+/**
+ * Function to register a hook function for a viewer to set/update its
+ * allowed time span.
+ * @param tab viewer's tab
+ * @param hook hook function of the viewer.
+ * @param hook_data hook data associated with the hook function.
+ */
+__EXPORT void lttvwindow_register_time_span_notify(Tab *tab,
+ LttvHook hook, gpointer hook_data)
+{
+ LttvAttributeValue value;
+ LttvHooks * tmp;
+ gboolean retval;
+
+ retval= lttv_iattribute_find_by_path(tab->attributes,
+ "hooks/updatetimespan", LTTV_POINTER, &value);
+ g_assert(retval);
+ tmp = (LttvHooks*)*(value.v_pointer);
+ if(tmp == NULL){
+ tmp = lttv_hooks_new();
+ *(value.v_pointer) = tmp;
+ }
+ lttv_hooks_add(tmp, hook,hook_data, LTTV_PRIO_DEFAULT);
+}
+/**
+ * Function to unregister a viewer's hook function which is used to
+ * set/update the time span allowed for the viewer.
+ * @param tab viewer's tab
+ * @param hook hook function of the viewer.
+ * @param hook_data hook data associated with the hook function.
+ */
+
+__EXPORT void lttvwindow_unregister_time_span_notify(Tab *tab,
+ LttvHook hook, gpointer hook_data)
+{
+ LttvAttributeValue value;
+ LttvHooks * tmp;
+ gboolean retval;
+
+ retval= lttv_iattribute_find_by_path(tab->attributes,
+ "hooks/updatetimespan", LTTV_POINTER, &value);
+ g_assert(retval);
+ tmp = (LttvHooks*)*(value.v_pointer);
+ if(tmp == NULL) return;
+ lttv_hooks_remove_data(tmp, hook, hook_data);
+}
+