wxWidgets/include/wx/dcbuffer.h
Robin Dunn 7775e41fd7 Restored old wxBufferedDC functionality until it can be decided how to
correct the current issues without making things worse.  Updated docs.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@25904 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
2004-02-21 19:09:59 +00:00

151 lines
4.2 KiB
C++

/////////////////////////////////////////////////////////////////////////////
// Name: wx/dcbuffer.h
// Purpose: wxBufferedDC class
// Author: Ron Lee <ron@debian.org>
// Modified by: Vadim Zeitlin (refactored, added bg preservation)
// Created: 16/03/02
// RCS-ID: $Id$
// Copyright: (c) Ron Lee
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#ifndef _WX_DCBUFFER_H_
#define _WX_DCBUFFER_H_
#include "wx/dcmemory.h"
#include "wx/dcclient.h"
// ----------------------------------------------------------------------------
// Double buffering helper.
// ----------------------------------------------------------------------------
class wxBufferedDC : public wxMemoryDC
{
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)
: m_dc( dc ),
m_buffer( buffer )
{
UseBuffer();
}
// 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)
: m_dc( dc ),
m_buffer( area.GetWidth(), area.GetHeight() )
{
UseBuffer();
}
// default copy ctor ok.
// 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.
void Init(wxDC *dc, const wxBitmap &buffer)
{
wxASSERT_MSG( m_dc == 0 && m_buffer == wxNullBitmap,
_T("wxBufferedDC already initialised") );
m_dc = dc;
m_buffer = buffer;
UseBuffer();
}
void Init(wxDC *dc, const wxSize &area)
{
Init(dc, wxBitmap(area.GetWidth(), area.GetHeight()));
}
// 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()
{
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 = NULL;
}
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);
}
// 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.
// ----------------------------------------------------------------------------
// Creates a double buffered wxPaintDC, optionally allowing the
// user to specify their own buffer to use.
class wxBufferedPaintDC : public wxBufferedDC
{
public:
// If no bitmap is supplied by the user, a temporary one wil; be created.
wxBufferedPaintDC(wxWindow *window, const wxBitmap& buffer = wxNullBitmap)
: m_paintdc(window)
{
window->PrepareDC( m_paintdc );
if( buffer != wxNullBitmap )
Init(&m_paintdc, buffer);
else
Init(&m_paintdc, window->GetClientSize());
}
// default copy ctor ok.
virtual ~wxBufferedPaintDC()
{
// We must UnMask here, else by the time the base class
// does it, the PaintDC will have already been destroyed.
UnMask();
}
private:
wxPaintDC m_paintdc;
DECLARE_NO_COPY_CLASS(wxBufferedPaintDC)
};
#endif // _WX_DCBUFFER_H_