>(
171  shared_from_this()),
172  node);
173 }
174 
175 void AccessibilityBridge::OnNodeDeleted(ui::AXTree* tree,
176  AccessibilityNodeId node_id) {
177  BASE_DCHECK(node_id != ui::AXNode::kInvalidAXID);
178  if (id_wrapper_map_.find(node_id) != id_wrapper_map_.end()) {
179  id_wrapper_map_.erase(node_id);
180  }
181 }
182 
183 void AccessibilityBridge::OnAtomicUpdateFinished(
184  ui::AXTree* tree,
185  bool root_changed,
186  const std::vector<ui::AXTreeObserver::Change>& changes) {
187  // The Flutter semantics update does not include child->parent relationship
188  // We have to update the relative bound offset container id here in order
189  // to calculate the screen bound correctly.
190  for (const auto& change : changes) {
191  ui::AXNode* node = change.node;
192  const ui::AXNodeData& data = node->data();
193  AccessibilityNodeId offset_container_id = -1;
194  if (node->parent()) {
195  offset_container_id = node->parent()->id();
196  }
197  node->SetLocation(offset_container_id, data.relative_bounds.bounds,
198  data.relative_bounds.transform.get());
199  }
200 }
201 
202 std::optional<ui::AXTreeUpdate>
203 AccessibilityBridge::CreateRemoveReparentedNodesUpdate() {
204  std::unordered_map<int32_t, ui::AXNodeData> updates;
205 
206  for (const auto& node_update : pending_semantics_node_updates_) {
207  for (int32_t child_id : node_update.second.children_in_traversal_order) {
208  // Skip nodes that don't exist or have a parent in the current tree.
209  ui::AXNode* child = tree_->GetFromId(child_id);
210  if (!child) {
211  continue;
212  }
213 
214  // Flutter's root node should never be reparented.
215  assert(child->parent());
216 
217  // Skip nodes whose parents are unchanged.
218  if (child->parent()->id() == node_update.second.id) {
219  continue;
220  }
221 
222  // This pending update moves the current child node.
223  // That new child must have a corresponding pending update.
224  assert(pending_semantics_node_updates_.find(child_id) !=
225  pending_semantics_node_updates_.end());
226 
227  // Create an update to remove the child from its previous parent.
228  int32_t parent_id = child->parent()->id();
229  if (updates.find(parent_id) == updates.end()) {
230  updates[parent_id] = tree_->GetFromId(parent_id)->data();
231  }
232 
233  ui::AXNodeData* parent = &updates[parent_id];
234  auto iter = std::find(parent->child_ids.begin(), parent->child_ids.end(),
235  child_id);
236 
237  assert(iter != parent->child_ids.end());
238  parent->child_ids.erase(iter);
239  }
240  }
241 
242  if (updates.empty()) {
243  return std::nullopt;
244  }
245 
246  ui::AXTreeUpdate update{
247  .tree_data = tree_->data(),
248  .nodes = std::vector<ui::AXNodeData>(),
249  };
250 
251  for (std::pair<int32_t, ui::AXNodeData> data : updates) {
252  update.nodes.push_back(std::move(data.second));
253  }
254 
255  return update;
256 }
257 
258 // Private method.
