// Name: wx/dcbuffer.h
// Purpose: wxBufferedDC class
// Author: Ron Lee <ron@debian.org>
-// Modified by:
+// Modified by: Vadim Zeitlin (refactored, added bg preservation)
// Created: 16/03/02
// RCS-ID: $Id$
// Copyright: (c) Ron Lee
#ifndef _WX_DCBUFFER_H_
#define _WX_DCBUFFER_H_
-#if defined(__GNUG__) && !defined(__APPLE__)
-#pragma interface "dcbuffer.h"
+#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
+ #pragma interface "dcbuffer.h"
#endif
#include "wx/dcmemory.h"
+#include "wx/dcclient.h"
-
-// ==============================================================
-// Double buffering helper.
-// --------------------------------------------------------------
-
-class WXDLLEXPORT wxBufferedDC : public wxMemoryDC
+// flags for wxBufferedDC ctor/Init()
+enum
{
-private:
+ // this is more efficient and hence default
+ wxBUFFER_DC_OVERWRITE_BG = 0,
- // 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:
+ // preserve the old background: more time consuming
+ wxBUFFER_DC_PRESERVE_BG = 1,
- // Default ctor, must subsequently call Init for
- // two stage construction.
- wxBufferedDC()
- : m_dc( 0 )
- {}
+ // flags used by default
+ wxBUFFER_DC_DEFAULT = wxBUFFER_DC_OVERWRITE_BG
+};
- // Construct a wxBufferedDC using a user supplied buffer.
+// ----------------------------------------------------------------------------
+// Double buffering helper.
+// ----------------------------------------------------------------------------
- wxBufferedDC( wxDC *dc, const wxBitmap &buffer );
+class WXDLLIMPEXP_ADV wxBufferedDC : public wxMemoryDC
+{
+public:
+ // Default ctor, must subsequently call Init for two stage construction.
+ wxBufferedDC() : m_dc( 0 )
+ {
+ }
- // Construct a wxBufferedDC with an internal buffer of 'area'
- // (where area is usually something like the size of the window
- // being buffered)
+ // Construct a wxBufferedDC using a user supplied buffer.
+ wxBufferedDC(wxDC *dc, const wxBitmap &buffer);
- wxBufferedDC( wxDC *dc, const wxSize &area );
+ // 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, int flags = wxBUFFER_DC_DEFAULT);
// 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 );
+ // The usually desired action in the dtor is to blit the buffer.
+ virtual ~wxBufferedDC() { if ( m_dc ) UnMask(); }
- // 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.
+ // 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, int flags = wxBUFFER_DC_DEFAULT);
+ // Blits the buffer to the dc, and detaches the dc from the buffer (so it
+ // can be effectively used once only).
+ //
+ // 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();
+
+private:
+ // check that the bitmap is valid and use it
+ void UseBuffer()
+ {
+ wxASSERT_MSG( m_buffer.Ok(), _T("invalid bitmap in wxBufferedDC") );
+
+ SelectObject(m_buffer);
+ }
+
+ // preserve the background if necessary
+ void SaveBg(const wxSize& area, int flags)
+ {
+ if ( flags & wxBUFFER_DC_PRESERVE_BG )
+ {
+ Blit(0, 0, area.GetWidth(), area.GetHeight(), m_dc, 0, 0);
+ }
+ }
+
+ // the underlying DC to which we copy everything drawn on this one in
+ // UnMask()
+ //
+ // NB: Without the existence of a wxNullDC, this must be a pointer, else it
+ // could probably be a reference.
+ wxDC *m_dc;
+
+ // the buffer (selected in this DC)
+ wxBitmap m_buffer;
+
+ DECLARE_NO_COPY_CLASS(wxBufferedDC)
};
-// ==============================================================
-// Double buffered PaintDC.
-// --------------------------------------------------------------
+// ----------------------------------------------------------------------------
+// Double buffered PaintDC.
+// ----------------------------------------------------------------------------
// Creates a double buffered wxPaintDC, optionally allowing the
// user to specify their own buffer to use.
-
-class WXDLLEXPORT wxBufferedPaintDC : public wxBufferedDC
+class WXDLLIMPEXP_ADV wxBufferedPaintDC : public wxBufferedDC
{
-private:
+public:
+ // this ctor creates a bitmap of the size of the window for buffering
+ wxBufferedPaintDC(wxWindow *window, int flags = wxBUFFER_DC_DEFAULT)
+ : m_paintdc(window)
+ {
+ Init(&m_paintdc, window->GetClientSize(), flags);
- wxPaintDC m_paintdc;
+ Prepare(window);
+ }
-public:
+ // the bitmap must be valid here
+ wxBufferedPaintDC(wxWindow *window, const wxBitmap& buffer)
+ : m_paintdc(window)
+ {
+ Init(&m_paintdc, buffer);
- wxBufferedPaintDC( wxWindow *window, const wxBitmap &buffer = wxNullBitmap );
+ Prepare(window);
+ }
// default copy ctor ok.
- ~wxBufferedPaintDC();
-};
+ virtual ~wxBufferedPaintDC()
+ {
+ // We must UnMask here, else by the time the base class
+ // does it, the PaintDC will have already been destroyed.
+ UnMask();
+ }
+
+private:
+ // prepare the underlying DC
+ void Prepare(wxWindow *window)
+ {
+ window->PrepareDC(m_paintdc);
+ }
+ wxPaintDC m_paintdc;
+
+ DECLARE_NO_COPY_CLASS(wxBufferedPaintDC)
+};
#endif // _WX_DCBUFFER_H_
-// vi:sts=4:sw=4:et
projects / wxWidgets.git / blobdiff