projects/activex/utils.h

   1 /*****************************************************************************
   2  * utils.h: ActiveX control for VLC
   3  *****************************************************************************
   4  * Copyright (C) 2005 the VideoLAN team
   5  *
   6  * Authors: Damien Fouilleul <Damien.Fouilleul@laposte.net>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  21  *****************************************************************************/
  22
  23 #ifndef __UTILS_H__
  24 #define __UTILS_H__
  25
  26 #include <ole2.h>
  27
  28 #include <vector>
  29
  30 // utilities
  31 extern char *CStrFromWSTR(UINT codePage, LPCWSTR wstr, UINT len);
  32 extern char *CStrFromBSTR(UINT codePage, BSTR bstr);
  33 extern BSTR BSTRFromCStr(UINT codePage, LPCSTR s);
  34
  35 // properties
  36 extern HRESULT GetObjectProperty(LPUNKNOWN object, DISPID dispID, VARIANT& v);
  37
  38 // properties
  39 extern HDC CreateDevDC(DVTARGETDEVICE *ptd);
  40 extern void DPFromHimetric(HDC hdc, LPPOINT pt, int count);
  41 extern void HimetricFromDP(HDC hdc, LPPOINT pt, int count);
  42
  43 // URL
  44 extern LPWSTR CombineURL(LPCWSTR baseUrl, LPCWSTR url);
  45
  46 /**************************************************************************************************/
  47
  48 /* this function object is used to dereference the iterator into a value */
  49 template <typename T, class Iterator>
  50 struct VLCDereference
  51 {
  52     T operator()(const Iterator& i) const
  53     {
  54         return *i;
  55     };
  56 };
  57
  58 template<REFIID EnumeratorIID, class Enumerator, typename T, class Iterator, typename Dereference = VLCDereference<T, Iterator> >
  59 class VLCEnumIterator : public Enumerator
  60 {
  61
  62 public:
  63
  64     VLCEnumIterator(const Iterator& from, const Iterator& to) :
  65         _refcount(1),
  66         _begin(from),
  67         _curr(from),
  68         _end(to)
  69     {};
  70
  71     VLCEnumIterator(const VLCEnumIterator& e) :
  72         Enumerator(),
  73         _refcount(e._refcount),
  74         _begin(e._begin),
  75         _curr(e._curr),
  76         _end(e._end)
  77     {};
  78
  79     virtual ~VLCEnumIterator()
  80     {};
  81
  82     // IUnknown methods
  83     STDMETHODIMP QueryInterface(REFIID riid, void **ppv)
  84     {
  85         if( NULL == ppv )
  86             return E_POINTER;
  87         if( (IID_IUnknown == riid)
  88          || (EnumeratorIID == riid) )
  89         {
  90             AddRef();
  91             *ppv = reinterpret_cast<LPVOID>(this);
  92             return NOERROR;
  93         }
  94         // standalone object
  95         return E_NOINTERFACE;
  96     };
  97
  98     STDMETHODIMP_(ULONG) AddRef(void)
  99     {
 100         return InterlockedIncrement(&_refcount);
 101     };
 102
 103     STDMETHODIMP_(ULONG) Release(void)
 104     {
 105         ULONG refcount = InterlockedDecrement(&_refcount);
 106         if( 0 == refcount )
 107         {
 108             delete this;
 109             return 0;
 110         }
 111         return refcount;
 112     };
 113
 114
 115     // IEnumXXXX methods
 116     STDMETHODIMP Next(ULONG celt, T *rgelt, ULONG *pceltFetched)
 117     {
 118         if( NULL == rgelt )
 119             return E_POINTER;
 120
 121         if( (celt > 1) && (NULL == pceltFetched) )
 122             return E_INVALIDARG;
 123
 124         ULONG c = 0;
 125
 126         while( (c < celt) && (_curr != _end) )
 127         {
 128             rgelt[c] = dereference(_curr);
 129             ++_curr;
 130             ++c;
 131         }
 132
 133         if( NULL != pceltFetched )
 134             *pceltFetched = c;
 135
 136         return (c == celt) ? S_OK : S_FALSE;
 137     };
 138
 139     STDMETHODIMP Skip(ULONG celt)
 140     {
 141         ULONG c = 0;
 142
 143         while( (c < celt) && (_curr != _end) )
 144         {
 145             ++_curr;
 146             ++c;
 147         }
 148         return (c == celt) ? S_OK : S_FALSE;
 149     };
 150
 151     STDMETHODIMP Reset(void)
 152     {
 153         _curr = _begin;
 154         return S_OK;
 155     };
 156
 157     STDMETHODIMP Clone(Enumerator **ppEnum)
 158     {
 159         if( NULL == ppEnum )
 160             return E_POINTER;
 161         *ppEnum = dynamic_cast<Enumerator *>(new VLCEnumIterator(*this));
 162         return (NULL != *ppEnum ) ? S_OK : E_OUTOFMEMORY;
 163     };
 164
 165 private:
 166
 167     LONG     _refcount;
 168     Iterator _begin, _curr, _end;
 169
 170     Dereference dereference;
 171
 172 };
 173
 174 #endif
 175