planning

node_modules/ol/events.js

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+/**
+ * @module ol/events
+ */
+import { clear } from './obj.js';
+/**
+ * Key to use with {@link module:ol/Observable.unByKey}.
+ * @typedef {Object} EventsKey
+ * @property {ListenerFunction} listener Listener.
+ * @property {import("./events/Target.js").EventTargetLike} target Target.
+ * @property {string} type Type.
+ * @api
+ */
+/**
+ * Listener function. This function is called with an event object as argument.
+ * When the function returns `false`, event propagation will stop.
+ *
+ * @typedef {function((Event|import("./events/Event.js").default)): (void|boolean)} ListenerFunction
+ * @api
+ */
+/**
+ * @typedef {Object} ListenerObject
+ * @property {ListenerFunction} handleEvent HandleEvent listener function.
+ */
+/**
+ * @typedef {ListenerFunction|ListenerObject} Listener
+ */
+/**
+ * Registers an event listener on an event target. Inspired by
+ * https://google.github.io/closure-library/api/source/closure/goog/events/events.js.src.html
+ *
+ * This function efficiently binds a `listener` to a `this` object, and returns
+ * a key for use with {@link module:ol/events.unlistenByKey}.
+ *
+ * @param {import("./events/Target.js").EventTargetLike} target Event target.
+ * @param {string} type Event type.
+ * @param {ListenerFunction} listener Listener.
+ * @param {Object} [opt_this] Object referenced by the `this` keyword in the
+ *     listener. Default is the `target`.
+ * @param {boolean} [opt_once] If true, add the listener as one-off listener.
+ * @return {EventsKey} Unique key for the listener.
+ */
+export function listen(target, type, listener, opt_this, opt_once) {
+    if (opt_this && opt_this !== target) {
+        listener = listener.bind(opt_this);
+    }
+    if (opt_once) {
+        var originalListener_1 = listener;
+        listener = function () {
+            target.removeEventListener(type, listener);
+            originalListener_1.apply(this, arguments);
+        };
+    }
+    var eventsKey = {
+        target: target,
+        type: type,
+        listener: listener,
+    };
+    target.addEventListener(type, listener);
+    return eventsKey;
+}
+/**
+ * Registers a one-off event listener on an event target. Inspired by
+ * https://google.github.io/closure-library/api/source/closure/goog/events/events.js.src.html
+ *
+ * This function efficiently binds a `listener` as self-unregistering listener
+ * to a `this` object, and returns a key for use with
+ * {@link module:ol/events.unlistenByKey} in case the listener needs to be
+ * unregistered before it is called.
+ *
+ * When {@link module:ol/events.listen} is called with the same arguments after this
+ * function, the self-unregistering listener will be turned into a permanent
+ * listener.
+ *
+ * @param {import("./events/Target.js").EventTargetLike} target Event target.
+ * @param {string} type Event type.
+ * @param {ListenerFunction} listener Listener.
+ * @param {Object} [opt_this] Object referenced by the `this` keyword in the
+ *     listener. Default is the `target`.
+ * @return {EventsKey} Key for unlistenByKey.
+ */
+export function listenOnce(target, type, listener, opt_this) {
+    return listen(target, type, listener, opt_this, true);
+}
+/**
+ * Unregisters event listeners on an event target. Inspired by
+ * https://google.github.io/closure-library/api/source/closure/goog/events/events.js.src.html
+ *
+ * The argument passed to this function is the key returned from
+ * {@link module:ol/events.listen} or {@link module:ol/events.listenOnce}.
+ *
+ * @param {EventsKey} key The key.
+ */
+export function unlistenByKey(key) {
+    if (key && key.target) {
+        key.target.removeEventListener(key.type, key.listener);
+        clear(key);
+    }
+}
+//# sourceMappingURL=events.js.map