src/msw/dcmemory.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        dcmemory.cpp
   3 // Purpose:     wxMemoryDC class
   4 // Author:      Julian Smart
   5 // Modified by:
   6 // Created:     01/02/97
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart and Markus Holzem
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifdef __GNUG__
  13 #pragma implementation
  14 #pragma implementation "dcmemory.h"
  15 #endif
  16
  17 // For compilers that support precompilation, includes "wx.h".
  18 #include "wx/wxprec.h"
  19
  20 #ifdef __BORLANDC__
  21 #pragma hdrstop
  22 #endif
  23
  24 #ifndef WX_PRECOMP
  25 #endif
  26
  27 #include "wx/dcmemory.h"
  28
  29 #include <windows.h>
  30
  31 #if !USE_SHARED_LIBRARY
  32 IMPLEMENT_DYNAMIC_CLASS(wxMemoryDC, wxDC)
  33 #endif
  34
  35 /*
  36  * Memory DC
  37  *
  38  */
  39
  40 wxMemoryDC::wxMemoryDC(void)
  41 {
  42   m_hDC = (WXHDC) ::CreateCompatibleDC(NULL);
  43   m_ok = (m_hDC != 0);
  44   m_bOwnsDC = TRUE;
  45
  46   SetBrush(*wxWHITE_BRUSH);
  47   SetPen(*wxBLACK_PEN);
  48 }
  49
  50 wxMemoryDC::wxMemoryDC(wxDC *old_dc)
  51 {
  52   old_dc->BeginDrawing();
  53
  54   m_hDC = (WXHDC) ::CreateCompatibleDC((HDC) old_dc->GetHDC());
  55   m_ok = (m_hDC != 0);
  56
  57   old_dc->EndDrawing();
  58
  59   SetBrush(*wxWHITE_BRUSH);
  60   SetPen(*wxBLACK_PEN);
  61 }
  62
  63 wxMemoryDC::~wxMemoryDC(void)
  64 {
  65 }
  66
  67 void wxMemoryDC::SelectObject(const wxBitmap& bitmap)
  68 {
  69   // Select old bitmap out of the device context
  70   if (m_oldBitmap)
  71   {
  72     ::SelectObject((HDC) m_hDC, (HBITMAP) m_oldBitmap);
  73     if (m_selectedBitmap.Ok())
  74     {
  75       m_selectedBitmap.SetSelectedInto(NULL);
  76       m_selectedBitmap = wxNullBitmap;
  77     }
  78   }
  79
  80   // Do own check for whether the bitmap is already selected into
  81   // a device context
  82   if (bitmap.GetSelectedInto() && (bitmap.GetSelectedInto() != this))
  83   {
  84     wxFatalError("Error in wxMemoryDC::SelectObject\nBitmap is selected in another wxMemoryDC.\nDelete the first wxMemoryDC or use SelectObject(NULL)");
  85     return;
  86   }
  87
  88   m_selectedBitmap = bitmap;
  89
  90   if (!m_selectedBitmap.Ok())
  91     return;
  92
  93   m_selectedBitmap.SetSelectedInto(this);
  94 #if WXDEBUG > 1
  95   wxDebugMsg("wxMemoryDC::SelectObject: Selecting HBITMAP %X\n", m_selectedBitmap.GetHBITMAP());
  96 #endif
  97   HBITMAP bm = (HBITMAP) ::SelectObject((HDC) m_hDC, (HBITMAP) m_selectedBitmap.GetHBITMAP());
  98
  99   if (bm == ERROR)
 100   {
 101     wxFatalError("Error in wxMemoryDC::SelectObject\nBitmap may not be loaded, or may be selected in another wxMemoryDC.\nDelete the first wxMemoryDC to deselect bitmap.");
 102   }
 103   else if (!m_oldBitmap)
 104     m_oldBitmap = (WXHBITMAP) bm;
 105 }
 106
 107 void wxMemoryDC::GetSize(int *width, int *height) const
 108 {
 109   if (!m_selectedBitmap.Ok())
 110   {
 111     *width = 0; *height = 0;
 112     return;
 113   }
 114   *width = m_selectedBitmap.GetWidth();
 115   *height = m_selectedBitmap.GetHeight();
 116 }
 117