include/wx/dfb/dfbptr.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/dfb/dfbptr.h
   3 // Purpose:     wxDfbPtr<T> for holding objects declared in wrapdfb.h
   4 // Author:      Vaclav Slavik
   5 // Created:     2006-08-09
   6 // RCS-ID:      $Id$
   7 // Copyright:   (c) 2006 REA Elektronik GmbH
   8 // Licence:     wxWindows licence
   9 /////////////////////////////////////////////////////////////////////////////
  10
  11 #ifndef _WX_DFB_DFBPTR_H_
  12 #define _WX_DFB_DFBPTR_H_
  13
  14 //-----------------------------------------------------------------------------
  15 // wxDFB_DECLARE_INTERFACE
  16 //-----------------------------------------------------------------------------
  17
  18 /**
  19     Forward declares wx wrapper around DirectFB interface @a name.
  20
  21     Also declares wx##name##Ptr typedef for wxDfbPtr<wx##name> pointer.
  22
  23     @param name  name of the DirectFB interface
  24  */
  25 #define wxDFB_DECLARE_INTERFACE(name)            \
  26     class wx##name;                              \
  27     typedef wxDfbPtr<wx##name> wx##name##Ptr;
  28
  29
  30 //-----------------------------------------------------------------------------
  31 // wxDfbPtr<T>
  32 //-----------------------------------------------------------------------------
  33
  34 class wxDfbWrapperBase;
  35
  36 class wxDfbPtrBase
  37 {
  38 protected:
  39     static void DoAddRef(wxDfbWrapperBase *ptr);
  40     static void DoRelease(wxDfbWrapperBase *ptr);
  41 };
  42
  43 /**
  44     This template implements smart pointer for keeping pointers to DirectFB
  45     wrappers (i.e. wxIFoo classes derived from wxDfbWrapper<T>). Interface's
  46     reference count is increased on copying and the interface is released when
  47     the pointer is deleted.
  48  */
  49 template<typename T>
  50 class wxDfbPtr : private wxDfbPtrBase
  51 {
  52 public:
  53     /**
  54         Creates the pointer from raw pointer to the wrapper.
  55
  56         Takes ownership of @a ptr, i.e. AddRef() is @em not called on it.
  57      */
  58     wxDfbPtr(T *ptr = NULL) : m_ptr(ptr) {}
  59
  60     /// Copy ctor
  61     wxDfbPtr(const wxDfbPtr& ptr) { InitFrom(ptr); }
  62
  63     /// Dtor. Releases the interface
  64     ~wxDfbPtr() { Reset(); }
  65
  66     /// Resets the pointer to NULL, decreasing reference count of the interface.
  67     void Reset()
  68     {
  69         if ( m_ptr )
  70         {
  71             this->DoRelease((wxDfbWrapperBase*)m_ptr);
  72             m_ptr = NULL;
  73         }
  74     }
  75
  76     /// Cast to the wrapper pointer
  77     operator T*() const { return m_ptr; }
  78
  79     // standard operators:
  80
  81     wxDfbPtr& operator=(T *ptr)
  82     {
  83         Reset();
  84         m_ptr = ptr;
  85         return *this;
  86     }
  87
  88     wxDfbPtr& operator=(const wxDfbPtr& ptr)
  89     {
  90         Reset();
  91         InitFrom(ptr);
  92         return *this;
  93     }
  94
  95     T& operator*() const { return *m_ptr; }
  96     T* operator->() const { return m_ptr; }
  97
  98 private:
  99     void InitFrom(const wxDfbPtr& ptr)
 100     {
 101         m_ptr = ptr.m_ptr;
 102         if ( m_ptr )
 103             this->DoAddRef((wxDfbWrapperBase*)m_ptr);
 104     }
 105
 106 private:
 107     T *m_ptr;
 108 };
 109
 110 #endif // _WX_DFB_DFBPTR_H_