Assigning keyCode a value in a document containing a form

W

WilliamRLinden

Hi world! we are pretty new to JavaScript and have been
struggling for now 2 days on this problem ... We would
appreciate mercy if anyone can give us some.

Basically we are trying to simulate the tab key when the
down arrow key is pressed. (we know there are other way
to control focus flow but we use a lot of dynamic jsp fields,
that will make the flow control a nightmare, we just want
basic tabbing from the arrow key)

1)We are able to capture a onkeydown event and reasign it with another
key value with no problem within an html document without a form.

example:

var ieKey = event.keyCode;

if (ieKey == 40) {
event.keyCode = 9;
}



however as soon as we insert a form tag in the document, this stops
functioning.
The asignment seems to be fine as an alert clearly shows, but the
instruction
seems to be ignored.

Find below the working (with no form) and non working script (with a
form).
You should be able to just cut and paste the code.


Without form (works)
=============
<html>
<head>

<title>arrow keys test 2</title>
<meta http-equiv="Content-Type" content="text/html;
charset=iso-8859-1">


<script>

function onLoadInit(){
document.onkeydown = keyDown;
}



function keyDown(e) {

var ieKey = event.keyCode;

if (ieKey == 38) {

alert("up arrow");
}



if (ieKey == 40) {

alert("down arrow");
event.keyCode = 9;
alert(event.keyCode);
}
}

</script>
</head>



<body onload="onLoadInit()" >



<center>
<strong><font size="+2">no form good</font></strong>
</center>


<BR> <input name="A" type="text" size="6">
<BR> <input name="B" type="text" size="6">
<BR> <input name="D" type="text" size="6">
<BR> <input name="E" type="text" size="6">
<BR> <input name="F" type="text" size="6">


<center><a href="balls.html">View Document</a></center>
<center><a href="balls.html">View Document</a></center>
<center><a href="balls.html">View Document</a></center>



</body>
</html>





With form (doesn't work)
==========


<html>
<head>

<title>arrow keys test 2</title>
<meta http-equiv="Content-Type" content="text/html;
charset=iso-8859-1">


<script>

function onLoadInit(){
document.onkeydown = keyDown;
}



function keyDown(e) {

var ieKey = event.keyCode;

if (ieKey == 38) {

alert("up arrow");
}



if (ieKey == 40) {

alert("down arrow");
event.keyCode = 9;
alert(event.keyCode);
}
}

</script>
</head>



<body onload="onLoadInit()" >

<form name="form1" method="get">


<center>
<strong><font size="+2">arrows 5</font></strong>
</center>


<BR> <input name="A" type="text" size="6">
<BR> <input name="B" type="text" size="6">
<BR> <input name="D" type="text" size="6">
<BR> <input name="E" type="text" size="6">
<BR> <input name="F" type="text" size="6">


<center><a href="balls.html">View Document</a></center>
<center><a href="balls.html">View Document</a></center>
<center><a href="balls.html">View Document</a></center>

</form>


</body>
</html>
 
J

Jonas Raoni

Basically we are trying to simulate the tab key when the
down arrow key is pressed. (we know there are other way
to control focus flow but we use a lot of dynamic jsp fields,
that will make the flow control a nightmare, we just want
basic tabbing from the arrow key)

event.keyCode = 9;
Click to expand...

If nothing changed, this works just on IE, so find another way, take a
look here: <URL:http://jsfromhell.com/forms/auto-tab>, with a little
modification, it will work for you.
 
S

SirWilliam

Thanks Jonas.

I had a look the at URL mentioned, pretty close to what we needed but
didn't realy shed any light on why our script didn't work when using a
form.

Now, just in case this might one day help some one else, here is how we
finally solved the problem:

The true purpose of us needing the script was to capture arrow key
presses and then to use these to navigate between the elements on a web
page, instead of using the tab and shift+tab key to tediously navigate
from element to element in the specified tab order.

