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 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 #ifdef __GNUG__
  21     #pragma implementation "dcmemory.h"
  22 #endif
  23
  24 // For compilers that support precompilation, includes "wx.h".
  25 #include "wx/wxprec.h"
  26
  27 #ifdef __BORLANDC__
  28     #pragma hdrstop
  29 #endif
  30
  31 #ifndef WX_PRECOMP
  32     #include "wx/utils.h"
  33     #include "wx/log.h"
  34 #endif
  35
  36 #include "wx/msw/private.h"
  37
  38 #include "wx/dcmemory.h"
  39
  40 // ----------------------------------------------------------------------------
  41 // wxWin macros
  42 // ----------------------------------------------------------------------------
  43
  44 IMPLEMENT_DYNAMIC_CLASS(wxMemoryDC, wxDC)
  45
  46 // ============================================================================
  47 // implementation
  48 // ============================================================================
  49
  50 // ----------------------------------------------------------------------------
  51 // wxMemoryDC
  52 // ----------------------------------------------------------------------------
  53
  54 wxMemoryDC::wxMemoryDC()
  55 {
  56     m_hDC = (WXHDC) ::CreateCompatibleDC((HDC) NULL);
  57     m_ok = (m_hDC != 0);
  58     m_bOwnsDC = TRUE;
  59
  60     SetBrush(*wxWHITE_BRUSH);
  61     SetPen(*wxBLACK_PEN);
  62
  63     // the background mode is only used for text background and is set in
  64     // DrawText() to OPAQUE as required, otherwise always TRANSPARENT
  65     ::SetBkMode( GetHdc(), TRANSPARENT );
  66 }
  67
  68 wxMemoryDC::wxMemoryDC(wxDC *old_dc)
  69 {
  70     old_dc->BeginDrawing();
  71
  72     m_hDC = (WXHDC) ::CreateCompatibleDC(GetHdcOf(*old_dc));
  73     m_ok = (m_hDC != 0);
  74
  75     old_dc->EndDrawing();
  76
  77     SetBrush(*wxWHITE_BRUSH);
  78     SetPen(*wxBLACK_PEN);
  79
  80     // the background mode is only used for text background and is set in
  81     // DrawText() to OPAQUE as required, otherwise always TRANSPARENT
  82     ::SetBkMode( GetHdc(), TRANSPARENT );
  83 }
  84
  85 wxMemoryDC::~wxMemoryDC()
  86 {
  87 }
  88
  89 void wxMemoryDC::SelectObject(const wxBitmap& bitmap)
  90 {
  91     // select old bitmap out of the device context
  92     if ( m_oldBitmap )
  93     {
  94         ::SelectObject(GetHdc(), (HBITMAP) m_oldBitmap);
  95         if ( m_selectedBitmap.Ok() )
  96         {
  97             m_selectedBitmap.SetSelectedInto(NULL);
  98             m_selectedBitmap = wxNullBitmap;
  99         }
 100     }
 101
 102     // check for whether the bitmap is already selected into a device context
 103     wxCHECK_RET( !bitmap.GetSelectedInto() ||
 104                  (bitmap.GetSelectedInto() == this),
 105                  wxT("Bitmap is selected in another wxMemoryDC, delete the first wxMemoryDC or use SelectObject(NULL)") );
 106
 107     m_selectedBitmap = bitmap;
 108     WXHBITMAP hBmp = m_selectedBitmap.GetHBITMAP();
 109     if ( !hBmp )
 110         return;
 111
 112     m_selectedBitmap.SetSelectedInto(this);
 113     hBmp = (WXHBITMAP)::SelectObject(GetHdc(), (HBITMAP)hBmp);
 114
 115     if ( !hBmp )
 116     {
 117         wxLogLastError(wxT("SelectObject(memDC, bitmap)"));
 118
 119         wxFAIL_MSG(wxT("Couldn't select a bitmap into wxMemoryDC"));
 120     }
 121     else if ( !m_oldBitmap )
 122     {
 123         m_oldBitmap = hBmp;
 124     }
 125 }
 126
 127 void wxMemoryDC::DoGetSize(int *width, int *height) const
 128 {
 129     if ( m_selectedBitmap.Ok() )
 130     {
 131         *width = m_selectedBitmap.GetWidth();
 132         *height = m_selectedBitmap.GetHeight();
 133     }
 134     else
 135     {
 136         *width = 0;
 137         *height = 0;
 138     }
 139 }
 140
 141 // the rest of this file deals with drawing rectangles workaround, disabled by
 142 // default
 143
 144 #define wxUSE_MEMORY_DC_DRAW_RECTANGLE 0
 145
 146 #if wxUSE_MEMORY_DC_DRAW_RECTANGLE
 147
 148 // For some reason, drawing a rectangle on a memory DC has problems.
 149 // Use this substitute if we can.
 150 static void wxDrawRectangle(wxDC& dc, wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 151 {
 152     wxBrush brush(dc.GetBrush());
 153     wxPen pen(dc.GetPen());
 154     if (brush.Ok() && brush.GetStyle() != wxTRANSPARENT)
 155     {
 156         HBRUSH hBrush = (HBRUSH) brush.GetResourceHandle() ;
 157         if (hBrush)
 158         {
 159             RECT rect;
 160             rect.left = x; rect.top = y;
 161             rect.right = x + width - 1;
 162             rect.bottom = y + height - 1;
 163             ::FillRect((HDC) dc.GetHDC(), &rect, hBrush);
 164         }
 165     }
 166     width --; height --;
 167     if (pen.Ok() && pen.GetStyle() != wxTRANSPARENT)
 168     {
 169         dc.DrawLine(x, y, x + width, y);
 170         dc.DrawLine(x, y, x, y + height);
 171         dc.DrawLine(x, y+height, x+width, y + height);
 172         dc.DrawLine(x+width, y+height, x+width, y);
 173     }
 174 }
 175
 176 #endif // wxUSE_MEMORY_DC_DRAW_RECTANGLE
 177
 178 void wxMemoryDC::DoDrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 179 {
 180     // Set this to 1 to work around an apparent video driver bug
 181     // (visible with e.g. 70x70 rectangle on a memory DC; see Drawing sample)
 182 #if wxUSE_MEMORY_DC_DRAW_RECTANGLE
 183     if (m_brush.Ok() && m_pen.Ok() &&
 184         (m_brush.GetStyle() == wxSOLID || m_brush.GetStyle() == wxTRANSPARENT) &&
 185         (m_pen.GetStyle() == wxSOLID || m_pen.GetStyle() == wxTRANSPARENT) &&
 186         (GetLogicalFunction() == wxCOPY))
 187     {
 188         wxDrawRectangle(* this, x, y, width, height);
 189     }
 190     else
 191 #endif // wxUSE_MEMORY_DC_DRAW_RECTANGLE
 192     {
 193         wxDC::DoDrawRectangle(x, y, width, height);
 194     }
 195 }
 196