1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/addon-sdk/source/lib/sdk/util/collection.js Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,115 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +"use strict";
1.9 +
1.10 +module.metadata = {
1.11 + "stability": "experimental"
1.12 +};
1.13 +
1.14 +exports.Collection = Collection;
1.15 +
1.16 +/**
1.17 + * Adds a collection property to the given object. Setting the property to a
1.18 + * scalar value empties the collection and adds the value. Setting it to an
1.19 + * array empties the collection and adds all the items in the array.
1.20 + *
1.21 + * @param obj
1.22 + * The property will be defined on this object.
1.23 + * @param propName
1.24 + * The name of the property.
1.25 + * @param array
1.26 + * If given, this will be used as the collection's backing array.
1.27 + */
1.28 +exports.addCollectionProperty = function addCollProperty(obj, propName, array) {
1.29 + array = array || [];
1.30 + let publicIface = new Collection(array);
1.31 +
1.32 + Object.defineProperty(obj, propName, {
1.33 + configurable: true,
1.34 + enumerable: true,
1.35 +
1.36 + set: function set(itemOrItems) {
1.37 + array.splice(0, array.length);
1.38 + publicIface.add(itemOrItems);
1.39 + },
1.40 +
1.41 + get: function get() {
1.42 + return publicIface;
1.43 + }
1.44 + });
1.45 +};
1.46 +
1.47 +/**
1.48 + * A collection is ordered, like an array, but its items are unique, like a set.
1.49 + *
1.50 + * @param array
1.51 + * The collection is backed by an array. If this is given, it will be
1.52 + * used as the backing array. This way the caller can fully control the
1.53 + * collection. Otherwise a new empty array will be used, and no one but
1.54 + * the collection will have access to it.
1.55 + */
1.56 +function Collection(array) {
1.57 + array = array || [];
1.58 +
1.59 + /**
1.60 + * Provides iteration over the collection. Items are yielded in the order
1.61 + * they were added.
1.62 + */
1.63 + this.__iterator__ = function Collection___iterator__() {
1.64 + let items = array.slice();
1.65 + for (let i = 0; i < items.length; i++)
1.66 + yield items[i];
1.67 + };
1.68 +
1.69 + /**
1.70 + * The number of items in the collection.
1.71 + */
1.72 + this.__defineGetter__("length", function Collection_get_length() {
1.73 + return array.length;
1.74 + });
1.75 +
1.76 + /**
1.77 + * Adds a single item or an array of items to the collection. Any items
1.78 + * already contained in the collection are ignored.
1.79 + *
1.80 + * @param itemOrItems
1.81 + * An item or array of items.
1.82 + * @return The collection.
1.83 + */
1.84 + this.add = function Collection_add(itemOrItems) {
1.85 + let items = toArray(itemOrItems);
1.86 + for (let i = 0; i < items.length; i++) {
1.87 + let item = items[i];
1.88 + if (array.indexOf(item) < 0)
1.89 + array.push(item);
1.90 + }
1.91 + return this;
1.92 + };
1.93 +
1.94 + /**
1.95 + * Removes a single item or an array of items from the collection. Any items
1.96 + * not contained in the collection are ignored.
1.97 + *
1.98 + * @param itemOrItems
1.99 + * An item or array of items.
1.100 + * @return The collection.
1.101 + */
1.102 + this.remove = function Collection_remove(itemOrItems) {
1.103 + let items = toArray(itemOrItems);
1.104 + for (let i = 0; i < items.length; i++) {
1.105 + let idx = array.indexOf(items[i]);
1.106 + if (idx >= 0)
1.107 + array.splice(idx, 1);
1.108 + }
1.109 + return this;
1.110 + };
1.111 +};
1.112 +
1.113 +function toArray(itemOrItems) {
1.114 + let isArr = itemOrItems &&
1.115 + itemOrItems.constructor &&
1.116 + itemOrItems.constructor.name === "Array";
1.117 + return isArr ? itemOrItems : [itemOrItems];
1.118 +}
