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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 */
#ifndef mozilla_dom_XULBroadcastManager_h
#define mozilla_dom_XULBroadcastManager_h
#include "mozilla/dom/Element.h"
#include "nsAtom.h"
class nsXULElement;
namespace mozilla {
namespace dom {
class XULBroadcastManager final {
explicit XULBroadcastManager(Document* aDocument);
* Checks whether an element uses any of the special broadcaster attributes
* or is an observes element. This mimics the logic in FindBroadcaster, but
* is intended to be a lighter weight check and doesn't actually guarantee
* that the element will need a listener.
static bool MayNeedListener(const Element& aElement);
nsresult AddListener(Element* aElement);
nsresult RemoveListener(Element* aElement);
void AttributeChanged(Element* aElement, int32_t aNameSpaceID,
nsAtom* aAttribute);
void MaybeBroadcast();
void DropDocumentReference(); // notification that doc is going away
enum HookupAction { eHookupAdd = 0, eHookupRemove };
nsresult UpdateListenerHookup(Element* aElement, HookupAction aAction);
void RemoveListenerFor(Element& aBroadcaster, Element& aListener,
const nsAString& aAttr);
void AddListenerFor(Element& aBroadcaster, Element& aListener,
const nsAString& aAttr, ErrorResult& aRv);
nsresult ExecuteOnBroadcastHandlerFor(Element* aBroadcaster,
Element* aListener, nsAtom* aAttr);
// The out params of FindBroadcaster only have values that make sense when
// the method returns NS_FINDBROADCASTER_FOUND. In all other cases, the
// values of the out params should not be relied on (though *aListener and
// *aBroadcaster do need to be released if non-null, of course).
nsresult FindBroadcaster(Element* aElement, Element** aListener,
nsString& aBroadcasterID, nsString& aAttribute,
Element** aBroadcaster);
void SynchronizeBroadcastListener(Element* aBroadcaster, Element* aListener,
const nsAString& aAttr);
// This reference is nulled by the Document in it's destructor through
// DropDocumentReference().
Document* MOZ_NON_OWNING_REF mDocument;
* A map from a broadcaster element to a list of listener elements.
PLDHashTable* mBroadcasterMap;
class nsDelayedBroadcastUpdate {
nsDelayedBroadcastUpdate(Element* aBroadcaster, Element* aListener,
const nsAString& aAttr)
: mBroadcaster(aBroadcaster),
mNeedsAttrChange(false) {}
nsDelayedBroadcastUpdate(Element* aBroadcaster, Element* aListener,
nsAtom* aAttrName, const nsAString& aAttr,
bool aSetAttr, bool aNeedsAttrChange)
: mBroadcaster(aBroadcaster),
mNeedsAttrChange(aNeedsAttrChange) {}
nsDelayedBroadcastUpdate(const nsDelayedBroadcastUpdate& aOther) = delete;
nsDelayedBroadcastUpdate(nsDelayedBroadcastUpdate&& aOther) = default;
nsCOMPtr<Element> mBroadcaster;
nsCOMPtr<Element> mListener;
// Note if mAttrName isn't used, this is the name of the attr, otherwise
// this is the value of the attribute.
nsString mAttr;
RefPtr<nsAtom> mAttrName;
bool mSetAttr;
bool mNeedsAttrChange;
class Comparator {
static bool Equals(const nsDelayedBroadcastUpdate& a,
const nsDelayedBroadcastUpdate& b) {
return a.mBroadcaster == b.mBroadcaster && a.mListener == b.mListener &&
a.mAttrName == b.mAttrName;
nsTArray<nsDelayedBroadcastUpdate> mDelayedBroadcasters;
nsTArray<nsDelayedBroadcastUpdate> mDelayedAttrChangeBroadcasts;
bool mHandlingDelayedAttrChange;
bool mHandlingDelayedBroadcasters;
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_XULBroadcastManager_h