SDL_SetEventFilter — Sets up a filter to process all events before they are posted to the event queue.
#include "SDL.h"
void
SDL_SetEventFilter( |
SDL_EventFilter | filter) ; |
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:
typedef int (*SDL_EventFilter)(const SDL_Event *event);
If the filter returns 1
,
then the event will be added to the internal queue. If it
returns 0
, then the event will
be dropped from the queue. This allows selective filtering of
dynamically.
There is one caveat when dealing with the SDL_QUITEVENT
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.
Note Events pushed onto the queue with
SDL_PushEvent
orSDL_PeepEvents
do not get passed through the event filter.
Note Be Careful! The event filter function may run in a different thread so be careful what you do within it.
SDL_Event(3), SDL_GetEventFilter(3), SDL_PushEvent(3)
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This manual page is taken from the SDL library, licensed under GNU LGPL. |