What is the best way to handle multiple key events in Javascript?

Question

Pressing space bar in game will make a character shoot, pressing space bar when a confirmation box is shown will make this box disappear and pressing space bar in a highscore fo

Answer 1

you could instead add and remove the event listener as needed.

let's assume you're using a javascript framework (if you're not, then you probably should be considering the amount of JS code involved in a game like this)

using PrototypeJS:

when game starts,

document.observe("keydown",shootHandler());

when the message box is created,

function createBox(text) {
    ...snip

    document.observe("keydown",closeBox());
    document.fire("game:pause");
}

and, for example

var paused = false;

function shoothandler() {
   if (!paused) {
       alert("pew! pew!");
   }
}

function closeBox() {
    $('messagebox').remove();
    document.fire("game:unpaused");
    document.stopObserving("keydown",closeBox());
}

document.observe("game:paused", function() { paused = true;});
document.observe("game:unpaused", function() { paused = false;});
document.observe("game:over", function() { document.stopObserving("keydown",shootHandler());});

I haven't included the high score screen but the theory is the same.

As you can see, I also used custom events to notify the pause status. The same event could also be fire by a puase button in the interface, etc...