51 lines
1.2 KiB
JavaScript
51 lines
1.2 KiB
JavaScript
"use strict";
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// our base collection
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var Backbone = require('backbone');
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module.exports = Backbone.Collection.extend({
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// ###next
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// returns next item when given an item in the collection
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next: function (item, filter, start) {
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var i = this.indexOf(item),
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newItem;
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if (i === -1) {
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i = 0;
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} else if (i + 1 >= this.length) {
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i = 0;
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} else {
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i = i + 1;
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}
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newItem = this.at(i);
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if (filter && newItem !== start) {
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if (!filter(newItem)) {
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return this.next(newItem, filter, start || item);
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}
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}
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return newItem;
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},
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// ###prev
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// returns previous item when given an item in the collection
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prev: function (item, filter, start) {
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var i = this.indexOf(item),
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newItem;
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if (i === -1) {
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i = 0;
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} else if (i === 0) {
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i = this.length - 1;
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} else {
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i = i - 1;
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}
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newItem = this.at(i);
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if (filter && newItem !== start) {
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if (!filter(newItem)) {
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return this.prev(newItem, filter, start || item);
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}
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}
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return this.at(i);
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}
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});
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