-
-
-/**
- * \brief Check if dates are overlapping
- * Check to see if two events overlap.
- * (This function is used in both Citadel and WebCit. If you change it in
- * one place, change it in the other. Better yet, put it in a library.)
- * \param t1start date one start
- * \param t1end date one end
- * \param t2start date one start
- * \param t2end date two end
- * \returns nonzero if they do.
- */
-int ical_ctdl_is_overlap(
- struct icaltimetype t1start,
- struct icaltimetype t1end,
- struct icaltimetype t2start,
- struct icaltimetype t2end
-) {
-
- if (icaltime_is_null_time(t1start)) return(0);
- if (icaltime_is_null_time(t2start)) return(0);
-
- /** First, check for all-day events */
- if (t1start.is_date) {
- if (!icaltime_compare_date_only(t1start, t2start)) {
- return(1);
- }
- if (!icaltime_is_null_time(t2end)) {
- if (!icaltime_compare_date_only(t1start, t2end)) {
- return(1);
- }
- }
- }
-
- if (t2start.is_date) {
- if (!icaltime_compare_date_only(t2start, t1start)) {
- return(1);
- }
- if (!icaltime_is_null_time(t1end)) {
- if (!icaltime_compare_date_only(t2start, t1end)) {
- return(1);
- }
- }
- }
-
- /** Now check for overlaps using date *and* time. */
-
- /** First, bail out if either event 1 or event 2 is missing end time. */
- if (icaltime_is_null_time(t1end)) return(0);
- if (icaltime_is_null_time(t2end)) return(0);
-
- /** If event 1 ends before event 2 starts, we're in the clear. */
- if (icaltime_compare(t1end, t2start) <= 0) return(0);
-
- /** If event 2 ends before event 1 starts, we're also ok. */
- if (icaltime_compare(t2end, t1start) <= 0) return(0);
-
- /** Otherwise, they overlap. */
- return(1);
-}
-
-
-