SDL_AddEventWatch - Man Page

#include <SDL3/SDL_events.h>

bool SDL_AddEventWatch(SDL_EventFilter filter, void *userdata);

filter will be called when an event happens, and its return value is ignored.

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.g. SIGINT), it will bypass the internal queue and be delivered to the watch callback immediately, and arrive at the next event poll.

Note: the callback is called for events posted by the user through SDL_PushEvent(), but not for disabled events, nor for events by a filter callback set with SDL_SetEventFilter(), nor for events posted by the user through SDL_PeepEvents().

filter

an SDL_EventFilter function to call when an event happens.

userdata

a pointer that is passed to filter.

Returns true on success or false on failure; call SDL_GetError() for more information.

It is safe to call this function from any thread.

This function is available since SDL 3.2.0.

SDL_RemoveEventWatch(3), SDL_SetEventFilter(3)

SDL_EventFilter.3type(3), SDL_GDKResumeGPU(3), SDL_GDKSuspendGPU(3), SDL_RemoveEventWatch(3), SDL_SetEventFilter(3).