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->GetImpl();
  84     wxMSWDCImpl *msw_impl = wxDynamicCast( impl, wxMSWDCImpl );
  85     if (!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 #ifdef __WXDEBUG__
 110             m_selectedBitmap.SetSelectedInto(NULL);
 111 #endif
 112             m_selectedBitmap = wxNullBitmap;
 113         }
 114     }
 115
 116     // check for whether the bitmap is already selected into a device context
 117     wxASSERT_MSG( !bitmap.GetSelectedInto() ||
 118                   (bitmap.GetSelectedInto() == this),
 119                   wxT("Bitmap is selected in another wxMemoryDC, delete the first wxMemoryDC or use SelectObject(NULL)") );
 120
 121     m_selectedBitmap = bitmap;
 122     WXHBITMAP hBmp = m_selectedBitmap.GetHBITMAP();
 123     if ( !hBmp )
 124         return;
 125
 126 #ifdef __WXDEBUG__
 127     m_selectedBitmap.SetSelectedInto(this);
 128 #endif
 129     hBmp = (WXHBITMAP)::SelectObject(GetHdc(), (HBITMAP)hBmp);
 130
 131     if ( !hBmp )
 132     {
 133         wxLogLastError(wxT("SelectObject(memDC, bitmap)"));
 134
 135         wxFAIL_MSG(wxT("Couldn't select a bitmap into wxMemoryDC"));
 136     }
 137     else if ( !m_oldBitmap )
 138     {
 139         m_oldBitmap = hBmp;
 140     }
 141 }
 142
 143 void wxMemoryDCImpl::DoGetSize(int *width, int *height) const
 144 {
 145     if ( m_selectedBitmap.Ok() )
 146     {
 147         *width = m_selectedBitmap.GetWidth();
 148         *height = m_selectedBitmap.GetHeight();
 149     }
 150     else
 151     {
 152         *width = 0;
 153         *height = 0;
 154     }
 155 }
 156
 157 // the rest of this file deals with drawing rectangles workaround, disabled by
 158 // default
 159
 160 #define wxUSE_MEMORY_DC_DRAW_RECTANGLE 0
 161
 162 #if wxUSE_MEMORY_DC_DRAW_RECTANGLE
 163
 164 // For some reason, drawing a rectangle on a memory DC has problems.
 165 // Use this substitute if we can.
 166 static void wxDrawRectangle(wxDC& dc, wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 167 {
 168     wxBrush brush(dc.GetBrush());
 169     wxPen pen(dc.GetPen());
 170     if (brush.Ok() && brush.GetStyle() != wxTRANSPARENT)
 171     {
 172         HBRUSH hBrush = (HBRUSH) brush.GetResourceHandle() ;
 173         if (hBrush)
 174         {
 175             RECT rect;
 176             rect.left = x; rect.top = y;
 177             rect.right = x + width - 1;
 178             rect.bottom = y + height - 1;
 179             ::FillRect((HDC) dc.GetHDC(), &rect, hBrush);
 180         }
 181     }
 182     width --; height --;
 183     if (pen.Ok() && pen.GetStyle() != wxTRANSPARENT)
 184     {
 185         dc.DrawLine(x, y, x + width, y);
 186         dc.DrawLine(x, y, x, y + height);
 187         dc.DrawLine(x, y+height, x+width, y + height);
 188         dc.DrawLine(x+width, y+height, x+width, y);
 189     }
 190 }
 191
 192 #endif // wxUSE_MEMORY_DC_DRAW_RECTANGLE
 193
 194 void wxMemoryDCImpl::DoDrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 195 {
 196     // Set this to 1 to work around an apparent video driver bug
 197     // (visible with e.g. 70x70 rectangle on a memory DC; see Drawing sample)
 198 #if wxUSE_MEMORY_DC_DRAW_RECTANGLE
 199     if (m_brush.Ok() && m_pen.Ok() &&
 200         (m_brush.GetStyle() == wxSOLID || m_brush.GetStyle() == wxTRANSPARENT) &&
 201         (m_pen.GetStyle() == wxSOLID || m_pen.GetStyle() == wxTRANSPARENT) &&
 202         (GetLogicalFunction() == wxCOPY))
 203     {
 204         wxDrawRectangle(* this, x, y, width, height);
 205     }
 206     else
 207 #endif // wxUSE_MEMORY_DC_DRAW_RECTANGLE
 208     {
 209         wxMSWDCImpl::DoDrawRectangle(x, y, width, height);
 210     }
 211 }