docs/latex/wx/eraseevt.tex

   1 \section{\class{wxEraseEvent}}\label{wxeraseevent}
   2
   3 An erase event is sent when a window's background needs to be repainted.
   4
   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
  15 \wxheading{Derived from}
  16
  17 \helpref{wxEvent}{wxevent}\\
  18 \helpref{wxObject}{wxobject}
  19
  20 \wxheading{Include files}
  21
  22 <wx/event.h>
  23
  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
  31 \twocolitem{{\bf EVT\_ERASE\_BACKGROUND(func)}}{Process a wxEVT\_ERASE\_BACKGROUND event.}
  32 \end{twocollist}%
  33
  34 \wxheading{Remarks}
  35
  36 Use the device context returned by \helpref{GetDC}{wxeraseeventgetdc} to draw on,
  37 don't create a wxPaintDC in the event handler.
  38
  39 \wxheading{See also}
  40
  41 %\helpref{wxWindow::OnEraseBackground}{wxwindowonerasebackground},
  42 \helpref{Event handling overview}{eventhandlingoverview}
  43
  44 \latexignore{\rtfignore{\wxheading{Members}}}
  45
  46 \membersection{wxEraseEvent::wxEraseEvent}\label{wxeraseeventctor}
  47
  48 \func{}{wxEraseEvent}{\param{int }{id = 0}, \param{wxDC* }{dc = NULL}}
  49
  50 Constructor.
  51
  52 \membersection{wxEraseEvent::GetDC}\label{wxeraseeventgetdc}
  53
  54 \constfunc{wxDC*}{GetDC}{\void}
  55
  56 Returns the device context associated with the erase event to draw on.
  57