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