X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/a660d684eda27638bca0384b2058911a31c8e845..d9605e634b503651fd349a3d2c6781b2407ea273:/docs/latex/wx/eraseevt.tex diff --git a/docs/latex/wx/eraseevt.tex b/docs/latex/wx/eraseevt.tex index f7397c2b42..18dfe5c574 100644 --- a/docs/latex/wx/eraseevt.tex +++ b/docs/latex/wx/eraseevt.tex @@ -2,11 +2,25 @@ 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} + + + \wxheading{Event table macros} To process an erase event, use this event handler macro to direct input to a member @@ -14,35 +28,30 @@ function that takes a wxEraseEvent argument. \twocolwidtha{7cm} \begin{twocollist}\itemsep=0pt -\twocolitem{{\bf EVT\_ERASE(func)}}{Process a wxEVT\_ERASE\_BACKGROUND event.} +\twocolitem{{\bf EVT\_ERASE\_BACKGROUND(func)}}{Process a wxEVT\_ERASE\_BACKGROUND event.} \end{twocollist}% \wxheading{Remarks} -If the {\bf m\_DC} member is non-NULL, draw into this device context. +Use the device context returned by \helpref{GetDC}{wxeraseeventgetdc} to draw on, +don't create a wxPaintDC in the event handler. \wxheading{See also} -\helpref{wxWindow::OnEraseBackground}{wxwindowonerasebackground}, \helpref{Event handling overview}{eventhandlingoverview} +%\helpref{wxWindow::OnEraseBackground}{wxwindowonerasebackground}, +\helpref{Event handling overview}{eventhandlingoverview} \latexignore{\rtfignore{\wxheading{Members}}} -\membersection{wxEraseEvent::wxEraseEvent} +\membersection{wxEraseEvent::wxEraseEvent}\label{wxeraseeventctor} \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 (may be NULL). - \membersection{wxEraseEvent::GetDC}\label{wxeraseeventgetdc} \constfunc{wxDC*}{GetDC}{\void} -Returns the device context to draw into. If this is non-NULL, you should draw -into it to perform the erase operation. +Returns the device context associated with the erase event to draw on.