Bug 1251712 - propagate a context flag for alerts, r=davdib

accessible/base/ARIAMap.cpp

@@ -43,7 +43,7 @@ static nsRoleMapEntry sWAIRoleMaps[] =
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eAlert,
     kNoReqStates
   },
   { // alertdialog

accessible/base/AccTypes.h

@@ -68,20 +68,21 @@ enum AccType {
  * type, the same accessible class can have several types.
  */
 enum AccGenericType {
-  eAutoComplete = 1 << 0,
-  eAutoCompletePopup = 1 << 1,
-  eButton = 1 << 2,
-  eCombobox = 1 << 3,
-  eDocument = 1 << 4,
-  eHyperText = 1 << 5,
-  eLandmark = 1 << 6,
-  eList = 1 << 7,
-  eListControl = 1 << 8,
-  eMenuButton = 1 << 9,
-  eSelect = 1 << 10,
-  eTable = 1 << 11,
-  eTableCell = 1 << 12,
-  eTableRow = 1 << 13,
+  eAlert = 1 << 0,
+  eAutoComplete = 1 << 1,
+  eAutoCompletePopup = 1 << 2,
+  eButton = 1 << 3,
+  eCombobox = 1 << 4,
+  eDocument = 1 << 5,
+  eHyperText = 1 << 6,
+  eLandmark = 1 << 7,
+  eList = 1 << 8,
+  eListControl = 1 << 9,
+  eMenuButton = 1 << 10,
+  eSelect = 1 << 11,
+  eTable = 1 << 12,
+  eTableCell = 1 << 13,
+  eTableRow = 1 << 14,
 
   eLastAccGenericType = eTableRow
 };

accessible/generic/Accessible.cpp

@@ -1982,6 +1982,10 @@ Accessible::BindToParent(Accessible* aParent, uint32_t aIndexInParent)
 
   if (mParent->IsARIAHidden() || aria::HasDefinedARIAHidden(mContent))
     SetARIAHidden(true);
+
+  mContextFlags |=
+    static_cast<uint32_t>((mParent->IsAlert() ||
+                           mParent->IsInsideAlert())) & eInsideAlert;
 }
 
 // Accessible protected
@@ -1999,7 +2003,7 @@ Accessible::UnbindFromParent()
 
   delete mBits.groupInfo;
   mBits.groupInfo = nullptr;
-  mContextFlags &= ~eHasNameDependentParent;
+  mContextFlags &= ~eHasNameDependentParent & ~eInsideAlert;
 }
 
 ////////////////////////////////////////////////////////////////////////////////

accessible/generic/Accessible.h

@@ -568,6 +568,8 @@ public:
     return mContent->IsAnyOfHTMLElements(nsGkAtoms::abbr, nsGkAtoms::acronym);
   }
 
+  bool IsAlert() const { return HasGenericType(eAlert); }
+
   bool IsApplication() const { return mType == eApplicationType; }
   ApplicationAccessible* AsApplication();
 
@@ -946,6 +948,11 @@ public:
   bool IsARIAHidden() const { return mContextFlags & eARIAHidden; }
   void SetARIAHidden(bool aIsDefined);
 
+  /**
+   * Return true if the element is inside an alert.
+   */
+  bool IsInsideAlert() const { return mContextFlags & eInsideAlert; }
+
 protected:
   virtual ~Accessible();
 
@@ -1034,8 +1041,9 @@ protected:
   enum ContextFlags {
     eHasNameDependentParent = 1 << 0, // Parent's name depends on this accessible.
     eARIAHidden = 1 << 1,
+    eInsideAlert = 1 << 2,
 
-    eLastContextFlag = eARIAHidden
+    eLastContextFlag = eInsideAlert
   };
 
 protected:
@@ -1141,9 +1149,9 @@ protected:
 
   static const uint8_t kChildrenFlagsBits = 2;
   static const uint8_t kStateFlagsBits = 11;
-  static const uint8_t kContextFlagsBits = 2;
+  static const uint8_t kContextFlagsBits = 3;
   static const uint8_t kTypeBits = 6;
-  static const uint8_t kGenericTypesBits = 14;
+  static const uint8_t kGenericTypesBits = 15;
 
   /**
    * Keep in sync with ChildrenFlags, StateFlags, ContextFlags, and AccTypes.

accessible/generic/DocAccessible.cpp

@@ -1764,22 +1764,16 @@ DocAccessible::UpdateTreeOnInsertion(Accessible* aContainer)
 
   // Check to see if change occurred inside an alert, and fire an EVENT_ALERT
   // if it did.
-  if (!(updateFlags & eAlertAccessible)) {
-    // XXX: tree traversal is perf issue, accessible should know if they are
-    // children of alert accessible to avoid this.
+  if (!(updateFlags & eAlertAccessible) &&
+      (aContainer->IsAlert() || aContainer->IsInsideAlert())) {
     Accessible* ancestor = aContainer;
-    while (ancestor) {
-      if (ancestor->ARIARole() == roles::ALERT) {
+    do {
+      if (ancestor->IsAlert()) {
         FireDelayedEvent(nsIAccessibleEvent::EVENT_ALERT, ancestor);
         break;
       }
-
-      // Don't climb above this document.
-      if (ancestor == this)
-        break;
-
-      ancestor = ancestor->Parent();
     }
+    while ((ancestor = ancestor->Parent()));
   }
 
   MaybeNotifyOfValueChange(aContainer);

accessible/xul/XULAlertAccessible.cpp

@@ -19,6 +19,7 @@ XULAlertAccessible::
   XULAlertAccessible(nsIContent* aContent, DocAccessible* aDoc) :
   AccessibleWrap(aContent, aDoc)
 {
+  mGenericTypes |= eAlert;
 }
 
 XULAlertAccessible::~XULAlertAccessible()