    Ext.define('Ext.rtl.resizer.BorderSplitterTracker', {
        override: 'Ext.resizer.BorderSplitterTracker',

        rtlDirections: {
            top: 'top',
            right: 'left',
            bottom: 'bottom',
            left: 'right'
        },

        getCollapseDirection: function() {
            var direction = this.splitter.getCollapseDirection();
            if (!this.splitter.getHierarchyState().rtl !== !Ext.rootHierarchyState.rtl) {
                direction = this.rtlDirections[direction];
            }
            return direction;
        }
    });