259 void AccessibilityBridge::GetSubTreeList(const SemanticsNode& target,
260  std::vector<SemanticsNode>& result) {
261  result.push_back(target);
262  for (int32_t child : target.children_in_traversal_order) {
263  auto iter = pending_semantics_node_updates_.find(child);
264  if (iter != pending_semantics_node_updates_.end()) {
265  SemanticsNode node = iter->second;
266  GetSubTreeList(node, result);
267  pending_semantics_node_updates_.erase(iter);
268  }
269  }
270 }
271 
272 void AccessibilityBridge::ConvertFlutterUpdate(const SemanticsNode& node,
273  ui::AXTreeUpdate& tree_update) {
274  ui::AXNodeData node_data;
275  node_data.id = node.id;
276  SetRoleFromFlutterUpdate(node_data, node);
277  SetStateFromFlutterUpdate(node_data, node);
278  SetActionsFromFlutterUpdate(node_data, node);
279  SetBooleanAttributesFromFlutterUpdate(node_data, node);
280  SetIntAttributesFromFlutterUpdate(node_data, node);
281  SetIntListAttributesFromFlutterUpdate(node_data, node);
282  SetStringListAttributesFromFlutterUpdate(node_data, node);
283  SetNameFromFlutterUpdate(node_data, node);
284  SetValueFromFlutterUpdate(node_data, node);
285  SetTooltipFromFlutterUpdate(node_data, node);
286  node_data.relative_bounds.bounds.SetRect(node.rect.left, node.rect.top,
287  node.rect.right - node.rect.left,
288  node.rect.bottom - node.rect.top);
289  node_data.relative_bounds.transform = std::make_unique<gfx::Transform>(
290  node.transform.scaleX, node.transform.skewX, node.transform.transX, 0,
291  node.transform.skewY, node.transform.scaleY, node.transform.transY, 0,
292  node.transform.pers0, node.transform.pers1, node.transform.pers2, 0, 0, 0,
293  0, 0);
294  for (auto child : node.children_in_traversal_order) {
295  node_data.child_ids.push_back(child);
296  }
297  SetTreeData(node, tree_update);
298  tree_update.nodes.push_back(node_data);
299 }
300 
301 void AccessibilityBridge::SetRoleFromFlutterUpdate(ui::AXNodeData& node_data,
302  const SemanticsNode& node) {
303  FlutterSemanticsFlag flags = node.flags;
304  if (flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsButton) {
305  node_data.role = ax::mojom::Role::kButton;
306  return;
307  }
308  if (flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsTextField &&
309  !(flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsReadOnly)) {
310  node_data.role = ax::mojom::Role::kTextField;
311  return;
312  }
313  if (flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsHeader) {
314  node_data.role = ax::mojom::Role::kHeader;
315  return;
316  }
317  if (flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsImage) {
318  node_data.role = ax::mojom::Role::kImage;
319  return;
320  }
321  if (flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsLink) {
322  node_data.role = ax::mojom::Role::kLink;
323  return;
324  }
325 
326  if (flags & kFlutterSemanticsFlagIsInMutuallyExclusiveGroup &&
327  flags & kFlutterSemanticsFlagHasCheckedState) {
328  node_data.role = ax::mojom::Role::kRadioButton;
329  return;
330  }
331  if (flags & kFlutterSemanticsFlagHasCheckedState) {
332  node_data.role = ax::mojom::Role::kCheckBox;
333  return;
334  }
335  if (flags & kFlutterSemanticsFlagHasToggledState) {
336  node_data.role = ax::mojom::Role::kSwitch;
337  return;
338  }
339  if (flags & kFlutterSemanticsFlagIsSlider) {
340  node_data.role = ax::mojom::Role::kSlider;
341  return;
342  }
343  // If the state cannot be derived from the flutter flags, we fallback to group
344  // or static text.
345  if (node.children_in_traversal_order.empty()) {
346  node_data.role = ax::mojom::Role::kStaticText;
347  } else {
348  node_data.role = ax::mojom::Role::kGroup;
349  }
350 }
351 
352 void AccessibilityBridge::SetStateFromFlutterUpdate(ui::AXNodeData& node_data,
353  const SemanticsNode& node) {
354  FlutterSemanticsFlag flags = node.flags;
355  FlutterSemanticsAction actions = node.actions;
356  if (flags & FlutterSemanticsFlag::kFlutterSemanticsFlagHasExpandedState &&
357  flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsExpanded) {
358  node_data.AddState(ax::mojom::State::kExpanded);
359  } else if (flags &
360  FlutterSemanticsFlag::kFlutterSemanticsFlagHasExpandedState) {
361  node_data.AddState(ax::mojom::State::kCollapsed);
362  }
363  if (flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsTextField &&
364  (flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsReadOnly) == 0) {
365  node_data.AddState(ax::mojom::State::kEditable);
366  }
367  if (node_data.role == ax::mojom::Role::kStaticText &&
368  (actions & kHasScrollingAction) == 0 && node.value.empty() &&
369  node.label.empty() && node.hint.empty()) {
370  node_data.AddState(ax::mojom::State::kIgnored);
371  } else {
372  // kFlutterSemanticsFlagIsFocusable means a keyboard focusable, it is
373  // different from semantics focusable.
