[wxWidgets.git] / docs / latex / wx / eraseevt.tex

\section{\class{wxEraseEvent}}\label{wxeraseevent}

An erase event is sent when a window's background needs to be repainted.

On some platforms, such as GTK+, this event is simulated (simply generated just before the
paint event) and may cause flicker. It is therefore recommended that
you set the text background colour explicitly in order to prevent flicker.
The default background colour under GTK+ is grey.

To intercept this event, use the EVT\_ERASE\_BACKGROUND macro in an event table definition.

You must call wxEraseEvent::GetDC and use the returned device context if it is non-NULL.
If it is NULL, create your own temporary wxClientDC object. 

\wxheading{Derived from}

\helpref{wxEvent}{wxevent}\\
\helpref{wxObject}{wxobject}

\wxheading{Include files}

<wx/event.h>

\wxheading{Event table macros}

To process an erase event, use this event handler macro to direct input to a member
function that takes a wxEraseEvent argument.

\twocolwidtha{7cm}
\begin{twocollist}\itemsep=0pt
\twocolitem{{\bf EVT\_ERASE\_BACKGROUND(func)}}{Process a wxEVT\_ERASE\_BACKGROUND event.}
\end{twocollist}%

\wxheading{Remarks}

Use the {\bf m\_DC} device context to draw into, don't create wxPaintDC in 
the event handler.

\wxheading{See also}

%\helpref{wxWindow::OnEraseBackground}{wxwindowonerasebackground},
\helpref{Event handling overview}{eventhandlingoverview}

\latexignore{\rtfignore{\wxheading{Members}}}

\membersection{wxEraseEvent::wxEraseEvent}

\func{}{wxEraseEvent}{\param{int }{id = 0}, \param{wxDC* }{dc = NULL}}

Constructor.

\membersection{wxEraseEvent::m\_dc}

\member{wxDC*}{m\_dc}

The device context associated with the erase event.

\membersection{wxEraseEvent::GetDC}\label{wxeraseeventgetdc}

\constfunc{wxDC*}{GetDC}{\void}

Returns the device context to draw into.
Commit	Line	Data
a660d684 KB	1	\section{\class{wxEraseEvent}}\label{wxeraseevent}
	2
	3	An erase event is sent when a window's background needs to be repainted.
	4
f4fcc291 JS	5	On some platforms, such as GTK+, this event is simulated (simply generated just before the
	6	paint event) and may cause flicker. It is therefore recommended that
	7	you set the text background colour explicitly in order to prevent flicker.
	8	The default background colour under GTK+ is grey.
	9
	10	To intercept this event, use the EVT\_ERASE\_BACKGROUND macro in an event table definition.
	11
	12	You must call wxEraseEvent::GetDC and use the returned device context if it is non-NULL.
	13	If it is NULL, create your own temporary wxClientDC object.
	14
a660d684 KB	15	\wxheading{Derived from}
	16
	17	\helpref{wxEvent}{wxevent}\\
	18	\helpref{wxObject}{wxobject}
	19
954b8ae6 JS	20	\wxheading{Include files}
	21
	22	<wx/event.h>
	23
a660d684 KB	24	\wxheading{Event table macros}
	25
	26	To process an erase event, use this event handler macro to direct input to a member
	27	function that takes a wxEraseEvent argument.
	28
	29	\twocolwidtha{7cm}
	30	\begin{twocollist}\itemsep=0pt
884360bc	31	\twocolitem{{\bf EVT\_ERASE\_BACKGROUND(func)}}{Process a wxEVT\_ERASE\_BACKGROUND event.}
a660d684 KB	32	\end{twocollist}%
	33
	34	\wxheading{Remarks}
	35
dce5c1db VS	36	Use the {\bf m\_DC} device context to draw into, don't create wxPaintDC in
dce5c1db VS	37	the event handler.
a660d684 KB	38
	39	\wxheading{See also}
	40
f4fcc291 JS	41	%\helpref{wxWindow::OnEraseBackground}{wxwindowonerasebackground},
f4fcc291 JS	42	\helpref{Event handling overview}{eventhandlingoverview}
a660d684 KB	43
	44	\latexignore{\rtfignore{\wxheading{Members}}}
	45
	46	\membersection{wxEraseEvent::wxEraseEvent}
	47
	48	\func{}{wxEraseEvent}{\param{int }{id = 0}, \param{wxDC* }{dc = NULL}}
	49
	50	Constructor.
	51
	52	\membersection{wxEraseEvent::m\_dc}
	53
	54	\member{wxDC*}{m\_dc}
	55
dce5c1db	56	The device context associated with the erase event.
a660d684 KB	57
	58	\membersection{wxEraseEvent::GetDC}\label{wxeraseeventgetdc}
	59
	60	\constfunc{wxDC*}{GetDC}{\void}
	61
dce5c1db	62	Returns the device context to draw into.
a660d684	63