[gnome-calendar] event-widget : Add/rework new event sort function

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 0a02a1269b449583d62b2e7364b8de89b796c148
Author: Abdullahi Usman <abdullahismn7 gmail com>
Date:   Sun Jun 18 23:48:25 2017 +0100

    event-widget : Add/rework new event sort function
    
    The overflow layout used to display "Other X events" text when
    there is no enough space to accomodate more events.
    
    But due to the way the events were sorted, some events are folded to
    'Other events' popover even when the cell has enough space to accomodate
    the event(s) or when it is not required to be folded.
    
    We rework how the events will be sorted.  First, the events are sorted by their
    start dates(starting with the closest).  But if two or more events have same start date
    then they are sorted according to their lengths.  And still if they have same start
    date and length then they are sorted according to their modified times(the closest first).
    
    https://bugzilla.gnome.org/show_bug.cgi?id=778478

 src/gcal-event-widget.c    |   28 ++++++++++++++++++++++++++++
 src/gcal-event-widget.h    |    3 +++
 src/gcal-subscriber-view.c |    2 +-
 3 files changed, 32 insertions(+), 1 deletions(-)
---
diff --git a/src/gcal-event-widget.c b/src/gcal-event-widget.c
index 3839499..b4a1f04 100644
--- a/src/gcal-event-widget.c
+++ b/src/gcal-event-widget.c
@@ -1239,3 +1239,31 @@ gcal_event_widget_compare_by_start_date (GcalEventWidget *widget1,
 {
   return g_date_time_compare (widget1->dt_start, widget2->dt_start);
 }
+
+gint
+gcal_event_widget_sort_events (GcalEventWidget *widget1,
+                               GcalEventWidget *widget2)
+{
+  g_autoptr (GDateTime) dt_time1, dt_time2;
+  icaltimetype *ical_dt;
+  gint diff;
+
+  dt_time1 = dt_time2 = NULL;
+  diff = gcal_event_widget_compare_by_start_date (widget1, widget2);
+
+  if (diff != 0)
+    return diff;
+
+  diff = gcal_event_widget_compare_by_length (widget1, widget2);
+
+  if (diff != 0)
+    return diff;
+
+  e_cal_component_get_last_modified (gcal_event_get_component (widget1->event), &ical_dt);
+  dt_time1 = icaltime_to_datetime (ical_dt);
+
+  e_cal_component_get_last_modified (gcal_event_get_component (widget2->event), &ical_dt);
+  dt_time2 = icaltime_to_datetime (ical_dt);
+
+  return g_date_time_compare (dt_time2, dt_time1);
+}
diff --git a/src/gcal-event-widget.h b/src/gcal-event-widget.h
index 7d23e8e..2cadca7 100644
--- a/src/gcal-event-widget.h
+++ b/src/gcal-event-widget.h
@@ -70,6 +70,9 @@ gint         gcal_event_widget_compare_by_length           (GcalEventWidget    *
 gint         gcal_event_widget_compare_by_start_date       (GcalEventWidget    *widget1,
                                                             GcalEventWidget    *widget2);
 
+gint         gcal_event_widget_sort_events                 (GcalEventWidget    *widget1,
+                                                            GcalEventWidget    *widget2);
+
 G_END_DECLS
 
 #endif /* __GCAL_EVENT_WIDGET_H__ */
diff --git a/src/gcal-subscriber-view.c b/src/gcal-subscriber-view.c
index 9b9368a..37a969b 100644
--- a/src/gcal-subscriber-view.c
+++ b/src/gcal-subscriber-view.c
@@ -240,7 +240,7 @@ gcal_subscriber_view_add (GtkContainer *container,
   if (gcal_event_is_multiday (event))
     {
       priv->multi_cell_children = g_list_insert_sorted (priv->multi_cell_children, widget,
-                                                       (GCompareFunc) gcal_event_widget_compare_by_length);
+                                                       (GCompareFunc) gcal_event_widget_sort_events);
     }
   else
     {