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/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((HDC) 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   // Check if the bitmap has the correct depth for this device context
  89 //  if (bitmap.Ok() && (bitmap.GetDepth() != GetDepth()))
  90   // JACS 11/12/98: disabling this since the Forty Thieves sample
  91   // shows this not working properly. In fact, if loading from a resource,
  92   // the depth should become the screen depth, so why was it being called?
  93 //  if (0)
  94 //  {
  95 //      // Make a new bitmap that has the correct depth.
  96 //      wxBitmap newBitmap = bitmap.GetBitmapForDC(* this);
  97 //
  98 //      m_selectedBitmap = newBitmap ;
  99 //  }
 100 //  else
 101 //  {
 102       m_selectedBitmap = bitmap;
 103 //  }
 104
 105   if (!m_selectedBitmap.Ok())
 106     return;
 107
 108   m_selectedBitmap.SetSelectedInto(this);
 109   HBITMAP bm = (HBITMAP) ::SelectObject((HDC) m_hDC, (HBITMAP) m_selectedBitmap.GetHBITMAP());
 110
 111   if (bm == ERROR)
 112   {
 113     wxFatalError("Error in wxMemoryDC::SelectObject\nBitmap may not be loaded, or may be selected in another wxMemoryDC.\nDelete the first wxMemoryDC to deselect bitmap.");
 114   }
 115   else if (!m_oldBitmap)
 116     m_oldBitmap = (WXHBITMAP) bm;
 117 }
 118
 119 void wxMemoryDC::DoGetSize(int *width, int *height) const
 120 {
 121   if (!m_selectedBitmap.Ok())
 122   {
 123     *width = 0; *height = 0;
 124     return;
 125   }
 126   *width = m_selectedBitmap.GetWidth();
 127   *height = m_selectedBitmap.GetHeight();
 128 }
 129