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 // Copyright:   (c) Julian Smart
   8 // Licence:     wxWindows licence
   9 /////////////////////////////////////////////////////////////////////////////
  10
  11 // ============================================================================
  12 // declarations
  13 // ============================================================================
  14
  15 // ----------------------------------------------------------------------------
  16 // headers
  17 // ----------------------------------------------------------------------------
  18
  19 // For compilers that support precompilation, includes "wx.h".
  20 #include "wx/wxprec.h"
  21
  22 #ifdef __BORLANDC__
  23     #pragma hdrstop
  24 #endif
  25
  26 #include "wx/dcmemory.h"
  27 #include "wx/msw/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 // wxMemoryDCImpl
  38 // ----------------------------------------------------------------------------
  39
  40 IMPLEMENT_ABSTRACT_CLASS(wxMemoryDCImpl, wxMSWDCImpl)
  41
  42 wxMemoryDCImpl::wxMemoryDCImpl( wxMemoryDC *owner )
  43         : wxMSWDCImpl( owner )
  44 {
  45     CreateCompatible(NULL);
  46     Init();
  47 }
  48
  49 wxMemoryDCImpl::wxMemoryDCImpl( wxMemoryDC *owner, wxBitmap& bitmap )
  50         : wxMSWDCImpl( owner )
  51 {
  52     CreateCompatible(NULL);
  53     Init();
  54     DoSelect(bitmap);
  55 }
  56
  57 wxMemoryDCImpl::wxMemoryDCImpl( wxMemoryDC *owner, wxDC *dc )
  58         : wxMSWDCImpl( owner )
  59 {
  60     wxCHECK_RET( dc, wxT("NULL dc in wxMemoryDC ctor") );
  61
  62     CreateCompatible(dc);
  63
  64     Init();
  65 }
  66
  67 void wxMemoryDCImpl::Init()
  68 {
  69     if ( m_ok )
  70     {
  71         SetBrush(*wxWHITE_BRUSH);
  72         SetPen(*wxBLACK_PEN);
  73
  74         // the background mode is only used for text background and is set in
  75         // DrawText() to OPAQUE as required, otherwise always TRANSPARENT
  76         ::SetBkMode( GetHdc(), TRANSPARENT );
  77     }
  78 }
  79
  80 bool wxMemoryDCImpl::CreateCompatible(wxDC *dc)
  81 {
  82     wxDCImpl *impl = dc ? dc->GetImpl() : NULL ;
  83     wxMSWDCImpl *msw_impl = wxDynamicCast( impl, wxMSWDCImpl );
  84     if ( dc && !msw_impl)
  85     {
  86         m_ok = false;
  87         return false;
  88     }
  89
  90     m_hDC = (WXHDC)::CreateCompatibleDC(dc ? GetHdcOf(*msw_impl) : NULL);
  91
  92     // as we created the DC, we must delete it in the dtor
  93     m_bOwnsDC = true;
  94
  95     m_ok = m_hDC != 0;
  96
  97     return m_ok;
  98 }
  99
 100 void wxMemoryDCImpl::DoSelect( const wxBitmap& bitmap )
 101 {
 102     // select old bitmap out of the device context
 103     if ( m_oldBitmap )
 104     {
 105         ::SelectObject(GetHdc(), (HBITMAP) m_oldBitmap);
 106         if ( m_selectedBitmap.IsOk() )
 107         {
 108             m_selectedBitmap.SetSelectedInto(NULL);
 109             m_selectedBitmap = wxNullBitmap;
 110         }
 111     }
 112
 113     // check for whether the bitmap is already selected into a device context
 114     wxASSERT_MSG( !bitmap.GetSelectedInto() ||
 115                   (bitmap.GetSelectedInto() == GetOwner()),
 116                   wxT("Bitmap is selected in another wxMemoryDC, delete the first wxMemoryDC or use SelectObject(NULL)") );
 117
 118     m_selectedBitmap = bitmap;
 119     WXHBITMAP hBmp = m_selectedBitmap.GetHBITMAP();
 120     if ( !hBmp )
 121         return;
 122
 123     m_selectedBitmap.SetSelectedInto(GetOwner());
 124     hBmp = (WXHBITMAP)::SelectObject(GetHdc(), (HBITMAP)hBmp);
 125
 126     if ( !hBmp )
 127     {
 128         wxLogLastError(wxT("SelectObject(memDC, bitmap)"));
 129
 130         wxFAIL_MSG(wxT("Couldn't select a bitmap into wxMemoryDC"));
 131     }
 132     else if ( !m_oldBitmap )
 133     {
 134         m_oldBitmap = hBmp;
 135     }
 136 }
 137
 138 void wxMemoryDCImpl::DoGetSize(int *width, int *height) const
 139 {
 140     if ( m_selectedBitmap.IsOk() )
 141     {
 142         *width = m_selectedBitmap.GetWidth();
 143         *height = m_selectedBitmap.GetHeight();
 144     }
 145     else
 146     {
 147         *width = 0;
 148         *height = 0;
 149     }
 150 }
 151
 152 // the rest of this file deals with drawing rectangles workaround, disabled by
 153 // default
 154
 155 #define wxUSE_MEMORY_DC_DRAW_RECTANGLE 0
 156
 157 #if wxUSE_MEMORY_DC_DRAW_RECTANGLE
 158
 159 // For some reason, drawing a rectangle on a memory DC has problems.
 160 // Use this substitute if we can.
 161 static void wxDrawRectangle(wxDC& dc, wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 162 {
 163     wxBrush brush(dc.GetBrush());
 164     wxPen pen(dc.GetPen());
 165     if (brush.IsOk() && brush.GetStyle() != wxTRANSPARENT)
 166     {
 167         HBRUSH hBrush = (HBRUSH) brush.GetResourceHandle() ;
 168         if (hBrush)
 169         {
 170             RECT rect;
 171             rect.left = x; rect.top = y;
 172             rect.right = x + width - 1;
 173             rect.bottom = y + height - 1;
 174             ::FillRect((HDC) dc.GetHDC(), &rect, hBrush);
 175         }
 176     }
 177     width --; height --;
 178     if (pen.IsOk() && pen.GetStyle() != wxTRANSPARENT)
 179     {
 180         dc.DrawLine(x, y, x + width, y);
 181         dc.DrawLine(x, y, x, y + height);
 182         dc.DrawLine(x, y+height, x+width, y + height);
 183         dc.DrawLine(x+width, y+height, x+width, y);
 184     }
 185 }
 186
 187 #endif // wxUSE_MEMORY_DC_DRAW_RECTANGLE
 188
 189 void wxMemoryDCImpl::DoDrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 190 {
 191     // Set this to 1 to work around an apparent video driver bug
 192     // (visible with e.g. 70x70 rectangle on a memory DC; see Drawing sample)
 193 #if wxUSE_MEMORY_DC_DRAW_RECTANGLE
 194     if (m_brush.IsOk() && m_pen.IsOk() &&
 195         (m_brush.GetStyle() == wxSOLID || m_brush.GetStyle() == wxTRANSPARENT) &&
 196         (m_pen.GetStyle() == wxSOLID || m_pen.GetStyle() == wxTRANSPARENT) &&
 197         (GetLogicalFunction() == wxCOPY))
 198     {
 199         wxDrawRectangle(* this, x, y, width, height);
 200     }
 201     else
 202 #endif // wxUSE_MEMORY_DC_DRAW_RECTANGLE
 203     {
 204         wxMSWDCImpl::DoDrawRectangle(x, y, width, height);
 205     }
 206 }