让Extjs EditorGridPanel 编辑时支持方向键

在用 extjs editorgridpanel 进行输入编辑的时候, 默认情况下只支持使用 tab 键可以实现焦点切换, 如果想让editorgridpanel 在编辑时通过方向键来实现焦点跳转切换，只需加上以下代码：

//让grid支持方向键盘 by liongis@163.com
Ext.override(Ext.grid.CellSelectionModel, {
    onEditorKey : function(field, e) {
        var smodel = this;
        var k = e.getKey(), newCell, g = smodel.grid, ed = g.activeEditor;
        switch(k){
            case e.TAB:
                 e.stopEvent();
                 ed.completeEdit();
                 if (e.shiftKey) {
                     newCell = g.walkCells(ed.row, ed.col-1, -1, smodel.acceptsNav, smodel);
                 } else {
                     newCell = g.walkCells(ed.row, ed.col+1, 1, smodel.acceptsNav, smodel);
                 }
                 if (ed.col == 1) {
                     if (e.shiftKey) {
                         newCell = g.walkCells(ed.row, ed.col+1, -1, smodel.acceptsNav, smodel);
                     } else {
                         newCell = g.walkCells(ed.row, ed.col+1, 1, smodel.acceptsNav, smodel);
                     }
                 }
                break;
            case e.UP:
                 e.stopEvent();
                 ed.completeEdit();
                 newCell = g.walkCells(ed.row-1, ed.col, -1, smodel.acceptsNav, smodel);
                break;
            case e.DOWN:
                 e.stopEvent();
                 ed.completeEdit();
                 newCell = g.walkCells(ed.row+1, ed.col, 1, smodel.acceptsNav, smodel);
                break;
            case e.LEFT:
                 e.stopEvent();
                 ed.completeEdit();
                 newCell = g.walkCells(ed.row, ed.col-1, -1, smodel.acceptsNav, smodel);
                 break;
             case e.RIGHT:
                 e.stopEvent();
                 ed.completeEdit();
                 newCell = g.walkCells(ed.row, ed.col+1, 1, smodel.acceptsNav, smodel);
                   break;
        }
       if (newCell) {
            g.startEditing(newCell[0], newCell[1]);
       }
     }
});

注意：这里重写的是：CellSelectionModel ，而不是RowSelectionModel