Quite a useful thing, much used in desktop apps for grouping elements of a similar nature - radio button sets, grouping input (address lines
etc). It can hold only one widget.
Reference:
Example Demo:
Example Code:
function doGet() {
//create application
var app = UiApp.createApplication();
//Create Caption Panel
var captionPanel = app.createCaptionPanel('My Panel');
//Add a widget to caption panel
captionPanel.add(app.createLabel('This is the content of caption panel'));
//add the caption panel to the application
app.add(captionPanel);
return app;
}