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 #pragma once
   9
  10 /* TODO: Use HSDB instead of PDB */
  11 class CLayerStringList :
  12     public CComObjectRootEx<CComMultiThreadModelNoCS>,
  13     public IEnumString
  14 {
  15 public:
  16     CLayerStringList()
  17         :m_root(TAGID_NULL), m_layer(TAGID_NULL)
  18     {
  19         WCHAR buf[MAX_PATH];
  20         SdbGetAppPatchDir(NULL, buf, MAX_PATH);
  21         StringCchCatW(buf, _countof(buf), L"\\sysmain.sdb");
  22         m_db = SdbOpenDatabase(buf, DOS_PATH);
  23         Reset();
  24     }
  25
  26     ~CLayerStringList()
  27     {
  28         SdbCloseDatabase(m_db);
  29     }
  30
  31     virtual HRESULT STDMETHODCALLTYPE Next(ULONG celt, LPOLESTR *rgelt, ULONG *pceltFetched)
  32     {
  33         if (pceltFetched)
  34             *pceltFetched = 0;
  35
  36         while (celt && m_layer)
  37         {
  38             TAGID nameid = SdbFindFirstTag(m_db, m_layer, TAG_NAME);
  39             if (!nameid)
  40                 return S_FALSE;
  41
  42             LPWSTR name = SdbGetStringTagPtr(m_db, nameid);
  43             if (!name)
  44                 return S_FALSE;
  45
  46             ULONG Size = wcslen(name) + 1;
  47
  48             *rgelt = (LPOLESTR)::CoTaskMemAlloc(Size * sizeof(WCHAR));
  49             StringCchCopyW(*rgelt, Size, name);
  50
  51             if (pceltFetched)
  52                 (*pceltFetched)++;
  53
  54             m_layer = SdbFindNextTag(m_db, m_root, m_layer);
  55             celt--;
  56             rgelt++;
  57         }
  58         return celt ? S_FALSE : S_OK;
  59     }
  60
  61     virtual HRESULT STDMETHODCALLTYPE Skip(ULONG celt)
  62     {
  63         while (m_layer && celt)
  64         {
  65             m_layer = SdbFindNextTag(m_db, m_root, m_layer);
  66             --celt;
  67         }
  68         return celt ? S_FALSE : S_OK;
  69     }
  70
  71     virtual HRESULT STDMETHODCALLTYPE Reset()
  72     {
  73         m_root = m_layer = TAGID_NULL;
  74         if (m_db)
  75         {
  76             m_root = SdbFindFirstTag(m_db, TAGID_ROOT, TAG_DATABASE);
  77             if (m_root != TAGID_NULL)
  78             {
  79                 m_layer = SdbFindFirstTag(m_db, m_root, TAG_LAYER);
  80                 return S_OK;
  81             }
  82         }
  83         return E_FAIL;
  84     }
  85
  86     virtual HRESULT STDMETHODCALLTYPE Clone(IEnumString **ppenum)
  87     {
  88         return E_NOTIMPL;
  89     }
  90
  91 protected:
  92     PDB m_db;
  93     TAGID m_root;
  94     TAGID m_layer;
  95
  96 public:
  97     BEGIN_COM_MAP(CLayerStringList)
  98         COM_INTERFACE_ENTRY_IID(IID_IEnumString, IEnumString)
  99     END_COM_MAP()
 100 };
 101