+/////////////////////////////////////////////////////////////////////////////
+// Name: wx/gdiobj.h
+// Purpose: wxGDIObject base header
+// Author: Julian Smart
+// Modified by:
+// Created:
+// Copyright: (c) Julian Smart
+// RCS-ID: $Id$
+// Licence: wxWindows Licence
+/////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_GDIOBJ_H_BASE_
+#define _WX_GDIOBJ_H_BASE_
+
+#include "wx/object.h"
+
+// ----------------------------------------------------------------------------
+// wxGDIRefData is the base class for wxXXXData structures which contain the
+// real data for the GDI object and are shared among all wxWin objects sharing
+// the same native GDI object
+// ----------------------------------------------------------------------------
+
+class WXDLLIMPEXP_CORE wxGDIRefData : public wxObjectRefData
+{
+public:
+ // override this in the derived classes to check if this data object is
+ // really fully initialized
+ virtual bool IsOk() const { return true; }
+};
+
+// ----------------------------------------------------------------------------
+// wxGDIObject: base class for bitmaps, pens, brushes, ...
+// ----------------------------------------------------------------------------
+
+class WXDLLIMPEXP_CORE wxGDIObject : public wxObject
+{
+public:
+ // checks if the object can be used
+ virtual bool IsOk() const
+ {
+ // the cast here is safe because the derived classes always create
+ // wxGDIRefData objects
+ return m_refData && static_cast<wxGDIRefData *>(m_refData)->IsOk();
+ }
+
+ // don't use in the new code, use IsOk() instead
+ bool IsNull() const { return m_refData == NULL; }
+
+ // older version, for backwards compatibility only (but not deprecated
+ // because it's still widely used)
+ bool Ok() const { return IsOk(); }
+
+#if defined(__WXMSW__) || defined(__WXPM__) || defined(__WXPALMOS__)
+ // Creates the resource
+ virtual bool RealizeResource() { return false; }
+
+ // Frees the resource
+ virtual bool FreeResource(bool WXUNUSED(force) = false) { return false; }
+
+ virtual bool IsFree() const { return false; }
+
+ // Returns handle.
+ virtual WXHANDLE GetResourceHandle() const { return 0; }
+#endif // defined(__WXMSW__) || defined(__WXPM__)
+
+protected:
+ // replace base class functions using wxObjectRefData with our own which
+ // use wxGDIRefData to ensure that we always work with data objects of the
+ // correct type (i.e. derived from wxGDIRefData)
+ virtual wxObjectRefData *CreateRefData() const
+ {
+ return CreateGDIRefData();
+ }
+
+ virtual wxObjectRefData *CloneRefData(const wxObjectRefData *data) const
+ {
+ return CloneGDIRefData(static_cast<const wxGDIRefData *>(data));
+ }
+
+ virtual wxGDIRefData *CreateGDIRefData() const = 0;
+ virtual wxGDIRefData *CloneGDIRefData(const wxGDIRefData *data) const = 0;
+
+ DECLARE_DYNAMIC_CLASS(wxGDIObject)
+};
+
+#endif // _WX_GDIOBJ_H_BASE_