fix incorrect stacking of overlapping events from multiple calendars

sort the event collection after adding a calendar, as the drawing
functions rely on the event collection to be sorted by begin date

Signed-off-by: Fabrizio Iannetti <fabrizio.iannetti@gmail.com>

src/model/events.rs

@@ -95,6 +95,10 @@ impl EventsCollection {
         }
         events_in_day
     }
+
+    pub fn sort(&mut self) {
+        self.events.sort_by_key(|event| event.begin);
+    }
 }
 
 impl Default for EventsCollection {

src/model/ical_bridge.rs

@@ -39,5 +39,7 @@ pub fn load_calendar(calendar_path: &std::path::Path, events: &mut EventsCollect
             _ => (),
         }
     }
+
+    events.sort();
 }
 

src/ui/calendar.rs

@@ -131,17 +131,20 @@ fn render_events_in_row(
     // update event bars
     for cell in row_grid {
         ev_y = y;
+        println!("col={}", cell.pos_x);
         for ev_bar in ev_bars.iter_mut() {
             if ev_bar.ev.begin == current_day || (ev_bar.ev.begin < first_day && current_day == first_day) {
                 // start of event
                 ev_bar.bounds.x = cell.x;
                 ev_bar.bounds.y = ev_y;
+                println!("start[{}] y={}", ev_bar.ev.text, ev_y);
             }
             if ev_bar.ev.end == current_day {
                 // end of event -> set width
                 ev_bar.bounds.width = cell.x + cell.width - ev_bar.bounds.x;
             }
             if ev_bar.ev.is_in_day(current_day) {
+                println!("ev_y {}->{}", ev_y, ev_y+ ev_height);
                 ev_y += ev_height;
             }
         }