Question

I am trying to draw a circle after a few calculations are performed over top of a td. When I ran the the following code, it works:

$('#priority_one').width($('#learning_streams').width());
$('#priority_one').height($('#learning_streams').height());
var priority_one_paper = new Raphael('priority_one', $('#priority_one').width(), $('#priority_one').height());
var priority_one_circle = priority_one_paper.circle((pos.left).toFixed(0), (pos.top).toFixed(0), (width/2).toFixed(0));
priority_one_circle.attr('stroke','#000000');

But when I try to make it dynamic (the td changes depending on the input by the user) it no longer works. Code:

function circlePriorityOne() {
    //priority_one is a div absolutely positioned over a table called learning_streams
    //sets size of priority_one based off the table learning_streams
    $('#priority_one').width($('#learning_streams').width());
    $('#priority_one').height($('#learning_streams').height());


    //creates the 'paper' to draw the circle on
    var priority_one_paper = new Raphael('priority_one', $('#priority_one').width(), $('#priority_one').height());

    var main = getMax(priority_one_count); //returns the id of the td to circle
    var pos = $('#'+main).position();
    var width = $('#'+main).width();

    //using toFixed() to get rid of decimals
    var priority_one_circle = priority_one_paper.circle((pos.left).toFixed(0), (pos.top).toFixed(0), (width/2).toFixed(0));
    priority_one_circle.attr('stroke','#000000');
}

See anything wrong with this? Thanks.

Answer 1

You’re right. .position() gets the current position relative to a parent element.

You should use .offset() instead, which gets the current position relative to the document

Edit
I’m not quite sure, because I haven’t tested it but it should do what you want^^

var td = $("#td"),
    pos_td = td.offset(),
    table = td.parents("table"),
    pos_table = table.offset();

// td's position relative to table
console.log("left: " + (pos_td.left - pos_table.left));
console.log("top: " + (pos_td.top - pos_td.top));