The Tor Browser: accessible/src/base/NotificationController.h@b8a032363ba2 (annotated)

accessible/src/base/NotificationController.h@b8a032363ba2 (annotated)

accessible/src/base/NotificationController.h

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #ifndef mozilla_a11y_NotificationController_h_
 #define mozilla_a11y_NotificationController_h_
 #include "EventQueue.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsRefreshDriver.h"
 #ifdef A11Y_LOG
 #include "Logging.h"
 #endif
 namespace mozilla {
 namespace a11y {
 class DocAccessible;
 /**
  * Notification interface.
  */
 class Notification
 {
 public:
   NS_INLINE_DECL_REFCOUNTING(Notification)
   /**
    * Process notification.
    */
   virtual void Process() = 0;
 protected:
   Notification() { }
   /**
    * Protected destructor, to discourage deletion outside of Release():
    */
   virtual ~Notification() { }
 private:
   Notification(const Notification&);
   Notification& operator = (const Notification&);
 };
 /**
  * Template class for generic notification.
  *
  * @note  Instance is kept as a weak ref, the caller must guarantee it exists
  *        longer than the document accessible owning the notification controller
  *        that this notification is processed by.
  */
 template<class Class, class Arg>
 class TNotification : public Notification
 {
 public:
   typedef void (Class::*Callback)(Arg*);
   TNotification(Class* aInstance, Callback aCallback, Arg* aArg) :
     mInstance(aInstance), mCallback(aCallback), mArg(aArg) { }
   virtual ~TNotification() { mInstance = nullptr; }
   virtual void Process()
   {
     (mInstance->*mCallback)(mArg);
     mInstance = nullptr;
     mCallback = nullptr;
     mArg = nullptr;
   }
 private:
   TNotification(const TNotification&);
   TNotification& operator = (const TNotification&);
   Class* mInstance;
   Callback mCallback;
   nsRefPtr<Arg> mArg;
 };
 /**
  * Used to process notifications from core for the document accessible.
  */
 class NotificationController : public EventQueue,
                                public nsARefreshObserver
 {
 public:
   NotificationController(DocAccessible* aDocument, nsIPresShell* aPresShell);
   virtual ~NotificationController();
   NS_IMETHOD_(MozExternalRefCountType) AddRef(void);
   NS_IMETHOD_(MozExternalRefCountType) Release(void);
   NS_DECL_CYCLE_COLLECTION_NATIVE_CLASS(NotificationController)
   /**
    * Shutdown the notification controller.
    */
   void Shutdown();
   /**
    * Put an accessible event into the queue to process it later.
    */
   void QueueEvent(AccEvent* aEvent)
   {
     if (PushEvent(aEvent))
       ScheduleProcessing();
   }
   /**
    * Schedule binding the child document to the tree of this document.
    */
   void ScheduleChildDocBinding(DocAccessible* aDocument);
   /**
    * Schedule the accessible tree update because of rendered text changes.
    */
   inline void ScheduleTextUpdate(nsIContent* aTextNode)
   {
     if (mTextHash.PutEntry(aTextNode))
       ScheduleProcessing();
   }
   /**
    * Pend accessible tree update for content insertion.
    */
   void ScheduleContentInsertion(Accessible* aContainer,
                                 nsIContent* aStartChildNode,
                                 nsIContent* aEndChildNode);
   /**
    * Process the generic notification synchronously if there are no pending
    * layout changes and no notifications are pending or being processed right
    * now. Otherwise, queue it up to process asynchronously.
    *
    * @note  The caller must guarantee that the given instance still exists when
    *        the notification is processed.
    */
   template<class Class, class Arg>
   inline void HandleNotification(Class* aInstance,
                                  typename TNotification<Class, Arg>::Callback aMethod,
                                  Arg* aArg)
   {
     if (!IsUpdatePending()) {
 #ifdef A11Y_LOG
       if (mozilla::a11y::logging::IsEnabled(mozilla::a11y::logging::eNotifications))
         mozilla::a11y::logging::Text("sync notification processing");
 #endif
       (aInstance->*aMethod)(aArg);
       return;
     }
     nsRefPtr<Notification> notification =
       new TNotification<Class, Arg>(aInstance, aMethod, aArg);
     if (notification && mNotifications.AppendElement(notification))
       ScheduleProcessing();
   }
   /**
    * Schedule the generic notification to process asynchronously.
    *
    * @note  The caller must guarantee that the given instance still exists when
