jQuery UI sortable scroll helper element offset Fi

Question

I have a problem with a jQuery UI 1.7.2 sortable list in Firefox 3.6, IE7-8 work fine. When I'm scrolled down a bit, the helper element seems to have an offset of the same height that I'm scrolled down from the mouse pointer which makes it impossible to see which item you originally started dragging. How do I fix this or work around the issue? If there is no fix what is a really good alternative drag-able plugin?

Here are my initialization parameters for the sortable.

$("#sortable").sortable( {placeholder: 'ui-state-highlight'  } );
$("#sortable").disableSelection();

Answer 1

For future readers with this problem. I upgraded from jqueryui 1.8 to 1.10.3 and the problem was solved with no css fixes.

http://jqueryui.com/

I also upgraded from jquery 1.8 to 1.10.2

http://jquery.com/

Answer 2

To summarize your efforts and provide a completed solution. The following seemed to work for Chrome 40+ and Firefox 30+

var isFirefox = /firefox/.test(navigator.userAgent.toLowerCase());
$('#target').sortable({
    connectWith: '#target-holder .elements',
    handle: ".element-header",
    start: function(ev, ui) {
        if( isFirefox ) {
            ui.item.css('margin-top', $(window).scrollTop() );
        }
    },
    sort: function(ev, ui) {
        if( isFirefox) {
            ui.helper.css({'top' : ui.position.top - $(window).scrollTop() + 'px'});
        } else {
            ui.helper.css({'top' : ui.position.top + $(window).scrollTop() + 'px'});
        }
    },
    beforeStop: function (ev, ui) {
        if( isFirefox ) {
            ui.item.css('margin-top', 0 );
        }
    }
});

Answer 3

I managed to figure out a fix for this:

$( "items" ).sortable({
start: function (event, ui) {
 if( ui.helper !== undefined )
  ui.helper.css('position','absolute').css('margin-top', $(window).scrollTop() );
},
beforeStop: function (event, ui) {
 if( ui.offset !== undefined )
  ui.helper.css('margin-top', 0);
},
placeholder: 'placeholder-class'
});

Basically, you need to listen for the sortable's "start" event to add the browser's current scrollTop() value to the helper's position, and then you need to listen for the sortable's "beforeStop" event, to remove that offset before the item is officially placed back into the list at its new position.

Hope that's helpful to someone!