I'm trying to do a kind of "key navigation" on my website: if it's pressed left_arrow, I return to the previous page and if it's pressed right_arrow i go to next page. I've done this, the "console.log("keydown")" works, but the function returns don't.
d3.select("body")
.on("keydown", function(e) {
console.log("keydown");
//return "line_chart.html";
if(e == 37) { // left
console.log("left");
return "line_chart1.html";
}
else if(e == 39) { // right
console.log("right");
return "line_chart2.html";
}
});
Instead of
.on("keydown", function(e) { //e is coming UNDEFINED
console.log("keydown");
//return "line_chart.html";
if(e == 37) { // left i found e as undefined
I got the keycode using d3.event.keycode and it worked something like below:
d3.select("body")
.on("keydown", function(e) {
console.log("keydown");
//return "line_chart.html";
if(d3.event.keycode == 37) { // left
console.log("left");
return "line_chart1.html";//this return will not do anything
}
else if(d3.event.keycode == 39) { // right
console.log("right");
return "line_chart2.html";//this return will not do anything
}
});
EDIT
d3.select("body")
.on("keydown", function(e) {
console.log("keydown");
//return "line_chart.html";
if(d3.event.keyCode == 37) { // left
console.log("left");
SOME_FUNCTION("line_chart1.html");
}
else if(d3.event.keyCode == 39) { // right
console.log("right");
SOME_FUNCTION("line_chart2.html");
}
});
Related
This question already has answers here:
Pressing spacebar scrolls page down?
(3 answers)
Closed 2 years ago.
I am working on a WebGL application and I use the spacebar for movement of the camera. The problem is, when I press the spacebar the website also scrolls down. Is there a way to disable this feature?
None of the answers so far works reliably. They work for about a second, then the site scrolls down for a tiny amount of time and then the cycle repeats.
This is my code for the keypresses:
window.addEventListener("keydown", (e) => {
if(e.repeat) { return; }
if(e.which == 27 || e.which == 9) {
document.exitPointerLock();
checkMouse = false;
}
if(checkMouse) {
if(e.which == 87) { forwardPressed = true; }
if(e.which == 83) { backwardPressed = true; }
if(e.which == 65) { leftPressed = true; }
if(e.which == 68) { rightPressed = true; }
if(e.which == 32) { upPressed = true; event.stopPropagation(); event.preventDefault(); }
if(e.which == 16) { downPressed = true; }
}
});
As you can see, for the space key there already is one solution implemented but both types of answers I have gotten so far don't work.
You can do it something like this
$(document).keypress(function(event){
var keycode = (event.keyCode ? event.keyCode : event.which);
if(keycode == '32') {
event.preventDefault();
}
});
Add this to your javascript:
let checkMouse = true
window.addEventListener("keydown", (e) => {
if(e.repeat) {
return;
}
if(e.which == 27 || e.which == 9) {
document.exitPointerLock();
checkMouse = false;
}
if(checkMouse) {
if(e.which == 87) { forwardPressed = true; }
if(e.which == 83) { backwardPressed = true; }
if(e.which == 65) { leftPressed = true; }
if(e.which == 68) { rightPressed = true; }
if(e.which == 32) { upPressed = true; event.stopPropagation(); event.preventDefault(); }
if(e.which == 16) { downPressed = true; }
}
if (e.which == 32) {
return !(e.keyCode == 32);
}
});
checkMouse wasn't initialised before. It's working fine here.
I would like the left and right arrow keys to trigger the back and next button clicks in my Javascript. I feel like I'm not quite implementing it correctly since my buttons work but the keystrokes do not.
function init() {
flashmovie = document.getElementById('flashmovie');
document.getElementById('back').onclick = function () {
if (c == 0) {
c = paths.length;
}
c--
displayFiles();
}
document.getElementById('next').onclick = function () {
if (c == paths.length - 1) {
c = -1;
}
c++;
displayFiles();
}
document.keypress(function (e) {
if (e.which == 37) {
$("#back").click();
}
});
document.keypress(function (e) {
if (e.which == 39) {
$("#next").click();
}
});
}
You probably want the keydown event.
function init() {
document.getElementById('back').onclick = function() {
console.log('back!');
}
document.getElementById('next').onclick = function() {
console.log('next!');
}
document.addEventListener('keydown', function(e) {
if (e.which == 37) {
$("#back").click();
}
});
document.addEventListener('keydown', function(e) {
if (e.which === 39) {
$("#next").click();
}
});
}
init();
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button id="back">Back</button>
<button id="next">Next</button>
I guessed which event listener style you'd want (native DOM versus jQuery) because you've got a mix, but this should get you pointed in the right direction.
From experience, if you have more than a very simple use case for handling keypresses, I'd recommend utilizing a library, like Keypress.
Without jquery, try this
document.onkeyup = function(e){
if (e.which == 37) {
$('#back').click();
} else if (e.which == 39) {
$('#next').click();
}
}
With jquery,
$(document).keypress(function(e){
if (e.which == 37) {
$('#back').click();
} else if (e.which == 39) {
$('#next').click();
}
});
I have a dashboard page that has a left pane which slides on click. I want to make the same thing happen on pressing the Left Arrow and the Right Arrow keys.
