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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
23 AccessibilityBridge::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
34 AccessibilityBridge::~AccessibilityBridge() {
35 event_generator_.ReleaseTree();
36 tree_->RemoveObserver(static_cast<ui::AXTreeObserver*>(this));
37 }
38
39 void AccessibilityBridge::AddFlutterSemanticsNodeUpdate(
40 const FlutterSemanticsNode2& node) {
41 pending_semantics_node_updates_[node.id] = FromFlutterSemanticsNode(node);
42 }
43
44 void AccessibilityBridge::AddFlutterSemanticsCustomActionUpdate(
45 const FlutterSemanticsCustomAction2& action) {
46 pending_semantics_custom_action_updates_[action.id] =
47 FromFlutterSemanticsCustomAction(action);
48 }
49
50 void AccessibilityBridge::CommitUpdates() {
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>
131 AccessibilityBridge::GetFlutterPlatformNodeDelegateFromID(
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>
146 AccessibilityBridge::GetPendingEvents() const {
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()) {
645 DispatchAccessibilityAction(
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
675 ui::AXNode* AccessibilityBridge::GetNodeFromTree(
676 ui::AXTreeID tree_id,
677 ui::AXNode::AXID node_id) const {
678 return GetNodeFromTree(node_id);
679 }
680
681 ui::AXNode* AccessibilityBridge::GetNodeFromTree(
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
690 ui::AXTreeID AccessibilityBridge::GetParentTreeID() const {
691 return ui::AXTreeIDUnknown();
692 }
693
694 ui::AXNode* AccessibilityBridge::GetRootAsAXNode() const {
695 return tree_->root();
696 }
697
698 ui::AXNode* AccessibilityBridge::GetParentNodeFromParentTreeAsAXNode() const {
699 return nullptr;
700 }
701
702 ui::AXTree* AccessibilityBridge::GetTree() const {
703 return tree_.get();
704 }
705
706 ui::AXPlatformNode* AccessibilityBridge::GetPlatformNodeFromTree(
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
716 ui::AXPlatformNode* AccessibilityBridge::GetPlatformNodeFromTree(
717 const ui::AXNode& node) const {
718 return GetPlatformNodeFromTree(node.id());
719 }
720
721 ui::AXPlatformNodeDelegate* AccessibilityBridge::RootDelegate() const {
722 return GetFlutterPlatformNodeDelegateFromID(GetRootAsAXNode()->id())
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::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.h:28
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
accessibility_bridge.h
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
flutter::AccessibilityBridge::RootDelegate
ui::AXPlatformNodeDelegate * RootDelegate() const override
Definition: accessibility_bridge.cc:721
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
~AccessibilityBridge()
Definition: accessibility_bridge.cc:34