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15b6757b 1/////////////////////////////////////////////////////////////////////////////
d54cf7ff 2// Name: dc.h
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3// Purpose: topic overview
4// Author: wxWidgets team
5// RCS-ID: $Id$
6// Licence: wxWindows license
7/////////////////////////////////////////////////////////////////////////////
8
880efa2a 9/**
36c9828f 10
880efa2a 11 @page overview_dc Device Contexts
36c9828f 12
98ba1eee 13 Classes: wxBufferedDC, wxBufferedPaintDC, wxDC, wxPostScriptDC,
3c4f71cc 14 wxMetafileDC, wxMemoryDC, wxPrinterDC, wxScreenDC, wxClientDC,
98ba1eee 15 wxPaintDC, wxWindowDC.
36c9828f 16
d54cf7ff 17 A wxDC is a @e device context onto which graphics and text can be drawn.
3c4f71cc 18 The device context is intended to represent a number of output devices in a
d54cf7ff 19 generic way, with the same API being used throughout.
36c9828f 20
d54cf7ff 21 Some device contexts are created temporarily in order to draw on a window.
98ba1eee 22 This is @true of wxScreenDC, wxClientDC, wxPaintDC, and wxWindowDC.
3c4f71cc 23 The following describes the differences between these device contexts and
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24 when you should use them.
25
26 @li @b wxScreenDC. Use this to paint on the screen, as opposed to an individual window.
27 @li @b wxClientDC. Use this to paint on the client area of window (the part without
98ba1eee 28 borders and other decorations), but do not use it from within an wxPaintEvent.
d54cf7ff 29 @li @b wxPaintDC. Use this to paint on the client area of a window, but @e only from
98ba1eee 30 within a wxPaintEvent.
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31 @li @b wxWindowDC. Use this to paint on the whole area of a window, including decorations.
32 This may not be available on non-Windows platforms.
36c9828f 33
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34 To use a client, paint or window device context, create an object on the stack with
35 the window as argument, for example:
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15b6757b 37 @code
d54cf7ff 38 void MyWindow::OnMyCmd(wxCommandEvent& event)
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39 {
40 wxClientDC dc(window);
41 DrawMyPicture(dc);
42 }
43 @endcode
36c9828f 44
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45 Try to write code so it is parameterised by wxDC - if you do this, the same piece of code may
46 write to a number of different devices, by passing a different device context. This doesn't
47 work for everything (for example not all device contexts support bitmap drawing) but
48 will work most of the time.
36c9828f 49
d54cf7ff 50*/
36c9828f 51