Can anybody help me on this? I could do it on click. Below is my solution:
$(document).ready(function() {
$('#opener, .left-panel-head').on('click', function() {
var panel = $('#LeftPanel');
if (panel.hasClass("visible")) {
panel.removeClass('visible').animate({'margin-left': '-300px'});
$('#rightPanel').animate({'width': '100%'});
} else {
panel.addClass('visible').animate({'margin-left': '0px'});
$('#rightPanel').animate({'width': '74%'});
}
return false;
});
});
function updatePanel(direction) {
if(direction === 'left') {
// pressing left
}else if(direction === 'right') {
// pressing right
}
};
$(document).keypress(function( event ) {
if(event.which == 37) {
updatePanel('left');
}else if(event.which == 39) {
updatePanel('right');
}
};
$('#opener, .left-panel-head').on('click', updatePanel('left'));
$('#opener, .right-panel-head').on('click', updatePanel('right'));
You can make your function an actual function instead of an anon function passed into your click event and then call it from multiple places.
(function($, document){
var $document = $(document);
//shared function
function stuff(){
}
//check if key pressed was one of the left or right arrows
function checkKey(e){
var c = e.which ? e.which : e.keyCode;
//left arrow, right arrow
if(c === 37 || c === 39){
//call stuff if left or right arrow was pressed
stuff();
}
}
//call stuff on click
$('#opener, .left-panel-head').on('click', stuff);
$document.on('keydown', checkKey);
})(jQuery, document);
I am trying to prevent scrolling when I use arrow keys in my HTML5 game. It is a maze game that you control with arrow keys or buttons on the screen, but whenever I press the 'up' or 'down' keys, it always scrolls.I am using:
document.addEventListener('keydown', function(e){
if(e.keyCode === 40) {
down();
} else if(e.keyCode === 38) {
up();
} else if(e.keyCode === 37) {
leftclick();
} else if(e.keyCode === 39) {
rightclick();
}
})
Is this possible with javascript? I want it to be able to scroll with my mouse, but not when I use arrow keys on my keyboard. My game is at http://thomaswd.com/maze. Please help. Thanks!
Use e.preventDefault() to prevent the normal key action from taking place.
document.addEventListener('keydown', function(e){
if(e.keyCode === 40) {
down();
e.preventDefault();
} else if(e.keyCode === 38) {
up();
e.preventDefault();
} else if(e.keyCode === 37) {
leftclick();
e.preventDefault();
} else if(e.keyCode === 39) {
rightclick();
e.preventDefault();
}
})
Try this:
document.addEventListener('keydown', function(e) {
if(e.keyCode > 36 && e.keyCode < 41) {
e.preventDefault();
}
if (e.keyCode === 40) {
down();
} else if (e.keyCode === 38) {
up();
} else if (e.keyCode === 37) {
leftclick();
} else if (e.keyCode === 39) {
rightclick();
}
return false;
}, false);
}
Try to add e.preventDefault(); at the end
I'm trying to set "mouseactive" to true less than a second after a key command, but I would like to cancel that action if the key is pressed within that time period. However I can't seem to figure out how to do this. This is what I have...
$(window).keydown(function(e) {
if (e.keyCode == 40) {
e.preventDefault();
mouseactive = false;
clearTimeout(t);
var t = setTimeout("mouseActive()",800);
} else if (e.keyCode == 38) {
e.preventDefault();
mouseactive = false;
clearTimeout(t);
var t = setTimeout("mouseActive()",800);
}
});
function mouseActive() {
mouseactive = true;
}
But this doesn't work, it doesn't set mouseactive back to true... can anyone tell me what I'm doing wrong here?
Edit: Cleaned up redundant code.
More Edits: Make sure your var t is defined outside any closure including $(document).ready. See below,
var t = null;
$(document).ready(function () {
//..below code except for var t = null
});
Declare var t outside the handler.
var t = null;
$(window).keydown(function(e) {
e.preventDefault();
if (e.keyCode == 40) {
mouseactive = false;
} else if (e.keyCode == 38) {
mouseactive = false;
}
if (t != null) clearTimeout(t);
t = setTimeout(mouseActive, 800);
});
function mouseActive() {
mouseactive = true;
}
Your problem is that t is not in scope the 2nd time the function runs. You need to make t a global variable .
var t;
$(window).keydown(function(e) {
if (e.keyCode == 40) {
e.preventDefault();
mouseactive = false;
clearTimeout(t);
t = setTimeout(mouseActive,800);
} else if (e.keyCode == 38) {
e.preventDefault();
mouseactive = false;
clearTimeout(t);
t = setTimeout(mouseActive,800);
}
});
function mouseActive() {
mouseactive = true;
}
P.S. Don't pass strings to setTimeout, pass functions. It uses eval when you pass strings.
you are redeclaring "t" all the time, try this:
var t = null;
$(window).keydown(function(e) {
if (e.keyCode == 40) {
e.preventDefault();
mouseactive = false;
if(t != null)
{
clearTimeout(t);
}
t = setTimeout("mouseActive()",800);
} else if (e.keyCode == 38) {
e.preventDefault();
mouseactive = false;
if(t != null)
{
clearTimeout(t);
}
t = setTimeout("mouseActive()",800);
}
});
function mouseActive() {
mouseactive = true;
}