move.js

;(function(){

/**
 * Require the module at `name`.
 *
 * @param {String} name
 * @return {Object} exports
 * @api public
 */

function require(name) {
  var module = require.modules[name];
  if (!module) throw new Error('failed to require "' + name + '"');

  if (!('exports' in module) && typeof module.definition === 'function') {
    module.client = module.component = true;
    module.definition.call(this, module.exports = {}, module);
    delete module.definition;
  }

  return module.exports;
}

/**
 * Meta info, accessible in the global scope unless you use AMD option.
 */

require.loader = 'component';

/**
 * Internal helper object, contains a sorting function for semantiv versioning
 */
require.helper = {};
require.helper.semVerSort = function(a, b) {
  var aArray = a.version.split('.');
  var bArray = b.version.split('.');
  for (var i=0; i<aArray.length; ++i) {
    var aInt = parseInt(aArray[i], 10);
    var bInt = parseInt(bArray[i], 10);
    if (aInt === bInt) {
      var aLex = aArray[i].substr((""+aInt).length);
      var bLex = bArray[i].substr((""+bInt).length);
      if (aLex === '' && bLex !== '') return 1;
      if (aLex !== '' && bLex === '') return -1;
      if (aLex !== '' && bLex !== '') return aLex > bLex ? 1 : -1;
      continue;
    } else if (aInt > bInt) {
      return 1;
    } else {
      return -1;
    }
  }
  return 0;
}

/**
 * Find and require a module which name starts with the provided name.
 * If multiple modules exists, the highest semver is used. 
 * This function can only be used for remote dependencies.

 * @param {String} name - module name: `user~repo`
 * @param {Boolean} returnPath - returns the canonical require path if true, 
 *                               otherwise it returns the epxorted module
 */
require.latest = function (name, returnPath) {
  function showError(name) {
    throw new Error('failed to find latest module of "' + name + '"');
  }
  // only remotes with semvers, ignore local files conataining a '/'
  var versionRegexp = /(.*)~(.*)@v?(\d+\.\d+\.\d+[^\/]*)$/;
  var remoteRegexp = /(.*)~(.*)/;
  if (!remoteRegexp.test(name)) showError(name);
  var moduleNames = Object.keys(require.modules);
  var semVerCandidates = [];
  var otherCandidates = []; // for instance: name of the git branch
  for (var i=0; i<moduleNames.length; i++) {
    var moduleName = moduleNames[i];
    if (new RegExp(name + '@').test(moduleName)) {
        var version = moduleName.substr(name.length+1);
        var semVerMatch = versionRegexp.exec(moduleName);
        if (semVerMatch != null) {
          semVerCandidates.push({version: version, name: moduleName});
        } else {
          otherCandidates.push({version: version, name: moduleName});
        } 
    }
  }
  if (semVerCandidates.concat(otherCandidates).length === 0) {
    showError(name);
  }
  if (semVerCandidates.length > 0) {
    var module = semVerCandidates.sort(require.helper.semVerSort).pop().name;
    if (returnPath === true) {
      return module;
    }
    return require(module);
  }
  // if the build contains more than one branch of the same module
  // you should not use this funciton
  var module = otherCandidates.sort(function(a, b) {return a.name > b.name})[0].name;
  if (returnPath === true) {
    return module;
  }
  return require(module);
}

/**
 * Registered modules.
 */

require.modules = {};

/**
 * Register module at `name` with callback `definition`.
 *
 * @param {String} name
 * @param {Function} definition
 * @api private
 */

require.register = function (name, definition) {
  require.modules[name] = {
    definition: definition
  };
};

/**
 * Define a module's exports immediately with `exports`.
 *
 * @param {String} name
 * @param {Generic} exports
 * @api private
 */

require.define = function (name, exports) {
  require.modules[name] = {
    exports: exports
  };
};
require.register("component~transform-property@0.0.1", function (exports, module) {

var styles = [
  'webkitTransform',
  'MozTransform',
  'msTransform',
  'OTransform',
  'transform'
];

var el = document.createElement('p');
var style;

for (var i = 0; i < styles.length; i++) {
  style = styles[i];
  if (null != el.style[style]) {
    module.exports = style;
    break;
  }
}

