how to detect a Key Sequence in Javascript

July 28, 2023

i am writing an userscript that post in a forum each time a shortcut sequence is executed [ ctrl + enter ], but the function that i wrote excecutes both keydowns as separate events, and not a single sequence.

i checked the related questions, but none of them really exlained how to configure the function to handle the sequence.

this is the code that i wrote :

let boutton_toast = document.querySelector('.btn-poster-msg');

function toast(e){
    if (e.ctrlKey && e.key=="Enter"){
       boutton_toast.click();
}
document.addEventListener("keydown", toast)

i feel like the answer is really obvious but i can’t guess it.

>Solution :

You could try creating a list (or any data structure really) that stores the variables, something like this:

pressedKeys = [];

function bothKeysPressed() {
    if (pressedKeys.includes('Enter') && pressedKeys.includes('Control')) {
      console.log("Enter and Control are pressed!");
    }
}

document.addEventListener('keydown', () => {
   pressedKeys.push(event.key)
   bothKeysPressed();
})

document.addEventListener('keyup', () => {
   pressedKeys = pressedKeys.filter(key => key !== event.key)
})

Then just include an additional function in your "keydown" listener that checks for the two keys you need.