Add the ability to check if an id is a valid event handler or not.

git-svn-id: svn+ssh://svn.gna.org/svn/warzone/trunk@5844 4a71c877-e1ca-e34f-864e-861f7616d084

lib/betawidget/widget.c

@@ -165,6 +165,11 @@ bool widgetIsA(const widget *self, const classInfo *instanceOf)
 	return false;
 }
 
+bool widgetIsEventHandler(const widget *self, int id)
+{
+	return widgetGetEventHandlerById(self, id) ? true : false;
+}
+
 static bool widgetAnimationTimerCallback(widget *self, const event *evt,
                                          int handlerId, void *userData)
 {

lib/betawidget/widget.h

@@ -726,6 +726,14 @@ int widgetAddTimerEventHandler(widget *self, eventType type, int interval,
  */
 void widgetRemoveEventHandler(widget *self, int id);
 
+/**
+ * Returns if id is that of a valid event handler.
+ *
+ * @param self  The widget to check if id is a valid event handler for.
+ * @param id    The id in question.
+ */
+bool widgetIsEventHandler(const widget *self, int id);
+
 /**
  * Returns the user-data for the event whose id is id.
  *