});

require.register("component~has-translate3d@0.0.3", function (exports, module) {

var prop = require('component~transform-property@0.0.1');

// IE <=8 doesn't have `getComputedStyle`
if (!prop || !window.getComputedStyle) {
  module.exports = false;

} else {
  var map = {
    webkitTransform: '-webkit-transform',
    OTransform: '-o-transform',
    msTransform: '-ms-transform',
    MozTransform: '-moz-transform',
    transform: 'transform'
  };

  // from: https://gist.github.com/lorenzopolidori/3794226
  var el = document.createElement('div');
  el.style[prop] = 'translate3d(1px,1px,1px)';
  document.body.insertBefore(el, null);
  var val = getComputedStyle(el).getPropertyValue(map[prop]);
  document.body.removeChild(el);
  module.exports = null != val && val.length && 'none' != val;
}

});

require.register("yields~has-transitions@1.0.0", function (exports, module) {
/**
 * Check if `el` or browser supports transitions.
 *
 * @param {Element} el
 * @return {Boolean}
 * @api public
 */

exports = module.exports = function(el){
  switch (arguments.length) {
    case 0: return bool;
    case 1: return bool
      ? transitions(el)
      : bool;
  }
};

/**
 * Check if the given `el` has transitions.
 *
 * @param {Element} el
 * @return {Boolean}
 * @api private
 */

function transitions(el, styl){
  if (el.transition) return true;
  styl = window.getComputedStyle(el);
  return !! parseFloat(styl.transitionDuration, 10);
}

/**
 * Style.
 */

var styl = document.body.style;

/**
 * Export support.
 */

var bool = 'transition' in styl
  || 'webkitTransition' in styl
  || 'MozTransition' in styl
  || 'msTransition' in styl;

});

require.register("component~event@0.1.4", function (exports, module) {
var bind = window.addEventListener ? 'addEventListener' : 'attachEvent',
    unbind = window.removeEventListener ? 'removeEventListener' : 'detachEvent',
    prefix = bind !== 'addEventListener' ? 'on' : '';

/**
 * Bind `el` event `type` to `fn`.
 *
 * @param {Element} el
 * @param {String} type
 * @param {Function} fn
 * @param {Boolean} capture
 * @return {Function}
 * @api public
 */

exports.bind = function(el, type, fn, capture){
  el[bind](prefix + type, fn, capture || false);
  return fn;
};

/**
 * Unbind `el` event `type`'s callback `fn`.
 *
 * @param {Element} el
 * @param {String} type
 * @param {Function} fn
 * @param {Boolean} capture
 * @return {Function}
 * @api public
 */

exports.unbind = function(el, type, fn, capture){
  el[unbind](prefix + type, fn, capture || false);
  return fn;
};
});

require.register("ecarter~css-emitter@0.0.1", function (exports, module) {
/**
 * Module Dependencies
 */

var events = require('component~event@0.1.4');

// CSS events

var watch = [
  'transitionend'
, 'webkitTransitionEnd'
, 'oTransitionEnd'
, 'MSTransitionEnd'
, 'animationend'
, 'webkitAnimationEnd'
, 'oAnimationEnd'
, 'MSAnimationEnd'
];

/**
 * Expose `CSSnext`
 */

module.exports = CssEmitter;

/**
 * Initialize a new `CssEmitter`
 *
 */

function CssEmitter(element){
  if (!(this instanceof CssEmitter)) return new CssEmitter(element);
  this.el = element;
}

/**
 * Bind CSS events.
 *
 * @api public
 */

CssEmitter.prototype.bind = function(fn){
  for (var i=0; i < watch.length; i++) {
    events.bind(this.el, watch[i], fn);
  }
  return this;
};

