Redactor formatting buttons active state

[yingban]

Hi,

I would like to know how I can add an active state, with a class for example on formatting buttons?
Foe this I would need some kind of on select event, which add a class to a button, and remove it on blur.

For example, if a user selects "Heading 1" for some text, he should be able to know that "Heading 1" was selected.

Thank you for your help.

[yingban]

I found a solution by using "ondropdown" event, which check my current selection text tag and classes, then toggle a class on the corresponding button.