.TH "SDL_SetEventFilter" "3" "Sun 10 Jun 2001, 19:40" "SDL" "SDL API Reference"

.SH "NAME"

SDL_SetEventFilter\- Sets up a filter to process all events before they are posted to the event queue\&.

.SH "SYNOPSIS"

.PP

\fB#include "SDL\&.h"

.sp

\fBvoid \fBSDL_SetEventFilter\fP\fR(\fBSDL_EventFilter filter\fR);

.SH "DESCRIPTION"

.PP

This function sets up a filter to process all events before they are posted to the event queue\&. This is a very powerful and flexible feature\&. The filter is prototyped as:

.PP

.nf

\f(CWtypedef int (*SDL_EventFilter)(const SDL_Event *event);\fR

.fi

.PP

If the filter returns \fB1\fR, then the event will be added to the internal queue\&. If it returns \fB0\fR, then the event will be dropped from the queue\&. This allows selective filtering of dynamically\&.

.PP

There is one caveat when dealing with the \fBSDL_QUITEVENT\fP event type\&. The event filter is only called when the window manager desires to close the application window\&. If the event filter returns 1, then the window will be closed, otherwise the window will remain open if possible\&. If the quit event is generated by an interrupt signal, it will bypass the internal queue and be delivered to the application at the next event poll\&.

.PP

.RS

\fBNote:

.PP

Events pushed onto the queue with \fI\fBSDL_PushEvent\fP\fR or \fI\fBSDL_PeepEvents\fP\fR do not get passed through the event filter\&.

.RE

.PP

.RS

\fBNote:

.PP

\fIBe Careful!\fP The event filter function may run in a different thread so be careful what you do within it\&.

.RE

.SH "SEE ALSO"

.PP

\fI\fBSDL_Event\fR\fR, \fI\fBSDL_GetEventFilter\fP\fR, \fI\fBSDL_PushEvent\fP\fR

...\" created by instant / docbook-to-man, Sun 10 Jun 2001, 19:40