longpress-final.js

// Define variable
let pressTimer = null;

// Create timeout ( run function after 1s )
let start = (e) => {

    if (e.type === 'click' && e.button !== 0) {
        return;
    }

    if (pressTimer === null) {
        pressTimer = setTimeout(() => {

            // Execute something !!!

        }, 1000);
    }
}

// Cancel Timeout
let cancel = (e) => {

    // Check if timer has a value or not
    if (pressTimer !== null) {
        clearTimeout(pressTimer);
        pressTimer = null;
    }
}

// select element with id longPressButton
let el = document.getElementById('longPressButton');

// Add Event listeners
el.addEventListener("mousedown", start);

// Cancel timeouts if this events happen
el.addEventListener("click", cancel);
el.addEventListener("mouseout", cancel);