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node_modules/vis/lib/Queue.js

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+/**
+ * A queue
+ * @param {Object} options
+ *            Available options:
+ *            - delay: number    When provided, the queue will be flushed
+ *                               automatically after an inactivity of this delay
+ *                               in milliseconds.
+ *                               Default value is null.
+ *            - max: number      When the queue exceeds the given maximum number
+ *                               of entries, the queue is flushed automatically.
+ *                               Default value of max is Infinity.
+ * @constructor Queue
+ */
+function Queue(options) {
+  // options
+  this.delay = null;
+  this.max = Infinity;
+
+  // properties
+  this._queue = [];
+  this._timeout = null;
+  this._extended = null;
+
+  this.setOptions(options);
+}
+
+/**
+ * Update the configuration of the queue
+ * @param {Object} options
+ *            Available options:
+ *            - delay: number    When provided, the queue will be flushed
+ *                               automatically after an inactivity of this delay
+ *                               in milliseconds.
+ *                               Default value is null.
+ *            - max: number      When the queue exceeds the given maximum number
+ *                               of entries, the queue is flushed automatically.
+ *                               Default value of max is Infinity.
+ */
+Queue.prototype.setOptions = function (options) {
+  if (options && typeof options.delay !== 'undefined') {
+    this.delay = options.delay;
+  }
+  if (options && typeof options.max !== 'undefined') {
+    this.max = options.max;
+  }
+
+  this._flushIfNeeded();
+};
+
+/**
+ * Extend an object with queuing functionality.
+ * The object will be extended with a function flush, and the methods provided
+ * in options.replace will be replaced with queued ones.
+ * @param {Object} object
+ * @param {Object} options
+ *            Available options:
+ *            - replace: Array.<string>
+ *                               A list with method names of the methods
+ *                               on the object to be replaced with queued ones.
+ *            - delay: number    When provided, the queue will be flushed
+ *                               automatically after an inactivity of this delay
+ *                               in milliseconds.
+ *                               Default value is null.
+ *            - max: number      When the queue exceeds the given maximum number
+ *                               of entries, the queue is flushed automatically.
+ *                               Default value of max is Infinity.
+ * @return {Queue} Returns the created queue
+ */
+Queue.extend = function (object, options) {
+  var queue = new Queue(options);
+
+  if (object.flush !== undefined) {
+    throw new Error('Target object already has a property flush');
+  }
+  object.flush = function () {
+    queue.flush();
+  };
+
+  var methods = [{
+    name: 'flush',
+    original: undefined
+  }];
+
+  if (options && options.replace) {
+    for (var i = 0; i < options.replace.length; i++) {
+      var name = options.replace[i];
+      methods.push({
+        name: name,
+        original: object[name]
+      });
+      queue.replace(object, name);
+    }
+  }
+
+  queue._extended = {
+    object: object,
+    methods: methods
+  };
+
+  return queue;
+};
+
+/**
+ * Destroy the queue. The queue will first flush all queued actions, and in
+ * case it has extended an object, will restore the original object.
+ */
+Queue.prototype.destroy = function () {
+  this.flush();
+
+  if (this._extended) {
+    var object = this._extended.object;
+    var methods = this._extended.methods;
+    for (var i = 0; i < methods.length; i++) {
+      var method = methods[i];
+      if (method.original) {
+        object[method.name] = method.original;
+      }
+      else {
+        delete object[method.name];
+      }
+    }
+    this._extended = null;
+  }
+};
+
+/**
+ * Replace a method on an object with a queued version
+ * @param {Object} object   Object having the method
+ * @param {string} method   The method name
+ */
+Queue.prototype.replace = function(object, method) {
+  var me = this;
+  var original = object[method];
+  if (!original) {
+    throw new Error('Method ' + method + ' undefined');
+  }
+
+  object[method] = function () {
+    // create an Array with the arguments
+    var args = [];
+    for (var i = 0; i < arguments.length; i++) {
+      args[i] = arguments[i];
+    }
+
+    // add this call to the queue
+    me.queue({
+      args: args,
+      fn: original,
+      context: this
+    });
+  };
+};
+
+/**
+ * Queue a call
+ * @param {function | {fn: function, args: Array} | {fn: function, args: Array, context: Object}} entry
+ */
+Queue.prototype.queue = function(entry) {
+  if (typeof entry === 'function') {
+    this._queue.push({fn: entry});
+  }
+  else {
+    this._queue.push(entry);
+  }
+
+  this._flushIfNeeded();
+};
+
+/**
+ * Check whether the queue needs to be flushed
+ * @private
+ */
+Queue.prototype._flushIfNeeded = function () {
+  // flush when the maximum is exceeded.
+  if (this._queue.length > this.max) {
+    this.flush();
+  }
+
+  // flush after a period of inactivity when a delay is configured
+  clearTimeout(this._timeout);
+  if (this.queue.length > 0 && typeof this.delay === 'number') {
+    var me = this;
+    this._timeout = setTimeout(function () {
+      me.flush();
+    }, this.delay);
+  }
+};
+
+/**
+ * Flush all queued calls
+ */
+Queue.prototype.flush = function () {
+  while (this._queue.length > 0) {
+    var entry = this._queue.shift();
+    entry.fn.apply(entry.context || entry.fn, entry.args || []);
+  }
+};
+
+module.exports = Queue;