374  // TODO(chunhtai): figure out whether something is not semantics focusable.
375  node_data.AddState(ax::mojom::State::kFocusable);
376  }
377 }
378 
379 void AccessibilityBridge::SetActionsFromFlutterUpdate(
380  ui::AXNodeData& node_data,
381  const SemanticsNode& node) {
382  FlutterSemanticsAction actions = node.actions;
383  if (actions & FlutterSemanticsAction::kFlutterSemanticsActionTap) {
384  node_data.AddAction(ax::mojom::Action::kDoDefault);
385  }
386  if (actions & FlutterSemanticsAction::kFlutterSemanticsActionScrollLeft) {
387  node_data.AddAction(ax::mojom::Action::kScrollLeft);
388  }
389  if (actions & FlutterSemanticsAction::kFlutterSemanticsActionScrollRight) {
390  node_data.AddAction(ax::mojom::Action::kScrollRight);
391  }
392  if (actions & FlutterSemanticsAction::kFlutterSemanticsActionScrollUp) {
393  node_data.AddAction(ax::mojom::Action::kScrollUp);
394  }
395  if (actions & FlutterSemanticsAction::kFlutterSemanticsActionScrollDown) {
396  node_data.AddAction(ax::mojom::Action::kScrollDown);
397  }
398  if (actions & FlutterSemanticsAction::kFlutterSemanticsActionIncrease) {
399  node_data.AddAction(ax::mojom::Action::kIncrement);
400  }
401  if (actions & FlutterSemanticsAction::kFlutterSemanticsActionDecrease) {
402  node_data.AddAction(ax::mojom::Action::kDecrement);
403  }
404  // Every node has show on screen action.
405  node_data.AddAction(ax::mojom::Action::kScrollToMakeVisible);
406 
407  if (actions & FlutterSemanticsAction::kFlutterSemanticsActionSetSelection) {
408  node_data.AddAction(ax::mojom::Action::kSetSelection);
409  }
410  if (actions & FlutterSemanticsAction::
411  kFlutterSemanticsActionDidGainAccessibilityFocus) {
412  node_data.AddAction(ax::mojom::Action::kSetAccessibilityFocus);
413  }
414  if (actions & FlutterSemanticsAction::
415  kFlutterSemanticsActionDidLoseAccessibilityFocus) {
416  node_data.AddAction(ax::mojom::Action::kClearAccessibilityFocus);
417  }
418  if (actions & FlutterSemanticsAction::kFlutterSemanticsActionCustomAction) {
419  node_data.AddAction(ax::mojom::Action::kCustomAction);
420  }
421 }
422 
423 void AccessibilityBridge::SetBooleanAttributesFromFlutterUpdate(
424  ui::AXNodeData& node_data,
425  const SemanticsNode& node) {
426  FlutterSemanticsAction actions = node.actions;
427  FlutterSemanticsFlag flags = node.flags;
428  node_data.AddBoolAttribute(ax::mojom::BoolAttribute::kScrollable,
429  actions & kHasScrollingAction);
430  node_data.AddBoolAttribute(
431  ax::mojom::BoolAttribute::kClickable,
432  actions & FlutterSemanticsAction::kFlutterSemanticsActionTap);
433  // TODO(chunhtai): figure out if there is a node that does not clip overflow.
434  node_data.AddBoolAttribute(ax::mojom::BoolAttribute::kClipsChildren,
435  !node.children_in_traversal_order.empty());
436  node_data.AddBoolAttribute(
437  ax::mojom::BoolAttribute::kSelected,
438  flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsSelected);
439  node_data.AddBoolAttribute(
440  ax::mojom::BoolAttribute::kEditableRoot,
441  flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsTextField &&
442  (flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsReadOnly) == 0);
443  // Mark nodes as line breaking so that screen readers don't
444  // merge all consecutive objects into one.
445  // TODO(schectman): When should a node have this attribute set?
