bug 1270916 - add a map from accessible and event type to an event r=davidb

accessible/base/NotificationController.cpp

@@ -449,3 +449,52 @@ NotificationController::WillRefresh(mozilla::TimeStamp aTime)
     mObservingState = eNotObservingRefresh;
   }
 }
+
+void
+NotificationController::EventMap::PutEvent(AccTreeMutationEvent* aEvent)
+{
+  EventType type = GetEventType(aEvent);
+  uint64_t addr = reinterpret_cast<uintptr_t>(aEvent->GetAccessible());
+  MOZ_ASSERT((addr & 0x3) == 0, "accessible is not 4 byte aligned");
+  addr |= type;
+  mTable.Put(addr, aEvent);
+}
+
+AccTreeMutationEvent*
+NotificationController::EventMap::GetEvent(Accessible* aTarget, EventType aType)
+{
+  uint64_t addr = reinterpret_cast<uintptr_t>(aTarget);
+  MOZ_ASSERT((addr & 0x3) == 0, "target is not 4 byte aligned");
+
+  addr |= aType;
+  return mTable.GetWeak(addr);
+}
+
+void
+NotificationController::EventMap::RemoveEvent(AccTreeMutationEvent* aEvent)
+{
+  EventType type = GetEventType(aEvent);
+  uint64_t addr = reinterpret_cast<uintptr_t>(aEvent->GetAccessible());
+  MOZ_ASSERT((addr & 0x3) == 0, "accessible is not 4 byte aligned");
+  addr |= type;
+
+  MOZ_ASSERT(mTable.GetWeak(addr) == aEvent, "mTable has the wrong event");
+  mTable.Remove(addr);
+}
+
+  NotificationController::EventMap::EventType
+NotificationController::EventMap::GetEventType(AccTreeMutationEvent* aEvent)
+{
+  switch(aEvent->GetEventType())
+  {
+    case nsIAccessibleEvent::EVENT_SHOW:
+      return ShowEvent;
+    case nsIAccessibleEvent::EVENT_HIDE:
+      return HideEvent;
+    case nsIAccessibleEvent::EVENT_REORDER:
+      return ReorderEvent;
+    default:
+      MOZ_ASSERT_UNREACHABLE("event has invalid type");
+      return ShowEvent;
+  }
+}

accessible/base/NotificationController.h

@@ -376,6 +376,32 @@ private:
 
   friend class MoveGuard;
   friend class EventTree;
+
+  /**
+   * A class to map an accessible and event type to an event.
+   */
+  class EventMap
+  {
+  public:
+    enum EventType
+    {
+      ShowEvent = 0x0,
+      HideEvent = 0x1,
+      ReorderEvent = 0x2,
+    };
+
+    void PutEvent(AccTreeMutationEvent* aEvent);
+    AccTreeMutationEvent* GetEvent(Accessible* aTarget, EventType aType);
+    void RemoveEvent(AccTreeMutationEvent* aEvent);
+    void Clear() { mTable.Clear(); }
+
+  private:
+    EventType GetEventType(AccTreeMutationEvent* aEvent);
+
+    nsRefPtrHashtable<nsUint64HashKey, AccTreeMutationEvent> mTable;
+  };
+
+  EventMap mMutationMap;
 };
 
 } // namespace a11y