/**
 * Unbind CSS events
 * 
 * @api public
 */

CssEmitter.prototype.unbind = function(fn){
  for (var i=0; i < watch.length; i++) {
    events.unbind(this.el, watch[i], fn);
  }
  return this;
};

/**
 * Fire callback only once
 * 
 * @api public
 */

CssEmitter.prototype.once = function(fn){
  var self = this;
  function on(){
    self.unbind(on);
    fn.apply(self.el, arguments);
  }
  self.bind(on);
  return this;
};


});

require.register("component~once@0.0.1", function (exports, module) {

/**
 * Identifier.
 */

var n = 0;

/**
 * Global.
 */

var global = (function(){ return this })();

/**
 * Make `fn` callable only once.
 *
 * @param {Function} fn
 * @return {Function}
 * @api public
 */

module.exports = function(fn) {
  var id = n++;

  function once(){
    // no receiver
    if (this == global) {
      if (once.called) return;
      once.called = true;
      return fn.apply(this, arguments);
    }

    // receiver
    var key = '__called_' + id + '__';
    if (this[key]) return;
    this[key] = true;
    return fn.apply(this, arguments);
  }

  return once;
};

});

require.register("yields~after-transition@0.0.1", function (exports, module) {

/**
 * dependencies
 */

var has = require('yields~has-transitions@1.0.0')
  , emitter = require('ecarter~css-emitter@0.0.1')
  , once = require('component~once@0.0.1');

/**
 * Transition support.
 */

var supported = has();

/**
 * Export `after`
 */

module.exports = after;

/**
 * Invoke the given `fn` after transitions
 *
 * It will be invoked only if the browser
 * supports transitions __and__
 * the element has transitions
 * set in `.style` or css.
 *
 * @param {Element} el
 * @param {Function} fn
 * @return {Function} fn
 * @api public
 */

function after(el, fn){
  if (!supported || !has(el)) return fn();
  emitter(el).bind(fn);
  return fn;
};

/**
 * Same as `after()` only the function is invoked once.
 *
 * @param {Element} el
 * @param {Function} fn
 * @return {Function}
 * @api public
 */

after.once = function(el, fn){
  var callback = once(fn);
  after(el, fn = function(){
    emitter(el).unbind(fn);
    callback();
  });
};

});

require.register("component~emitter@1.2.0", function (exports, module) {

/**
 * Expose `Emitter`.
 */

module.exports = Emitter;

/**
 * Initialize a new `Emitter`.
 *
 * @api public
 */

function Emitter(obj) {
  if (obj) return mixin(obj);
};

/**
 * Mixin the emitter properties.
 *
 * @param {Object} obj
 * @return {Object}
 * @api private
 */

function mixin(obj) {
  for (var key in Emitter.prototype) {
    obj[key] = Emitter.prototype[key];
  }
  return obj;
}

/**
 * Listen on the given `event` with `fn`.
 *
 * @param {String} event
 * @param {Function} fn
 * @return {Emitter}
 * @api public
 */

Emitter.prototype.on =
Emitter.prototype.addEventListener = function(event, fn){
  this._callbacks = this._callbacks || {};
  (this._callbacks['$' + event] = this._callbacks['$' + event] || [])
    .push(fn);
  return this;
};

/**
 * Adds an `event` listener that will be invoked a single
 * time then automatically removed.
 *
 * @param {String} event
 * @param {Function} fn
 * @return {Emitter}
 * @api public
 */

Emitter.prototype.once = function(event, fn){
  function on() {
    this.off(event, on);
    fn.apply(this, arguments);
  }

  on.fn = fn;
  this.on(event, on);
  return this;
};

/**
 * Remove the given callback for `event` or all
 * registered callbacks.
 *
 * @param {String} event
 * @param {Function} fn
 * @return {Emitter}
 * @api public
 */

Emitter.prototype.off =
Emitter.prototype.removeListener =
Emitter.prototype.removeAllListeners =
Emitter.prototype.removeEventListener = function(event, fn){
  this._callbacks = this._callbacks || {};

  // all
  if (0 == arguments.length) {
    this._callbacks = {};
    return this;
  }

