拖动时在鼠标下保持帮助

Question

I'm trying to implement something very close to what the 'Sortable Widget' would do, though I can't use it because of other things that doesn't work with the premade widget. So I'm trying to recreate it's functionality with draggable and droppable elements:

$(".Element").draggable({
    helper: 'original',
    drag: function(event, ui) {

        ElementWidth = $(this).outerWidth(true);
        if($(this).prev().length){
            LeftElementWidth = $(this).prev().outerWidth(true);
            LeftElementLeftOffset = $(this).prev().offset().left;
            if(parseFloat(ui.offset.left+(ElementWidth/2)) < parseFloat(LeftElementLeftOffset+(LeftElementWidth/2))){
                $(this).prev().before($(this));
            }
        }

        if($(this).next().length){
            RightElementWidth = $(this).next().outerWidth(true);
            RightElementLeftOffset = $(this).next().offset().left;
            if(parseFloat(ui.offset.left+(ElementWidth/2)) > parseFloat(RightElementLeftOffset+(RightElementWidth/2))){
                $(this).next().after($(this));
            }
        }
    }
}); 

$("#Container").droppable({ accept: '.Element' });

It works fine, except for that the draggable-helper doesn't stay underneath the mouse-cursor when I move it's element to the next position. Check out this fiddle:

http://jsfiddle.net/5qFhg/15/

You'll see what happens when you try to sort the green boxes. How can I keep the helper in position?

Answer 1

http://jsfiddle.net/margaret_/XM6f8/1/

Is this what you are looking for? Are you okay with using knockout? I can't add comments 'cause I don't have 50 reputation.

<a href="#" data-bind="text: name, click: function() { viewModel.selectTask($data); },     visible: $data !== viewModel.selectedTask()"></a>
<input data-bind="value: name, visibleAndSelect: $data === viewModel.selectedTask(), event: { blur: function() { viewModel.selectTask(''); } }" />

Use parent and previous location to mimic the function.

ko.bindingHandlers.sortableList = {
init: function(element, valueAccessor, allBindingsAccessor, context) {
    $(element).data("sortList", valueAccessor()); //attach meta-data
    $(element).sortable({
        start: function(event, ui) {
            //track the original position of the element
            var parent = ui.item.parent();
            var prev = ui.item.prev();
            //create a function to move it back (if it has a prev sibling, insert after it, otherwise put it at the beginning)
            ui.item.moveItemBack = prev.length ? function() { ui.item.insertAfter(prev); } : function() { parent.prepend(ui.item); };
        },
        update: function(event, ui) {
            var item = ui.item.data("sortItem");
            if (item) {
                //identify parents
                var originalParent = ui.item.data("parentList");
                var newParent = ui.item.parent().data("sortList");

                //figure out its new position
                var position = ko.utils.arrayIndexOf(ui.item.parent().children(), ui.item[0]);

                if (position >= 0) {
                    //move the element back to its original position and let KO handle adding it to the new parent
                    if (originalParent !== newParent) {
                        ui.item.moveItemBack();
                    }

                    //place item in the proper position
                    newParent.remove(item);
                    newParent.splice(position, 0, item);
                }
            }
        },
        connectWith: '.container'
    });
}

Do you want the divs to appear side by side?