// set a background to let user see limits of the component
componentPanel.setBackground(new Color(Display.getCurrent(), 255, 175, 175));// PINK as in awt
final TextField theComponent = new TextField(componentPanel, SWT.NONE);
theComponent.setText("A TextField");
theComponent.setLayoutData(new RowData(100, 30));
// ----------
Group testPanel = getTestPanel(mainComposite, theComponent);
GridData testPanelGridData = new GridData();
testPanelGridData.grabExcessHorizontalSpace = true;