  // specific event
  var callbacks = this._callbacks['$' + event];
  if (!callbacks) return this;

  // remove all handlers
  if (1 == arguments.length) {
    delete this._callbacks['$' + event];
    return this;
  }

  // remove specific handler
  var cb;
  for (var i = 0; i < callbacks.length; i++) {
    cb = callbacks[i];
    if (cb === fn || cb.fn === fn) {
      callbacks.splice(i, 1);
      break;
    }
  }
  return this;
};

/**
 * Emit `event` with the given args.
 *
 * @param {String} event
 * @param {Mixed} ...
 * @return {Emitter}
 */

Emitter.prototype.emit = function(event){
  this._callbacks = this._callbacks || {};
  var args = [].slice.call(arguments, 1)
    , callbacks = this._callbacks['$' + event];

  if (callbacks) {
    callbacks = callbacks.slice(0);
    for (var i = 0, len = callbacks.length; i < len; ++i) {
      callbacks[i].apply(this, args);
    }
  }

  return this;
};

/**
 * Return array of callbacks for `event`.
 *
 * @param {String} event
 * @return {Array}
 * @api public
 */

Emitter.prototype.listeners = function(event){
  this._callbacks = this._callbacks || {};
  return this._callbacks['$' + event] || [];
};

/**
 * Check if this emitter has `event` handlers.
 *
 * @param {String} event
 * @return {Boolean}
 * @api public
 */

Emitter.prototype.hasListeners = function(event){
  return !! this.listeners(event).length;
};

});

require.register("yields~css-ease@0.0.1", function (exports, module) {

/**
 * CSS Easing functions
 */

module.exports = {
    'in':                'ease-in'
  , 'out':               'ease-out'
  , 'in-out':            'ease-in-out'
  , 'snap':              'cubic-bezier(0,1,.5,1)'
  , 'linear':            'cubic-bezier(0.250, 0.250, 0.750, 0.750)'
  , 'ease-in-quad':      'cubic-bezier(0.550, 0.085, 0.680, 0.530)'
  , 'ease-in-cubic':     'cubic-bezier(0.550, 0.055, 0.675, 0.190)'
  , 'ease-in-quart':     'cubic-bezier(0.895, 0.030, 0.685, 0.220)'
  , 'ease-in-quint':     'cubic-bezier(0.755, 0.050, 0.855, 0.060)'
  , 'ease-in-sine':      'cubic-bezier(0.470, 0.000, 0.745, 0.715)'
  , 'ease-in-expo':      'cubic-bezier(0.950, 0.050, 0.795, 0.035)'
  , 'ease-in-circ':      'cubic-bezier(0.600, 0.040, 0.980, 0.335)'
  , 'ease-in-back':      'cubic-bezier(0.600, -0.280, 0.735, 0.045)'
  , 'ease-out-quad':     'cubic-bezier(0.250, 0.460, 0.450, 0.940)'
  , 'ease-out-cubic':    'cubic-bezier(0.215, 0.610, 0.355, 1.000)'
  , 'ease-out-quart':    'cubic-bezier(0.165, 0.840, 0.440, 1.000)'
  , 'ease-out-quint':    'cubic-bezier(0.230, 1.000, 0.320, 1.000)'
  , 'ease-out-sine':     'cubic-bezier(0.390, 0.575, 0.565, 1.000)'
  , 'ease-out-expo':     'cubic-bezier(0.190, 1.000, 0.220, 1.000)'
  , 'ease-out-circ':     'cubic-bezier(0.075, 0.820, 0.165, 1.000)'
  , 'ease-out-back':     'cubic-bezier(0.175, 0.885, 0.320, 1.275)'
  , 'ease-out-quad':     'cubic-bezier(0.455, 0.030, 0.515, 0.955)'
  , 'ease-out-cubic':    'cubic-bezier(0.645, 0.045, 0.355, 1.000)'
  , 'ease-in-out-quart': 'cubic-bezier(0.770, 0.000, 0.175, 1.000)'
  , 'ease-in-out-quint': 'cubic-bezier(0.860, 0.000, 0.070, 1.000)'
  , 'ease-in-out-sine':  'cubic-bezier(0.445, 0.050, 0.550, 0.950)'
  , 'ease-in-out-expo':  'cubic-bezier(1.000, 0.000, 0.000, 1.000)'
  , 'ease-in-out-circ':  'cubic-bezier(0.785, 0.135, 0.150, 0.860)'
  , 'ease-in-out-back':  'cubic-bezier(0.680, -0.550, 0.265, 1.550)'
};

