src/generic/dcbuffer.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        dcbuffer.cpp
   3 // Purpose:     wxBufferedDC class
   4 // Author:      Ron Lee <ron@debian.org>
   5 // Modified by:
   6 // Created:     16/03/02
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Ron Lee
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12
  13 #ifdef __GNUG__
  14     #pragma implementation "dcbuffer.h"
  15 #endif
  16
  17 #include "wx/wxprec.h"
  18
  19 #ifdef __BORLANDC__
  20     #pragma hdrstop
  21 #endif
  22
  23 #ifndef WX_PRECOMP
  24 #include "wx/window.h"
  25 #endif
  26
  27 #include "wx/dcbuffer.h"
  28
  29
  30 // ==============================================================
  31 //   Double buffering helper.
  32 // --------------------------------------------------------------
  33
  34 wxBufferedDC::wxBufferedDC( wxDC *dc, const wxBitmap &buffer )
  35     : m_dc( dc )
  36     , m_buffer( buffer )
  37 {
  38     SelectObject( m_buffer );
  39 }
  40
  41 wxBufferedDC::wxBufferedDC( wxDC *dc, const wxSize &area )
  42     : m_dc( dc )
  43     , m_buffer( area.GetWidth(), area.GetHeight() )
  44 {
  45     SelectObject( m_buffer );
  46 }
  47
  48 wxBufferedDC::~wxBufferedDC()
  49 {
  50     if( m_dc != 0 )
  51     {
  52         UnMask();
  53     }
  54 }
  55
  56 void wxBufferedDC::Init( wxDC *dc, const wxBitmap &buffer )
  57 {
  58     wxASSERT_MSG( m_dc == 0 && m_buffer == wxNullBitmap,
  59                   _T("wxBufferedDC already initialised") );
  60
  61     m_dc = dc;
  62     m_buffer = buffer;
  63     SelectObject( m_buffer );
  64 }
  65
  66 void wxBufferedDC::Init( wxDC *dc, const wxSize &area )
  67 {
  68     wxASSERT_MSG( m_dc == 0 && m_buffer == wxNullBitmap,
  69                   _T("wxBufferedDC already initialised") );
  70
  71     m_dc = dc;
  72     m_buffer = wxBitmap( area.GetWidth(), area.GetHeight() );
  73     SelectObject( m_buffer );
  74 }
  75
  76 void wxBufferedDC::UnMask()
  77 {
  78     wxASSERT_MSG( m_dc != 0, _T("No low level DC associated with buffer (anymore)") );
  79
  80     m_dc->Blit( 0, 0, m_buffer.GetWidth(), m_buffer.GetHeight(), this, 0, 0 );
  81     m_dc = 0;
  82 }
  83
  84
  85 // ==============================================================
  86 //   Double buffered PaintDC.
  87 // --------------------------------------------------------------
  88
  89 wxBufferedPaintDC::wxBufferedPaintDC( wxWindow *window, const wxBitmap &buffer )
  90     : m_paintdc( window )
  91 {
  92     window->PrepareDC( m_paintdc );
  93
  94     if( buffer != wxNullBitmap )
  95         Init( &m_paintdc, buffer );
  96     else
  97         Init( &m_paintdc, window->GetClientSize() );
  98 }
  99
 100 wxBufferedPaintDC::~wxBufferedPaintDC()
 101 {
 102         // We must UnMask here, else by the time the base class
 103         // does it, the PaintDC will have already been destroyed.
 104
 105     UnMask();
 106 }
 107
 108
 109 // vi:sts=4:sw=4:et