janus/lib/collection/derived/indexof-fold.js

the two-faced application library-framework

// Generated by CoffeeScript 1.12.2
(function() {
  var Base, IndexOfFold, Varying,
    extend = function(child, parent) { for (var key in parent) { if (hasProp.call(parent, key)) child[key] = parent[key]; } function ctor() { this.constructor = child; } ctor.prototype = parent.prototype; child.prototype = new ctor(); child.__super__ = parent.prototype; return child; },
    hasProp = {}.hasOwnProperty;

  Varying = require('../../core/varying').Varying;

  Base = require('../../core/base').Base;

  IndexOfFold = (function(superClass) {
    extend(IndexOfFold, superClass);

    function IndexOfFold(list, x) {
      IndexOfFold.__super__.constructor.call(this);
      this._list = list;
      this._varying = new Varying(-1);
      this.listenTo(this._list, 'added', (function(_this) {
        return function(obj, idx) {
          return _this._addObj(obj, idx);
        };
      })(this));
      this.listenTo(this._list, 'moved', (function(_this) {
        return function(obj, idx, oldIdx) {
          return _this._moveObj(obj, idx, oldIdx);
        };
      })(this));
      this.listenTo(this._list, 'removed', (function(_this) {
        return function(obj, idx) {
          return _this._removeObj(obj, idx);
        };
      })(this));
      this._targetObservation = Varying.of(x).react((function(_this) {
        return function(value) {
          return _this._handleValue(value);
        };
      })(this));
    }

    IndexOfFold.prototype._handleValue = function(value) {
      this._value = value;
      this._set(this._list.list.indexOf(value));
    };

    IndexOfFold.prototype._addObj = function(obj, idx) {
      if ((obj === this._value) && ((idx < this._lastIdx) || (this._lastIdx === -1))) {
        this._set(idx);
      } else if (idx <= this._lastIdx) {
        this._set(this._lastIdx + 1);
      }
    };

    IndexOfFold.prototype._moveObj = function(obj, idx, oldIdx) {
      if (oldIdx === this._lastIdx) {
        this._set(idx);
      } else if ((idx <= this._lastIdx) && (oldIdx > this._lastIdx)) {
        this._set(this._lastIdx + 1);
      } else if ((idx >= this._lastIdx) && (oldIdx < this._lastIdx)) {
        this._set(this._lastIdx - 1);
      }
    };

    IndexOfFold.prototype._removeObj = function(obj, idx) {
      if (idx === this._lastIdx) {
        this._set(this._list.list.indexOf(this._value));
      } else if (idx < this._lastIdx) {
        this._set(this._lastIdx - 1);
      }
    };

    IndexOfFold.prototype._set = function(idx) {
      this._lastIdx = idx;
      this._varying.set(idx);
    };

    IndexOfFold.prototype.__destroy = function() {
      this._targetObservation.stop();
    };

    IndexOfFold.indexOf = function(list, x) {
      return Varying.managed((function() {
        return new IndexOfFold(list, x);
      }), (function(iof) {
        return iof._varying;
      }));
    };

    return IndexOfFold;

  })(Base);

  module.exports = {
    IndexOfFold: IndexOfFold
  };

}).call(this);