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| -rw-r--r-- | accessible/base/AccEvent.h | 562 |
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diff --git a/accessible/base/AccEvent.h b/accessible/base/AccEvent.h new file mode 100644 index 0000000000..a4ff82916a --- /dev/null +++ b/accessible/base/AccEvent.h @@ -0,0 +1,562 @@ +/* -*- 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/LocalAccessible.h" + +class nsEventShell; +namespace mozilla { + +namespace dom { +class Selection; +} + +namespace a11y { + +class DocAccessible; +class EventQueue; +class TextRange; + +// 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, + + // 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 accessible. + AccEvent(uint32_t aEventType, LocalAccessible* aAccessible, + EIsFromUserInput aIsFromUserInput = eAutoDetect, + EEventRule aEventRule = eRemoveDupes); + + // 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); + } + + LocalAccessible* GetAccessible() const { return mAccessible; } + DocAccessible* Document() const { return mAccessible->Document(); } + + /** + * Down casting. + */ + enum EventGroup { + eGenericEvent, + eStateChangeEvent, + eTextChangeEvent, + eTreeMutationEvent, + eMutationEvent, + eReorderEvent, + eHideEvent, + eShowEvent, + eCaretMoveEvent, + eTextSelChangeEvent, + eSelectionChangeEvent, + eObjectAttrChangedEvent, + eScrollingEvent, + eAnnouncementEvent, + }; + + 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: + virtual ~AccEvent() {} + + bool mIsFromUserInput; + uint32_t mEventType; + EEventRule mEventRule; + RefPtr<LocalAccessible> mAccessible; + + friend class EventQueue; + friend class EventTree; + friend class ::nsEventShell; + friend class NotificationController; +}; + +/** + * Accessible state change event. + */ +class AccStateChangeEvent : public AccEvent { + public: + AccStateChangeEvent(LocalAccessible* aAccessible, uint64_t aState, + bool aIsEnabled, + EIsFromUserInput aIsFromUserInput = eAutoDetect) + : AccEvent(nsIAccessibleEvent::EVENT_STATE_CHANGE, aAccessible, + aIsFromUserInput, eCoalesceStateChange), + mState(aState), + mIsEnabled(aIsEnabled) {} + + AccStateChangeEvent(LocalAccessible* 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 override { + 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(LocalAccessible* aAccessible, int32_t aStart, + const nsAString& aModifiedText, bool aIsInserted, + EIsFromUserInput aIsFromUserInput = eAutoDetect); + + // AccEvent + static const EventGroup kEventGroup = eTextChangeEvent; + virtual unsigned int GetEventGroups() const override { + 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; + } + const nsString& ModifiedText() const { return mModifiedText; } + + private: + int32_t mStart; + bool mIsInserted; + nsString mModifiedText; + + friend class EventTree; + friend class NotificationController; +}; + +/** + * A base class for events related to tree mutation, either an AccMutation + * event, or an AccReorderEvent. + */ +class AccTreeMutationEvent : public AccEvent { + public: + AccTreeMutationEvent(uint32_t aEventType, LocalAccessible* aTarget) + : AccEvent(aEventType, aTarget, eAutoDetect, eCoalesceReorder), + mGeneration(0) {} + + // Event + static const EventGroup kEventGroup = eTreeMutationEvent; + virtual unsigned int GetEventGroups() const override { + return AccEvent::GetEventGroups() | (1U << eTreeMutationEvent); + } + + void SetNextEvent(AccTreeMutationEvent* aNext) { mNextEvent = aNext; } + void SetPrevEvent(AccTreeMutationEvent* aPrev) { mPrevEvent = aPrev; } + AccTreeMutationEvent* NextEvent() const { return mNextEvent; } + AccTreeMutationEvent* PrevEvent() const { return mPrevEvent; } + + /** + * A sequence number to know when this event was fired. + */ + uint32_t EventGeneration() const { return mGeneration; } + void SetEventGeneration(uint32_t aGeneration) { mGeneration = aGeneration; } + + private: + RefPtr<AccTreeMutationEvent> mNextEvent; + RefPtr<AccTreeMutationEvent> mPrevEvent; + uint32_t mGeneration; +}; + +/** + * Base class for show and hide accessible events. + */ +class AccMutationEvent : public AccTreeMutationEvent { + public: + AccMutationEvent(uint32_t aEventType, LocalAccessible* aTarget) + : AccTreeMutationEvent(aEventType, aTarget) { + // Don't