#include <MTobjects.h> // https://github.com/OlivierPcheux/MTobjects

const byte buttonPin = 9;
const byte ledPins[] = {2, 3, 4, 5};
const byte ledCnt = sizeof ledPins / sizeof * ledPins;
const byte pot1Pin = A0;
const byte pot2Pin = A1;

volatile bool blinkMode = true; // modified through button ISR

void onPress() {blinkMode = !blinkMode;}
MTbutton Bouton(buttonPin, onPress, nullptr); // no need for an onRelease callback

void setup() {
  for (byte aPin : ledPins)pinMode(aPin, OUTPUT);
  pinMode(buttonPin, INPUT_PULLUP);
}

void loop() {
  int pot1 = analogRead(pot1Pin);
  int pot2 = analogRead(pot2Pin);
  if (blinkMode) { // atomic read for a byte size flag
    for (byte aPin : ledPins) digitalWrite(aPin, HIGH);
    delay(pot1);
    for (byte aPin : ledPins) digitalWrite(aPin, LOW);
    delay(pot2);
  } else {
    for (byte i = 0; i < ledCnt; i++) {
      digitalWrite(ledPins[i], HIGH);
      delay(pot1 + pot2);
      digitalWrite(ledPins[i], LOW);
    }
  }
}