/*!
 * Masonry layout mode
 * sub-classes Masonry
 * http://masonry.desandro.com
 */

( function( window ) {

'use strict';

// -------------------------- helpers -------------------------- //

// extend objects
function extend( a, b ) {
  for ( var prop in b ) {
    a[ prop ] = b[ prop ];
  }
  return a;
}

// -------------------------- masonryDefinition -------------------------- //

// used for AMD definition and requires
function masonryDefinition( LayoutMode, Masonry ) {
  // create an Outlayer layout class
  var MasonryMode = LayoutMode.create('masonry');

  // save on to these methods
  var _getElementOffset = MasonryMode.prototype._getElementOffset;
  var layout = MasonryMode.prototype.layout;
  var _getMeasurement = MasonryMode.prototype._getMeasurement;

  // sub-class Masonry
  extend( MasonryMode.prototype, Masonry.prototype );

  // set back, as it was overwritten by Masonry
  MasonryMode.prototype._getElementOffset = _getElementOffset;
  MasonryMode.prototype.layout = layout;
  MasonryMode.prototype._getMeasurement = _getMeasurement;

  var measureColumns = MasonryMode.prototype.measureColumns;
  MasonryMode.prototype.measureColumns = function() {
    // set items, used if measuring first item
    this.items = this.isotope.filteredItems;
    measureColumns.call( this );
  };

  return MasonryMode;
}

// -------------------------- transport -------------------------- //

if ( typeof define === 'function' && define.amd ) {
  // AMD
  define( [
      '../layout-mode',
      'masonry/masonry'
    ],
    masonryDefinition );
} else {
  // browser global
  masonryDefinition(
    window.Isotope.LayoutMode,
    window.Masonry
  );
}

})( window );