dll/shellext/acppage/CLayerStringList.hpp

   1 /*
   2  * PROJECT:     ReactOS Compatibility Layer Shell Extension
   3  * LICENSE:     GPL-2.0+ (https://spdx.org/licenses/GPL-2.0+)
   4  * PURPOSE:     CLayerStringList implementation
   5  * COPYRIGHT:   Copyright 2015-2017 Mark Jansen (mark.jansen@reactos.org)
   6  */
   7
   8
   9 /* TODO: Use HSDB instead of PDB */
  10 class CLayerStringList :
  11     public CComObjectRootEx<CComMultiThreadModelNoCS>,
  12     public IEnumString
  13 {
  14 public:
  15     CLayerStringList()
  16         :m_root(TAGID_NULL), m_layer(TAGID_NULL)
  17     {
  18         WCHAR buf[MAX_PATH];
  19         SdbGetAppPatchDir(NULL, buf, MAX_PATH);
  20         StringCchCatW(buf, _countof(buf), L"\\sysmain.sdb");
  21         m_db = SdbOpenDatabase(buf, DOS_PATH);
  22         Reset();
  23     }
  24
  25     ~CLayerStringList()
  26     {
  27         SdbCloseDatabase(m_db);
  28     }
  29
  30     virtual HRESULT STDMETHODCALLTYPE Next(ULONG celt, LPOLESTR *rgelt, ULONG *pceltFetched)
  31     {
  32         if (pceltFetched)
  33             *pceltFetched = 0;
  34
  35         while (celt && m_layer)
  36         {
  37             TAGID nameid = SdbFindFirstTag(m_db, m_layer, TAG_NAME);
  38             if (!nameid)
  39                 return S_FALSE;
  40
  41             LPWSTR name = SdbGetStringTagPtr(m_db, nameid);
  42             if (!name)
  43                 return S_FALSE;
  44
  45             ULONG Size = wcslen(name) + 1;
  46
  47             *rgelt = (LPOLESTR)::CoTaskMemAlloc(Size * sizeof(WCHAR));
  48             StringCchCopyW(*rgelt, Size, name);
  49
  50             if (pceltFetched)
  51                 (*pceltFetched)++;
  52
  53             m_layer = SdbFindNextTag(m_db, m_root, m_layer);
  54             celt--;
  55             rgelt++;
  56         }
  57         return celt ? S_FALSE : S_OK;
  58     }
  59
  60     virtual HRESULT STDMETHODCALLTYPE Skip(ULONG celt)
  61     {
  62         while (m_layer && celt)
  63         {
  64             m_layer = SdbFindNextTag(m_db, m_root, m_layer);
  65             --celt;
  66         }
  67         return celt ? S_FALSE : S_OK;
  68     }
  69
  70     virtual HRESULT STDMETHODCALLTYPE Reset()
  71     {
  72         m_root = m_layer = TAGID_NULL;
  73         if (m_db)
  74         {
  75             m_root = SdbFindFirstTag(m_db, TAGID_ROOT, TAG_DATABASE);
  76             if (m_root != TAGID_NULL)
  77             {
  78                 m_layer = SdbFindFirstTag(m_db, m_root, TAG_LAYER);
  79                 return S_OK;
  80             }
  81         }
  82         return E_FAIL;
  83     }
  84
  85     virtual HRESULT STDMETHODCALLTYPE Clone(IEnumString **ppenum)
  86     {
  87         return E_NOTIMPL;
  88     }
  89
  90 protected:
  91     PDB m_db;
  92     TAGID m_root;
  93     TAGID m_layer;
  94
  95 public:
  96     BEGIN_COM_MAP(CLayerStringList)
  97         COM_INTERFACE_ENTRY_IID(IID_IEnumString, IEnumString)
  98     END_COM_MAP()
  99 };
 100