gecko-dev/accessible/base/AccEvent.h

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/* -*- 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 accessible.
AccEvent(uint32_t aEventType, Accessible* 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); }
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,
eObjectAttrChangedEvent
};
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;
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; }
Accessible* Parent() const { return mParent; }
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:
explicit 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,
Accessible* aOldAccessible,
int32_t aOldStart, int32_t aOldEnd,
int16_t aReason,
EIsFromUserInput aIsFromUserInput = eFromUserInput);
virtual ~AccVCChangeEvent() { }
// AccEvent
static const EventGroup kEventGroup = eVirtualCursorChangeEvent;
virtual unsigned int GetEventGroups() const
{
return AccEvent::GetEventGroups() | (1U << eVirtualCursorChangeEvent);
}
// AccTableChangeEvent
Accessible* OldAccessible() const { return mOldAccessible; }
int32_t OldStartOffset() const { return mOldStart; }
int32_t OldEndOffset() const { return mOldEnd; }
int32_t Reason() const { return mReason; }
private:
nsRefPtr<Accessible> mOldAccessible;
int32_t mOldStart;
int32_t mOldEnd;
int16_t mReason;
};
/**
* Accessible object attribute changed event.
*/
class AccObjectAttrChangedEvent: public AccEvent
{
public:
AccObjectAttrChangedEvent(Accessible* aAccessible, nsIAtom* aAttribute) :
AccEvent(::nsIAccessibleEvent::EVENT_OBJECT_ATTRIBUTE_CHANGED, aAccessible),
mAttribute(aAttribute) { }
// AccEvent
static const EventGroup kEventGroup = eObjectAttrChangedEvent;
virtual unsigned int GetEventGroups() const
{
return AccEvent::GetEventGroups() | (1U << eObjectAttrChangedEvent);
}
// AccObjectAttrChangedEvent
nsIAtom* GetAttribute() const { return mAttribute; }
private:
nsCOMPtr<nsIAtom> mAttribute;
virtual ~AccObjectAttrChangedEvent() { }
};
/**
* 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