A basic pauseable transitionable.

CustomTransitionable

define(function(require, exports, module) {
	var Transitionable = require('famous/transitions/Transitionable');

	function CustomTransitionable() {
		Transitionable.apply(this, arguments);
	}

	CustomTransitionable.prototype = Object.create(Transitionable.prototype);
	CustomTransitionable.prototype.constructor = CustomTransitionable;

	CustomTransitionable.prototype.pause = function pause () {
		if(!this.isActive()) return;

		this.pausedDestination = this.currentAction[0];
		this.pausedTransition = _getpausedTransition.call(this, this.currentAction);
		this.pausedCallback = this._callback;

		this.halt();
	}

	CustomTransitionable.prototype.resume = function resume () {
		if(this.pausedDestination) {
			this.set(this.pausedDestination, this.pausedTransition, this.pausedCallback);
		}
		this.pausedDestination = null;
		this.pausedTransition = null;
		this.pausedCallback = null;
	}

	function _getpausedTransition (currentAction) {
		var progress;
		var currentState = this.get();
		var adjustedTransition;

		// if transitioning an array simply look at first element in array.
		if (Array.isArray(currentState)) progress = currentState[0] / currentAction[0][0];
		else progress = currentState / currentAction[0];

		// adjust transition based on current progress.
		adjustedTransition = currentAction[1];
		adjustedTransition.duration = adjustedTransition.duration * (1 - progress);

		return adjustedTransition;
	}

	module.exports = CustomTransitionable;
});