SmartGWT: make a grid cell non-editable/readonly

You can override the method protected boolean canEditCell(int rowNum, int colNum) in ListGrid

public class XmlTreeGrid extends TreeGrid {

 public XmlTreeGrid() {
                // 
 }

 protected boolean canEditCell(int rowNum, int colNum) {
  if (colNum == 0) {
   return false;
  }
  XmlTreeNode node = (XmlTreeNode) getRecord(rowNum);
  if (node.value() == null) {
   return false;
  }
  return true;
 }

}

See Also here