event-widget: show start time when event is timed

We differentiate all day events from timed events by their
ordering, but we don't give any visual clues of this
differentiation.

Fix that by adding the start time of the event when it's a
timed event.

https://bugzilla.gnome.org/show_bug.cgi?id=753131

src/gcal-event-widget.c

@@ -423,6 +423,7 @@ gcal_event_widget_draw (GtkWidget *widget,
 
   PangoLayout *layout;
   PangoFontDescription *font_desc;
+  gchar *display_text;
 
   self = GCAL_EVENT_WIDGET (widget);
   context = gtk_widget_get_style_context (widget);
@@ -436,9 +437,30 @@ gcal_event_widget_draw (GtkWidget *widget,
   gtk_render_background (context, cr, 0, 0, width, height);
   gtk_render_frame (context, cr, 0, 0, width, height);
 
+  /*
+   * The text displayed in the widget includes the time when the event
+   * is timed, or not if the event is all day.
+   */
+  if (gcal_event_get_all_day (self->event))
+    {
+      display_text = g_strdup (gcal_event_get_summary (self->event));
+    }
+  else
+    {
+      GDateTime *local_start_time;
+      gchar *start_time;
+
+      local_start_time = g_date_time_to_local (gcal_event_get_date_start (self->event));
+      start_time = g_date_time_format (local_start_time, "%R%p");
+      display_text = g_strdup_printf ("(%s) %s", start_time, gcal_event_get_summary (self->event));
+
+      g_clear_pointer (&local_start_time, g_date_time_unref);
+      g_clear_pointer (&start_time, g_free);
+    }
+
   /* FIXME for RTL alignment and icons positions */
   gtk_style_context_get (context, state, "font", &font_desc, NULL);
-  layout = gtk_widget_create_pango_layout (widget, gcal_event_get_summary (self->event));
+  layout = gtk_widget_create_pango_layout (widget, display_text);
   pango_layout_set_font_description (layout, font_desc);
   pango_layout_set_ellipsize (layout, PANGO_ELLIPSIZE_END);
   pango_layout_set_width (layout, (width - (padding.left + padding.right) ) * PANGO_SCALE);
@@ -512,6 +534,7 @@ gcal_event_widget_draw (GtkWidget *widget,
 
   pango_font_description_free (font_desc);
   g_object_unref (layout);
+  g_free (display_text);
 
   return FALSE;
 }