In the end I changed the approach completely and instead of simulating
tab key presses I created a virtual grid with each element (html tag)
to be navigated to/from containing X and Y coordinates as two
additional parameters in the tag declaration. Then when an arrow key
event is captured I simply focus directly on the next element using the
coordinate system to identify which tag should receive the focus next.


***************************************************************
Here is the JavaScript (I used a file called arrowNav.js)

***************************************************************

var Xval,Yval,xMaxArray;
var yMax = 0;


function setXY() {

Xval = document.activeElement.x;
Yval = document.activeElement.y;
}



function getMax() {

//Work Out maximum Y
//------------------
for (var i=0;i < document.all.length;i++) {
if (document.all.y > yMax) {
yMax = document.all.y;
}
}

xMaxArray = new Array(yMax+1);
for (var i=0;i<(yMax+1);i++)
xMaxArray = 0;


//Work Out maximum X's
//--------------------
for (var i=0;i < document.all.length;i++) {
if (document.all.x > xMaxArray[document.all.y]) {
xMaxArray[document.all.y] = document.all.x;
}
}

}



function handleKey(evt) {

var ieKey;

//if (window.Event) ieKey = evt.which;
//else ieKey = event.keyCode;

ieKey = event.keyCode;


//Move Up
//-------
if (ieKey == 38) {

// Make sure we or not as high as we can go
//-----------------------------------------
if (Yval > 1) {
Yval--;

// If we are moving to a row with less elements i.e less X
coordinates
// make sure we re-adjust x grid value to reflect the max for that
row
//---------------------------------------------------------------------
if (Xval > xMaxArray[Yval]) {
Xval = xMaxArray[Yval];
}

for (var i=0;i < document.all.length;i++)
if ((document.all.x == Xval) && (document.all.y ==
Yval)) {
//alert(document.all.name)
document.all.focus();
}
}
}


//Move Down
//---------
if (ieKey == 40) {

// Make sure we or not as low as we can go
//-----------------------------------------
if (Yval < yMax) {
Yval++;


// If we are moving to a row with less elements i.e less X
coordinates
// make sure we re-adjust x grid value to reflect the max for that
row
//---------------------------------------------------------------------
if (Xval > xMaxArray[Yval]) {
Xval = xMaxArray[Yval];
}

for (var i=0;i < document.all.length;i++)
if ((document.all.x == Xval) && (document.all.y ==
Yval)) {
//alert(document.all.name)
document.all.focus();
}
}
}

//Move Right
//----------
if (ieKey == 39) {

//alert(document.all['T1'].type);


if (!((document.activeElement.type == "text") &&
(document.activeElement.value != ""))) {

// Make sure we or not as far right as we can go
//----------------------------------------------
if(Xval < xMaxArray[Yval]) {
Xval++;

for (var i=0;i < document.all.length;i++)
if ((document.all.x == Xval) && (document.all.y ==
Yval)) {
//alert(document.all.name)
document.all.focus();
}
}
}
}



//Move Left
//---------
if (ieKey == 37) {


if (!((document.activeElement.type == "text") &&
(document.activeElement.value != ""))) {

// Make sure we or not as far left as we can go
//---------------------------------------------
if (Xval > 1) {
Xval--;

for (var i=0;i < document.all.length;i++)
if ((document.all.x == Xval) && (document.all.y ==
Yval)) {
//alert(document.all.name)
document.all.focus();
}
}
}
}

return fals;
}

// Add main document event Listener
document.onkeydown=handleKey;








**************************************************
AN HTML FILE USING THE SCRIPT

**************************************************

<html>
<head>

<title>God damn Arrows</title>
<meta http-equiv="Content-Type" content="text/html;
charset=iso-8859-1">


<!-- Specify arrowNav.js as the file containing the script -->
<script src="arrowNav.js"> </script>

</head>






<!-- Call getMax() function on body load to ensure script can
calculate
Maximum X,Y grid values ------------------------------------------->

