we can update value with a click on the calendar icon (idem on comboBox):

PHP Code:
        FormPanel panel = new FormPanel();
        
panel.setSize(340180);
        
panel.setFrame(false);
        
panel.setHeaderVisible(false);
        
panel.setBodyBorder(false);
        
panel.setButtonAlign(HorizontalAlignment.CENTER);
        
panel.setLayout(new FitLayout());

        
TabPanel tabs = new TabPanel();

        
TabItem personal = new TabItem();
        
personal.setText("Personal Details");
        
personal.setLayout(new FormLayout());

        
DateField d = new DateField();
        
d.setFieldLabel("d");
        
d.setReadOnly(true);
        
personal.add(d);

        
tabs.add(personal);
        
panel.add(tabs);

        
Viewport v = new Viewport();
        
v.add(panel);
        
RootPanel.get().add(v);