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 #if wxUSE_GRAPHICS_CONTEXT
  36 #include "wx/graphics.h"
  37 #endif
  38
  39 #include "wx/msw/private.h"
  40
  41 // ----------------------------------------------------------------------------
  42 // wxMemoryDCImpl
  43 // ----------------------------------------------------------------------------
  44
  45 IMPLEMENT_ABSTRACT_CLASS(wxMemoryDCImpl, wxMSWDCImpl)
  46
  47 wxMemoryDCImpl::wxMemoryDCImpl( wxMemoryDC *owner )
  48         : wxMSWDCImpl( owner )
  49 {
  50     CreateCompatible(NULL);
  51     Init();
  52 }
  53
  54 wxMemoryDCImpl::wxMemoryDCImpl( wxMemoryDC *owner, wxBitmap& bitmap )
  55         : wxMSWDCImpl( owner )
  56 {
  57     CreateCompatible(NULL);
  58     Init();
  59     DoSelect(bitmap);
  60 }
  61
  62 wxMemoryDCImpl::wxMemoryDCImpl( wxMemoryDC *owner, wxDC *dc )
  63         : wxMSWDCImpl( owner )
  64 {
  65     wxCHECK_RET( dc, _T("NULL dc in wxMemoryDC ctor") );
  66
  67     CreateCompatible(dc);
  68
  69     Init();
  70 }
  71
  72 void wxMemoryDCImpl::Init()
  73 {
  74     if ( m_ok )
  75     {
  76         SetBrush(*wxWHITE_BRUSH);
  77         SetPen(*wxBLACK_PEN);
  78
  79         // the background mode is only used for text background and is set in
  80         // DrawText() to OPAQUE as required, otherwise always TRANSPARENT
  81         ::SetBkMode( GetHdc(), TRANSPARENT );
  82     }
  83 }
  84
  85 #if wxUSE_GRAPHICS_CONTEXT
  86 wxGraphicsContext* wxMemoryDCImpl::CreateGraphicsContext()
  87 {
  88     wxMemoryDC *memdc = (wxMemoryDC*) GetOwner();
  89     return wxGraphicsRenderer::GetDefaultRenderer()->CreateContext( *memdc );
  90 }
  91 #endif
  92
  93 bool wxMemoryDCImpl::CreateCompatible(wxDC *dc)
  94 {
  95     wxDCImpl *impl = dc ? dc->GetImpl() : NULL ;
  96     wxMSWDCImpl *msw_impl = wxDynamicCast( impl, wxMSWDCImpl );
  97     if ( dc && !msw_impl)
  98     {
  99         m_ok = false;
 100         return false;
 101     }
 102
 103     m_hDC = (WXHDC)::CreateCompatibleDC(dc ? GetHdcOf(*msw_impl) : NULL);
 104
 105     // as we created the DC, we must delete it in the dtor
 106     m_bOwnsDC = true;
 107
 108     m_ok = m_hDC != 0;
 109
 110     return m_ok;
 111 }
 112
 113 void wxMemoryDCImpl::DoSelect( const wxBitmap& bitmap )
 114 {
 115     // select old bitmap out of the device context
 116     if ( m_oldBitmap )
 117     {
 118         ::SelectObject(GetHdc(), (HBITMAP) m_oldBitmap);
 119         if ( m_selectedBitmap.Ok() )
 120         {
 121 #ifdef __WXDEBUG__
 122             m_selectedBitmap.SetSelectedInto(NULL);
 123 #endif
 124             m_selectedBitmap = wxNullBitmap;
 125         }
 126     }
 127
 128     // check for whether the bitmap is already selected into a device context
 129     wxASSERT_MSG( !bitmap.GetSelectedInto() ||
 130                   (bitmap.GetSelectedInto() == GetOwner()),
 131                   wxT("Bitmap is selected in another wxMemoryDC, delete the first wxMemoryDC or use SelectObject(NULL)") );
 132
 133     m_selectedBitmap = bitmap;
 134     WXHBITMAP hBmp = m_selectedBitmap.GetHBITMAP();
 135     if ( !hBmp )
 136         return;
 137
 138 #ifdef __WXDEBUG__
 139     m_selectedBitmap.SetSelectedInto(GetOwner());
 140 #endif
 141     hBmp = (WXHBITMAP)::SelectObject(GetHdc(), (HBITMAP)hBmp);
 142
 143     if ( !hBmp )
 144     {
 145         wxLogLastError(wxT("SelectObject(memDC, bitmap)"));
 146
 147         wxFAIL_MSG(wxT("Couldn't select a bitmap into wxMemoryDC"));
 148     }
 149     else if ( !m_oldBitmap )
 150     {
 151         m_oldBitmap = hBmp;
 152     }
 153 }
 154
 155 void wxMemoryDCImpl::DoGetSize(int *width, int *height) const
 156 {
 157     if ( m_selectedBitmap.Ok() )
 158     {
 159         *width = m_selectedBitmap.GetWidth();
 160         *height = m_selectedBitmap.GetHeight();
 161     }
 162     else
 163     {
 164         *width = 0;
 165         *height = 0;
 166     }
 167 }
 168
 169 // the rest of this file deals with drawing rectangles workaround, disabled by
 170 // default
 171
 172 #define wxUSE_MEMORY_DC_DRAW_RECTANGLE 0
 173
 174 #if wxUSE_MEMORY_DC_DRAW_RECTANGLE
 175
 176 // For some reason, drawing a rectangle on a memory DC has problems.
 177 // Use this substitute if we can.
 178 static void wxDrawRectangle(wxDC& dc, wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 179 {
 180     wxBrush brush(dc.GetBrush());
 181     wxPen pen(dc.GetPen());
 182     if (brush.Ok() && brush.GetStyle() != wxTRANSPARENT)
 183     {
 184         HBRUSH hBrush = (HBRUSH) brush.GetResourceHandle() ;
 185         if (hBrush)
 186         {
 187             RECT rect;
 188             rect.left = x; rect.top = y;
 189             rect.right = x + width - 1;
 190             rect.bottom = y + height - 1;
 191             ::FillRect((HDC) dc.GetHDC(), &rect, hBrush);
 192         }
 193     }
 194     width --; height --;
 195     if (pen.Ok() && pen.GetStyle() != wxTRANSPARENT)
 196     {
 197         dc.DrawLine(x, y, x + width, y);
 198         dc.DrawLine(x, y, x, y + height);
 199         dc.DrawLine(x, y+height, x+width, y + height);
 200         dc.DrawLine(x+width, y+height, x+width, y);
 201     }
 202 }
 203
 204 #endif // wxUSE_MEMORY_DC_DRAW_RECTANGLE
 205
 206 void wxMemoryDCImpl::DoDrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 207 {
 208     // Set this to 1 to work around an apparent video driver bug
 209     // (visible with e.g. 70x70 rectangle on a memory DC; see Drawing sample)
 210 #if wxUSE_MEMORY_DC_DRAW_RECTANGLE
 211     if (m_brush.Ok() && m_pen.Ok() &&
 212         (m_brush.GetStyle() == wxSOLID || m_brush.GetStyle() == wxTRANSPARENT) &&
 213         (m_pen.GetStyle() == wxSOLID || m_pen.GetStyle() == wxTRANSPARENT) &&
 214         (GetLogicalFunction() == wxCOPY))
 215     {
 216         wxDrawRectangle(* this, x, y, width, height);
 217     }
 218     else
 219 #endif // wxUSE_MEMORY_DC_DRAW_RECTANGLE
 220     {
 221         wxMSWDCImpl::DoDrawRectangle(x, y, width, height);
 222     }
 223 }