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: dcmemory.cpp 42755 2006-10-30 19:41:46Z VZ $
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
IMPLEMENT_DYNAMIC_CLASS(wxMemoryDC,wxDC)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
Init()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
CreateCompatible(wxDC * dc)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
DoSelect(const wxBitmap & bitmap)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
DoGetSize(int * width,int * height) const126 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.
wxDrawRectangle(wxDC & dc,wxCoord x,wxCoord y,wxCoord width,wxCoord height)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
DoDrawRectangle(wxCoord x,wxCoord y,wxCoord width,wxCoord height)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 }
195