SDL_AddEventWatch - Man Page
Add a callback to be triggered when an event is added to the event queue.
Header File
Defined in SDL3/SDL_events.h
Synopsis
#include "SDL3/SDL.h" bool SDL_AddEventWatch(SDL_EventFilter filter, void *userdata);
Description
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 ().
Function Parameters
- filter
an SDL_EventFilter
function to call when an event happens.- userdata
a pointer that is passed to filter .
Return Value
Returns true on success or false on failure; call
SDL_GetError () for more information.
Thread Safety
It is safe to call this function from any thread.
Availability
This function is available since SDL 3.2.0.
See Also
·(3), SDL_RemoveEventWatch(3), ·(3), SDL_SetEventFilter(3)
Referenced By
SDL_EventFilter.3type(3), SDL_GDKResumeGPU(3), SDL_GDKSuspendGPU(3), SDL_RemoveEventWatch(3), SDL_SetEventFilter(3).