// 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
#define _WX_DCBUFFER_H_
#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
-#pragma interface "dcbuffer.h"
+ #pragma interface "dcbuffer.h"
#endif
#include "wx/dcmemory.h"
#include "wx/dcclient.h"
-
-// ==============================================================
-// Double buffering helper.
-// --------------------------------------------------------------
-
-class WXDLLIMPEXP_ADV 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.
+ // preserve the old background: more time consuming
+ wxBUFFER_DC_PRESERVE_BG = 1,
- wxDC *m_dc;
- wxBitmap m_buffer;
-
-public:
- // Default ctor, must subsequently call Init for
- // two stage construction.
-
- wxBufferedDC()
- : m_dc( 0 )
- {}
+ // flags used by default
+ wxBUFFER_DC_DEFAULT = wxBUFFER_DC_PRESERVE_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();
+ // The usually desired action in the dtor is to blit the buffer.
+ virtual ~wxBufferedDC() { if ( m_dc ) UnMask(); }
- // 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.
+ // 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);
- 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 (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();
- // 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.
+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);
+ }
+ }
+
+ // Without the existence of a wxNullDC, this must be
+ // a pointer, else it could probably be a reference.
+ wxDC *m_dc;
- void UnMask();
+ 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 WXDLLIMPEXP_ADV wxBufferedPaintDC : public wxBufferedDC
{
-private:
-
- wxPaintDC m_paintdc;
-
public:
-
- wxBufferedPaintDC( wxWindow *window, const wxBitmap &buffer = wxNullBitmap );
+ // this ctor creates a bitmap of the size of the window for buffering
+ wxBufferedPaintDC(wxWindow *window, int flags = wxBUFFER_DC_DEFAULT)
+ : wxBufferedDC(&m_paintdc, window->GetClientSize(), flags),
+ m_paintdc(window)
+ {
+ Prepare(window);
+ }
+
+ // the bitmap must be valid here
+ wxBufferedPaintDC(wxWindow *window, const wxBitmap& buffer)
+ : wxBufferedDC(&m_paintdc, buffer)
+ {
+ 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_
/////////////////////////////////////////////////////////////////////////////
-// Name: dcbuffer.cpp
+// Name: generic/dcbuffer.cpp
// 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
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
-
#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
#pragma implementation "dcbuffer.h"
#endif
#endif
#ifndef WX_PRECOMP
-#include "wx/window.h"
+ #include "wx/window.h"
#endif
#include "wx/dcbuffer.h"
+// ----------------------------------------------------------------------------
+// Double buffering helper.
+// ----------------------------------------------------------------------------
-// ==============================================================
-// Double buffering helper.
-// --------------------------------------------------------------
-
-wxBufferedDC::wxBufferedDC( wxDC *dc, const wxBitmap &buffer )
- : m_dc( dc )
- , m_buffer( buffer )
+wxBufferedDC::wxBufferedDC(wxDC *dc, const wxBitmap& buffer)
+ : m_dc( dc ),
+ m_buffer( buffer )
{
- SelectObject( m_buffer );
+ UseBuffer();
}
-wxBufferedDC::wxBufferedDC( wxDC *dc, const wxSize &area )
- : m_dc( dc )
- , m_buffer( area.GetWidth(), area.GetHeight() )
+wxBufferedDC::wxBufferedDC(wxDC *dc, const wxSize& area, int flags)
+ : m_dc( dc ),
+ m_buffer( area.GetWidth(), area.GetHeight() )
{
- SelectObject( m_buffer );
-}
+ UseBuffer();
-wxBufferedDC::~wxBufferedDC()
-{
- if( m_dc != 0 )
- {
- UnMask();
- }
+ SaveBg(area, flags);
}
void wxBufferedDC::Init( wxDC *dc, const wxBitmap &buffer )
m_dc = dc;
m_buffer = buffer;
- SelectObject( m_buffer );
+
+ UseBuffer();
}
-void wxBufferedDC::Init( wxDC *dc, const wxSize &area )
+void wxBufferedDC::Init(wxDC *dc, const wxSize& area, int flags)
{
- wxASSERT_MSG( m_dc == 0 && m_buffer == wxNullBitmap,
- _T("wxBufferedDC already initialised") );
+ Init(dc, wxBitmap(area.GetWidth(), area.GetHeight()));
- m_dc = dc;
- m_buffer = wxBitmap( area.GetWidth(), area.GetHeight() );
- SelectObject( m_buffer );
+ SaveBg(area, flags);
}
void wxBufferedDC::UnMask()
{
- wxASSERT_MSG( m_dc != 0, _T("No low level DC associated with buffer (anymore)") );
+ wxASSERT_MSG( m_dc != 0,
+ _T("No underlying DC associated with wxBufferedDC (anymore)") );
m_dc->Blit( 0, 0, m_buffer.GetWidth(), m_buffer.GetHeight(), this, 0, 0 );
- m_dc = 0;
+ m_dc = NULL;
}
-
-// ==============================================================
-// Double buffered PaintDC.
-// --------------------------------------------------------------
-
-wxBufferedPaintDC::wxBufferedPaintDC( wxWindow *window, const wxBitmap &buffer )
- : m_paintdc( window )
-{
- window->PrepareDC( m_paintdc );
-
- if( buffer != wxNullBitmap )
- Init( &m_paintdc, buffer );
- else
- Init( &m_paintdc, window->GetClientSize() );
-}
-
-wxBufferedPaintDC::~wxBufferedPaintDC()
-{
- // We must UnMask here, else by the time the base class
- // does it, the PaintDC will have already been destroyed.
-
- UnMask();
-}
-
-
-// vi:sts=4:sw=4:et
projects / wxWidgets.git / commitdiff
