reactos/dll/shellext/acppage/CLayerStringList.hpp

   1 /*
   2  * Copyright 2015-2017 Mark Jansen
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  17  */
  18
  19
  20 /* TODO: Use HSDB instead of PDB */
  21 class CLayerStringList :
  22     public CComObjectRootEx<CComMultiThreadModelNoCS>,
  23     public IEnumString
  24 {
  25 public:
  26     CLayerStringList()
  27         :m_root(TAGID_NULL), m_layer(TAGID_NULL)
  28     {
  29         WCHAR buf[MAX_PATH];
  30         SdbGetAppPatchDir(NULL, buf, MAX_PATH);
  31         StringCchCatW(buf, _countof(buf), L"\\sysmain.sdb");
  32         m_db = SdbOpenDatabase(buf, DOS_PATH);
  33         Reset();
  34     }
  35
  36     ~CLayerStringList()
  37     {
  38         SdbCloseDatabase(m_db);
  39     }
  40
  41     virtual HRESULT STDMETHODCALLTYPE Next(ULONG celt, LPOLESTR *rgelt, ULONG *pceltFetched)
  42     {
  43         if (pceltFetched)
  44             *pceltFetched = 0;
  45
  46         while (celt && m_layer)
  47         {
  48             TAGID nameid = SdbFindFirstTag(m_db, m_layer, TAG_NAME);
  49             if (!nameid)
  50                 return S_FALSE;
  51
  52             LPWSTR name = SdbGetStringTagPtr(m_db, nameid);
  53             if (!name)
  54                 return S_FALSE;
  55
  56             ULONG Size = wcslen(name) + 1;
  57
  58             *rgelt = (LPOLESTR)::CoTaskMemAlloc(Size * sizeof(WCHAR));
  59             StringCchCopyW(*rgelt, Size, name);
  60
  61             if (pceltFetched)
  62                 (*pceltFetched)++;
  63
  64             m_layer = SdbFindNextTag(m_db, m_root, m_layer);
  65             celt--;
  66             rgelt++;
  67         }
  68         return celt ? S_FALSE : S_OK;
  69     }
  70
  71     virtual HRESULT STDMETHODCALLTYPE Skip(ULONG celt)
  72     {
  73         while (m_layer && celt)
  74         {
  75             m_layer = SdbFindNextTag(m_db, m_root, m_layer);
  76             --celt;
  77         }
  78         return celt ? S_FALSE : S_OK;
  79     }
  80
  81     virtual HRESULT STDMETHODCALLTYPE Reset()
  82     {
  83         m_root = m_layer = TAGID_NULL;
  84         if (m_db)
  85         {
  86             m_root = SdbFindFirstTag(m_db, TAGID_ROOT, TAG_DATABASE);
  87             if (m_root != TAGID_NULL)
  88             {
  89                 m_layer = SdbFindFirstTag(m_db, m_root, TAG_LAYER);
  90                 return S_OK;
  91             }
  92         }
  93         return E_FAIL;
  94     }
  95
  96     virtual HRESULT STDMETHODCALLTYPE Clone(IEnumString **ppenum)
  97     {
  98         return E_NOTIMPL;
  99     }
 100
 101 protected:
 102     PDB m_db;
 103     TAGID m_root;
 104     TAGID m_layer;
 105
 106 public:
 107     BEGIN_COM_MAP(CLayerStringList)
 108         COM_INTERFACE_ENTRY_IID(IID_IEnumString, IEnumString)
 109     END_COM_MAP()
 110 };
 111