// is always completely visible and the rest of the width is evenly
// distributed between the other columns.
// If the first column is bigger than the half of the table width
// the tree column is set to the half table width. The user can
// still make the column smaller or bigger.
ColumnSizeConstraint csc = new RatioConstraint(true);
csc.addMaxSizeForColumn(0, 0.5);
setAutoResizeMode(AUTO_RESIZE_NEXT_COLUMN);
setColumnSizeConstraint(csc);
setShowGrid(false);