Button right click

For an exam work we need to create a game, For this project i choose minesweeper.
a field is represented as a button.
Each button can be checked and can be marked.
the check part of the project works but Now i’m looking for a way to mark the button with de right click on the button.
The buttons are placed on a grid layout and I want to override the clickEvent. but in Vaadin 7 the “getButton().Equals(MouseButton.LEFT)” wont work.
Can someone point me in the right direction please.