How can I add a hover-text (i.e. a text box containing some explanation or details appearing when I hover with the mouse over a component) to TextFields, Tabs, Links, Labels, etc.
I googled and scanned the "Book of Vaadin" as well as "Building Modern Web Apps ..." books and neither contains any relevant info on hover-texts.
Have I missed something? Or are they known under some different term?
For example you can add a title:
yourComponent.getElement().setAttribute("title", "Your Explanation");
Read more about the title attribute in the docs: https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/title
If the native title attribute is not enough, you can look into add-ons. The Vaadin Directory has a Tooltips4Vaadin, or Tooltip. The second one is CVAL 3.0 licensed, but I believe it should be Apache 2.0. At least the corresponding web component is Apache 2.0.