    /**
     * @private
     */
    Ext.define('Ext.fx.animation.Fade', {
        extend: 'Ext.fx.animation.Abstract',

        alternateClassName: 'Ext.fx.animation.FadeIn',

        alias: ['animation.fade', 'animation.fadeIn'],

        config: {
            /**
             * @cfg {Boolean} out True if you want to make this animation fade out, instead of fade in.
             * @accessor
             */

            out: false,

            before: {
                display: null,
                opacity: 0
            },

            after: {
                opacity: null
            },
            reverse: null
        },

        updateOut: function(newOut) {
            var to   = this.getTo(),
                from = this.getFrom();

            if (newOut) {
                from.set('opacity', 1);
                to.set('opacity',   0);
            } else {
                from.set('opacity', 0);
                to.set('opacity',   1);
            }
        }
    });