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 #endif
  25
  26 #include "wx/dcmemory.h"
  27
  28 #include <windows.h>
  29
  30 #if !USE_SHARED_LIBRARY
  31 IMPLEMENT_DYNAMIC_CLASS(wxMemoryDC, wxDC)
  32 #endif
  33
  34 /*
  35  * Memory DC
  36  *
  37  */
  38
  39 wxMemoryDC::wxMemoryDC(void)
  40 {
  41   m_hDC = (WXHDC) ::CreateCompatibleDC(NULL);
  42   m_ok = (m_hDC != 0);
  43   m_bOwnsDC = TRUE;
  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   // Check if the bitmap has the correct depth for this device context
  88   if (bitmap.Ok() && (bitmap.GetDepth() != GetDepth()))
  89   {
  90       // Make a new bitmap that has the correct depth.
  91       wxBitmap newBitmap = bitmap.GetBitmapForDC(* this);
  92
  93       m_selectedBitmap = newBitmap ;
  94   }
  95   else
  96   {
  97       m_selectedBitmap = bitmap;
  98   }
  99
 100   if (!m_selectedBitmap.Ok())
 101     return;
 102
 103   m_selectedBitmap.SetSelectedInto(this);
 104   HBITMAP bm = (HBITMAP) ::SelectObject((HDC) m_hDC, (HBITMAP) m_selectedBitmap.GetHBITMAP());
 105
 106   if (bm == ERROR)
 107   {
 108     wxFatalError("Error in wxMemoryDC::SelectObject\nBitmap may not be loaded, or may be selected in another wxMemoryDC.\nDelete the first wxMemoryDC to deselect bitmap.");
 109   }
 110   else if (!m_oldBitmap)
 111     m_oldBitmap = (WXHBITMAP) bm;
 112 }
 113
 114 void wxMemoryDC::GetSize(int *width, int *height) const
 115 {
 116   if (!m_selectedBitmap.Ok())
 117   {
 118     *width = 0; *height = 0;
 119     return;
 120   }
 121   *width = m_selectedBitmap.GetWidth();
 122   *height = m_selectedBitmap.GetHeight();
 123 }
 124