| .TH "SDL_SetEventFilter" "3" "Tue 11 Sep 2001, 22:59" "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, Tue 11 Sep 2001, 22:59 |