<body onload="getMax()">

<form name="form1">
<center>
<font size="+2">The <b>ultimate</b> arrow key TesT ... ever</font>
</center>

<BR> <center><a name="L1" x="1" y="1" href="balls.html">Link1 (1,1)</a>

<BR><BR> <input name="T1" value="Text1 (1,2)" x="1" y="2" type="text"
onfocus="setXY()">
<input name="T2" value="Text2 (2,2)" x="2" y="2" type="text"
onfocus="setXY()">



<BR><BR> <a name="L2" x="1" y="3" href="balls.html" onfocus="setXY()">
Link2 (1,3)</a> &nbsp some irelavant text &nbsp
<a name="L3" x="2" y="3" href="balls.html" onfocus="setXY()"> Link3
(2,3)</a> &nbsp
<a name="L4" x="3" y="3" href="balls.html" onfocus="setXY()"> Link4
(3,3)</a> &nbsp
<a name="L5" x="4" y="3" href="balls.html" onfocus="setXY()"> Link5
(4,3)</a>


<BR> <a name="L6" x="1" y="4" href="balls.html" onfocus="setXY()">
Link6 (1,4)</a> &nbsp some irelavant text &nbsp
<a name="L7" x="2" y="4" href="balls.html" onfocus="setXY()"> Link7
(2,4)</a> &nbsp
<a name="L8" x="3" y="4" href="balls.html" onfocus="setXY()"> Link8
(3,4)</a> &nbsp
<a name="L9" x="4" y="4" href="balls.html" onfocus="setXY()"> Link9
(4,4)</a>


<BR><BR> <input name="T3" value="Text3 (1,5)" x="1" y="5" type="text"
onfocus="setXY()">

<BR><BR> Some more useless text

<BR><BR> <input name="T4" value="Text4 (1,6)" x="1" y="6" type="text"
onfocus="setXY()">
<input name="T5" value="Text5 (2,6)" x="2" y="6" type="text"
onfocus="setXY()">



</center>
</form>
</body>
</html>



It looks a little but chaotic, but thats just the text wrapping, copy
and paste into a proper editor and it should all come out a bit
clearer.

With a bit of luck this might actually save the universe one day.
And remember:
Beer is not the answer, it is the question...the answer is YES!!!!

ciao
will
 
S

SirWilliam

PS: I take what I said about the wrapping being sorted in a proper
editor back...
 
J

Jonas Raoni

SirWilliam said:
Thanks Jonas.

I had a look the at URL mentioned, pretty close to what we needed but
didn't realy shed any light on why our script didn't work when using a
form.
Ok

<input name="T2" value="Text2 (2,2)" x="2" y="2" type="text"> onfocus="setXY()">
Click to expand...

Instead of setting this manually, you can make it automatic, by keeping
track of all the inputs offsets, then you just need to check who's the
nearest from the current input offset or create your grid dinamically
(if your page layout doesn't change while filling the fields, that would
be the best solution) ;]

getOffset = function(o){
for(var r = {x: o.offsetLeft, y: o.offsetTop, h: o.offsetHeight, w:
o.offsetWidth};
o = o.offsetParent; r.x += o.offsetLeft, r.y += o.offsetTop);
return r;
}
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Similar Threads

Registration Form 7
I Need Help with making a function that draws in a canvas using location data. 1
How to store data from a sign up form on a website into an sql databse 1
Help with my responsive home page 2
Uncaught ReferenceError: item is not defined at HTMLButtonElement.onclick in the: <button onclick="item.inserir()">Inserir dados</button> 1
Centering a button using flexbox 2
Registration form 13
Help with Visual Lightbox: Scripts 2

Members online

Total: 29 (members: 1, guests: 28)
Robots: 472

Forum statistics

Threads
473,769
Messages
2,569,580
Members
45,055
Latest member
SlimSparkKetoACVReview

Latest Threads

Top