Its simple in JSF, but no so simple in vaadin 8… NumberField lets anything to write
ValueChangeEvent is only triggered when a the value is a number, but if i write a non numeric character, it wont be triggered again, until i delete all non numeric chars, so solutions like the last, arent work https://stackoverflow.com/questions/17144798/how-do-i-create-a-textfield-which-supports-numbers-only-in-vaadin
Why its even possible to write non numeric in a component, called NUMBERField?