Added wxBufferedDC class.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@14651 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/dcbuffer.h

@@ -0,0 +1,103 @@
+/////////////////////////////////////////////////////////////////////////////
+// Name:        wx/dcbuffer.h
+// Purpose:     wxBufferedDC class
+// Author:      Ron Lee <ron@debian.org>
+// Modified by:
+// Created:     16/03/02
+// RCS-ID:      $Id$
+// Copyright:   (c) Ron Lee
+// Licence:     wxWindows licence
+/////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_DCBUFFER_H_
+#define _WX_DCBUFFER_H_
+
+#ifdef __GNUG__
+#pragma interface "dcbuffer.h"
+#endif
+
+#include "wx/dcmemory.h"
+
+
+// ==============================================================
+//   Double buffering helper.
+// --------------------------------------------------------------
+
+class wxBufferedDC : public wxMemoryDC
+{
+private:
+
+        // Without the existence of a wxNullDC, this must be
+        // a pointer, else it could probably be a reference.
+
+    wxDC        *m_dc;
+    wxBitmap    m_buffer;
+
+public:
+
+        // Default ctor, must subsequently call Init for
+        // two stage construction.
+
+    wxBufferedDC()
+        : m_dc( 0 )
+    {}
+
+        // Construct a wxBufferedDC using a user supplied buffer.
+
+    wxBufferedDC( wxDC *dc, const wxBitmap &buffer );
+
+        // Construct a wxBufferedDC with an internal buffer of 'area'
+        // (where area is usually something like the size of the window
+        // being buffered)
+
+    wxBufferedDC( wxDC *dc, const wxSize &area );
+
+    // default copy ctor ok.
+
+        // The usually desired  action in the dtor is to blit the buffer.
+
+    ~wxBufferedDC();
+
+        // These reimplement the actions of the ctors for
+        // two stage creation, but are not used by the ctors
+        // themselves to save a few cpu cycles.
+
+    void Init( wxDC *dc, const wxBitmap &bitmap );
+    void Init( wxDC *dc, const wxSize &area );
+
+        // Blits the buffer to the dc, and detaches the dc from
+        // the buffer.  Usually called in the dtor or by the dtor
+        // of derived classes if the BufferedDC must blit before
+        // the derived class (which may own the dc it's blitting
+        // to) is destroyed.
+
+    void UnMask();
+};
+
+
+// ==============================================================
+//   Double buffered PaintDC.
+// --------------------------------------------------------------
+
+// Creates a double buffered wxPaintDC, optionally allowing the
+// user to specify their own buffer to use.
+
+class wxBufferedPaintDC : public wxBufferedDC
+{
+private:
+
+    wxPaintDC    m_paintdc;
+
+public:
+
+    wxBufferedPaintDC( wxWindow *window, const wxBitmap &buffer = wxNullBitmap );
+
+    // default copy ctor ok.
+
+    ~wxBufferedPaintDC();
+};
+
+
+#endif  // _WX_DCBUFFER_H_
+
+// vi:sts=4:sw=4:et