[Fuchsia] Add special handling of a11y root node
The root of the Fuchsia semantic tree always has root id 0. This isn't
a constraint in Chromium, so some special handling has been added to
ensure the semantic tree received by Fuchsia maintains a consistent,
valid state.
Test: Expanded AccessibilityBridgeTest.
Bug: fuchsia:42172
Change-Id: Ic1e2398e0a6793bcbfef36643af64b78f79fea22
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1954321
Commit-Queue: Sharon Yang <[email protected]>
Reviewed-by: Kevin Marshall <[email protected]>
Cr-Commit-Position: refs/heads/master@{#726157}
diff --git a/fuchsia/engine/browser/accessibility_bridge.h b/fuchsia/engine/browser/accessibility_bridge.h
index 1e93610..936d2baf 100644
--- a/fuchsia/engine/browser/accessibility_bridge.h
+++ b/fuchsia/engine/browser/accessibility_bridge.h
@@ -50,9 +50,30 @@
private:
FRIEND_TEST_ALL_PREFIXES(AccessibilityBridgeTest, OnSemanticsModeChanged);
- // Handles batching of semantic nodes and committing them to the SemanticTree.
+ // A struct used for caching semantic information. This allows for updates and
+ // deletes to be stored in the same vector to preserve all ordering
+ // information.
+ struct SemanticUpdateOrDelete {
+ enum Type { UPDATE, DELETE };
+
+ SemanticUpdateOrDelete(SemanticUpdateOrDelete&& m);
+ SemanticUpdateOrDelete(Type type,
+ fuchsia::accessibility::semantics::Node node,
+ uint32_t id_to_delete);
+ ~SemanticUpdateOrDelete() = default;
+
+ Type type;
+ fuchsia::accessibility::semantics::Node update_node;
+ uint32_t id_to_delete;
+ };
+
+ // Processes pending data and commits it to the Semantic Tree.
void TryCommit();
+ // Helper function for TryCommit() that sends the contents of |to_send_| to
+ // the Semantic Tree, starting at |start|.
+ void DispatchSemanticsMessages(size_t start, size_t size);
+
// Callback for SemanticTree::CommitUpdates.
void OnCommitComplete();
@@ -60,6 +81,11 @@
// root.
uint32_t ConvertToFuchsiaNodeId(int32_t ax_node_id);
+ // Deletes all nodes in subtree rooted at and including |node|, unless |node|
+ // is the root of the tree.
+ // |tree| and |node| are owned by the accessibility bridge.
+ void DeleteSubtree(ui::AXTree* tree, ui::AXNode* node);
+
// content::WebContentsObserver implementation.
void AccessibilityEventReceived(
const content::AXEventNotificationDetails& details) override;
@@ -76,6 +102,7 @@
// ui::AXTreeObserver implementation.
void OnNodeWillBeDeleted(ui::AXTree* tree, ui::AXNode* node) override;
+ void OnSubtreeWillBeDeleted(ui::AXTree* tree, ui::AXNode* node) override;
void OnAtomicUpdateFinished(
ui::AXTree* tree,
bool root_changed,
@@ -86,8 +113,8 @@
content::WebContents* web_contents_;
ui::AXSerializableTree tree_;
- std::vector<fuchsia::accessibility::semantics::Node> to_send_;
- std::vector<uint32_t> to_delete_;
+ // Cache for pending data to be sent to the Semantic Tree between commits.
+ std::vector<SemanticUpdateOrDelete> to_send_;
bool commit_inflight_ = false;
// Maintain a map of callbacks as multiple hit test events can happen at once.
