We Keep Coding

Detecting Alt key in Chrome

In my app I need to handle Alt key press/release to toggle additional information on tooltips. However, the first time Alt is pressed, document loses keyboard focus, because it goes to Chrome's menu. If I click any part of the document, it works again (once).
I can avoid this by calling preventDefault, but that also disables keyboard shortcuts such as Alt+Left/Right, which is undesirable.
I can also handle mousemove and check altKey flag, but it looks very awkward when things only update when mouse is moved.
Is there any way to reliably detect current Alt key state in my situation? I would really rather not switch to a different key.
Update: I suppose the best solution would be to call preventDefault only when a tooltip is active.
document.addEventListener("keydown", (e) => {
if (this.curComponent) e.preventDefault();
if (e.which === 18) {
this.outer.classList.add("AltKey");
}
});
document.addEventListener("keyup", (e) => {
if (this.curComponent) e.preventDefault();
if (e.which === 18) {
this.outer.classList.remove("AltKey");
}
});

I had the same issue and I solved thanks to this answer:
document.addEventListener("keyup", (e) => {
if (e.key === "Alt") {
return true; // Instead of e.preventDefault();
});
return true restores normal behavior of Alt+Left/Right chrome keyboard shortcuts.

Keyboard value both left/ right side ALT = 18
jQuery:
$(document).keyup(function(e){
if(e.which == 18){
alert("Alt key press");
}
});
JavaScript
document.keyup = function(e){
if(e.which == 18){
alert("Alt key press");
}
}

Keypress to change class in jQuery

I have a problem I can't seem to sort out.
I have a form with a custom styled button (input type=button). When typing in the text field, I want people to be able to press the TAB key and go to the button. However, it won't use a tab-index so my solution was to highlight the label and change the CSS to give the button a new border color. However, the border color will not change on keypress in any browser other than Firefox.
Here is what I have:
$(function() {
$("#email").bind("keypress", function(e) {
if (e.keyCode == 13) {
send();
return false;
};
if (e.keyCode == 9) {
$("#submit_btn").removeClass('submit1').addClass('submit1after');
};
});
};
The first enter keypress is to serialize and email the form and all.
I can't seem to get it to work for the life of me. What am I doing wrong? Is there a better solution to what I'm trying to accomplish?
Thanks for taking the time,
Armik

Use keydown instead, for me that works (see demo: http://jsfiddle.net/npGtX/2/)
$(function () {
$("#email").bind("keydown", function (e) {
if (e.keyCode == 13) {
send();
return false;
};
if (e.keyCode == 9) {
$("#submit_btn").removeClass('submit1').addClass('submit1after');
};
});
};
Also I found this: Suppressing keyPress for non-character keys?
keypress is not necessarily triggered when the keypress is not a
character. So the browser may not trigger an event on backspace, F1,
the down key, etc.

You can use the keyup event and event object's which property, jQuery normalizes the which property and it's cross-browser:
$(function() {
$("#email").bind("keyup", function(e) {
if (e.which == 13) {
send();
return false;
};
if (e.which == 9) {
$("#submit_btn").toggleClass('submit1 submit1after');
};
});
};

$(function() {
$("#email").keypress(function(e) {
if (e.keyCode == 13 || e.which== 13) {
send();
return false;
};
if (e.keyCode == 9 || e.which== 9) {
$("#submit_btn").removeClass('submit1').addClass('submit1after');
};
});
};

jQuery to trigger CSS3 button

I have this CSS3 enter button
here:
If you click it, it seems like it's pressed. I want to achieve the same effect (probably using jQuery), by pressing the enter key physically on my keyboard.
I did something like this: (sorry if it's completely wrong, I don't do jQuery at all)
<script type="text/javascript">
$(document).ready(function(){
$("enter").keypress(function(event){
if(event.keyCode == 13){
$(this).toggleClass(".button-clicked");
}
});
});
</script>
The CSS selector for the unpressed button is:
.button and .button.orange {}
The CSS selector for the pressed button is:
.button:active, .button-clicked {}
Thanks for your help!

