How to set a border on a Vaadin component?

Question

I would like to programmatically set a border around a Form component in Java. How can I do this without having to edit the css style sheet?

Answer 1

Vaadin Flow — Style::set to specify CSS

In Vaadin Flow (Vaadin versions 10 and later), you can conveniently set CSS for a widget or layout programmatically. No need to edit separate CSS files, even though styling with CSS files is the recommended way.

1. On your widget/layout, call getStyle to retrieve the Style object.
2. On that Style object, call set to pass the name and value of your CSS property.

For example, I find setting a bright colored border on my nested layouts quite helpful for debugging.

myVerticalLayout.getStyle().set( "border" , "6px dotted DarkOrange" ) ; 

You can see this in action with this screenshot on my Answer to another Vaadin question here: