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.TH SDL_AddEventWatch 3 "SDL 3.1.0" "SDL" "SDL3 FUNCTIONS"
.SH NAME
SDL_AddEventWatch \- Add a callback to be triggered when an event is added to the event queue\[char46]
.SH SYNOPSIS
.nf
.B #include \(dqSDL3/SDL.h\(dq
.PP
.BI "int SDL_AddEventWatch(SDL_EventFilter filter, void *userdata);
.fi
.SH DESCRIPTION

.BR filter
will be called when an event happens, and its return value is
ignored\[char46]
.B WARNING
: Be very careful of what you do in the event filter function,
as it may run in a different thread!

If the quit event is generated by a signal (e\[char46]g\[char46] SIGINT), it will bypass
the internal queue and be delivered to the watch callback immediately, and
arrive at the next event poll\[char46]

Note: the callback is called for events posted by the user through

.BR SDL_PushEvent
(), but not for disabled events, nor for
events by a filter callback set with

.BR SDL_SetEventFilter
(), nor for events posted by the
user through 
.BR SDL_PeepEvents
()\[char46]

.SH FUNCTION PARAMETERS
.TP
.I filter
an 
.BR SDL_EventFilter
 function to call when an event happens\[char46]
.TP
.I userdata
a pointer that is passed to
.BR filter

.SH RETURN VALUE
Returns 0 on success, or a negative error code on failure; call

.BR SDL_GetError
() for more information\[char46]

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

.SH SEE ALSO
.BR SDL_DelEventWatch (3),
.BR SDL_SetEventFilter (3)