coalesce these since they are coalesced by reorder event. Coalesce + // contained text change events. + mParent = mAccessible->LocalParent(); + } + virtual ~AccMutationEvent() {} + + // Event + static const EventGroup kEventGroup = eMutationEvent; + virtual unsigned int GetEventGroups() const override { + return AccTreeMutationEvent::GetEventGroups() | (1U << eMutationEvent); + } + + // MutationEvent + bool IsShow() const { return mEventType == nsIAccessibleEvent::EVENT_SHOW; } + bool IsHide() const { return mEventType == nsIAccessibleEvent::EVENT_HIDE; } + + LocalAccessible* LocalParent() const { return mParent; } + + protected: + RefPtr<LocalAccessible> mParent; + RefPtr<AccTextChangeEvent> mTextChangeEvent; + + friend class EventTree; + friend class NotificationController; +}; + +/** + * Accessible hide event. + */ +class AccHideEvent : public AccMutationEvent { + public: + explicit AccHideEvent(LocalAccessible* aTarget, bool aNeedsShutdown = true); + + // Event + static const EventGroup kEventGroup = eHideEvent; + virtual unsigned int GetEventGroups() const override { + return AccMutationEvent::GetEventGroups() | (1U << eHideEvent); + } + + // AccHideEvent + LocalAccessible* TargetParent() const { return mParent; } + LocalAccessible* TargetNextSibling() const { return mNextSibling; } + LocalAccessible* TargetPrevSibling() const { return mPrevSibling; } + bool NeedsShutdown() const { return mNeedsShutdown; } + + protected: + bool mNeedsShutdown; + RefPtr<LocalAccessible> mNextSibling; + RefPtr<LocalAccessible> mPrevSibling; + + friend class EventTree; + friend class NotificationController; +}; + +/** + * Accessible show event. + */ +class AccShowEvent : public AccMutationEvent { + public: + explicit AccShowEvent(LocalAccessible* aTarget) + : AccMutationEvent(::nsIAccessibleEvent::EVENT_SHOW, aTarget) {} + + // Event + static const EventGroup kEventGroup = eShowEvent; + virtual unsigned int GetEventGroups() const override { + return AccMutationEvent::GetEventGroups() | (1U << eShowEvent); + } +}; + +/** + * Class for reorder accessible event. Takes care about + */ +class AccReorderEvent : public AccTreeMutationEvent { + public: + explicit AccReorderEvent(LocalAccessible* aTarget) + : AccTreeMutationEvent(::nsIAccessibleEvent::EVENT_REORDER, aTarget) {} + virtual ~AccReorderEvent() {} + + // Event + static const EventGroup kEventGroup = eReorderEvent; + virtual unsigned int GetEventGroups() const override { + return AccTreeMutationEvent::GetEventGroups() | (1U << eReorderEvent); + } + + /* + * Make this an inner reorder event that is coalesced into + * a reorder event of an ancestor. + */ + void SetInner() { mEventType = ::nsIAccessibleEvent::EVENT_INNER_REORDER; } +}; + +/** + * Accessible caret move event. + */ +class AccCaretMoveEvent : public AccEvent { + public: + AccCaretMoveEvent(LocalAccessible* aAccessible, int32_t aCaretOffset, + bool aIsSelectionCollapsed, bool aIsAtEndOfLine, + int32_t aGranularity, + EIsFromUserInput aIsFromUserInput = eAutoDetect) + : AccEvent(::nsIAccessibleEvent::EVENT_TEXT_CARET_MOVED, aAccessible, + aIsFromUserInput), + mCaretOffset(aCaretOffset), + mIsSelectionCollapsed(aIsSelectionCollapsed), + mIsAtEndOfLine(aIsAtEndOfLine), + mGranularity(aGranularity) {} + virtual ~AccCaretMoveEvent() {} + + // AccEvent + static const EventGroup kEventGroup = eCaretMoveEvent; + virtual unsigned int GetEventGroups() const override { + return AccEvent::GetEventGroups() | (1U << eCaretMoveEvent); + } + + // AccCaretMoveEvent + int32_t GetCaretOffset() const { return mCaretOffset; } + + bool IsSelectionCollapsed() const { return mIsSelectionCollapsed; } + bool IsAtEndOfLine() { return mIsAtEndOfLine; } + + int32_t GetGranularity() const { return mGranularity; } + + private: + int32_t mCaretOffset; + + bool mIsSelectionCollapsed; + bool mIsAtEndOfLine; + int32_t mGranularity; +}; + +/** + * Accessible text selection change event. + */ +class AccTextSelChangeEvent : public AccEvent { + public: + AccTextSelChangeEvent(HyperTextAccessible* aTarget, + dom::Selection* aSelection, int32_t aReason, + int32_t aGranularity); + virtual ~AccTextSelChangeEvent(); + + // AccEvent + static const EventGroup kEventGroup = eTextSelChangeEvent; + virtual unsigned int GetEventGroups() const override { + return AccEvent::GetEventGroups() | (1U << eTextSelChangeEvent); + } + + // AccTextSelChangeEvent + + /** + * Return true if the text selection change wasn't caused by pure caret move. + */ + bool IsCaretMoveOnly() const; + + int32_t GetGranularity() const { return mGranularity; } + + /** + * Return selection ranges in document/control. + */ + void SelectionRanges(nsTArray<a11y::TextRange>* aRanges) const; + + private: + RefPtr<dom::Selection> mSel; + int32_t mReason; + int32_t mGranularity; + + friend class EventQueue; + friend class SelectionManager; +}; + +/** + * Accessible widget selection change event. + */ +class AccSelChangeEvent : public AccEvent { + public: + enum SelChangeType { eSelectionAdd, eSelectionRemove }; + + AccSelChangeEvent(LocalAccessible* aWidget, LocalAccessible* aItem, + SelChangeType aSelChangeType); + + virtual ~AccSelChangeEvent() {} + + // AccEvent + static const EventGroup kEventGroup = eSelectionChangeEvent; + virtual unsigned int GetEventGroups() const override { + return AccEvent::GetEventGroups() | (1U << eSelectionChangeEvent); + } + + // AccSelChangeEvent + LocalAccessible* Widget() const { return mWidget; } + + private: + RefPtr<LocalAccessible> mWidget; + RefPtr<LocalAccessible> mItem; + SelChangeType mSelChangeType; + uint32_t mPreceedingCount; + AccSelChangeEvent* mPackedEvent; + + friend class EventQueue; +}; + +/** + * Accessible object attribute changed event. + */ +class AccObjectAttrChangedEvent : public AccEvent { + public: + AccObjectAttrChangedEvent(LocalAccessible* aAccessible, nsAtom* aAttribute) + : AccEvent(::nsIAccessibleEvent::EVENT_OBJECT_ATTRIBUTE_CHANGED, + aAccessible), + mAttribute(aAttribute) {} + + // AccEvent + static const EventGroup kEventGroup = eObjectAttrChangedEvent; + virtual unsigned int GetEventGroups() const override { + return AccEvent::GetEventGroups() | (1U << eObjectAttrChangedEvent); + } + + // AccObjectAttrChangedEvent + nsAtom* GetAttribute() const { return mAttribute; } + + private: + RefPtr<nsAtom> mAttribute; + + virtual ~AccObjectAttrChangedEvent() {} +}; + +/** + * Accessible scroll event. + */ +class AccScrollingEvent : public AccEvent { + public: + AccScrollingEvent(uint32_t aEventType, LocalAccessible* aAccessible, + uint32_t aScrollX, uint32_t aScrollY, uint32_t aMaxScrollX, + uint32_t aMaxScrollY) + : AccEvent(aEventType, aAccessible), + mScrollX(aScrollX), + mScrollY(aScrollY), + mMaxScrollX(aMaxScrollX), + mMaxScrollY(aMaxScrollY) {} + + virtual ~AccScrollingEvent() {} + + // AccEvent + static const EventGroup kEventGroup = eScrollingEvent; + virtual unsigned int GetEventGroups() const override { + return AccEvent::GetEventGroups() | (1U << eScrollingEvent); + } + + // The X scrolling offset of the container when the event was fired. + uint32_t ScrollX() { return mScrollX; } + // The Y scrolling offset of the container when the event was fired. + uint32_t ScrollY() { return mScrollY; } + // The max X offset of the container. + uint32_t MaxScrollX() { return mMaxScrollX; } + // The max Y offset of the container. + uint32_t MaxScrollY() { return mMaxScrollY; } + + private: + uint32_t mScrollX; + uint32_t mScrollY; + uint32_t mMaxScrollX; + uint32_t mMaxScrollY; +}; + +/** + * Accessible announcement event. + */ +class AccAnnouncementEvent : public AccEvent { + public: + AccAnnouncementEvent(LocalAccessible* aAccessible, + const nsAString& aAnnouncement, uint16_t aPriority) + : AccEvent(nsIAccessibleEvent::EVENT_ANNOUNCEMENT, aAccessible), + mAnnouncement(aAnnouncement), + mPriority(aPriority) {} + + virtual ~AccAnnouncementEvent() {} + + // AccEvent + static const EventGroup kEventGroup = eAnnouncementEvent; + virtual unsigned int GetEventGroups() const override { + return AccEvent::GetEventGroups() | (1U << eAnnouncementEvent); + } + + const nsString& Announcement() const { return mAnnouncement; } + + uint16_t Priority() { return mPriority; } + + private: + nsString mAnnouncement; + uint16_t mPriority; +}; + +/** + * Downcast the generic accessible event object to derived type. + */ +class downcast_accEvent { + public: + explicit 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 |