1 /*
2  *    IEnumIDList
3  *
4  *    Copyright 1998    Juergen Schmied <juergen.schmied@metronet.de>
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
19  */
20 
21 #include "precomp.h"
22 
23 WINE_DEFAULT_DEBUG_CHANNEL(shell);
24 
25 CEnumIDListBase::CEnumIDListBase() :
26     mpFirst(NULL),
27     mpLast(NULL),
28     mpCurrent(NULL)
29 {
30 }
31 
32 CEnumIDListBase::~CEnumIDListBase()
33 {
34     DeleteList();
35 }
36 
37 /**************************************************************************
38  *  AddToEnumList()
39  */
40 BOOL CEnumIDListBase::AddToEnumList(LPITEMIDLIST pidl)
41 {
42     ENUMLIST *pNew;
43 
44     TRACE("(%p)->(pidl=%p)\n", this, pidl);
45 
46     if (!pidl)
47         return FALSE;
48 
49     pNew = static_cast<ENUMLIST *>(SHAlloc(sizeof(ENUMLIST)));
50     if (pNew)
51     {
52       /*set the next pointer */
53       pNew->pNext = NULL;
54       pNew->pidl = pidl;
55 
56       /*is This the first item in the list? */
57       if (!mpFirst)
58       {
59         mpFirst = pNew;
60         mpCurrent = pNew;
61       }
62 
63       if (mpLast)
64       {
65         /*add the new item to the end of the list */
66         mpLast->pNext = pNew;
67       }
68 
69       /*update the last item pointer */
70       mpLast = pNew;
71       TRACE("-- (%p)->(first=%p, last=%p)\n", this, mpFirst, mpLast);
72       return TRUE;
73     }
74     return FALSE;
75 }
76 
77 /**************************************************************************
78 *   DeleteList()
79 */
80 BOOL CEnumIDListBase::DeleteList()
81 {
82     ENUMLIST                    *pDelete;
83 
84     TRACE("(%p)->()\n", this);
85 
86     while (mpFirst)
87     {
88         pDelete = mpFirst;
89         mpFirst = pDelete->pNext;
90         SHFree(pDelete->pidl);
91         SHFree(pDelete);
92     }
93     mpFirst = NULL;
94     mpLast = NULL;
95     mpCurrent = NULL;
96     return TRUE;
97 }
98 
99 HRESULT CEnumIDListBase::AppendItemsFromEnumerator(IEnumIDList* pEnum)
100 {
101     LPITEMIDLIST pidl;
102     DWORD dwFetched;
103 
104     if (!pEnum)
105         return E_INVALIDARG;
106 
107     pEnum->Reset();
108 
109     while((S_OK == pEnum->Next(1, &pidl, &dwFetched)) && dwFetched)
110         AddToEnumList(pidl);
111 
112     return S_OK;
113 }
114 
115 /**************************************************************************
116  *  IEnumIDList_fnNext
117  */
118 
119 HRESULT WINAPI CEnumIDListBase::Next(
120     ULONG celt,
121     LPITEMIDLIST * rgelt,
122     ULONG *pceltFetched)
123 {
124     ULONG    i;
125     HRESULT  hr = S_OK;
126     LPITEMIDLIST  temp;
127 
128     TRACE("(%p)->(%d,%p, %p)\n", this, celt, rgelt, pceltFetched);
129 
130 /* It is valid to leave pceltFetched NULL when celt is 1. Some of explorer's
131  * subsystems actually use it (and so may a third party browser)
132  */
133     if(pceltFetched)
134       *pceltFetched = 0;
135 
136     *rgelt=0;
137 
138     if(celt > 1 && !pceltFetched)
139     { return E_INVALIDARG;
140     }
141 
142     if(celt > 0 && !mpCurrent)
143     { return S_FALSE;
144     }
145 
146     for(i = 0; i < celt; i++)
147     { if(!mpCurrent)
148       { hr = S_FALSE;
149         break;
150       }
151 
152       temp = ILClone(mpCurrent->pidl);
153       if (!temp)
154       { hr = i ? S_FALSE : E_OUTOFMEMORY;
155         break;
156       }
157       rgelt[i] = temp;
158       mpCurrent = mpCurrent->pNext;
159     }
160     if(pceltFetched)
161     {  *pceltFetched = i;
162     }
163 
164     return hr;
165 }
166 
167 /**************************************************************************
168 *  IEnumIDList_fnSkip
169 */
170 HRESULT WINAPI CEnumIDListBase::Skip(
171     ULONG celt)
172 {
173     DWORD    dwIndex;
174     HRESULT  hr = S_OK;
175 
176     TRACE("(%p)->(%u)\n", this, celt);
177 
178     for(dwIndex = 0; dwIndex < celt; dwIndex++)
179     { if(!mpCurrent)
180       { hr = S_FALSE;
181         break;
182       }
183       mpCurrent = mpCurrent->pNext;
184     }
185     return hr;
186 }
187 
188 /**************************************************************************
189 *  IEnumIDList_fnReset
190 */
191 HRESULT WINAPI CEnumIDListBase::Reset()
192 {
193     TRACE("(%p)\n", this);
194     mpCurrent = mpFirst;
195     return S_OK;
196 }
197 
198 /**************************************************************************
199 *  IEnumIDList_fnClone
200 */
201 HRESULT WINAPI CEnumIDListBase::Clone(LPENUMIDLIST *ppenum)
202 {
203     TRACE("(%p)->() to (%p)->() E_NOTIMPL\n", this, ppenum);
204     return E_NOTIMPL;
205 }
206 
207 /**************************************************************************
208  *  IEnumIDList_Folder_Constructor
209  *
210  */
211 HRESULT IEnumIDList_Constructor(IEnumIDList **enumerator)
212 {
213     return ShellObjectCreator<CEnumIDListBase>(IID_PPV_ARG(IEnumIDList, enumerator));
214 }
215