});

require.register("component~query@0.0.3", function (exports, module) {
function one(selector, el) {
  return el.querySelector(selector);
}

exports = module.exports = function(selector, el){
  el = el || document;
  return one(selector, el);
};

exports.all = function(selector, el){
  el = el || document;
  return el.querySelectorAll(selector);
};

exports.engine = function(obj){
  if (!obj.one) throw new Error('.one callback required');
  if (!obj.all) throw new Error('.all callback required');
  one = obj.one;
  exports.all = obj.all;
  return exports;
};

});

require.register("move", function (exports, module) {
/**
 * Module Dependencies.
 */

var Emitter = require('component~emitter@1.2.0');
var query = require('component~query@0.0.3');
var after = require('yields~after-transition@0.0.1');
var has3d = require('component~has-translate3d@0.0.3');
var ease = require('yields~css-ease@0.0.1');

/**
 * CSS Translate
 */

var translate = has3d
  ? ['translate3d(', ', 0)']
  : ['translate(', ')'];

/**
 * Export `Move`
 */

module.exports = Move;

/**
 * Get computed style.
 */

var style = window.getComputedStyle
  || window.currentStyle;

/**
 * Library version.
 */

Move.version = '0.5.0';

/**
 * Export `ease`
 */

Move.ease = ease;

/**
 * Defaults.
 *
 *   `duration` - default duration of 500ms
 *
 */

Move.defaults = {
  duration: 500
};

/**
 * Default element selection utilized by `move(selector)`.
 *
 * Override to implement your own selection, for example
 * with jQuery one might write:
 *
 *     move.select = function(selector) {
 *       return jQuery(selector).get(0);
 *     };
 *
 * @param {Object|String} selector
 * @return {Element}
 * @api public
 */

Move.select = function(selector){
  if ('string' != typeof selector) return selector;
  return query(selector);
};

/**
 * Initialize a new `Move` with the given `el`.
 *
 * @param {Element} el
 * @api public
 */

function Move(el) {
  if (!(this instanceof Move)) return new Move(el);
  if ('string' == typeof el) el = query(el);
  if (!el) throw new TypeError('Move must be initialized with element or selector');
  this.el = el;
  this._props = {};
  this._rotate = 0;
  this._transitionProps = [];
  this._transforms = [];
  this.duration(Move.defaults.duration)
};


/**
 * Inherit from `EventEmitter.prototype`.
 */

Emitter(Move.prototype);

/**
 * Buffer `transform`.
 *
 * @param {String} transform
 * @return {Move} for chaining
 * @api private
 */

Move.prototype.transform = function(transform){
  this._transforms.push(transform);
  return this;
};

/**
 * Skew `x` and `y`.
 *
 * @param {Number} x
 * @param {Number} y
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.skew = function(x, y){
  return this.transform('skew('
    + x + 'deg, '
    + (y || 0)
    + 'deg)');
};

/**
 * Skew x by `n`.
 *
 * @param {Number} n
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.skewX = function(n){
  return this.transform('skewX(' + n + 'deg)');
};

/**
 * Skew y by `n`.
 *
 * @param {Number} n
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.skewY = function(n){
  return this.transform('skewY(' + n + 'deg)');
};

/**
 * Translate `x` and `y` axis.
 *
 * @param {Number} x
 * @param {Number} y
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.translate =
Move.prototype.to = function(x, y){
  return this.transform(translate.join(''
    + x +'px, '
    + (y || 0)
    + 'px'));
};

