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 #include "wx/msw/winundef.h"
  31
  32 #if !USE_SHARED_LIBRARY
  33 IMPLEMENT_DYNAMIC_CLASS(wxMemoryDC, wxDC)
  34 #endif
  35
  36 /*
  37  * Memory DC
  38  *
  39  */
  40
  41 wxMemoryDC::wxMemoryDC(void)
  42 {
  43   m_hDC = (WXHDC) ::CreateCompatibleDC((HDC) NULL);
  44   m_ok = (m_hDC != 0);
  45   m_bOwnsDC = TRUE;
  46
  47   SetBrush(*wxWHITE_BRUSH);
  48   SetPen(*wxBLACK_PEN);
  49 }
  50
  51 wxMemoryDC::wxMemoryDC(wxDC *old_dc)
  52 {
  53   old_dc->BeginDrawing();
  54
  55   m_hDC = (WXHDC) ::CreateCompatibleDC((HDC) old_dc->GetHDC());
  56   m_ok = (m_hDC != 0);
  57
  58   old_dc->EndDrawing();
  59
  60   SetBrush(*wxWHITE_BRUSH);
  61   SetPen(*wxBLACK_PEN);
  62 }
  63
  64 wxMemoryDC::~wxMemoryDC(void)
  65 {
  66 }
  67
  68 void wxMemoryDC::SelectObject(const wxBitmap& bitmap)
  69 {
  70   // Select old bitmap out of the device context
  71   if (m_oldBitmap)
  72   {
  73     ::SelectObject((HDC) m_hDC, (HBITMAP) m_oldBitmap);
  74     if (m_selectedBitmap.Ok())
  75     {
  76       m_selectedBitmap.SetSelectedInto(NULL);
  77       m_selectedBitmap = wxNullBitmap;
  78     }
  79   }
  80
  81   // Do own check for whether the bitmap is already selected into
  82   // a device context
  83   if (bitmap.GetSelectedInto() && (bitmap.GetSelectedInto() != this))
  84   {
  85     wxFatalError(_T("Error in wxMemoryDC::SelectObject\nBitmap is selected in another wxMemoryDC.\nDelete the first wxMemoryDC or use SelectObject(NULL)"));
  86     return;
  87   }
  88
  89   // Check if the bitmap has the correct depth for this device context
  90 //  if (bitmap.Ok() && (bitmap.GetDepth() != GetDepth()))
  91   // JACS 11/12/98: disabling this since the Forty Thieves sample
  92   // shows this not working properly. In fact, if loading from a resource,
  93   // the depth should become the screen depth, so why was it being called?
  94 //  if (0)
  95 //  {
  96 //      // Make a new bitmap that has the correct depth.
  97 //      wxBitmap newBitmap = bitmap.GetBitmapForDC(* this);
  98 //
  99 //      m_selectedBitmap = newBitmap ;
 100 //  }
 101 //  else
 102 //  {
 103       m_selectedBitmap = bitmap;
 104 //  }
 105
 106   if (!m_selectedBitmap.Ok())
 107     return;
 108
 109   m_selectedBitmap.SetSelectedInto(this);
 110   HBITMAP bm = (HBITMAP) ::SelectObject((HDC) m_hDC, (HBITMAP) m_selectedBitmap.GetHBITMAP());
 111
 112   if (bm == ERROR)
 113   {
 114     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."));
 115   }
 116   else if (!m_oldBitmap)
 117     m_oldBitmap = (WXHBITMAP) bm;
 118 }
 119
 120 void wxMemoryDC::DoGetSize(int *width, int *height) const
 121 {
 122   if (!m_selectedBitmap.Ok())
 123   {
 124     *width = 0; *height = 0;
 125     return;
 126   }
 127   *width = m_selectedBitmap.GetWidth();
 128   *height = m_selectedBitmap.GetHeight();
 129 }
 130