    /**
     * This layout manager is used to center contents within a container. As a subclass of
     * {@link Ext.layout.container.Fit fit layout}, CenterLayout expects to have one child
     * item; multiple items will be placed overlapping. The layout does not require any config
     * options. Items in the container can use percentage width or height rather than be fit
     * to the full size of the container.
     *
     * Example usage:
     *
     *      // The content panel is centered in the container
     *
     *      var p = Ext.create('Ext.Panel', {
     *          title: 'Center Layout',
     *          layout: 'ux.center',
     *          items: [{
     *              title: 'Centered Content',
     *              width: '75%',  // assign 75% of the container width to the item
     *              html: 'Some content'
     *          }]
     *      });
     *
     * If you leave the title blank and specify no border you can create a non-visual, structural
     * container just for centering the contents.
     *
     *      var p = Ext.create('Ext.Container', {
     *          layout: 'ux.center',
     *          items: [{
     *              title: 'Centered Content',
     *              width: 300,
     *              height: '90%', // assign 90% of the container height to the item
     *              html: 'Some content'
     *          }]
     *      });
     */
    Ext.define('Ext.ux.layout.Center', {
        extend: 'Ext.layout.container.Fit',
        alias: 'layout.ux.center',

        percentRe: /^\d+(?:\.\d+)?\%$/,

        itemCls: 'ux-layout-center-item',

        initLayout: function () {
            this.callParent(arguments);

            this.owner.addCls('ux-layout-center');
        },

        getItemSizePolicy: function (item) {
            var policy = this.callParent(arguments);
            if (typeof item.width == 'number') {
                policy = this.sizePolicies[policy.setsHeight ? 2 : 0];
            }
            return policy;
        },

        getPos: function (itemContext, info, dimension) {
            var size = itemContext.props[dimension] + info.margins[dimension],
                pos = Math.round((info.targetSize[dimension] - size) / 2);

            return Math.max(pos, 0);
        },

        getSize: function (item, info, dimension) {
            var ratio = item[dimension];

            if (typeof ratio == 'string' && this.percentRe.test(ratio)) {
                ratio = parseFloat(ratio) / 100;
            } else {
                ratio = item[dimension + 'Ratio']; // backwards compat
            }

            return info.targetSize[dimension] * (ratio || 1) - info.margins[dimension];
        },

        positionItemX: function (itemContext, info) {
            var left = this.getPos(itemContext, info, 'width');

            itemContext.setProp('x', left);
        },

        positionItemY: function (itemContext, info) {
            var top = this.getPos(itemContext, info, 'height');

            itemContext.setProp('y', top);
        },

        setItemHeight: function (itemContext, info) {
            var height = this.getSize(itemContext.target, info, 'height');

            itemContext.setHeight(height);
        },

        setItemWidth: function (itemContext, info) {
            var width = this.getSize(itemContext.target, info, 'width');

            itemContext.setWidth(width);
        }
    });