xpcom/ds/nsStringEnumerator.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   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 String Enumerator.
  16  *
  17  * The Initial Developer of the Original Code is
  18  * Netscape Communications Corp.
  19  * Portions created by the Initial Developer are Copyright (C) 2003
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *   Alec Flett <alecf@netscape.com>
  24  *
  25  * Alternatively, the contents of this file may be used under the terms of
  26  * either the GNU General Public License Version 2 or later (the "GPL"), or
  27  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  28  * in which case the provisions of the GPL or the LGPL are applicable instead
  29  * of those above. If you wish to allow use of your version of this file only
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  34  * the provisions above, a recipient may use your version of this file under
  35  * the terms of any one of the MPL, the GPL or the LGPL.
  36  *
  37  * ***** END LICENSE BLOCK ***** */
  38
  39 #include "nsIStringEnumerator.h"
  40 #include "nsVoidArray.h"
  41
  42 // nsIStringEnumerator/nsIUTF8StringEnumerator implementations
  43 //
  44 // Currently all implementations support both interfaces. The
  45 // constructors below provide the most common interface for the given
  46 // type (i.e. nsIStringEnumerator for PRUnichar* strings, and so
  47 // forth) but any resulting enumerators can be queried to the other
  48 // type. Internally, the enumerators will hold onto the type that was
  49 // passed in and do conversion if GetNext() for the other type of
  50 // string is called.
  51
  52 // There are a few different types of enumerators:
  53
  54 //
  55 // These enumerators hold a pointer to the array. Be careful
  56 // because modifying the array may confuse the iterator, especially if
  57 // you insert or remove elements in the middle of the array.
  58 //
  59
  60 // The non-adopting enumerator requires that the array sticks around
  61 // at least as long as the enumerator does. These are for constant
  62 // string arrays that the enumerator does not own, this could be used
  63 // in VERY specialized cases such as when the provider KNOWS that the
  64 // string enumerator will be consumed immediately, or will at least
  65 // outlast the array.
  66 // For example:
  67 //
  68 // nsCStringArray array;
  69 // array.AppendCString("abc");
  70 // array.AppendCString("def");
  71 // NS_NewStringEnumerator(&enumerator, &array, PR_TRUE);
  72 //
  73 // // call some internal method which iterates the enumerator
  74 // InternalMethod(enumerator);
  75 // NS_RELEASE(enumerator);
  76 //
  77 NS_COM nsresult
  78 NS_NewUTF8StringEnumerator(nsIUTF8StringEnumerator** aResult,
  79                            const nsCStringArray* aArray);
  80
  81 NS_COM nsresult
  82 NS_NewStringEnumerator(nsIStringEnumerator** aResult,
  83                        const nsStringArray* aArray);
  84
  85 // Adopting string enumerators assume ownership of the array and will
  86 // call |operator delete| on the array when the enumerator is destroyed
  87 // this is useful when the provider creates an array solely for the
  88 // purpose of creating the enumerator.
  89 // For example:
  90 //
  91 // nsCStringArray* array = new nsCStringArray;
  92 // array->AppendString("abcd");
  93 // NS_NewAdoptingStringEnumerator(&result, array);
  94 NS_COM nsresult
  95 NS_NewAdoptingStringEnumerator(nsIStringEnumerator** aResult,
  96                                nsStringArray* aArray);
  97
  98 NS_COM nsresult
  99 NS_NewAdoptingUTF8StringEnumerator(nsIUTF8StringEnumerator** aResult,
 100                                    nsCStringArray* aArray);
 101
 102
 103 // these versions take a refcounted "owner" which will be addreffed
 104 // when the enumerator is created, and destroyed when the enumerator
 105 // is released. This allows providers to give non-owning pointers to
 106 // ns*StringArray member variables without worrying about lifetime
 107 // issues
 108 // For example:
 109 //
 110 // nsresult MyClass::Enumerate(nsIUTF8StringEnumerator** aResult) {
 111 //     mCategoryList->AppendString("abcd");
 112 //     return NS_NewStringEnumerator(aResult, mCategoryList, this);
 113 // }
 114 //
 115 NS_COM nsresult
 116 NS_NewStringEnumerator(nsIStringEnumerator** aResult,
 117                        const nsStringArray* aArray,
 118                        nsISupports* aOwner);
 119 NS_COM nsresult
 120 NS_NewUTF8StringEnumerator(nsIUTF8StringEnumerator** aResult,
 121                            const nsCStringArray* aArray,
 122                            nsISupports* aOwner);