    *        the notification is processed.
    */
   template<class Class, class Arg>
   inline void ScheduleNotification(Class* aInstance,
                                    typename TNotification<Class, Arg>::Callback aMethod,
                                    Arg* aArg)
   {
     nsRefPtr<Notification> notification =
       new TNotification<Class, Arg>(aInstance, aMethod, aArg);
     if (notification && mNotifications.AppendElement(notification))
       ScheduleProcessing();
   }
 #ifdef DEBUG
   bool IsUpdating() const
     { return mObservingState == eRefreshProcessingForUpdate; }
 #endif
 protected:
   nsCycleCollectingAutoRefCnt mRefCnt;
   NS_DECL_OWNINGTHREAD
   /**
    * Start to observe refresh to make notifications and events processing after
    * layout.
    */
   void ScheduleProcessing();
   /**
    * Return true if the accessible tree state update is pending.
    */
   bool IsUpdatePending();
 private:
   NotificationController(const NotificationController&);
   NotificationController& operator = (const NotificationController&);
   // nsARefreshObserver
   virtual void WillRefresh(mozilla::TimeStamp aTime);
 private:
   /**
    * Indicates whether we're waiting on an event queue processing from our
    * notification controller to flush events.
    */
   enum eObservingState {
     eNotObservingRefresh,
     eRefreshObserving,
     eRefreshProcessing,
     eRefreshProcessingForUpdate
   };
   eObservingState mObservingState;
   /**
    * The presshell of the document accessible.
    */
   nsIPresShell* mPresShell;
   /**
    * Child documents that needs to be bound to the tree.
    */
   nsTArray<nsRefPtr<DocAccessible> > mHangingChildDocuments;
   /**
    * Storage for content inserted notification information.
    */
   class ContentInsertion
   {
   public:
     ContentInsertion(DocAccessible* aDocument, Accessible* aContainer);
     virtual ~ContentInsertion() { mDocument = nullptr; }
     NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(ContentInsertion)
     NS_DECL_CYCLE_COLLECTION_NATIVE_CLASS(ContentInsertion)
     bool InitChildList(nsIContent* aStartChildNode, nsIContent* aEndChildNode);
     void Process();
   private:
     ContentInsertion();
     ContentInsertion(const ContentInsertion&);
     ContentInsertion& operator = (const ContentInsertion&);
     // The document used to process content insertion, matched to document of
     // the notification controller that this notification belongs to, therefore
     // it's ok to keep it as weak ref.
     DocAccessible* mDocument;
     // The container accessible that content insertion occurs within.
     nsRefPtr<Accessible> mContainer;
     // Array of inserted contents.
     nsTArray<nsCOMPtr<nsIContent> > mInsertedContent;
   };
   /**
    * A pending accessible tree update notifications for content insertions.
    * Don't make this an nsAutoTArray; we use SwapElements() on it.
    */
   nsTArray<nsRefPtr<ContentInsertion> > mContentInsertions;
   template<class T>
   class nsCOMPtrHashKey : public PLDHashEntryHdr
   {
   public:
     typedef T* KeyType;
     typedef const T* KeyTypePointer;
     nsCOMPtrHashKey(const T* aKey) : mKey(const_cast<T*>(aKey)) {}
     nsCOMPtrHashKey(const nsPtrHashKey<T> &aToCopy) : mKey(aToCopy.mKey) {}
     ~nsCOMPtrHashKey() { }
     KeyType GetKey() const { return mKey; }
     bool KeyEquals(KeyTypePointer aKey) const { return aKey == mKey; }
     static KeyTypePointer KeyToPointer(KeyType aKey) { return aKey; }
     static PLDHashNumber HashKey(KeyTypePointer aKey)
       { return NS_PTR_TO_INT32(aKey) >> 2; }
     enum { ALLOW_MEMMOVE = true };
    protected:
      nsCOMPtr<T> mKey;
   };
   /**
    * A pending accessible tree update notifications for rendered text changes.
    */
   nsTHashtable<nsCOMPtrHashKey<nsIContent> > mTextHash;
   /**
    * Update the accessible tree for pending rendered text change notifications.
    */
   static PLDHashOperator TextEnumerator(nsCOMPtrHashKey<nsIContent>* aEntry,
                                         void* aUserArg);
   /**
    * Other notifications like DOM events. Don't make this an nsAutoTArray; we
    * use SwapElements() on it.
    */
   nsTArray<nsRefPtr<Notification> > mNotifications;
 };
 } // namespace a11y
 } // namespace mozilla
 #endif // mozilla_a11y_NotificationController_h_

The Tor Browser / annotate

accessible/src/base/NotificationController.h@b8a032363ba2 (annotated)

accessible/src/base/NotificationController.h