date-selector: add gcal_date_selector_use_24h_format function

Will be used later on in order to avoid retrieving this value multiple times with GSettings.

src/gcal-date-selector.c

@@ -446,6 +446,21 @@ gcal_date_selector_new (void)
   return g_object_new (GCAL_TYPE_DATE_SELECTOR, NULL);
 }
 
+void
+gcal_date_selector_use_24h_format (GcalDateSelector *selector,
+                                   gboolean          use_24h_format)
+{
+  GcalDateSelectorPrivate *priv;
+
+  g_return_if_fail (GCAL_IS_DATE_SELECTOR (selector));
+  priv = gcal_date_selector_get_instance_private (selector);
+
+  priv->format_24h = use_24h_format;
+
+  /* update values */
+  gcal_date_selector_set_date (selector, priv->day, priv->month, priv->year);
+}
+
 void
 gcal_date_selector_set_date (GcalDateSelector *selector,
                              gint              day,

src/gcal-date-selector.h

@@ -54,6 +54,9 @@ GType            gcal_date_selector_get_type        (void);
 
 GtkWidget*       gcal_date_selector_new             (void);
 
+void             gcal_date_selector_use_24h_format  (GcalDateSelector *selector,
+                                                     gboolean          use_24h_format);
+
 void             gcal_date_selector_set_date        (GcalDateSelector *selector,
                                                      gint              day,
                                                      gint              month,