include/wx/msw/ole/oleutils.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        oleutils.h
   3 // Purpose:     OLE helper routines, OLE debugging support &c
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     19.02.1998
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
   9 // Licence:     wxWindows licence
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef   _WX_OLEUTILS_H
  13 #define   _WX_OLEUTILS_H
  14
  15 #ifdef __GNUG__
  16 #pragma interface "oleutils.h"
  17 #endif
  18
  19 #include "wx/defs.h"
  20
  21 // ============================================================================
  22 // General purpose functions and macros
  23 // ============================================================================
  24
  25 // ----------------------------------------------------------------------------
  26 // misc helper functions/macros
  27 // ----------------------------------------------------------------------------
  28
  29 // release the interface pointer (if !NULL)
  30 inline void ReleaseInterface(IUnknown *pIUnk)
  31 {
  32   if ( pIUnk != NULL )
  33     pIUnk->Release();
  34 }
  35
  36 // release the interface pointer (if !NULL) and make it NULL
  37 #define   RELEASE_AND_NULL(p)   if ( (p) != NULL ) { p->Release(); p = NULL; };
  38
  39 // return TRUE if the iid is in the array
  40 bool IsIidFromList(REFIID riid, const IID *aIids[], size_t nCount);
  41
  42 // ============================================================================
  43 // IUnknown implementation helpers
  44 // ============================================================================
  45
  46 /*
  47    The most dumb implementation of IUnknown methods. We don't support
  48    aggregation nor containment, but for 99% of cases this simple
  49    implementation is quite enough.
  50
  51    Usage is trivial: here is all you should have
  52    1) DECLARE_IUNKNOWN_METHOS in your (IUnknown derived!) class declaration
  53    2) BEGIN/END_IID_TABLE with ADD_IID in between for all interfaces you
  54       support (at least all for which you intent to return 'this' from QI,
  55       i.e. you should derive from IFoo if you have ADD_IID(Foo)) somewhere else
  56    3) IMPLEMENT_IUNKNOWN_METHOS somewhere also
  57
  58    These macros are quite simple: AddRef and Release are trivial and QI does
  59    lookup in a static member array of IIDs and returns 'this' if it founds
  60    the requested interface in it or E_NOINTERFACE if not.
  61  */
  62
  63 // declare the methods and the member variable containing reference count
  64 // you must also define the ms_aIids array somewhere with BEGIN_IID_TABLE
  65 // and friends (see below)
  66 #define   DECLARE_IUNKNOWN_METHODS                                            \
  67   public:                                                                     \
  68     STDMETHODIMP          QueryInterface(REFIID, void **);                    \
  69     STDMETHODIMP_(ULONG)  AddRef();                                           \
  70     STDMETHODIMP_(ULONG)  Release();                                          \
  71   private:                                                                    \
  72     static  const IID    *ms_aIids[];                                         \
  73     ULONG                 m_cRef
  74
  75 // macros for declaring supported interfaces
  76 // NB: you should write ADD_INTERFACE(Foo) and not ADD_INTERFACE(IID_IFoo)!
  77 #define BEGIN_IID_TABLE(cname)  const IID *cname::ms_aIids[] = {
  78 #define ADD_IID(iid)                                             &IID_I##iid,
  79 #define END_IID_TABLE                                          }
  80
  81 // implementation is as straightforward as possible
  82 // Parameter:  classname - the name of the class
  83 #define   IMPLEMENT_IUNKNOWN_METHODS(classname)                               \
  84   STDMETHODIMP classname::QueryInterface(REFIID riid, void **ppv)             \
  85   {                                                                           \
  86     wxLogQueryInterface(#classname, riid);                                    \
  87                                                                               \
  88     if ( IsIidFromList(riid, ms_aIids, WXSIZEOF(ms_aIids)) ) {                  \
  89       *ppv = this;                                                            \
  90       AddRef();                                                               \
  91                                                                               \
  92       return S_OK;                                                            \
  93     }                                                                         \
  94     else {                                                                    \
  95       *ppv = NULL;                                                            \
  96                                                                               \
  97       return (HRESULT) E_NOINTERFACE;                                                   \
  98     }                                                                         \
  99   }                                                                           \
 100                                                                               \
 101   STDMETHODIMP_(ULONG) classname::AddRef()                                    \
 102   {                                                                           \
 103     wxLogAddRef(#classname, m_cRef);                                          \
 104                                                                               \
 105     return ++m_cRef;                                                          \
 106   }                                                                           \
 107                                                                               \
 108   STDMETHODIMP_(ULONG) classname::Release()                                   \
 109   {                                                                           \
 110     wxLogRelease(#classname, m_cRef);                                         \
 111                                                                               \
 112     if ( --m_cRef == 0 ) {                                                    \
 113       delete this;                                                            \
 114       return 0;                                                               \
 115     }                                                                         \
 116     else                                                                      \
 117       return m_cRef;                                                          \
 118   }
 119
 120 // ============================================================================
 121 // Debugging support
 122 // ============================================================================
 123
 124 // VZ: I don't know it's not done for compilers other than VC++ but I leave it
 125 //     as is. Please note, though, that tracing OLE interface calls may be
 126 //     incredibly useful when debugging OLE programs.
 127 #if defined(__WXDEBUG__) && defined(__VISUALC__) && (__VISUALC__ >= 1000)
 128 // ----------------------------------------------------------------------------
 129 // All OLE specific log functions have DebugTrace level (as LogTrace)
 130 // ----------------------------------------------------------------------------
 131
 132 // tries to translate riid into a symbolic name, if possible
 133 void wxLogQueryInterface(const char *szInterface, REFIID riid);
 134
 135 // these functions print out the new value of reference counter
 136 void wxLogAddRef (const char *szInterface, ULONG cRef);
 137 void wxLogRelease(const char *szInterface, ULONG cRef);
 138
 139 #else   //!WXDEBUG
 140   #define   wxLogQueryInterface(szInterface, riid)
 141   #define   wxLogAddRef(szInterface, cRef)
 142   #define   wxLogRelease(szInterface, cRef)
 143 #endif  //WXDEBUG
 144
 145 #endif  //_WX_OLEUTILS_H
 146