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

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

accessible/src/base/AccEvent.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 _AccEvent_H_
 #define _AccEvent_H_
 #include "nsIAccessibleEvent.h"
 #include "mozilla/a11y/Accessible.h"
 namespace mozilla {
 namespace dom {
 class Selection;
 }
 namespace a11y {
 class DocAccessible;
 // Constants used to point whether the event is from user input.
 enum EIsFromUserInput
 {
   // eNoUserInput: event is not from user input
   eNoUserInput = 0,
   // eFromUserInput: event is from user input
   eFromUserInput = 1,
   // eAutoDetect: the value should be obtained from event state manager
   eAutoDetect = -1
 };
 /**
  * Generic accessible event.
  */
 class AccEvent
 {
 public:
   // Rule for accessible events.
   // The rule will be applied when flushing pending events.
   enum EEventRule {
     // eAllowDupes : More than one event of the same type is allowed.
     //    This event will always be emitted. This flag is used for events that
     //    don't support coalescence.
     eAllowDupes,
      // eCoalesceReorder : For reorder events from the same subtree or the same
      //    node, only the umbrella event on the ancestor will be emitted.
     eCoalesceReorder,
      // eCoalesceMutationTextChange : coalesce text change events caused by
      // tree mutations of the same tree level.
     eCoalesceMutationTextChange,
     // eCoalesceOfSameType : For events of the same type, only the newest event
     // will be processed.
     eCoalesceOfSameType,
     // eCoalesceSelectionChange: coalescence of selection change events.
     eCoalesceSelectionChange,
     // eCoalesceStateChange: coalesce state change events.
     eCoalesceStateChange,
     // eCoalesceTextSelChange: coalescence of text selection change events.
     eCoalesceTextSelChange,
      // eRemoveDupes : For repeat events, only the newest event in queue
      //    will be emitted.
     eRemoveDupes,
      // eDoNotEmit : This event is confirmed as a duplicate, do not emit it.
     eDoNotEmit
   };
   // Initialize with an nsIAccessible
   AccEvent(uint32_t aEventType, Accessible* aAccessible,
            EIsFromUserInput aIsFromUserInput = eAutoDetect,
            EEventRule aEventRule = eRemoveDupes);
   virtual ~AccEvent() {}
   // AccEvent
   uint32_t GetEventType() const { return mEventType; }
   EEventRule GetEventRule() const { return mEventRule; }
   bool IsFromUserInput() const { return mIsFromUserInput; }
   EIsFromUserInput FromUserInput() const
     { return static_cast<EIsFromUserInput>(mIsFromUserInput); }
   Accessible* GetAccessible() const { return mAccessible; }
   DocAccessible* GetDocAccessible() const { return mAccessible->Document(); }
   /**
    * Down casting.
    */
   enum EventGroup {
     eGenericEvent,
     eStateChangeEvent,
     eTextChangeEvent,
     eMutationEvent,
     eReorderEvent,
     eHideEvent,
     eShowEvent,
     eCaretMoveEvent,
     eTextSelChangeEvent,
     eSelectionChangeEvent,
     eTableChangeEvent,
     eVirtualCursorChangeEvent
   };
   static const EventGroup kEventGroup = eGenericEvent;
   virtual unsigned int GetEventGroups() const
   {
     return 1U << eGenericEvent;
   }
   /**
    * Reference counting and cycle collection.
    */
   NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(AccEvent)
   NS_DECL_CYCLE_COLLECTION_NATIVE_CLASS(AccEvent)
 protected:
   bool mIsFromUserInput;
   uint32_t mEventType;
   EEventRule mEventRule;
   nsRefPtr<Accessible> mAccessible;
   friend class EventQueue;
   friend class AccReorderEvent;
 };
 /**
  * Accessible state change event.
