Question

I am using this following code to position the dialog to the center of the window.

var dialog = $('#dialogBox');
var windowHeight = $(window).height();
var windowWidth = $(window).width();
var dHeight = $('#dialogBox').height();
var dWidth = $('#dialogBox').width();
$('#dialogBox').css({top:windowHeight/2 - dHeight/2, left:windowWidth/2 - dWidth/2}).show();

It positions the div to the center of the window. But i wants to position the dialog to the center of current visible area. So the dialog will be positioned center of the window even if i scroll down or scroll up. How to do it with jquery?

Any suggestions would be appreciative!!!

Thanks.

Answer 1

You can make it dead-centered like this:

$('#elementID').css({
  position:'absolute',
  top:'50%',
  left:'50%',
  width:'600px',                 // adjust width
  height:'300px',                // adjust height
  zIndex:1000,
  marginTop:'-150px'             // half of height
  marginLeft:'-300px'            // half of width
});

Note that element will appear at the center but with scrolling it won’t move. If you want to make it appear at center, you need to set position to fixed instead. However, this won’t work in IE6. So decision is yours 🙂

---

You can also create quick simple jQuery plugin:

(function($){
    $.fn.centerIt = function(settings){

        var opts = $.extend({}, $.fn.centerIt.defaults, settings);

        return this.each(function(settings){
          var options = $.extend({}, opts, $(this).data());
          var $this = $(this);

          $this.css({
            position:options.position,
            top:'50%',
            left:'50%',
            width:options.width,                 // adjust width
            height:options.height,               // adjust height
            zIndex:1000,
            marginTop:parseInt((options.height / 2), 10) + 'px'  // half of height
            marginLeft:parseInt((options.width / 2), 10) + 'px'  // half of height
          });

        });
    }

    // plugin defaults - added as a property on our plugin function
    $.fn.centerIt.defaults = {
      width: '600px',
      height: '600px',
      position:'absolute'
    }

})(jQuery);

And later use it like:

$('#elementId').centerIt({width:'400px', height:'200px'});