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
  45   SetBrush(*wxWHITE_BRUSH);
  46   SetPen(*wxBLACK_PEN);
  47 }
  48
  49 wxMemoryDC::wxMemoryDC(wxDC *old_dc)
  50 {
  51   old_dc->BeginDrawing();
  52
  53   m_hDC = (WXHDC) ::CreateCompatibleDC((HDC) old_dc->GetHDC());
  54   m_ok = (m_hDC != 0);
  55
  56   old_dc->EndDrawing();
  57
  58   SetBrush(*wxWHITE_BRUSH);
  59   SetPen(*wxBLACK_PEN);
  60 }
  61
  62 wxMemoryDC::~wxMemoryDC(void)
  63 {
  64 }
  65
  66 void wxMemoryDC::SelectObject(const wxBitmap& bitmap)
  67 {
  68   // Select old bitmap out of the device context
  69   if (m_oldBitmap)
  70   {
  71     ::SelectObject((HDC) m_hDC, (HBITMAP) m_oldBitmap);
  72     if (m_selectedBitmap.Ok())
  73     {
  74       m_selectedBitmap.SetSelectedInto(NULL);
  75       m_selectedBitmap = wxNullBitmap;
  76     }
  77   }
  78
  79   // Do own check for whether the bitmap is already selected into
  80   // a device context
  81   if (bitmap.GetSelectedInto() && (bitmap.GetSelectedInto() != this))
  82   {
  83     wxFatalError("Error in wxMemoryDC::SelectObject\nBitmap is selected in another wxMemoryDC.\nDelete the first wxMemoryDC or use SelectObject(NULL)");
  84     return;
  85   }
  86
  87   m_selectedBitmap = bitmap;
  88
  89   if (!m_selectedBitmap.Ok())
  90     return;
  91
  92   m_selectedBitmap.SetSelectedInto(this);
  93 #if DEBUG > 1
  94   wxDebugMsg("wxMemoryDC::SelectObject: Selecting HBITMAP %X\n", m_selectedBitmap.GetHBITMAP());
  95 #endif
  96   HBITMAP bm = ::SelectObject((HDC) m_hDC, (HBITMAP) m_selectedBitmap.GetHBITMAP());
  97
  98   if (bm == ERROR)
  99   {
 100     wxFatalError("Error in wxMemoryDC::SelectObject\nBitmap may not be loaded, or may be selected in another wxMemoryDC.\nDelete the first wxMemoryDC to deselect bitmap.");
 101   }
 102   else if (!m_oldBitmap)
 103     m_oldBitmap = (WXHBITMAP) bm;
 104 }
 105
 106 void wxMemoryDC::GetSize(int *width, int *height) const
 107 {
 108   if (!m_selectedBitmap.Ok())
 109   {
 110     *width = 0; *height = 0;
 111     return;
 112   }
 113   *width = m_selectedBitmap.GetWidth();
 114   *height = m_selectedBitmap.GetHeight();
 115 }
 116