  */
 class AccStateChangeEvent: public AccEvent
 {
 public:
   AccStateChangeEvent(Accessible* aAccessible, uint64_t aState,
                       bool aIsEnabled,
                       EIsFromUserInput aIsFromUserInput = eAutoDetect) :
     AccEvent(nsIAccessibleEvent::EVENT_STATE_CHANGE, aAccessible,
              aIsFromUserInput, eCoalesceStateChange),
              mState(aState), mIsEnabled(aIsEnabled) { }
   AccStateChangeEvent(Accessible* aAccessible, uint64_t aState) :
     AccEvent(::nsIAccessibleEvent::EVENT_STATE_CHANGE, aAccessible,
              eAutoDetect, eCoalesceStateChange), mState(aState)
     { mIsEnabled = (mAccessible->State() & mState) != 0; }
   // AccEvent
   static const EventGroup kEventGroup = eStateChangeEvent;
   virtual unsigned int GetEventGroups() const
   {
     return AccEvent::GetEventGroups() | (1U << eStateChangeEvent);
   }
   // AccStateChangeEvent
   uint64_t GetState() const { return mState; }
   bool IsStateEnabled() const { return mIsEnabled; }
 private:
   uint64_t mState;
   bool mIsEnabled;
   friend class EventQueue;
 };
 /**
  * Accessible text change event.
  */
 class AccTextChangeEvent: public AccEvent
 {
 public:
   AccTextChangeEvent(Accessible* aAccessible, int32_t aStart,
                      const nsAString& aModifiedText, bool aIsInserted,
                      EIsFromUserInput aIsFromUserInput = eAutoDetect);
   // AccEvent
   static const EventGroup kEventGroup = eTextChangeEvent;
   virtual unsigned int GetEventGroups() const
   {
     return AccEvent::GetEventGroups() | (1U << eTextChangeEvent);
   }
   // AccTextChangeEvent
   int32_t GetStartOffset() const { return mStart; }
   uint32_t GetLength() const { return mModifiedText.Length(); }
   bool IsTextInserted() const { return mIsInserted; }
   void GetModifiedText(nsAString& aModifiedText)
     { aModifiedText = mModifiedText; }
 private:
   int32_t mStart;
   bool mIsInserted;
   nsString mModifiedText;
   friend class EventQueue;
   friend class AccReorderEvent;
 };
 /**
  * Base class for show and hide accessible events.
  */
 class AccMutationEvent: public AccEvent
 {
 public:
   AccMutationEvent(uint32_t aEventType, Accessible* aTarget,
                    nsINode* aTargetNode) :
     AccEvent(aEventType, aTarget, eAutoDetect, eCoalesceMutationTextChange)
   {
     // Don't coalesce these since they are coalesced by reorder event. Coalesce
     // contained text change events.
     mParent = mAccessible->Parent();
   }
   virtual ~AccMutationEvent() { }
   // Event
   static const EventGroup kEventGroup = eMutationEvent;
   virtual unsigned int GetEventGroups() const
   {
     return AccEvent::GetEventGroups() | (1U << eMutationEvent);
   }
   // MutationEvent
   bool IsShow() const { return mEventType == nsIAccessibleEvent::EVENT_SHOW; }
   bool IsHide() const { return mEventType == nsIAccessibleEvent::EVENT_HIDE; }
 protected:
   nsCOMPtr<nsINode> mNode;
   nsRefPtr<Accessible> mParent;
   nsRefPtr<AccTextChangeEvent> mTextChangeEvent;
   friend class EventQueue;
 };
 /**
  * Accessible hide event.
  */
 class AccHideEvent: public AccMutationEvent
 {
 public:
   AccHideEvent(Accessible* aTarget, nsINode* aTargetNode);
   // Event
   static const EventGroup kEventGroup = eHideEvent;
   virtual unsigned int GetEventGroups() const
   {
     return AccMutationEvent::GetEventGroups() | (1U << eHideEvent);
   }
   // AccHideEvent
   Accessible* TargetParent() const { return mParent; }
   Accessible* TargetNextSibling() const { return mNextSibling; }
   Accessible* TargetPrevSibling() const { return mPrevSibling; }
 protected:
   nsRefPtr<Accessible> mNextSibling;
   nsRefPtr<Accessible> mPrevSibling;
   friend class EventQueue;
 };
 /**
  * Accessible show event.
