I needed for my GWT project a panel that supports showing a set of widgets in a group (GroupBox panle). I needed the exact functionality like the HTML fieldset/legend tags:

I didn’t found any ready-to-use widget so I implemented one myself. Here is the source code:

import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Element;
import com.google.gwt.user.client.ui.FlowPanel;

public class GroupBoxPanel extends FlowPanel {

private Element legend;

public GroupBoxPanel() {
Element fieldset = DOM.createFieldSet();
this.legend = DOM.createLegend();
DOM.appendChild(fieldset, legend);
setElement(fieldset);
}

public String getCaption() {
return DOM.getInnerText(this.legend);
}

public void setCaption(String caption) {
DOM.setInnerText(this.legend, caption);
}
}

It was really easy to extend the flow panel and add <fieldset> and <legend> tags around the panel element. Hope this widget will be useful to everybody. I may wish to modify the CSS to make it look better.