Upload Widget Button Styling

Hi,

I am looking as using an icon only look for the "upload " button. So I want to replace the regular button with upload text  to a VaadinIcon. this is very simple for regular buttons but I am not able to do the same with the "upload" component.

For regular buttons, the following works:
Button btn = new Button();
btn.setIcon(VaadinIcons.Upload);
btn.addStyleName(ValoTheme.BUTTON_ICON_ONLY);

How can I achieve the same for upload compoment please help.

The easiest way to do this in Vaadin 8 is to use Upload Button add-on https://vaadin.com/directory/component/uploadbutton-add-on