/**
 * Translate on the x axis to `n`.
 *
 * @param {Number} n
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.translateX =
Move.prototype.x = function(n){
  return this.transform('translateX(' + n + 'px)');
};

/**
 * Translate on the y axis to `n`.
 *
 * @param {Number} n
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.translateY =
Move.prototype.y = function(n){
  return this.transform('translateY(' + n + 'px)');
};

/**
 * Scale the x and y axis by `x`, or
 * individually scale `x` and `y`.
 *
 * @param {Number} x
 * @param {Number} y
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.scale = function(x, y){
  return this.transform('scale('
    + x + ', '
    + (y || x)
    + ')');
};

/**
 * Scale x axis by `n`.
 *
 * @param {Number} n
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.scaleX = function(n){
  return this.transform('scaleX(' + n + ')')
};

/**
 * Apply a matrix transformation
 *
 * @param {Number} m11 A matrix coefficient
 * @param {Number} m12 A matrix coefficient
 * @param {Number} m21 A matrix coefficient
 * @param {Number} m22 A matrix coefficient
 * @param {Number} m31 A matrix coefficient
 * @param {Number} m32 A matrix coefficient
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.matrix = function(m11, m12, m21, m22, m31, m32){
  return this.transform('matrix(' + [m11,m12,m21,m22,m31,m32].join(',') + ')');
};

/**
 * Scale y axis by `n`.
 *
 * @param {Number} n
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.scaleY = function(n){
  return this.transform('scaleY(' + n + ')')
};

/**
 * Rotate `n` degrees.
 *
 * @param {Number} n
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.rotate = function(n){
  return this.transform('rotate(' + n + 'deg)');
};

/**
 * Set transition easing function to to `fn` string.
 *
 * When:
 *
 *   - null "ease" is used
 *   - "in" "ease-in" is used
 *   - "out" "ease-out" is used
 *   - "in-out" "ease-in-out" is used
 *
 * @param {String} fn
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.ease = function(fn){
  fn = ease[fn] || fn || 'ease';
  return this.setVendorProperty('transition-timing-function', fn);
};

/**
 * Set animation properties
 *
 * @param {String} name
 * @param {Object} props
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.animate = function(name, props){
  for (var i in props){
    if (props.hasOwnProperty(i)){
      this.setVendorProperty('animation-' + i, props[i])
    }
  }
  return this.setVendorProperty('animation-name', name);
}

/**
 * Set duration to `n`.
 *
 * @param {Number|String} n
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.duration = function(n){
  n = this._duration = 'string' == typeof n
    ? parseFloat(n) * 1000
    : n;
  return this.setVendorProperty('transition-duration', n + 'ms');
};

/**
 * Delay the animation by `n`.
 *
 * @param {Number|String} n
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.delay = function(n){
  n = 'string' == typeof n
    ? parseFloat(n) * 1000
    : n;
  return this.setVendorProperty('transition-delay', n + 'ms');
};

/**
 * Set `prop` to `val`, deferred until `.end()` is invoked.
 *
 * @param {String} prop
 * @param {String} val
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.setProperty = function(prop, val){
  this._props[prop] = val;
  return this;
};

/**
 * Set a vendor prefixed `prop` with the given `val`.
 *
 * @param {String} prop
 * @param {String} val
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.setVendorProperty = function(prop, val){
  this.setProperty('-webkit-' + prop, val);
  this.setProperty('-moz-' + prop, val);
  this.setProperty('-ms-' + prop, val);
  this.setProperty('-o-' + prop, val);
  return this;
};

/**
 * Set `prop` to `value`, deferred until `.end()` is invoked
 * and adds the property to the list of transition props.
 *
 * @param {String} prop
 * @param {String} val
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.set = function(prop, val){
  if (typeof prop == "object") {
    for (var key in prop) {
      if (prop.hasOwnProperty(key)) {
        this.transition(key);
        this._props[key] = prop[key];
      }
    }
  } else {
    this.transition(prop);
    this._props[prop] = val;  
  } 
  return this;
};

