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 #include "wx/msw/dcmemory.h"
  29
  30 #ifndef WX_PRECOMP
  31     #include "wx/utils.h"
  32     #include "wx/log.h"
  33 #endif
  34
  35 #include "wx/msw/private.h"
  36
  37 // ----------------------------------------------------------------------------
  38 // wxMemoryDCImpl
  39 // ----------------------------------------------------------------------------
  40
  41 IMPLEMENT_ABSTRACT_CLASS(wxMemoryDCImpl, wxMSWDCImpl)
  42
  43 wxMemoryDCImpl::wxMemoryDCImpl( wxMemoryDC *owner )
  44         : wxMSWDCImpl( owner )
  45 {
  46     CreateCompatible(NULL);
  47     Init();
  48 }
  49
  50 wxMemoryDCImpl::wxMemoryDCImpl( wxMemoryDC *owner, wxBitmap& bitmap )
  51         : wxMSWDCImpl( owner )
  52 {
  53     CreateCompatible(NULL);
  54     Init();
  55     DoSelect(bitmap);
  56 }
  57
  58 wxMemoryDCImpl::wxMemoryDCImpl( wxMemoryDC *owner, wxDC *dc )
  59         : wxMSWDCImpl( owner )
  60 {
  61     wxCHECK_RET( dc, _T("NULL dc in wxMemoryDC ctor") );
  62
  63     CreateCompatible(dc);
  64
  65     Init();
  66 }
  67
  68 void wxMemoryDCImpl::Init()
  69 {
  70     if ( m_ok )
  71     {
  72         SetBrush(*wxWHITE_BRUSH);
  73         SetPen(*wxBLACK_PEN);
  74
  75         // the background mode is only used for text background and is set in
  76         // DrawText() to OPAQUE as required, otherwise always TRANSPARENT
  77         ::SetBkMode( GetHdc(), TRANSPARENT );
  78     }
  79 }
  80
  81 bool wxMemoryDCImpl::CreateCompatible(wxDC *dc)
  82 {
  83     wxDCImpl *impl = dc ? dc->GetImpl() : NULL ;
  84     wxMSWDCImpl *msw_impl = wxDynamicCast( impl, wxMSWDCImpl );
  85     if ( dc && !msw_impl)
  86     {
  87         m_ok = false;
  88         return false;
  89     }
  90
  91     m_hDC = (WXHDC)::CreateCompatibleDC(dc ? GetHdcOf(*msw_impl) : NULL);
  92
  93     // as we created the DC, we must delete it in the dtor
  94     m_bOwnsDC = true;
  95
  96     m_ok = m_hDC != 0;
  97
  98     return m_ok;
  99 }
 100
 101 void wxMemoryDCImpl::DoSelect( const wxBitmap& bitmap )
 102 {
 103     // select old bitmap out of the device context
 104     if ( m_oldBitmap )
 105     {
 106         ::SelectObject(GetHdc(), (HBITMAP) m_oldBitmap);
 107         if ( m_selectedBitmap.Ok() )
 108         {
 109             m_selectedBitmap.SetSelectedInto(NULL);
 110             m_selectedBitmap = wxNullBitmap;
 111         }
 112     }
 113
 114     // check for whether the bitmap is already selected into a device context
 115     wxASSERT_MSG( !bitmap.GetSelectedInto() ||
 116                   (bitmap.GetSelectedInto() == GetOwner()),
 117                   wxT("Bitmap is selected in another wxMemoryDC, delete the first wxMemoryDC or use SelectObject(NULL)") );
 118
 119     m_selectedBitmap = bitmap;
 120     WXHBITMAP hBmp = m_selectedBitmap.GetHBITMAP();
 121     if ( !hBmp )
 122         return;
 123
 124     m_selectedBitmap.SetSelectedInto(GetOwner());
 125     hBmp = (WXHBITMAP)::SelectObject(GetHdc(), (HBITMAP)hBmp);
 126
 127     if ( !hBmp )
 128     {
 129         wxLogLastError(wxT("SelectObject(memDC, bitmap)"));
 130
 131         wxFAIL_MSG(wxT("Couldn't select a bitmap into wxMemoryDC"));
 132     }
 133     else if ( !m_oldBitmap )
 134     {
 135         m_oldBitmap = hBmp;
 136     }
 137 }
 138
 139 void wxMemoryDCImpl::DoGetSize(int *width, int *height) const
 140 {
 141     if ( m_selectedBitmap.Ok() )
 142     {
 143         *width = m_selectedBitmap.GetWidth();
 144         *height = m_selectedBitmap.GetHeight();
 145     }
 146     else
 147     {
 148         *width = 0;
 149         *height = 0;
 150     }
 151 }
 152
 153 // the rest of this file deals with drawing rectangles workaround, disabled by
 154 // default
 155
 156 #define wxUSE_MEMORY_DC_DRAW_RECTANGLE 0
 157
 158 #if wxUSE_MEMORY_DC_DRAW_RECTANGLE
 159
 160 // For some reason, drawing a rectangle on a memory DC has problems.
 161 // Use this substitute if we can.
 162 static void wxDrawRectangle(wxDC& dc, wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 163 {
 164     wxBrush brush(dc.GetBrush());
 165     wxPen pen(dc.GetPen());
 166     if (brush.Ok() && brush.GetStyle() != wxTRANSPARENT)
 167     {
 168         HBRUSH hBrush = (HBRUSH) brush.GetResourceHandle() ;
 169         if (hBrush)
 170         {
 171             RECT rect;
 172             rect.left = x; rect.top = y;
 173             rect.right = x + width - 1;
 174             rect.bottom = y + height - 1;
 175             ::FillRect((HDC) dc.GetHDC(), &rect, hBrush);
 176         }
 177     }
 178     width --; height --;
 179     if (pen.Ok() && pen.GetStyle() != wxTRANSPARENT)
 180     {
 181         dc.DrawLine(x, y, x + width, y);
 182         dc.DrawLine(x, y, x, y + height);
 183         dc.DrawLine(x, y+height, x+width, y + height);
 184         dc.DrawLine(x+width, y+height, x+width, y);
 185     }
 186 }
 187
 188 #endif // wxUSE_MEMORY_DC_DRAW_RECTANGLE
 189
 190 void wxMemoryDCImpl::DoDrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 191 {
 192     // Set this to 1 to work around an apparent video driver bug
 193     // (visible with e.g. 70x70 rectangle on a memory DC; see Drawing sample)
 194 #if wxUSE_MEMORY_DC_DRAW_RECTANGLE
 195     if (m_brush.Ok() && m_pen.Ok() &&
 196         (m_brush.GetStyle() == wxSOLID || m_brush.GetStyle() == wxTRANSPARENT) &&
 197         (m_pen.GetStyle() == wxSOLID || m_pen.GetStyle() == wxTRANSPARENT) &&
 198         (GetLogicalFunction() == wxCOPY))
 199     {
 200         wxDrawRectangle(* this, x, y, width, height);
 201     }
 202     else
 203 #endif // wxUSE_MEMORY_DC_DRAW_RECTANGLE
 204     {
 205         wxMSWDCImpl::DoDrawRectangle(x, y, width, height);
 206     }
 207 }