/* set z-tree as group(role) since it contains multiple roles including a focus button.
     * set header and footer as grid(role)
     * set set cave table as treegrid(role) since it contains a tree
     */
    var exTree = {};
    zk.override(zul.sel.Tree.prototype, exTree, {
        bind_: function() {
            exTree.bind_.apply(this, arguments);
            this.$n().setAttribute('role', 'group');
            setFocusAnchorAriaLabel.bind(this)();
            this.$n('cave').setAttribute('role', 'treegrid'); //zk-5448
            //zk-5374
            var headTbl = this.$n('headtbl');
            if (headTbl) {
                headTbl.setAttribute('role', 'grid');
            }
            var footTbl = this.$n('foottbl');
            if (footTbl) {
                footTbl.setAttribute('role', 'grid');
            }
            this.$n('rows').setAttribute('role', 'rowgroup');
            //for paging control
            jq('.z-tree-paging-bottom', this.$n()).attr('role', 'row');
            jq('.z-paging', this.$n()).attr('role', 'gridcell');
        },

        //in tree-rod.js
        _setPadSize: function(pad, padId, sz) {
            //set pad size
            this._padsz[padId] = sz;
            var s = pad.style;
            s.display = sz ? 'block' : 'none';
            var html = '<table id="' + this.uuid + '-' + padId + '-tbl" role="none">';
            
            while (true) {
              html += '<tr><td style="height:' + Math.min(sz, maxsz) + 'px"></td></tr>';
              sz -= maxsz;
              if (sz <= 0) //last one
                break;
            }
            
            html += '</table>';
            jq(pad).empty().append(html);
        },
    });

    //zk-5374
    var _xTreecols = {};
    zk.override(zul.sel.Treecols.prototype, _xTreecols, {
        bind_: function () {
            _xTreecols.bind_.apply(this, arguments);
            this.$n().setAttribute('role', 'row');
        }
    });

    //zk-5374
    var _xTreecol = {};
    zk.override(zul.sel.Treecol.prototype, _xTreecol, {
        bind_: function () {
            _xTreecol.bind_.apply(this, arguments);
            this.$n().setAttribute('role', 'columnheader');
        }
    });

function setFocusAnchorAriaLabel(){
    this.$n('a').setAttribute('aria-label', 'focus');
}