src/msw/dcmemory.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/msw/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
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 // For compilers that support precompilation, includes "wx.h".
  21 #include "wx/wxprec.h"
  22
  23 #ifdef __BORLANDC__
  24     #pragma hdrstop
  25 #endif
  26
  27 #include "wx/dcmemory.h"
  28
  29 #ifndef WX_PRECOMP
  30     #include "wx/utils.h"
  31     #include "wx/log.h"
  32 #endif
  33
  34 #include "wx/msw/private.h"
  35
  36 // ----------------------------------------------------------------------------
  37 // wxWin macros
  38 // ----------------------------------------------------------------------------
  39
  40 IMPLEMENT_DYNAMIC_CLASS(wxMemoryDC, wxDC)
  41
  42 // ============================================================================
  43 // implementation
  44 // ============================================================================
  45
  46 // ----------------------------------------------------------------------------
  47 // wxMemoryDC
  48 // ----------------------------------------------------------------------------
  49
  50 wxMemoryDC::wxMemoryDC( const wxBitmap& bitmap )
  51 {
  52     CreateCompatible(NULL);
  53
  54     Init();
  55
  56     if ( bitmap.IsOk() )
  57         SelectObject(bitmap);
  58 }
  59
  60 wxMemoryDC::wxMemoryDC(wxDC *dc)
  61 {
  62     wxCHECK_RET( dc, _T("NULL dc in wxMemoryDC ctor") );
  63
  64     CreateCompatible(dc);
  65
  66     Init();
  67 }
  68
  69 void wxMemoryDC::Init()
  70 {
  71     if ( m_ok )
  72     {
  73         SetBrush(*wxWHITE_BRUSH);
  74         SetPen(*wxBLACK_PEN);
  75
  76         // the background mode is only used for text background and is set in
  77         // DrawText() to OPAQUE as required, otherwise always TRANSPARENT
  78         ::SetBkMode( GetHdc(), TRANSPARENT );
  79     }
  80 }
  81
  82 bool wxMemoryDC::CreateCompatible(wxDC *dc)
  83 {
  84     m_hDC = (WXHDC)::CreateCompatibleDC(dc ? GetHdcOf(*dc) : NULL);
  85
  86     // as we created the DC, we must delete it in the dtor
  87     m_bOwnsDC = true;
  88
  89     m_ok = m_hDC != 0;
  90
  91     return m_ok;
  92 }
  93
  94 void wxMemoryDC::SelectObject(const wxBitmap& bitmap)
  95 {
  96     // select old bitmap out of the device context
  97     if ( m_oldBitmap )
  98     {
  99         ::SelectObject(GetHdc(), (HBITMAP) m_oldBitmap);
 100         if ( m_selectedBitmap.Ok() )
 101         {
 102 #ifdef __WXDEBUG__
 103             m_selectedBitmap.SetSelectedInto(NULL);
 104 #endif
 105             m_selectedBitmap = wxNullBitmap;
 106         }
 107     }
 108
 109     // check for whether the bitmap is already selected into a device context
 110     wxASSERT_MSG( !bitmap.GetSelectedInto() ||
 111                   (bitmap.GetSelectedInto() == this),
 112                   wxT("Bitmap is selected in another wxMemoryDC, delete the first wxMemoryDC or use SelectObject(NULL)") );
 113
 114     m_selectedBitmap = bitmap;
 115     WXHBITMAP hBmp = m_selectedBitmap.GetHBITMAP();
 116     if ( !hBmp )
 117         return;
 118
 119 #ifdef __WXDEBUG__
 120     m_selectedBitmap.SetSelectedInto(this);
 121 #endif
 122     hBmp = (WXHBITMAP)::SelectObject(GetHdc(), (HBITMAP)hBmp);
 123
 124     if ( !hBmp )
 125     {
 126         wxLogLastError(wxT("SelectObject(memDC, bitmap)"));
 127
 128         wxFAIL_MSG(wxT("Couldn't select a bitmap into wxMemoryDC"));
 129     }
 130     else if ( !m_oldBitmap )
 131     {
 132         m_oldBitmap = hBmp;
 133     }
 134 }
 135
 136 void wxMemoryDC::DoGetSize(int *width, int *height) const
 137 {
 138     if ( m_selectedBitmap.Ok() )
 139     {
 140         *width = m_selectedBitmap.GetWidth();
 141         *height = m_selectedBitmap.GetHeight();
 142     }
 143     else
 144     {
 145         *width = 0;
 146         *height = 0;
 147     }
 148 }
 149
 150 // the rest of this file deals with drawing rectangles workaround, disabled by
 151 // default
 152
 153 #define wxUSE_MEMORY_DC_DRAW_RECTANGLE 0
 154
 155 #if wxUSE_MEMORY_DC_DRAW_RECTANGLE
 156
 157 // For some reason, drawing a rectangle on a memory DC has problems.
 158 // Use this substitute if we can.
 159 static void wxDrawRectangle(wxDC& dc, wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 160 {
 161     wxBrush brush(dc.GetBrush());
 162     wxPen pen(dc.GetPen());
 163     if (brush.Ok() && brush.GetStyle() != wxTRANSPARENT)
 164     {
 165         HBRUSH hBrush = (HBRUSH) brush.GetResourceHandle() ;
 166         if (hBrush)
 167         {
 168             RECT rect;
 169             rect.left = x; rect.top = y;
 170             rect.right = x + width - 1;
 171             rect.bottom = y + height - 1;
 172             ::FillRect((HDC) dc.GetHDC(), &rect, hBrush);
 173         }
 174     }
 175     width --; height --;
 176     if (pen.Ok() && pen.GetStyle() != wxTRANSPARENT)
 177     {
 178         dc.DrawLine(x, y, x + width, y);
 179         dc.DrawLine(x, y, x, y + height);
 180         dc.DrawLine(x, y+height, x+width, y + height);
 181         dc.DrawLine(x+width, y+height, x+width, y);
 182     }
 183 }
 184
 185 #endif // wxUSE_MEMORY_DC_DRAW_RECTANGLE
 186
 187 void wxMemoryDC::DoDrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 188 {
 189     // Set this to 1 to work around an apparent video driver bug
 190     // (visible with e.g. 70x70 rectangle on a memory DC; see Drawing sample)
 191 #if wxUSE_MEMORY_DC_DRAW_RECTANGLE
 192     if (m_brush.Ok() && m_pen.Ok() &&
 193         (m_brush.GetStyle() == wxSOLID || m_brush.GetStyle() == wxTRANSPARENT) &&
 194         (m_pen.GetStyle() == wxSOLID || m_pen.GetStyle() == wxTRANSPARENT) &&
 195         (GetLogicalFunction() == wxCOPY))
 196     {
 197         wxDrawRectangle(* this, x, y, width, height);
 198     }
 199     else
 200 #endif // wxUSE_MEMORY_DC_DRAW_RECTANGLE
 201     {
 202         wxDC::DoDrawRectangle(x, y, width, height);
 203     }
 204 }