1 : /* vim: set shiftwidth=4 tabstop=8 autoindent cindent expandtab: */
2 : /* ***** BEGIN LICENSE BLOCK *****
3 : * Version: MPL 1.1/GPL 2.0/LGPL 2.1
4 : *
5 : * The contents of this file are subject to the Mozilla Public License Version
6 : * 1.1 (the "License"); you may not use this file except in compliance with
7 : * the License. You may obtain a copy of the License at
8 : * http://www.mozilla.org/MPL/
9 : *
10 : * Software distributed under the License is distributed on an "AS IS" basis,
11 : * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
12 : * for the specific language governing rights and limitations under the
13 : * License.
14 : *
15 : * The Original Code is nsStubDocumentObserver.
16 : *
17 : * The Initial Developer of the Original Code is the Mozilla Foundation.
18 : * Portions created by the Initial Developer are Copyright (C) 2004
19 : * the Initial Developer. All Rights Reserved.
20 : *
21 : * Contributor(s):
22 : * L. David Baron <dbaron@dbaron.org>, Mozilla Corporation (original author)
23 : *
24 : * Alternatively, the contents of this file may be used under the terms of
25 : * either the GNU General Public License Version 2 or later (the "GPL"), or
26 : * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
27 : * in which case the provisions of the GPL or the LGPL are applicable instead
28 : * of those above. If you wish to allow use of your version of this file only
29 : * under the terms of either the GPL or the LGPL, and not to allow others to
30 : * use your version of this file under the terms of the MPL, indicate your
31 : * decision by deleting the provisions above and replace them with the notice
32 : * and other provisions required by the GPL or the LGPL. If you do not delete
33 : * the provisions above, a recipient may use your version of this file under
34 : * the terms of any one of the MPL, the GPL or the LGPL.
35 : *
36 : * ***** END LICENSE BLOCK ***** */
37 :
38 : /*
39 : * nsStubImageDecoderObserver is an implementation of the imgIDecoderObserver
40 : * interface (except for the methods on nsISupports) that is intended to be
41 : * used as a base class within the content/layout library. All methods do
42 : * nothing.
43 : */
44 :
45 : #ifndef nsStubImageDecoderObserver_h_
46 : #define nsStubImageDecoderObserver_h_
47 :
48 : #include "imgIDecoderObserver.h"
49 :
50 : /**
51 : * There are two advantages to inheriting from nsStubImageDecoderObserver
52 : * rather than directly from imgIDecoderObserver:
53 : * 1. smaller compiled code size (since there's no need for the code
54 : * for the empty virtual function implementations for every
55 : * imgIDecoderObserver implementation)
56 : * 2. the performance of document's loop over observers benefits from
57 : * the fact that more of the functions called are the same (which
58 : * can reduce instruction cache misses and perhaps improve branch
59 : * prediction)
60 : */
61 0 : class nsStubImageDecoderObserver : public imgIDecoderObserver {
62 : public:
63 : NS_DECL_IMGICONTAINEROBSERVER
64 : NS_DECL_IMGIDECODEROBSERVER
65 : };
66 :
67 : #endif /* !defined(nsStubImageDecoderObserver_h_) */
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