/**
 * Increment `prop` by `val`, deferred until `.end()` is invoked
 * and adds the property to the list of transition props.
 *
 * @param {String} prop
 * @param {Number} val
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.add = function(prop, val){
  if (!style) return;
  var self = this;
  return this.on('start', function(){
    var curr = parseInt(self.current(prop), 10);
    self.set(prop, curr + val + 'px');
  });
};

/**
 * Decrement `prop` by `val`, deferred until `.end()` is invoked
 * and adds the property to the list of transition props.
 *
 * @param {String} prop
 * @param {Number} val
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.sub = function(prop, val){
  if (!style) return;
  var self = this;
  return this.on('start', function(){
    var curr = parseInt(self.current(prop), 10);
    self.set(prop, curr - val + 'px');
  });
};

/**
 * Get computed or "current" value of `prop`.
 *
 * @param {String} prop
 * @return {String}
 * @api public
 */

Move.prototype.current = function(prop){
  return style(this.el).getPropertyValue(prop);
};

/**
 * Add `prop` to the list of internal transition properties.
 *
 * @param {String} prop
 * @return {Move} for chaining
 * @api private
 */

Move.prototype.transition = function(prop){
  if (!this._transitionProps.indexOf(prop)) return this;
  this._transitionProps.push(prop);
  return this;
};

/**
 * Commit style properties, aka apply them to `el.style`.
 *
 * @return {Move} for chaining
 * @see Move#end()
 * @api private
 */

Move.prototype.applyProperties = function(){
  for (var prop in this._props) {
    this.el.style.setProperty(prop, this._props[prop], '');
  }
  return this;
};

/**
 * Re-select element via `selector`, replacing
 * the current element.
 *
 * @param {String} selector
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.move =
Move.prototype.select = function(selector){
  this.el = Move.select(selector);
  return this;
};

/**
 * Defer the given `fn` until the animation
 * is complete. `fn` may be one of the following:
 *
 *   - a function to invoke
 *   - an instanceof `Move` to call `.end()`
 *   - nothing, to return a clone of this `Move` instance for chaining
 *
 * @param {Function|Move} fn
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.then = function(fn){
  // invoke .end()
  if (fn instanceof Move) {
    this.on('end', function(){
      fn.end();
    });
  // callback
  } else if ('function' == typeof fn) {
    this.on('end', fn);
  // chain
  } else {
    var clone = new Move(this.el);
    clone._transforms = this._transforms.slice(0);
    this.then(clone);
    clone.parent = this;
    return clone;
  }

  return this;
};

/**
 * Pop the move context.
 *
 * @return {Move} parent Move
 * @api public
 */

Move.prototype.pop = function(){
  return this.parent;
};

/**
 * Reset duration.
 *
 * @return {Move}
 * @api public
 */

Move.prototype.reset = function(){
  this.el.style.webkitTransitionDuration =
  this.el.style.mozTransitionDuration =
  this.el.style.msTransitionDuration =
  this.el.style.oTransitionDuration = '';
  return this;
};

/**
 * Start animation, optionally calling `fn` when complete.
 *
 * @param {Function} fn
 * @return {Move} for chaining
 * @api public
 */

Move.prototype.end = function(fn){
  var self = this;

  // emit "start" event
  this.emit('start');

  // transforms
  if (this._transforms.length) {
    this.setVendorProperty('transform', this._transforms.join(' '));
  }

  // transition properties
  this.setVendorProperty('transition-properties', this._transitionProps.join(', '));
  this.applyProperties();

  // callback given
  if (fn) this.then(fn);

  // emit "end" when complete
  after.once(this.el, function(){
    self.reset();
    self.emit('end');
  });

  return this;
};

});

if (typeof exports == "object") {
  module.exports = require("move");
} else if (typeof define == "function" && define.amd) {
  define("move", [], function(){ return require("move"); });
} else {
  (this || window)["move"] = require("move");
}
})()