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 "dcmemory.h"
  14 #endif
  15
  16 // For compilers that support precompilation, includes "wx.h".
  17 #include "wx/wxprec.h"
  18
  19 #ifdef __BORLANDC__
  20 #pragma hdrstop
  21 #endif
  22
  23 #ifndef WX_PRECOMP
  24 #include "wx/utils.h"
  25 #endif
  26
  27 #include "wx/msw/private.h"
  28
  29 #include "wx/dcmemory.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((HDC) NULL);
  43   m_ok = (m_hDC != 0);
  44   m_bOwnsDC = TRUE;
  45
  46   SetBrush(*wxWHITE_BRUSH);
  47   SetPen(*wxBLACK_PEN);
  48
  49   // the background mode is only used for text background
  50   // and is set in DrawText() to OPAQUE as required, other-
  51   // wise always TRANSPARENT, RR
  52   ::SetBkMode( GetHdc(), TRANSPARENT );
  53
  54 }
  55
  56 wxMemoryDC::wxMemoryDC(wxDC *old_dc)
  57 {
  58   old_dc->BeginDrawing();
  59
  60   m_hDC = (WXHDC) ::CreateCompatibleDC((HDC) old_dc->GetHDC());
  61   m_ok = (m_hDC != 0);
  62
  63   old_dc->EndDrawing();
  64
  65   SetBrush(*wxWHITE_BRUSH);
  66   SetPen(*wxBLACK_PEN);
  67
  68   // the background mode is only used for text background
  69   // and is set in DrawText() to OPAQUE as required, other-
  70   // wise always TRANSPARENT, RR
  71   ::SetBkMode( GetHdc(), TRANSPARENT );
  72
  73 }
  74
  75 wxMemoryDC::~wxMemoryDC(void)
  76 {
  77 }
  78
  79 void wxMemoryDC::SelectObject(const wxBitmap& bitmap)
  80 {
  81   // Select old bitmap out of the device context
  82   if (m_oldBitmap)
  83   {
  84     ::SelectObject((HDC) m_hDC, (HBITMAP) m_oldBitmap);
  85     if (m_selectedBitmap.Ok())
  86     {
  87       m_selectedBitmap.SetSelectedInto(NULL);
  88       m_selectedBitmap = wxNullBitmap;
  89     }
  90   }
  91
  92   // Do own check for whether the bitmap is already selected into
  93   // a device context
  94   if (bitmap.GetSelectedInto() && (bitmap.GetSelectedInto() != this))
  95   {
  96     wxFatalError(_T("Error in wxMemoryDC::SelectObject\nBitmap is selected in another wxMemoryDC.\nDelete the first wxMemoryDC or use SelectObject(NULL)"));
  97     return;
  98   }
  99
 100   // Check if the bitmap has the correct depth for this device context
 101 //  if (bitmap.Ok() && (bitmap.GetDepth() != GetDepth()))
 102   // JACS 11/12/98: disabling this since the Forty Thieves sample
 103   // shows this not working properly. In fact, if loading from a resource,
 104   // the depth should become the screen depth, so why was it being called?
 105 //  if (0)
 106 //  {
 107 //      // Make a new bitmap that has the correct depth.
 108 //      wxBitmap newBitmap = bitmap.GetBitmapForDC(* this);
 109 //
 110 //      m_selectedBitmap = newBitmap ;
 111 //  }
 112 //  else
 113 //  {
 114       m_selectedBitmap = bitmap;
 115 //  }
 116
 117   if (!m_selectedBitmap.Ok())
 118     return;
 119
 120   m_selectedBitmap.SetSelectedInto(this);
 121   HBITMAP bm = (HBITMAP) ::SelectObject((HDC) m_hDC, (HBITMAP) m_selectedBitmap.GetHBITMAP());
 122
 123   if (bm == ERROR)
 124   {
 125     wxFatalError(_T("Error in wxMemoryDC::SelectObject\nBitmap may not be loaded, or may be selected in another wxMemoryDC.\nDelete the first wxMemoryDC to deselect bitmap."));
 126   }
 127   else if (!m_oldBitmap)
 128     m_oldBitmap = (WXHBITMAP) bm;
 129 }
 130
 131 void wxMemoryDC::DoGetSize(int *width, int *height) const
 132 {
 133   if (!m_selectedBitmap.Ok())
 134   {
 135     *width = 0; *height = 0;
 136     return;
 137   }
 138   *width = m_selectedBitmap.GetWidth();
 139   *height = m_selectedBitmap.GetHeight();
 140 }
 141