mixGridDataLayer.setColumnWidthByPosition(0, 100);
mixGridDataLayer.setColumnWidthByPosition(1, 100);
final NatTable mixGrid = new NatTable(gridPanel, gridLayer, false);
mixGrid.addConfiguration(new DefaultNatTableStyleConfiguration());
mixGrid.addConfiguration(new HeaderMenuConfiguration(mixGrid));
mixGrid.configure();
GridDataFactory.fillDefaults().grab(true, true).applyTo(mixGrid);
Button addColumnButton = new Button(buttonPanel, SWT.PUSH);
addColumnButton.setText("add column - no width");
addColumnButton.addSelectionListener(new SelectionAdapter() {