446  // https://github.com/flutter/flutter/issues/118184
447  node_data.AddBoolAttribute(ax::mojom::BoolAttribute::kIsLineBreakingObject,
448  true);
449 }
450 
451 void AccessibilityBridge::SetIntAttributesFromFlutterUpdate(
452  ui::AXNodeData& node_data,
453  const SemanticsNode& node) {
454  FlutterSemanticsFlag flags = node.flags;
455  node_data.AddIntAttribute(ax::mojom::IntAttribute::kTextDirection,
456  node.text_direction);
457 
458  int sel_start = node.text_selection_base;
459  int sel_end = node.text_selection_extent;
460  if (flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsTextField &&
461  (flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsReadOnly) == 0 &&
462  !node.value.empty()) {
463  // By default the text field selection should be at the end.
464  sel_start = sel_start == -1 ? node.value.length() : sel_start;
465  sel_end = sel_end == -1 ? node.value.length() : sel_end;
466  }
467  node_data.AddIntAttribute(ax::mojom::IntAttribute::kTextSelStart, sel_start);
468  node_data.AddIntAttribute(ax::mojom::IntAttribute::kTextSelEnd, sel_end);
469 
470  if (node_data.role == ax::mojom::Role::kRadioButton ||
471  node_data.role == ax::mojom::Role::kCheckBox) {
472  node_data.AddIntAttribute(
473  ax::mojom::IntAttribute::kCheckedState,
474  static_cast<int32_t>(
475  flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsCheckStateMixed
476  ? ax::mojom::CheckedState::kMixed
477  : flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsChecked
478  ? ax::mojom::CheckedState::kTrue
479  : ax::mojom::CheckedState::kFalse));
480  } else if (node_data.role == ax::mojom::Role::kSwitch) {
481  node_data.AddIntAttribute(
482  ax::mojom::IntAttribute::kCheckedState,
483  static_cast<int32_t>(
484  flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsToggled
485  ? ax::mojom::CheckedState::kTrue
486  : ax::mojom::CheckedState::kFalse));
487  }
488 }
489 
490 void AccessibilityBridge::SetIntListAttributesFromFlutterUpdate(
491  ui::AXNodeData& node_data,
492  const SemanticsNode& node) {
493  FlutterSemanticsAction actions = node.actions;
494  if (actions & FlutterSemanticsAction::kFlutterSemanticsActionCustomAction) {
495  std::vector<int32_t> custom_action_ids;
496  for (size_t i = 0; i < node.custom_accessibility_actions.size(); i++) {
497  custom_action_ids.push_back(node.custom_accessibility_actions[i]);
498  }
499  node_data.AddIntListAttribute(ax::mojom::IntListAttribute::kCustomActionIds,
500  custom_action_ids);
501  }
502 }
503 
504 void AccessibilityBridge::SetStringListAttributesFromFlutterUpdate(
505  ui::AXNodeData& node_data,
506  const SemanticsNode& node) {
507  FlutterSemanticsAction actions = node.actions;
508  if (actions & FlutterSemanticsAction::kFlutterSemanticsActionCustomAction) {
509  std::vector<std::string> custom_action_description;
510  for (size_t i = 0; i < node.custom_accessibility_actions.size(); i++) {
511  auto iter = pending_semantics_custom_action_updates_.find(
512  node.custom_accessibility_actions[i]);
513  BASE_DCHECK(iter != pending_semantics_custom_action_updates_.end());
514  custom_action_description.push_back(iter->second.label);
515  }
516  node_data.AddStringListAttribute(
517  ax::mojom::StringListAttribute::kCustomActionDescriptions,
518  custom_action_description);
519  }
520 }
521 
522 void AccessibilityBridge::SetNameFromFlutterUpdate(ui::AXNodeData& node_data,
523  const SemanticsNode& node) {
524  node_data.SetName(node.label);
525 }
526 
527 void AccessibilityBridge::SetValueFromFlutterUpdate(ui::AXNodeData& node_data,
528  const SemanticsNode& node) {
529  node_data.SetValue(node.value);
530 }
531 
532 void AccessibilityBridge::SetTooltipFromFlutterUpdate(
533  ui::AXNodeData& node_data,
534  const SemanticsNode& node) {
535  node_data.SetTooltip(node.tooltip);
536 }
537 
538 void AccessibilityBridge::SetTreeData(const SemanticsNode& node,
539  ui::AXTreeUpdate& tree_update) {
540  FlutterSemanticsFlag flags = node.flags;
541  // Set selection of the focused node if:
542  // 1. this text field has a valid selection
543  // 2. this text field doesn't have a valid selection but had selection stored
544  // in the tree.