  */
 class AccShowEvent: public AccMutationEvent
 {
 public:
   AccShowEvent(Accessible* aTarget, nsINode* aTargetNode);
   // Event
   static const EventGroup kEventGroup = eShowEvent;
   virtual unsigned int GetEventGroups() const
   {
     return AccMutationEvent::GetEventGroups() | (1U << eShowEvent);
   }
 };
 /**
  * Class for reorder accessible event. Takes care about
  */
 class AccReorderEvent : public AccEvent
 {
 public:
   AccReorderEvent(Accessible* aTarget) :
     AccEvent(::nsIAccessibleEvent::EVENT_REORDER, aTarget,
              eAutoDetect, eCoalesceReorder) { }
   virtual ~AccReorderEvent() { }
   // Event
   static const EventGroup kEventGroup = eReorderEvent;
   virtual unsigned int GetEventGroups() const
   {
     return AccEvent::GetEventGroups() | (1U << eReorderEvent);
   }
   /**
    * Get connected with mutation event.
    */
   void AddSubMutationEvent(AccMutationEvent* aEvent)
     { mDependentEvents.AppendElement(aEvent); }
   /**
    * Do not emit the reorder event and its connected mutation events.
    */
   void DoNotEmitAll()
   {
     mEventRule = AccEvent::eDoNotEmit;
     uint32_t eventsCount = mDependentEvents.Length();
     for (uint32_t idx = 0; idx < eventsCount; idx++)
       mDependentEvents[idx]->mEventRule = AccEvent::eDoNotEmit;
   }
   /**
    * Return true if the given accessible is a target of connected mutation
    * event.
    */
   uint32_t IsShowHideEventTarget(const Accessible* aTarget) const;
 protected:
   /**
    * Show and hide events causing this reorder event.
    */
   nsTArray<AccMutationEvent*> mDependentEvents;
   friend class EventQueue;
 };
 /**
  * Accessible caret move event.
  */
 class AccCaretMoveEvent: public AccEvent
 {
 public:
   AccCaretMoveEvent(Accessible* aAccessible, int32_t aCaretOffset,
                     EIsFromUserInput aIsFromUserInput = eAutoDetect) :
     AccEvent(::nsIAccessibleEvent::EVENT_TEXT_CARET_MOVED, aAccessible,
              aIsFromUserInput),
     mCaretOffset(aCaretOffset) { }
   virtual ~AccCaretMoveEvent() { }
   // AccEvent
   static const EventGroup kEventGroup = eCaretMoveEvent;
   virtual unsigned int GetEventGroups() const
   {
     return AccEvent::GetEventGroups() | (1U << eCaretMoveEvent);
   }
   // AccCaretMoveEvent
   int32_t GetCaretOffset() const { return mCaretOffset; }
 private:
   int32_t mCaretOffset;
 };
 /**
  * Accessible text selection change event.
  */
 class AccTextSelChangeEvent : public AccEvent
 {
 public:
   AccTextSelChangeEvent(HyperTextAccessible* aTarget,
                         dom::Selection* aSelection,
                         int32_t aReason);
   virtual ~AccTextSelChangeEvent();
   // AccEvent
   static const EventGroup kEventGroup = eTextSelChangeEvent;
   virtual unsigned int GetEventGroups() const
   {
     return AccEvent::GetEventGroups() | (1U << eTextSelChangeEvent);
   }
   // AccTextSelChangeEvent
   /**
    * Return true if the text selection change wasn't caused by pure caret move.
