Function _handlerIndex

docs/app/js/sanddance-app.js:123323–123328

* Utility method for finding the array index of an event handler. * @param {Array} h - An array of registered event handlers. * @param {string} type - The event type. * @param {function} handler - The event handler instance to find. * @return {number} - The handler's array index or -1 if

(h17, type8, handler)

   * @param {function} handler - The event handler instance to find.
   * @return {number} - The handler's array index or -1 if not registered.
   */ _handlerIndex (h17, type8, handler) {
        for(let i = h17 ? h17.length : 0; --i >= 0;){
            if (h17[i].type === type8 && (!handler || h17[i].handler === handler)) return i;
        }
        return -1;
    },
    /**
   * Returns an array with registered event handlers.
   * @param {string} [type] - The event type to query. Any annotations