Handling events example

This example shows the simplest possible way to register a handler for an ecore event, this way we can focus on the important aspects. The example will start the main loop and quit it when it receives the ECORE_EVENT_SIGNAL_EXIT event. This event is triggered by a SIGTERM(pressing ctrl+c).

So let's start with the function we want called when we receive the event, instead of just stopping the main loop we'll also print a message, that's just so it's clear that it got called:

static Eina_Bool
_quitter(void *data EINA_UNUSED, int ev_type EINA_UNUSED, void *event EINA_UNUSED)
{
   printf("Leaving already?\n");
   ecore_main_loop_quit();
   return ECORE_CALLBACK_DONE;
}

Note:

We return ECORE_CALLBACK_DONE because we don't want any other handlers for this event to be called, the program is quitting after all.

We then have our main function and the obligatory initialization of ecore:

int
main(void)
{
   ecore_init();

We then get to the one line of our example that makes everything work, the registering of the callback:

   ecore_event_handler_add(ECORE_EVENT_SIGNAL_EXIT, _quitter, NULL);

Note:

The NULL there is because there is no need to pass data to the callback.

And the all that is left to do is start the main loop:

   ecore_main_loop_begin();

   return 0;
}

Full source code for this example: ecore_event_example_01::c.