PopupButton isn’t intended to be used as a help page, take a look at the contextHelp attribute instead. For complex layout you can subscribe on ContextClickEvent and show MessageDialog with help text.
In order to display scrollbars, ScrollBox component must have size, in your layout it has auto size which means that it has size equals to it content size, hence no scrollbars available.
PopupButton can show its popup in different location if no enough space available to display popup.
I’ll try to use the component you suggested.
I saw that is possible to create a MessageDialog from the Controller using HTML, It’s possibile to put an image inside the MessageDialog ?
Thank you,