Button clicked, NEGEDGE interrupt fired multiple times

[Piscenois]

I'm sorry if I was not very clear. I have 4 "normal" buttons and 1 rotary push button (= rotary encoder and push button at the same time).
I started speaking about the buttons, I searched solution for them but, when I worried about the rotary encoder, I saw some differences and spoke about it.
Finally, I think I will use hardware interrupt to poll both "normal" and rotary. But the debounce method will be different. The machine state solution seems efficient for rotary and the Elliot's ultimate debouncer for push buttons.

Regards