545  if (flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsTextField &&
546  flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsFocused) {
547  if (node.text_selection_base != -1) {
548  tree_update.tree_data.sel_anchor_object_id = node.id;
549  tree_update.tree_data.sel_anchor_offset = node.text_selection_base;
550  tree_update.tree_data.sel_focus_object_id = node.id;
551  tree_update.tree_data.sel_focus_offset = node.text_selection_extent;
552  tree_update.has_tree_data = true;
553  } else if (tree_update.tree_data.sel_anchor_object_id == node.id) {
554  tree_update.tree_data.sel_anchor_object_id = ui::AXNode::kInvalidAXID;
555  tree_update.tree_data.sel_anchor_offset = -1;
556  tree_update.tree_data.sel_focus_object_id = ui::AXNode::kInvalidAXID;
557  tree_update.tree_data.sel_focus_offset = -1;
558  tree_update.has_tree_data = true;
559  }
560  }
561 
562  if (flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsFocused &&
563  tree_update.tree_data.focus_id != node.id) {
564  tree_update.tree_data.focus_id = node.id;
565  tree_update.has_tree_data = true;
566  } else if ((flags & FlutterSemanticsFlag::kFlutterSemanticsFlagIsFocused) ==
567  0 &&
568  tree_update.tree_data.focus_id == node.id) {
569  tree_update.tree_data.focus_id = ui::AXNode::kInvalidAXID;
570  tree_update.has_tree_data = true;
571  }
572 }
573 
574 AccessibilityBridge::SemanticsNode
575 AccessibilityBridge::FromFlutterSemanticsNode(
576  const FlutterSemanticsNode2& flutter_node) {
577  SemanticsNode result;
578  result.id = flutter_node.id;
579  result.flags = flutter_node.flags;
580  result.actions = flutter_node.actions;
581  result.text_selection_base = flutter_node.text_selection_base;
582  result.text_selection_extent = flutter_node.text_selection_extent;
583  result.scroll_child_count = flutter_node.scroll_child_count;
584  result.scroll_index = flutter_node.scroll_index;
585  result.scroll_position = flutter_node.scroll_position;
586  result.scroll_extent_max = flutter_node.scroll_extent_max;
587  result.scroll_extent_min = flutter_node.scroll_extent_min;
588  result.elevation = flutter_node.elevation;
589  result.thickness = flutter_node.thickness;
590  if (flutter_node.label) {
591  result.label = std::string(flutter_node.label);
592  }
593  if (flutter_node.hint) {
594  result.hint = std::string(flutter_node.hint);
595  }
596  if (flutter_node.value) {
597  result.value = std::string(flutter_node.value);
598  }
599  if (flutter_node.increased_value) {
600  result.increased_value = std::string(flutter_node.increased_value);
601  }
602  if (flutter_node.decreased_value) {
603  result.decreased_value = std::string(flutter_node.decreased_value);
604  }
605  if (flutter_node.tooltip) {
606  result.tooltip = std::string(flutter_node.tooltip);
607  }
608  result.text_direction = flutter_node.text_direction;
609  result.rect = flutter_node.rect;
610  result.transform = flutter_node.transform;
611  if (flutter_node.child_count > 0) {
612  result.children_in_traversal_order = std::vector<int32_t>(
613  flutter_node.children_in_traversal_order,
614  flutter_node.children_in_traversal_order + flutter_node.child_count);
615  }
616  if (flutter_node.custom_accessibility_actions_count > 0) {
617  result.custom_accessibility_actions = std::vector<int32_t>(
618  flutter_node.custom_accessibility_actions,
619  flutter_node.custom_accessibility_actions +
620  flutter_node.custom_accessibility_actions_count);
621  }
622  return result;
623 }
624 
625 AccessibilityBridge::SemanticsCustomAction
626 AccessibilityBridge::FromFlutterSemanticsCustomAction(
627  const FlutterSemanticsCustomAction2& flutter_custom_action) {