I haven't tested this, but I think you should be able to do something like
I have just tested this (and linked to a demo, below the jQuery), and it works pretty well:
$('body').keydown(
function(e){
if (e.which == 13) { // enter
$('buttonSelector').addClass('button-clicked');
}
}).keyup(
function(e){
if (e.which == 13) { // enter
$('buttonSelector').removeClass('button-clicked');
}
});
JS Fiddle demo.
With this the keydown causes the button to appear pressed so long as the enter key is pressed, and, on release, triggers the keyup() handler, changing the style of the button so as to appear un-clicked.
Refined the above, somewhat, using on(), though having to use an if/else if statement to check the function type:
$('body').on('keydown keyup', function(e) {
if (e.type == 'keydown') {
if (e.which == 13) { // enter
$('#button').addClass('button-clicked');
}
}
else if (e.type == 'keyup') {
if (e.which == 13) { // enter
$('#button').removeClass('button-clicked');
}
}
});
JS Fiddle demo.
References:
keydown().
keyup().
addClass().
removeClass().
on().

You are trying to apply the keypress to an <enter></enter> element (which doesn't exist), try doing this:
<script type="text/javascript">
$(document).ready(function(){
$("body").keypress(function(event){
if(event.keyCode == 13){
$(".button").toggleClass("button-clicked");
}
});
});
</script>

Close but how about this:
//bind to the `keydown` event when the `document` is focused
$(document).on('keydown', function (event) {
//if enter is pressed
if (event.keyCode == 13) {
//add the `.button-clicked` class to any element with the `.button` class
$('.button').addClass('button-clicked');
}
}).on('keyup', function (event) {
if (event.keyCode == 13) {
$('.button').removeClass('button-clicked');
}
});
Here is a jsfiddle: http://jsfiddle.net/jasper/T5yEu/2/
Notice that I added !important to the .button-clicked class on several of the rules to make sure they are added to the element.

Bind enter key to specific button on page

<input type="button" id="save_post" class="button" value="Post" style="cursor:pointer;"/>
How can I bind the enter key on the persons keyboard to this specific button on the page? It's not in a form, and nor do I want it to be.
Thanks!

This will click the button regardless of where the "Enter" happens on the page:
$(document).keypress(function(e){
if (e.which == 13){
$("#save_post").click();
}
});

If you want to use pure javascript :
document.onkeydown = function (e) {
e = e || window.event;
switch (e.which || e.keyCode) {
case 13 : //Your Code Here (13 is ascii code for 'ENTER')
break;
}
}

using jQuery :
$('body').on('keypress', 'input', function(args) {
if (args.keyCode == 13) {
$("#save_post").click();
return false;
}
});
Or to bind specific inputs to different buttons you can use selectors
$('body').on('keypress', '#MyInputId', function(args) {
if (args.keyCode == 13) {
$('#MyButtonId').click();
return false;
}
});

Vanilla JS version with listener:
window.addEventListener('keyup', function(event) {
if (event.keyCode === 13) {
alert('enter was pressed!');
}
});
Also don't forget to remove event listener, if this code is shared between the pages.

Maybe not quite what you're looking for but there is a HTML property that lets you assign a specific button called an access key to focus or trigger an element. It's like this:
<a href='https://www.google.com' accesskey='h'>
This can be done with most elements.
Here's the catch: it doesn't always work. for IE and chrome, you need to be holding alt as well. On firefox, you need to be holding alt and shift (and control if on mac). For safari, you need to be holding control and alt. On opera 15+ you need alt, before 12.1 you need shift and esc.
Source: W3Schools

Overwriting key events

How to overwrite or remove key events, that is on a website? I'm writing a script for GreaseMonkey and I want to make event on Enter button, but when I press the ENTER button, it triggers function on website.
EDIT 1: Here is the website, that I need to do this http://lockerz.com/auth/express_signup

One of these two should do it for you. I used the first one, although someone on SO told me the second one will work also. I went for the hammer.
Sorry, first one wasn't a cut and paste answer. I use using it to return up/down arrow control on a website. I changed it so that it identifies keycode 13 instead.
(function() {
function keykiller(event) {
if (event.keyCode == 13 )
{
event.cancelBubble = true;
event.stopPropagation();
return false;
}
}
window.addEventListener('keypress', keykiller, true);
window.addEventListener('keydown', keykiller, true);
})();

Searching quickly on SO:
jQuery Event Keypress: Which key was pressed?
Code from there:
var code = (e.keyCode ? e.keyCode : e.which);
if(code == 13) { //Enter keycode
//Do something
}

Without a library, use: http://jsfiddle.net/4FBJV/1/.
document.addEventListener('keypress', function(e) {
if(e.keyCode === 13) {
alert('Enter pressed');
return false;
}
});