Imagine this code:
if (navigator.appName == "Opera")
document.onkeypress = function (e) { console.log(e.keyCode); };
else
document.onkeydown = function (e) { console.log(e.keyCode); };
What it does is pretty obvious, I guess. The problem is, if you hold the key for a long period of time, it will be registered a lot of times. In my app, this is a problem because it makes my app do a lot of unnecessary puting. Is it possible to somehow only get a keypress once, but with info on how long the key was held?
Imagine this code:
if (navigator.appName == "Opera")
document.onkeypress = function (e) { console.log(e.keyCode); };
else
document.onkeydown = function (e) { console.log(e.keyCode); };
What it does is pretty obvious, I guess. The problem is, if you hold the key for a long period of time, it will be registered a lot of times. In my app, this is a problem because it makes my app do a lot of unnecessary puting. Is it possible to somehow only get a keypress once, but with info on how long the key was held?
-
I'm no expert on logic or anything but shouldn't the branches of an if statement differ?
:)– Šime Vidas Commented Jun 24, 2011 at 19:59 - Do you use a library like jQuery? – Šime Vidas Commented Jun 24, 2011 at 20:03
- Oops, yes, you're right, of course they should differ %) No, I don't use jQuery or any other framework. – Aleksejs Popovs Commented Jun 25, 2011 at 7:47
2 Answers
Reset to default 13Here you go:
var pressed = {};
window.onkeydown = function(e) {
if ( pressed[e.which] ) return;
pressed[e.which] = e.timeStamp;
};
window.onkeyup = function(e) {
if ( !pressed[e.which] ) return;
var duration = ( e.timeStamp - pressed[e.which] ) / 1000;
// Key "e.which" was pressed for "duration" seconds
pressed[e.which] = 0;
};
Live demo: http://jsfiddle/EeXVX/1/show/
(remove the "show/" part of the URL to view the code for the demo)
So you have the pressed object which monitors which keys are currently being pressed and at what point (in time) they have been pressed.
Inside the keyup handler, you determine if the key was being pressed, and if so, calculate the duration by subtracting the time-stamps of the keyup/keydown events.
Have you tried doing somethign like,
- onkeydown, remove keydown listener.
- onkeyup, attach keydown listener again and puter the time?