628  SemanticsCustomAction result;
629  result.id = flutter_custom_action.id;
630  result.override_action = flutter_custom_action.override_action;
631  if (flutter_custom_action.label) {
632  result.label = std::string(flutter_custom_action.label);
633  }
634  if (flutter_custom_action.hint) {
635  result.hint = std::string(flutter_custom_action.hint);
636  }
637  return result;
638 }
639 
640 void AccessibilityBridge::SetLastFocusedId(AccessibilityNodeId node_id) {
641  if (last_focused_id_ != node_id) {
642  auto last_focused_child =
643  GetFlutterPlatformNodeDelegateFromID(last_focused_id_);
644  if (!last_focused_child.expired()) {
646  last_focused_id_,
647  FlutterSemanticsAction::
648  kFlutterSemanticsActionDidLoseAccessibilityFocus,
649  {});
650  }
651  last_focused_id_ = node_id;
652  }
653 }
654 
655 AccessibilityNodeId AccessibilityBridge::GetLastFocusedId() {
656  return last_focused_id_;
657 }
658 
659 gfx::NativeViewAccessible AccessibilityBridge::GetNativeAccessibleFromId(
660  AccessibilityNodeId id) {
661  auto platform_node_delegate = GetFlutterPlatformNodeDelegateFromID(id).lock();
662  if (!platform_node_delegate) {
663  return nullptr;
664  }
665  return platform_node_delegate->GetNativeViewAccessible();
666 }
667 
668 gfx::RectF AccessibilityBridge::RelativeToGlobalBounds(const ui::AXNode* node,
669  bool& offscreen,
670  bool clip_bounds) {
671  return tree_->RelativeToTreeBounds(node, gfx::RectF(), &offscreen,
672  clip_bounds);
673 }
674 
676  ui::AXTreeID tree_id,
677  ui::AXNode::AXID node_id) const {
678  return GetNodeFromTree(node_id);
679 }
680 
682  ui::AXNode::AXID node_id) const {
683  return tree_->GetFromId(node_id);
684 }
685 
686 ui::AXTreeID AccessibilityBridge::GetTreeID() const {
687  return tree_->GetAXTreeID();
688 }
689 
691  return ui::AXTreeIDUnknown();
692 }
693 
695  return tree_->root();
696 }
697 
699  return nullptr;
700 }
701 
702 ui::AXTree* AccessibilityBridge::GetTree() const {
703  return tree_.get();
704 }
705 
707  const ui::AXNode::AXID node_id) const {
708  auto platform_delegate_weak = GetFlutterPlatformNodeDelegateFromID(node_id);
709  auto platform_delegate = platform_delegate_weak.lock();
710  if (!platform_delegate) {
711  return nullptr;
712  }
713  return platform_delegate->GetPlatformNode();
714 }
715 
717  const ui::AXNode& node) const {
718  return GetPlatformNodeFromTree(node.id());
719 }
720 
721 ui::AXPlatformNodeDelegate* AccessibilityBridge::RootDelegate() const {
723  .lock()
724  .get();
725 }
726 
727 } // namespace flutter
flutter::AccessibilityBridge::GetTreeID
ui::AXTreeID GetTreeID() const override
Definition: accessibility_bridge.cc:686
flutter::AccessibilityBridge::OnAccessibilityEvent
virtual void OnAccessibilityEvent(ui::AXEventGenerator::TargetedEvent targeted_event)=0
Handle accessibility events generated due to accessibility tree changes. These events are needed to b...
flutter::AccessibilityBridge::GetPlatformNodeFromTree
ui::AXPlatformNode * GetPlatformNodeFromTree(const ui::AXNode::AXID node_id) const override
Definition: accessibility_bridge.cc:706
flutter::AccessibilityBridge::GetTree
ui::AXTree * GetTree() const override
Definition: accessibility_bridge.cc:702
flutter::AccessibilityBridge::GetRootAsAXNode
ui::AXNode * GetRootAsAXNode() const override
Definition: accessibility_bridge.cc:694
flutter::AccessibilityBridge::AddFlutterSemanticsCustomActionUpdate
void AddFlutterSemanticsCustomActionUpdate(const FlutterSemanticsCustomAction2 &action)
Adds a custom semantics action update to the pending semantics update. Calling this method alone will...
