week-header, week-grid: update drawing when time changes

When minutes change, the week grid should update the today strip
if it's visible and, if the day change, week header should update
the blue week name.

src/views/gcal-week-header.c

@@ -64,6 +64,7 @@ struct _GcalWeekHeader
   gboolean          expanded;
 
   gboolean          use_24h_format;
+  gint              redraw_timeout_id;
 
   icaltimetype     *active_date;
   icaltimetype     *current_date;
@@ -921,6 +922,12 @@ gcal_week_header_finalize (GObject *object)
   g_clear_pointer (&self->active_date, g_free);
   g_clear_pointer (&self->current_date, g_free);
 
+  if (self->redraw_timeout_id > 0)
+    {
+      g_source_remove (self->redraw_timeout_id);
+      self->redraw_timeout_id = 0;
+    }
+
   for (i = 0; i < 7; i++)
     g_list_free (self->events[i]);
 }
@@ -1143,6 +1150,14 @@ gcal_week_header_draw (GtkWidget      *widget,
 
   GTK_WIDGET_CLASS (gcal_week_header_parent_class)->draw (widget, cr);
 
+  /* Fire the redraw timeout if needed */
+  if (self->redraw_timeout_id == 0)
+    {
+      self->redraw_timeout_id = g_timeout_add_seconds (5,
+                                                       (GSourceFunc) gtk_widget_queue_draw,
+                                                       self);
+    }
+
   g_clear_pointer (&week_start, g_date_time_unref);
   g_clear_pointer (&week_end, g_date_time_unref);