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source: vbox/trunk/src/libs/xpcom18a4/xpcom/ds/nsSupportsArrayEnumerator.cpp@ 4837

Last change on this file since 4837 was 1, checked in by vboxsync, 54 years ago

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1/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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 mozilla.org code.
16 *
17 * The Initial Developer of the Original Code is
18 * Netscape Communications Corporation.
19 * Portions created by the Initial Developer are Copyright (C) 1998
20 * the Initial Developer. All Rights Reserved.
21 *
22 * Contributor(s):
23 *
24 * Alternatively, the contents of this file may be used under the terms of
25 * either of the GNU General Public License Version 2 or later (the "GPL"),
26 * or 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#include "nsSupportsArrayEnumerator.h"
39#include "nsISupportsArray.h"
40
41nsSupportsArrayEnumerator::nsSupportsArrayEnumerator(nsISupportsArray* array)
42 : mArray(array), mCursor(0)
43{
44 NS_ASSERTION(array, "null array");
45 NS_ADDREF(mArray);
46}
47
48nsSupportsArrayEnumerator::~nsSupportsArrayEnumerator()
49{
50 NS_RELEASE(mArray);
51}
52
53NS_IMPL_ISUPPORTS2(nsSupportsArrayEnumerator, nsIBidirectionalEnumerator, nsIEnumerator)
54
55NS_IMETHODIMP
56nsSupportsArrayEnumerator::First()
57{
58 mCursor = 0;
59 PRUint32 cnt;
60 nsresult rv = mArray->Count(&cnt);
61 if (NS_FAILED(rv)) return rv;
62 PRInt32 end = (PRInt32)cnt;
63 if (mCursor < end)
64 return NS_OK;
65 else
66 return NS_ERROR_FAILURE;
67}
68
69NS_IMETHODIMP
70nsSupportsArrayEnumerator::Next()
71{
72 PRUint32 cnt;
73 nsresult rv = mArray->Count(&cnt);
74 if (NS_FAILED(rv)) return rv;
75 PRInt32 end = (PRInt32)cnt;
76 if (mCursor < end) // don't count upward forever
77 mCursor++;
78 if (mCursor < end)
79 return NS_OK;
80 else
81 return NS_ERROR_FAILURE;
82}
83
84NS_IMETHODIMP
85nsSupportsArrayEnumerator::CurrentItem(nsISupports **aItem)
86{
87 NS_ASSERTION(aItem, "null out parameter");
88 PRUint32 cnt;
89 nsresult rv = mArray->Count(&cnt);
90 if (NS_FAILED(rv)) return rv;
91 if (mCursor >= 0 && mCursor < (PRInt32)cnt) {
92 *aItem = mArray->ElementAt(mCursor);
93 return NS_OK;
94 }
95 return NS_ERROR_FAILURE;
96}
97
98NS_IMETHODIMP
99nsSupportsArrayEnumerator::IsDone()
100{
101 PRUint32 cnt;
102 nsresult rv = mArray->Count(&cnt);
103 if (NS_FAILED(rv)) return rv;
104 return (mCursor >= 0 && mCursor < (PRInt32)cnt)
105 ? NS_ENUMERATOR_FALSE : NS_OK;
106}
107
108////////////////////////////////////////////////////////////////////////////////
109
110NS_IMETHODIMP
111nsSupportsArrayEnumerator::Last()
112{
113 PRUint32 cnt;
114 nsresult rv = mArray->Count(&cnt);
115 if (NS_FAILED(rv)) return rv;
116 mCursor = cnt - 1;
117 return NS_OK;
118}
119
120NS_IMETHODIMP
121nsSupportsArrayEnumerator::Prev()
122{
123 if (mCursor >= 0)
124 --mCursor;
125 if (mCursor >= 0)
126 return NS_OK;
127 else
128 return NS_ERROR_FAILURE;
129}
130
131////////////////////////////////////////////////////////////////////////////////
132
133NS_COM nsresult
134NS_NewISupportsArrayEnumerator(nsISupportsArray* array,
135 nsIBidirectionalEnumerator* *aInstancePtrResult)
136{
137 if (aInstancePtrResult == 0)
138 return NS_ERROR_NULL_POINTER;
139 nsSupportsArrayEnumerator* e = new nsSupportsArrayEnumerator(array);
140 if (e == 0)
141 return NS_ERROR_OUT_OF_MEMORY;
142 NS_ADDREF(e);
143 *aInstancePtrResult = e;
144 return NS_OK;
145}
146
147////////////////////////////////////////////////////////////////////////////////
148
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