Automatically fire AX events on Mac based on tree changes

content/browser/accessibility/browser_accessibility_manager_mac.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/accessibility/browser_accessibility_manager_mac.h"
 
 #include "base/bind.h"
 #import "base/mac/mac_util.h"
 #import "base/mac/scoped_nsobject.h"
 #import "base/mac/sdk_forward_declarations.h"
@@ skipping 344 matching lines @@
 }
 
 void BrowserAccessibilityManagerMac::OnAccessibilityEvents(
     const std::vector<AXEventNotificationDetails>& details) {
   text_edits_.clear();
   // Call the base method last as it might delete the tree if it receives an
   // invalid message.
   BrowserAccessibilityManager::OnAccessibilityEvents(details);
 }
 
+void BrowserAccessibilityManagerMac::OnTreeDataChanged(
+    ui::AXTree* tree,
+    const ui::AXTreeData& old_tree_data,
+    const ui::AXTreeData& new_tree_data) {
+  BrowserAccessibilityManager::OnTreeDataChanged(tree, old_tree_data,
+                                                 new_tree_data);
+  if (new_tree_data.loaded && !old_tree_data.loaded)
+    tree_events_[tree->root()->id()].insert(ui::AX_EVENT_LOAD_COMPLETE);
+  if (new_tree_data.sel_anchor_object_id !=
+          old_tree_data.sel_anchor_object_id ||
+      new_tree_data.sel_anchor_offset != old_tree_data.sel_anchor_offset ||
+      new_tree_data.sel_anchor_affinity != old_tree_data.sel_anchor_affinity ||
+      new_tree_data.sel_focus_object_id != old_tree_data.sel_focus_object_id ||
+      new_tree_data.sel_focus_offset != old_tree_data.sel_focus_offset ||
+      new_tree_data.sel_focus_affinity != old_tree_data.sel_focus_affinity) {
+    tree_events_[tree->root()->id()].insert(
+        ui::AX_EVENT_DOCUMENT_SELECTION_CHANGED);
+  }
+}
+
 void BrowserAccessibilityManagerMac::OnNodeDataWillChange(
     ui::AXTree* tree,
     const ui::AXNodeData& old_node_data,
     const ui::AXNodeData& new_node_data) {
   BrowserAccessibilityManager::OnNodeDataWillChange(tree, old_node_data,
                                                     new_node_data);
 
   // Starting from OS X 10.11, if the user has edited some text we need to
   // dispatch the actual text that changed on the value changed notification.
   // We run this code on all OS X versions to get the highest test coverage.
@@ skipping 29 matching lines @@
     while (i < old_text.length() && i < new_text.length() &&
            old_text[i] == new_text[i]) {
       ++i;
     }
     size_t length = (old_text.length() - i) - (new_text.length() - i);
     base::string16 deleted_text = old_text.substr(i, length);
     text_edits_[new_node_data.id] = deleted_text;
   }
 }
 