    */
   bool IsCaretMoveOnly() const;
 private:
   nsRefPtr<dom::Selection> mSel;
   int32_t mReason;
   friend class EventQueue;
   friend class SelectionManager;
 };
 /**
  * Accessible widget selection change event.
  */
 class AccSelChangeEvent : public AccEvent
 {
 public:
   enum SelChangeType {
     eSelectionAdd,
     eSelectionRemove
   };
   AccSelChangeEvent(Accessible* aWidget, Accessible* aItem,
                     SelChangeType aSelChangeType);
   virtual ~AccSelChangeEvent() { }
   // AccEvent
   static const EventGroup kEventGroup = eSelectionChangeEvent;
   virtual unsigned int GetEventGroups() const
   {
     return AccEvent::GetEventGroups() | (1U << eSelectionChangeEvent);
   }
   // AccSelChangeEvent
   Accessible* Widget() const { return mWidget; }
 private:
   nsRefPtr<Accessible> mWidget;
   nsRefPtr<Accessible> mItem;
   SelChangeType mSelChangeType;
   uint32_t mPreceedingCount;
   AccSelChangeEvent* mPackedEvent;
   friend class EventQueue;
 };
 /**
  * Accessible table change event.
  */
 class AccTableChangeEvent : public AccEvent
 {
 public:
   AccTableChangeEvent(Accessible* aAccessible, uint32_t aEventType,
                       int32_t aRowOrColIndex, int32_t aNumRowsOrCols);
   // AccEvent
   static const EventGroup kEventGroup = eTableChangeEvent;
   virtual unsigned int GetEventGroups() const
   {
     return AccEvent::GetEventGroups() | (1U << eTableChangeEvent);
   }
   // AccTableChangeEvent
   uint32_t GetIndex() const { return mRowOrColIndex; }
   uint32_t GetCount() const { return mNumRowsOrCols; }
 private:
   uint32_t mRowOrColIndex;   // the start row/column after which the rows are inserted/deleted.
   uint32_t mNumRowsOrCols;   // the number of inserted/deleted rows/columns
 };
 /**
  * Accessible virtual cursor change event.
  */
 class AccVCChangeEvent : public AccEvent
 {
 public:
   AccVCChangeEvent(Accessible* aAccessible,
                    nsIAccessible* aOldAccessible,
                    int32_t aOldStart, int32_t aOldEnd,
                    int16_t aReason);
   virtual ~AccVCChangeEvent() { }
   // AccEvent
   static const EventGroup kEventGroup = eVirtualCursorChangeEvent;
   virtual unsigned int GetEventGroups() const
   {
     return AccEvent::GetEventGroups() | (1U << eVirtualCursorChangeEvent);
   }
   // AccTableChangeEvent
   nsIAccessible* OldAccessible() const { return mOldAccessible; }
   int32_t OldStartOffset() const { return mOldStart; }
   int32_t OldEndOffset() const { return mOldEnd; }
   int32_t Reason() const { return mReason; }
 private:
   nsRefPtr<nsIAccessible> mOldAccessible;
   int32_t mOldStart;
   int32_t mOldEnd;
   int16_t mReason;
 };
 /**
  * Downcast the generic accessible event object to derived type.
  */
 class downcast_accEvent
 {
 public:
   downcast_accEvent(AccEvent* e) : mRawPtr(e) { }
   template<class Destination>
   operator Destination*() {
     if (!mRawPtr)
       return nullptr;
     return mRawPtr->GetEventGroups() & (1U << Destination::kEventGroup) ?
       static_cast<Destination*>(mRawPtr) : nullptr;
   }
 private:
   AccEvent* mRawPtr;
 };
 /**
  * Return a new xpcom accessible event for the given internal one.
  */
 already_AddRefed<nsIAccessibleEvent>
 MakeXPCEvent(AccEvent* aEvent);
 } // namespace a11y
 } // namespace mozilla
 #endif

The Tor Browser / annotate

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

accessible/src/base/AccEvent.h