Definition: accessibility_bridge.cc:44
flutter::AccessibilityBridge::GetParentNodeFromParentTreeAsAXNode
ui::AXNode * GetParentNodeFromParentTreeAsAXNode() const override
Definition: accessibility_bridge.cc:698
flutter::FlutterPlatformNodeDelegate::OwnerBridge::DispatchAccessibilityAction
virtual void DispatchAccessibilityAction(AccessibilityNodeId target, FlutterSemanticsAction action, fml::MallocMapping data)=0
Dispatch accessibility action back to the Flutter framework. These actions are generated in the nativ...
ui
Definition: window_binding_handler.h:18
flutter::AccessibilityBridge::GetFlutterPlatformNodeDelegateFromID
std::weak_ptr< FlutterPlatformNodeDelegate > GetFlutterPlatformNodeDelegateFromID(AccessibilityNodeId id) const
Get the flutter platform node delegate with the given id from this accessibility bridge....
Definition: accessibility_bridge.cc:131
flutter::AccessibilityBridge::GetParentTreeID
ui::AXTreeID GetParentTreeID() const override
Definition: accessibility_bridge.cc:690
flutter::AccessibilityBridge::AccessibilityBridge
AccessibilityBridge()
Creates a new instance of a accessibility bridge.
Definition: accessibility_bridge.cc:23
flutter::AccessibilityNodeId
ui::AXNode::AXID AccessibilityNodeId
Definition: flutter_platform_node_delegate.h:15
flutter
Definition: accessibility_bridge_windows.cc:11
flutter::kHasScrollingAction
constexpr int kHasScrollingAction
Definition: accessibility_bridge.cc:16
flutter::AccessibilityBridge::CreateFlutterPlatformNodeDelegate
virtual std::shared_ptr< FlutterPlatformNodeDelegate > CreateFlutterPlatformNodeDelegate()=0
Creates a platform specific FlutterPlatformNodeDelegate. Ownership passes to the caller....
flutter::AccessibilityBridge::CommitUpdates
void CommitUpdates()
Flushes the pending updates and applies them to this accessibility bridge. Calling this with no pendi...
Definition: accessibility_bridge.cc:50
flutter::AccessibilityBridge::GetAXTreeData
const ui::AXTreeData & GetAXTreeData() const
Get the ax tree data from this accessibility bridge. The tree data contains information such as the i...
Definition: accessibility_bridge.cc:141
flutter::AccessibilityBridge::GetPendingEvents
const std::vector< ui::AXEventGenerator::TargetedEvent > GetPendingEvents() const
Gets all pending accessibility events generated during semantics updates. This is useful when decidin...
Definition: accessibility_bridge.cc:146
flutter::AccessibilityBridge::GetNodeFromTree
ui::AXNode * GetNodeFromTree(const ui::AXTreeID tree_id, const ui::AXNode::AXID node_id) const override
Definition: accessibility_bridge.cc:675
action
int action
Definition: keyboard_key_handler_unittests.cc:116
flutter::AccessibilityBridge::RootDelegate
ui::AXPlatformNodeDelegate * RootDelegate() const override
Definition: accessibility_bridge.cc:721
accessibility_bridge.h
flutter::AccessibilityBridge::AddFlutterSemanticsNodeUpdate
void AddFlutterSemanticsNodeUpdate(const FlutterSemanticsNode2 &node)
Adds a semantics node update to the pending semantics update. Calling this method alone will NOT upda...
Definition: accessibility_bridge.cc:39
flutter::AccessibilityBridge::~AccessibilityBridge
virtual ~AccessibilityBridge()
Definition: accessibility_bridge.cc:34