asked on

"Draw" Rectangle using JavaScript

Hi to all,

I am following the following post:
http://www.emanueleferonato.com/2006/09/02/click-image-and-get-coordinates-with-javascript/
Where a user can basically point to an area on an image and then get the X and Y coordinates. My end goal is to give the user the ability to drag and drop an area on the image and then get the image map coordinates.

The following link basically demonstrates my end goal, but there is no drag and drop functionality. You basically have to click twice on the image and then a "White" block is drawn. I want to give the user a See through block, but with the border visible.
http://www.shawngo.com/mappr/clicktest.html

Can someone please help me in getting this done.

Code Below:

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script language="JavaScript">
function point_it(event){
pos_x = event.offsetX?(event.offsetX):event.pageX-document.getElementById("pointer_div").offsetLeft;
pos_y = event.offsetY?(event.offsetY):event.pageY-document.getElementById("pointer_div").offsetTop;
document.getElementById("cross").style.left = (pos_x-1) ;
document.getElementById("cross").style.top = (pos_y-15) ;
document.getElementById("cross").style.visibility = "visible" ;
document.pointform.form_x.value = pos_x;
document.pointform.form_y.value = pos_y;
}
</script>
</head>
<body>
<form name="pointform" method="post">
<div id="pointer_div" onclick="point_it(event)" style = "background-image:url('sun.jpg');width:500px;height:333px;">
<img src="point.gif" id="cross" style="position:relative;visibility:hidden;z-index:2;"></div>
You pointed on x = <input type="text" name="form_x" size="4" /> - y = <input type="text" name="form_y" size="4" />
</form> 
</body>
</html>

Open in new window

ASKER CERTIFIED SOLUTION

Michel Plungjan

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

ALawrence007

ASKER

mplungjan:

This is EXACTLY what I was looking for and really an amazing tool!

The following is what I am looking at and exactly what needs to happen in my application:
http://marqueetool.net/examples/send-cropped-image-coordinates-to-the-server/

The only thing I am having issues with is the getCoords(). The example and documentation is not very clear on that. I followed the example, but I am not getting the desired result: The coordinates are not being populated in my input boxes.

I don't understand the code below:

Do I have to create another page?

Thanks

And on the server: <? header("Content-Type: image/jpeg"); $image = dirname(__FILE__) . "/images/examples/example5.jpg"; if ($w && $h) { $image_rs = @imagecreatefromjpeg($image); $new_rs = @imagecreatetruecolor($w, $h); @imagecopy ($new_rs, $image_rs, 0, 0, $x, $y, $w, $h); @imagejpeg($new_rs); } readfile($image); ?>

Open in new window

ALawrence007

ASKER

My Bad..... I found my issue......

Thanks mplungjan !!!!

ALawrence007

ASKER

Awesome tool and help!!

Michel Plungjan

you are welcome :)

&quot;Draw&quot; Rectangle using JavaScript

"Draw" Rectangle using JavaScript