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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
#ifndef mozilla_a11y_EventQueue_h_
#define mozilla_a11y_EventQueue_h_
#include "AccEvent.h"
#include "mozilla/Assertions.h"
namespace mozilla {
namespace a11y {
class DocAccessible;
/**
* Used to organize and coalesce pending events.
*/
class EventQueue {
protected:
explicit EventQueue(DocAccessible* aDocument) : mDocument(aDocument) {
MOZ_ASSERT(mDocument,
"There's no point creating an event queue for a null document");
}
/**
* Put an accessible event into the queue to process it later.
*/
bool PushEvent(AccEvent* aEvent);
/**
* Puts name and/or description change events into the queue, if needed.
*/
bool PushNameOrDescriptionChange(AccEvent* aOrigEvent);
/**
* Process events from the queue and fires events.
*/
void ProcessEventQueue();
private:
EventQueue(const EventQueue&) = delete;
EventQueue& operator=(const EventQueue&) = delete;
// Event queue processing
/**
* Coalesce redundant events from the queue.
*/
void CoalesceEvents();
/**
* Coalesce events from the same subtree.
*/
void CoalesceReorderEvents(AccEvent* aTailEvent);
/**
* Coalesce two selection change events within the same select control.
*/
void CoalesceSelChangeEvents(AccSelChangeEvent* aTailEvent,
AccSelChangeEvent* aThisEvent,
uint32_t aThisIndex);
protected:
/**
* The document accessible reference owning this queue.
*/
DocAccessible* mDocument;
/**
* Pending events array. Don't make this an AutoTArray; we use
* SwapElements() on it.
*/
nsTArray<RefPtr<AccEvent>> mEvents;
// Pending focus event.
RefPtr<AccEvent> mFocusEvent;
};
} // namespace a11y
} // namespace mozilla
#endif // mozilla_a11y_EventQueue_h_