+bool IsContainerWithSelectableChildrenRole(ui::AXRole role) {
+  switch (role) {
+    case ui::AX_ROLE_COMBO_BOX:
+    case ui::AX_ROLE_GRID:
+    case ui::AX_ROLE_LIST_BOX:
+    case ui::AX_ROLE_MENU:
+    case ui::AX_ROLE_MENU_BAR:
+    case ui::AX_ROLE_RADIO_GROUP:
+    case ui::AX_ROLE_TAB_LIST:
+    case ui::AX_ROLE_TOOLBAR:
+    case ui::AX_ROLE_TREE:
+    case ui::AX_ROLE_TREE_GRID:
+      return true;
+    default:
+      return false;
+  }
+}
+
+bool IsRowContainer(ui::AXRole role) {
+  switch (role) {
+    case ui::AX_ROLE_TREE:
+    case ui::AX_ROLE_TREE_GRID:
+    case ui::AX_ROLE_GRID:
+    case ui::AX_ROLE_TABLE:
+      return true;
+    default:
+      return false;
+  }
+}
+
+void BrowserAccessibilityManagerMac::OnStateChanged(ui::AXTree* tree,
+                                                    ui::AXNode* node,
+                                                    ui::AXState state,
+                                                    bool new_value) {
+  BrowserAccessibilityManager::OnStateChanged(tree, node, state, new_value);
+  if (state == ui::AX_STATE_EXPANDED) {
+    if (node->data().role == ui::AX_ROLE_ROW ||
+        node->data().role == ui::AX_ROLE_TREE_ITEM) {
+      if (new_value)
+        tree_events_[node->id()].insert(ui::AX_EVENT_ROW_EXPANDED);
+      else
+        tree_events_[node->id()].insert(ui::AX_EVENT_ROW_COLLAPSED);
+      ui::AXNode* container = node;
+      while (container && !IsRowContainer(container->data().role))
+        container = container->parent();
+      if (container)
+        tree_events_[container->id()].insert(ui::AX_EVENT_ROW_COUNT_CHANGED);
+    } else {
+      tree_events_[node->id()].insert(ui::AX_EVENT_EXPANDED_CHANGED);
+    }
+  }
+  if (state == ui::AX_STATE_SELECTED) {
+    ui::AXNode* container = node;
+    while (container &&
+           !IsContainerWithSelectableChildrenRole(container->data().role))
+      container = container->parent();
+    if (container)
+      tree_events_[container->id()].insert(
+          ui::AX_EVENT_SELECTED_CHILDREN_CHANGED);
+  }
+}
+
+void BrowserAccessibilityManagerMac::OnStringAttributeChanged(
+    ui::AXTree* tree,
+    ui::AXNode* node,
+    ui::AXStringAttribute attr,
+    const std::string& old_value,
+    const std::string& new_value) {
+  BrowserAccessibilityManager::OnStringAttributeChanged(tree, node, attr,
+                                                        old_value, new_value);
+  switch (attr) {
+    case ui::AX_ATTR_VALUE:
+      tree_events_[node->id()].insert(ui::AX_EVENT_VALUE_CHANGED);
+      break;
+    case ui::AX_ATTR_ARIA_INVALID_VALUE:
+      tree_events_[node->id()].insert(ui::AX_EVENT_INVALID_STATUS_CHANGED);
+      break;
+    case ui::AX_ATTR_LIVE_STATUS:
+      tree_events_[node->id()].insert(ui::AX_EVENT_LIVE_REGION_CREATED);
+      break;
+    default:
+      break;
+  }
+}
+
+void BrowserAccessibilityManagerMac::OnIntAttributeChanged(
+    ui::AXTree* tree,
+    ui::AXNode* node,
+    ui::AXIntAttribute attr,
+    int32_t old_value,
+    int32_t new_value) {
+  BrowserAccessibilityManager::OnIntAttributeChanged(tree, node, attr,
+                                                     old_value, new_value);
+  switch (attr) {
+    case ui::AX_ATTR_CHECKED_STATE:
+      tree_events_[node->id()].insert(ui::AX_EVENT_VALUE_CHANGED);
+      break;
+    case ui::AX_ATTR_ACTIVEDESCENDANT_ID:
+      tree_events_[node->id()].insert(ui::AX_EVENT_ACTIVEDESCENDANTCHANGED);
+      break;
+    case ui::AX_ATTR_INVALID_STATE:
+      tree_events_[node->id()].insert(ui::AX_EVENT_INVALID_STATUS_CHANGED);
+      break;
+    default:
+      break;
+  }
+}
+
+void BrowserAccessibilityManagerMac::OnFloatAttributeChanged(
+    ui::AXTree* tree,
+    ui::AXNode* node,
+    ui::AXFloatAttribute attr,
+    float old_value,
+    float new_value) {
+  BrowserAccessibilityManager::OnFloatAttributeChanged(tree, node, attr,
+                                                       old_value, new_value);
+  if (attr == ui::AX_ATTR_VALUE_FOR_RANGE)
+    tree_events_[node->id()].insert(ui::AX_EVENT_VALUE_CHANGED);
+}
+
+void BrowserAccessibilityManagerMac::OnAtomicUpdateFinished(
+    ui::AXTree* tree,
+    bool root_changed,
+    const std::vector<Change>& changes) {
+  BrowserAccessibilityManager::OnAtomicUpdateFinished(tree, root_changed,
+                                                      changes);
+  for (const auto& change : changes) {
+    if ((change.type == NODE_CREATED || change.type == SUBTREE_CREATED) &&
+        change.node->data().HasStringAttribute(ui::AX_ATTR_LIVE_STATUS)) {
+      if (change.node->data().role == ui::AX_ROLE_ALERT)
+        tree_events_[change.node->id()].insert(ui::AX_EVENT_ALERT);
+      else
+        tree_events_[change.node->id()].insert(
+            ui::AX_EVENT_LIVE_REGION_CREATED);
+      continue;
+    }
+    if (change.node->data().HasStringAttribute(
+            ui::AX_ATTR_CONTAINER_LIVE_STATUS)) {
+      ui::AXNode* live_root = change.node;
+      while (live_root &&
+             !live_root->data().HasStringAttribute(ui::AX_ATTR_LIVE_STATUS))
+        live_root = live_root->parent();
+      if (live_root)
+        tree_events_[live_root->id()].insert(ui::AX_EVENT_LIVE_REGION_CHANGED);
+    }
+  }
+}
+
 NSDictionary* BrowserAccessibilityManagerMac::
     GetUserInfoForSelectedTextChangedNotification() {
   NSMutableDictionary* user_info = [[[NSMutableDictionary alloc] init]
       autorelease];
   [user_info setObject:@YES forKey:NSAccessibilityTextStateSyncKey];
   [user_info setObject:@(AXTextStateChangeTypeUnknown)
                 forKey:NSAccessibilityTextStateChangeTypeKey];
   [user_info setObject:@(AXTextSelectionDirectionUnknown)
                 forKey:NSAccessibilityTextSelectionDirection];
   [user_info setObject:@(AXTextSelectionGranularityUnknown)
@@ skipping 50 matching lines @@
     NSAccessibilityTextChangeValues : changes,
     NSAccessibilityTextChangeElement : native_node
   };
 }
 
 NSView* BrowserAccessibilityManagerMac::GetParentView() {
   return delegate() ? delegate()->AccessibilityGetAcceleratedWidget() : nullptr;
 }
 
 }  // namespace content