Calendar - Signal callback and getters.

Most of setters explained on previous examples have associated getters. That's the subject of this example. We'll add a callback to display all calendar information every time user interacts with the calendar.

Let's check our callback function:

static void
_print_cal_info_cb(void *data EINA_UNUSED, Evas_Object *obj,
                   void *event_info EINA_UNUSED)
{
   int year_min, year_max;
   Eina_Bool sel_enabled;
   const char **wds;
   struct tm sel_time;
   double interval;

To get selected day, we need to call elm_calendar_selected_time_get(), but to assure nothing wrong happened, we must check for function return. It'll return EINA_FALSE if fail. Otherwise we can use time set to our structure stime.

   if (!elm_calendar_selected_time_get(obj, &sel_time))
     return;

Next we'll get information from calendar and place on declared vars:

   interval = elm_calendar_interval_get(obj);
   elm_calendar_min_max_year_get(obj, &year_min, &year_max);
   sel_enabled = (elm_calendar_select_mode_get(obj) != ELM_CALENDAR_SELECT_MODE_NONE);
   wds = elm_calendar_weekdays_names_get(obj);

The only tricky part is that last line gets an array of strings (char arrays), one for each weekday.

Then we can simple print that to stdin:

   printf("Day: %i, Mon: %i, Year %i, WeekDay: %i<br>\n"
          "Interval: %0.2f, Year_Min: %i, Year_Max %i, Sel Enabled : %i<br>\n"
          "Weekdays: %s, %s, %s, %s, %s, %s, %s<br>\n\n",
          sel_time.tm_mday, sel_time.tm_mon, sel_time.tm_year + 1900, sel_time.tm_wday,
          interval, year_min, year_max, sel_enabled,
          wds[0], wds[1], wds[2], wds[3], wds[4], wds[5], wds[6]);
}

struct tm is declared on time.h. You can check ctime manpage to read about it.

To register this callback, that will be called every time user selects a day or goes to next or previous month, just add a callback for signal changed.

   evas_object_smart_callback_add(cal, "changed", _print_cal_info_cb, NULL);

Our example will look like this:

See the full source code calendar_example_05.c here.