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.TH SDL_SetEventFilter 3 "SDL 3.1.0" "SDL" "SDL3 FUNCTIONS"
.SH NAME
SDL_SetEventFilter \- Set up a filter to process all events before they change internal state and are posted to the internal event queue\[char46]
.SH SYNOPSIS
.nf
.B #include \(dqSDL3/SDL.h\(dq
.PP
.BI "void SDL_SetEventFilter(SDL_EventFilter filter, void *userdata);
.fi
.SH DESCRIPTION
If the filter function returns 1 when called, then the event will be added
to the internal queue\[char46] If it returns 0, then the event will be dropped from
the queue, but the internal state will still be updated\[char46] This allows
selective filtering of dynamically arriving events\[char46]
.B WARNING
: Be very careful of what you do in the event filter function,
as it may run in a different thread!

On platforms that support it, if the quit event is generated by an
interrupt signal (e\[char46]g\[char46] pressing Ctrl-C), it will be delivered to the
application at the next event poll\[char46]

There is one caveat when dealing with the ::
.BR SDL_QuitEvent

event type\[char46] The event filter is only called when the window manager desires
to close the application window\[char46] If the event filter returns 1, then the
window will be closed, otherwise the window will remain open if possible\[char46]

Note: Disabled events never make it to the event filter function; see

.BR SDL_SetEventEnabled
()\[char46]

Note: If you just want to inspect events without filtering, you should use

.BR SDL_AddEventWatch
() instead\[char46]

Note: Events pushed onto the queue with 
.BR SDL_PushEvent
()
get passed through the event filter, but events pushed onto the queue with

.BR SDL_PeepEvents
() do not\[char46]

.SH FUNCTION PARAMETERS
.TP
.I filter
An 
.BR SDL_EventFilter
 function to call when an event happens
.TP
.I userdata
a pointer that is passed to
.BR filter

.SH AVAILABILITY
This function is available since SDL 3\[char46]0\[char46]0\[char46]

.SH SEE ALSO
.BR SDL_AddEventWatch (3),
.BR SDL_SetEventEnabled (3),
.BR SDL_GetEventFilter (3),
.BR SDL_PeepEvents (3),
.BR SDL_PushEvent (3)