gecko-dev/dom/base/nsStubDocumentObserver.h
2015-05-03 15:32:37 -04:00

36 lines
1.3 KiB
C++

/* -*- 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 http://mozilla.org/MPL/2.0/. */
/*
* nsStubDocumentObserver is an implementation of the nsIDocumentObserver
* interface (except for the methods on nsISupports) that is intended to be
* used as a base class within the content/layout library. All methods do
* nothing.
*/
#ifndef nsStubDocumentObserver_h_
#define nsStubDocumentObserver_h_
#include "nsIDocumentObserver.h"
/**
* There are two advantages to inheriting from nsStubDocumentObserver
* rather than directly from nsIDocumentObserver:
* 1. smaller compiled code size (since there's no need for the code
* for the empty virtual function implementations for every
* nsIDocumentObserver implementation)
* 2. the performance of document's loop over observers benefits from
* the fact that more of the functions called are the same (which
* can reduce instruction cache misses and perhaps improve branch
* prediction)
*/
class nsStubDocumentObserver : public nsIDocumentObserver {
public:
NS_DECL_NSIDOCUMENTOBSERVER
};
#endif /* !defined(nsStubDocumentObserver_h_) */