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(wxDC *dc)
  51 {
  52     wxCHECK_RET( dc, _T("NULL dc in wxMemoryDC ctor") );
  53
  54     CreateCompatible(dc);
  55
  56     Init();
  57 }
  58
  59 void wxMemoryDC::Init()
  60 {
  61     if ( m_ok )
  62     {
  63         SetBrush(*wxWHITE_BRUSH);
  64         SetPen(*wxBLACK_PEN);
  65
  66         // the background mode is only used for text background and is set in
  67         // DrawText() to OPAQUE as required, otherwise always TRANSPARENT
  68         ::SetBkMode( GetHdc(), TRANSPARENT );
  69     }
  70 }
  71
  72 bool wxMemoryDC::CreateCompatible(wxDC *dc)
  73 {
  74     m_hDC = (WXHDC)::CreateCompatibleDC(dc ? GetHdcOf(*dc) : NULL);
  75
  76     // as we created the DC, we must delete it in the dtor
  77     m_bOwnsDC = true;
  78
  79     m_ok = m_hDC != 0;
  80
  81     return m_ok;
  82 }
  83
  84 void wxMemoryDC::DoSelect( const wxBitmap& bitmap)
  85 {
  86     // select old bitmap out of the device context
  87     if ( m_oldBitmap )
  88     {
  89         ::SelectObject(GetHdc(), (HBITMAP) m_oldBitmap);
  90         if ( m_selectedBitmap.Ok() )
  91         {
  92 #ifdef __WXDEBUG__
  93             m_selectedBitmap.SetSelectedInto(NULL);
  94 #endif
  95             m_selectedBitmap = wxNullBitmap;
  96         }
  97     }
  98
  99     // check for whether the bitmap is already selected into a device context
 100     wxASSERT_MSG( !bitmap.GetSelectedInto() ||
 101                   (bitmap.GetSelectedInto() == this),
 102                   wxT("Bitmap is selected in another wxMemoryDC, delete the first wxMemoryDC or use SelectObject(NULL)") );
 103
 104     m_selectedBitmap = bitmap;
 105     WXHBITMAP hBmp = m_selectedBitmap.GetHBITMAP();
 106     if ( !hBmp )
 107         return;
 108
 109 #ifdef __WXDEBUG__
 110     m_selectedBitmap.SetSelectedInto(this);
 111 #endif
 112     hBmp = (WXHBITMAP)::SelectObject(GetHdc(), (HBITMAP)hBmp);
 113
 114     if ( !hBmp )
 115     {
 116         wxLogLastError(wxT("SelectObject(memDC, bitmap)"));
 117
 118         wxFAIL_MSG(wxT("Couldn't select a bitmap into wxMemoryDC"));
 119     }
 120     else if ( !m_oldBitmap )
 121     {
 122         m_oldBitmap = hBmp;
 123     }
 124 }
 125
 126 void wxMemoryDC::DoGetSize(int *width, int *height) const
 127 {
 128     if ( m_selectedBitmap.Ok() )
 129     {
 130         *width = m_selectedBitmap.GetWidth();
 131         *height = m_selectedBitmap.GetHeight();
 132     }
 133     else
 134     {
 135         *width = 0;
 136         *height = 0;
 137     }
 138 }
 139
 140 // the rest of this file deals with drawing rectangles workaround, disabled by
 141 // default
 142
 143 #define wxUSE_MEMORY_DC_DRAW_RECTANGLE 0
 144
 145 #if wxUSE_MEMORY_DC_DRAW_RECTANGLE
 146
 147 // For some reason, drawing a rectangle on a memory DC has problems.
 148 // Use this substitute if we can.
 149 static void wxDrawRectangle(wxDC& dc, wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 150 {
 151     wxBrush brush(dc.GetBrush());
 152     wxPen pen(dc.GetPen());
 153     if (brush.Ok() && brush.GetStyle() != wxTRANSPARENT)
 154     {
 155         HBRUSH hBrush = (HBRUSH) brush.GetResourceHandle() ;
 156         if (hBrush)
 157         {
 158             RECT rect;
 159             rect.left = x; rect.top = y;
 160             rect.right = x + width - 1;
 161             rect.bottom = y + height - 1;
 162             ::FillRect((HDC) dc.GetHDC(), &rect, hBrush);
 163         }
 164     }
 165     width --; height --;
 166     if (pen.Ok() && pen.GetStyle() != wxTRANSPARENT)
 167     {
 168         dc.DrawLine(x, y, x + width, y);
 169         dc.DrawLine(x, y, x, y + height);
 170         dc.DrawLine(x, y+height, x+width, y + height);
 171         dc.DrawLine(x+width, y+height, x+width, y);
 172     }
 173 }
 174
 175 #endif // wxUSE_MEMORY_DC_DRAW_RECTANGLE
 176
 177 void wxMemoryDC::DoDrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 178 {
 179     // Set this to 1 to work around an apparent video driver bug
 180     // (visible with e.g. 70x70 rectangle on a memory DC; see Drawing sample)
 181 #if wxUSE_MEMORY_DC_DRAW_RECTANGLE
 182     if (m_brush.Ok() && m_pen.Ok() &&
 183         (m_brush.GetStyle() == wxSOLID || m_brush.GetStyle() == wxTRANSPARENT) &&
 184         (m_pen.GetStyle() == wxSOLID || m_pen.GetStyle() == wxTRANSPARENT) &&
 185         (GetLogicalFunction() == wxCOPY))
 186     {
 187         wxDrawRectangle(* this, x, y, width, height);
 188     }
 189     else
 190 #endif // wxUSE_MEMORY_DC_DRAW_RECTANGLE
 191     {
 192         wxDC::DoDrawRectangle(x, y, width, height);
 193     }
 194 }