X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/d54cf7ff131b62cc83116d5bfb8d2b5c49de9574..4e15d1caa03346c126015019c1fdf093033ef40b:/docs/doxygen/overviews/dc.h?ds=sidebyside diff --git a/docs/doxygen/overviews/dc.h b/docs/doxygen/overviews/dc.h index 69c496d217..973183fc1a 100644 --- a/docs/doxygen/overviews/dc.h +++ b/docs/doxygen/overviews/dc.h @@ -3,49 +3,46 @@ // Purpose: topic overview // Author: wxWidgets team // RCS-ID: $Id$ -// Licence: wxWindows license +// Licence: wxWindows licence ///////////////////////////////////////////////////////////////////////////// -/*! +/** - @page overview_dc Device context overview +@page overview_dc Device Contexts - Classes: #wxBufferedDC, #wxBufferedPaintDC, #wxDC, #wxPostScriptDC, - #wxMetafileDC, #wxMemoryDC, #wxPrinterDC, #wxScreenDC, #wxClientDC, - #wxPaintDC, #wxWindowDC. +A wxDC is a @e device context onto which graphics and text can be drawn. +The device context is intended to represent a number of output devices in a +generic way, with the same API being used throughout. - A wxDC is a @e device context onto which graphics and text can be drawn. - The device context is intended to represent a number of output devices in a - generic way, with the same API being used throughout. +Some device contexts are created temporarily in order to draw on a window. +This is @true of wxScreenDC, wxClientDC, wxPaintDC, and wxWindowDC. +The following describes the differences between these device contexts and +when you should use them. - Some device contexts are created temporarily in order to draw on a window. - This is @true of #wxScreenDC, #wxClientDC, #wxPaintDC, and #wxWindowDC. - The following describes the differences between these device contexts and - when you should use them. +@li @b wxScreenDC. Use this to paint on the screen, as opposed to an individual window. +@li @b wxClientDC. Use this to paint on the client area of window (the part without + borders and other decorations), but do not use it from within an wxPaintEvent. +@li @b wxPaintDC. Use this to paint on the client area of a window, but @e only from + within a wxPaintEvent. +@li @b wxWindowDC. Use this to paint on the whole area of a window, including decorations. + This may not be available on non-Windows platforms. - @li @b wxScreenDC. Use this to paint on the screen, as opposed to an individual window. - @li @b wxClientDC. Use this to paint on the client area of window (the part without - borders and other decorations), but do not use it from within an #wxPaintEvent. - @li @b wxPaintDC. Use this to paint on the client area of a window, but @e only from - within a #wxPaintEvent. - @li @b wxWindowDC. Use this to paint on the whole area of a window, including decorations. - This may not be available on non-Windows platforms. +To use a client, paint or window device context, create an object on the stack with +the window as argument, for example: - To use a client, paint or window device context, create an object on the stack with - the window as argument, for example: +@code +void MyWindow::OnMyCmd(wxCommandEvent& event) +{ + wxClientDC dc(window); + DrawMyPicture(dc); +} +@endcode - @code - void MyWindow::OnMyCmd(wxCommandEvent& event) - { - wxClientDC dc(window); - DrawMyPicture(dc); - } - @endcode +Try to write code so it is parameterised by wxDC - if you do this, the same piece of code may +write to a number of different devices, by passing a different device context. This doesn't +work for everything (for example not all device contexts support bitmap drawing) but +will work most of the time. - Try to write code so it is parameterised by wxDC - if you do this, the same piece of code may - write to a number of different devices, by passing a different device context. This doesn't - work for everything (for example not all device contexts support bitmap drawing) but - will work most of the time. +@see @ref group_class_dc */ -