restructure EventHandler

src/utils/EventHandler.js

@@ -1,70 +1,66 @@
-/**
- * @module utils
- */
+import { Transaction } from './Transaction.js' // eslint-disable-line
+import { YEvent } from './YEvent.js' // eslint-disable-line
+import * as f from 'lib0/function.js'
 
 /**
  * General event handler implementation.
+ *
+ * @template ARG0, ARG1
  */
 export class EventHandler {
   constructor () {
-    this.eventListeners = []
-  }
-
-  /**
-   * To prevent memory leaks, call this method when the eventListeners won't be
-   * used anymore.
-   */
-  destroy () {
-    this.eventListeners = null
-  }
-
-  /**
-   * Adds an event listener that is called when
-   * {@link EventHandler#callEventListeners} is called.
-   *
-   * @param {Function} f The event handler.
-   */
-  addEventListener (f) {
-    this.eventListeners.push(f)
-  }
-
-  /**
-   * Removes an event listener.
-   *
-   * @param {Function} f The event handler that was added with
-   *                     {@link EventHandler#addEventListener}
-   */
-  removeEventListener (f) {
-    this.eventListeners = this.eventListeners.filter(g => f !== g)
-  }
-
-  /**
-   * Removes all event listeners.
-   */
-  removeAllEventListeners () {
-    this.eventListeners = []
-  }
-
-  /**
-   * Call all event listeners that were added via
-   * {@link EventHandler#addEventListener}.
-   *
-   * @param {Transaction} transaction The transaction object
-   * @param {YEvent} event An event object that describes the change on a type.
-   */
-  callEventListeners (transaction, event) {
-    for (var i = 0; i < this.eventListeners.length; i++) {
-      try {
-        const f = this.eventListeners[i]
-        f(event, transaction)
-      } catch (e) {
-        /*
-          Your observer threw an error. This error was caught so that Yjs
-          can ensure data consistency! In order to debug this error you
-          have to check "Pause On Caught Exceptions" in developer tools.
-        */
-        console.error(e)
-      }
-    }
+    /**
+     * @type {Array<function(ARG0, ARG1):void>}
+     */
+    this.l = []
   }
 }
+
+/**
+ * @template ARG0,ARG1
+ * @returns {EventHandler<ARG0,ARG1>}
+ */
+export const create = () => new EventHandler()
+
+/**
+ * Adds an event listener that is called when
+ * {@link EventHandler#callEventListeners} is called.
+ *
+ * @template ARG0,ARG1
+ * @param {EventHandler<ARG0,ARG1>} eventHandler
+ * @param {function(ARG0,ARG1):void} f The event handler.
+ */
+export const addEventListener = (eventHandler, f) =>
+  eventHandler.l.push(f)
+
+/**
+ * Removes an event listener.
+ *
+ * @template ARG0,ARG1
+ * @param {EventHandler<ARG0,ARG1>} eventHandler
+ * @param {function(ARG0,ARG1):void} f The event handler that was added with
+ *                     {@link EventHandler#addEventListener}
+ */
+export const removeEventListener = (eventHandler, f) => {
+  eventHandler.l = eventHandler.l.filter(g => f !== g)
+}
+
+/**
+ * Removes all event listeners.
+ * @template ARG0,ARG1
+ * @param {EventHandler<ARG0,ARG1>} eventHandler
+ */
+export const removeAllEventListeners = eventHandler => {
+  eventHandler.l.length = 0
+}
+
+/**
+ * Call all event listeners that were added via
+ * {@link EventHandler#addEventListener}.
+ *
+ * @template ARG0,ARG1
+ * @param {EventHandler<ARG0,ARG1>} eventHandler
+ * @param {[ARG0,ARG1]} args
+ */
+export const callEventListeners = (eventHandler, args) =>
+  f.callAll(eventHandler.l, args)