Combining AngularJS, jQueryUI, Angular-Drag-Drop for sorted list

Question

I have the following situation where I need to allow a user to select objects from a list and drag/drop them into a certain slot:

The objects can be one to three times the size of a slot. So if a user drags Object 1 to Slot 0, then it only occupies Slot 0 (startSlot = 0 and endSlot = 0). However if a user drags Object 3 to Slot 3, then it occupies Slots 3, 4, and 5 (startSlot = 3 and endSlot = 5).

Once the objects are dropped into the slots, a user can reorder the objects by clicking and dragging the objects up and down in the slots. Objects cannot overlap each other:

I am using Angular, so I'm reading a list of objects from a database and I have a variable for the number of slots. I have attempted a couple of solutions. I believe the use of jQuery and jQueryUI draggable, droppable, and sortable is part of the solution, here is the first fiddle demonstrating drag/drop and sortable:

http://jsfiddle.net/mduvall216/6hfuzvws/4/

The problem with this fiddle is that I need a set number of slots. Once an object is placed in the slots, it replaces 1 to 3 slots depending on the size of the object. The second fiddle below integrates AngularJS:

http://jsfiddle.net/mduvall216/zg5x4b6k/4/

The problem here is that I know I need some type of grid to snap the objects to once dragged from the object list. The result that I'm looking for is a json list of objects in their assigned slots:

[{id:obj1,startSlot:0,endSlot:0},{id:obj3,startSlot:3,endSlot:5}]

I'm also sure the solution would need codf0rmer's Angular Drag-Drop located here:

https://github.com/codef0rmer/angular-dragdrop

But I'm having problems trying to get that integrated into my fiddle to test. This is an interesting challenge I've been spinning on for a while, if anyone can be of assistance it would be greatly appreciated. Thanks for your time.

Answer 1

I started a basic implementation of your requirements using the HTML5 Drag & Drop API and jQuery. The API is lightweight and doesn't require any 3rd party scripts. The code should be easy to customize. The provided example is only a starting point and by no means production ready and should be optimized and possibly turned into a jQuery plugin module before use. This would increase the re-usability of the module.

Leave any further questions about the code in the comments.

JSFiddle Example without sortable:

JSFiddle with sortable

html:

<ul class="select-list">
    <li class="header">Object List</li>
    <li data-slots="1" class="s1">Object 1</li>
    <li data-slots="2" class="s2">Object 2</li>
    <li data-slots="3" class="s3">Object 3</li>
</ul>
<ul class="drop-list" id="sortable">
    <li>Slot 1</li>
    <li>Slot 2</li>
    <li>Slot 3</li>
    <li>Slot 4</li>
    <li>Slot 5</li>
    <li>Slot 6</li>
    <li>Slot 7</li>
    <li>Slot 8</li>
    <li>Slot 9</li>
    <li>Slot 10</li>
    <li>Slot 11</li>
    <li>Slot 12</li>
    <li>Slot 13</li>
</ul>

javascript without sortable:

(function ($, undefined) {
    // document ready function
    $(function () {
        init();

        $('ul.select-list').on({
            'dragstart': dragstart,
                'dragend': dragend
        }, 'li');

        $('ul.drop-list').on({
            'dragenter dragover': dragover,
                'dragleave': dragleave,
                'drop': drop
        }, 'li.dropzone');
    });

    // Initializes the lists
    function init() {
        $('ul.select-list').find('li').not('[class="header"]').each(function () {
            var height = getSlotHeight() * $(this).data('slots');
            $(this).height(height);
        }).attr('draggable', true);

        $('ul.drop-list').find('li').each(function () {
            $(this).height(getSlotHeight());
        }).addClass('dropzone');
    }

    // Get the height of grid slots
    function getSlotHeight() {
        return 20;
    }

    /**
    * Checks whether target is a kompatible dropzone
    * A dropzone needs the dropzone class
    * and needs to have enough consequent slots to drop the object into
    */
    function isDropZone(target, draggedObj) {
        var isDropZone = true;
        var slots = draggedObj.data('slots');
        for (var i = 1; i < slots; i++) {
            target = target.next();
            if (target.size() == 0 || !target.hasClass('dropzone')) {
                isDropZone = false;
                break;
            }
        }
        return isDropZone;
    }    

    /* 
    * The following events are executed in the order the handlers are declared
    * dragstart being first and dragend being last
    */

    // dragstart event handler
    function dragstart(e) {
        e.stopPropagation();
        var dt = e.originalEvent.dataTransfer;
        dt.effectAllowed = 'move';
        dt.setData('text/html', '');
        $('ul.select-list').data({
            draggedObj: $(this)
        });
    }

    // dragover event handler
    function dragover(e) {
        e.preventDefault();
        e.stopPropagation();
        var data = $('ul.select-list').data();
        if (!data.draggedObj || !isDropZone($(this), data.draggedObj)) {
            e.originalEvent.dataTransfer.dropEffect = 'none';
            return;
        }
        e.originalEvent.dataTransfer.dropEffect = 'move';
        var item = $(this).addClass('dragover');
        var slots = data.draggedObj.data('slots');
        for (var i = 1; i < slots; i++) {
            item = item.next('li').addClass('dragover');
        }
        return false;
    }

    // dragleave event handler
    function dragleave(e) {
        e.preventDefault();
        e.stopPropagation();
        var data = $('ul.select-list').data();
        if (!data.draggedObj || !isDropZone($(this), data.draggedObj)) {
            return;
        }
        var item = $(this).removeClass('dragover');
        var slots = data.draggedObj.data('slots');
        for (var i = 1; i < slots; i++) {
            item = item.next('li').removeClass('dragover');
        }
        return false;
    }

    // drop event handler
    function drop(e) {
        e.stopPropagation();
        e.preventDefault();
        var data = $('ul.select-list').data();
        if (data.draggedObj || !isDropZone($(this), data.draggedObj)) {
            data.target = $(this);
            data.draggedObj.trigger('dragend');
        }
        return false;
    }

    // dragend event handler
    function dragend(e) {
        var data = $('ul.select-list').data();
        if (data.draggedObj && data.target && isDropZone(data.target, data.draggedObj)) {
            var item = data.target.hide();
            var slots = data.draggedObj.data('slots');
            for (var i = 1; i < slots; i++) {
                item = item.next('li').hide();
            }
            data.target.before(data.draggedObj);
        }

        data.target = undefined;
        data.draggedObj = undefined;
        $('ul.drop-list').find('li').removeClass('dragover');
    }
}(jQuery));

css:

ul {
     list-style-type: none;
     margin: 0;
     padding: 0;
     float: left;
 }
 li {
     width: 150px;
 }
 li.header {
     height:20px;
     font-weight:bold;
 }
 .select-list li {
     margin-bottom: 10px;
 }
 .drop-list {
     margin-left:20px;
 }
 .drop-list li {
     background-color: #ccc;
     border-left: 1px solid black;
     border-right: 1px solid black;
     border-top: 1px solid black;
 }
 .drop-list li.dragover {
     background-color:#fff;
 }
 .drop-list li:last-child {
     border-bottom: 1px solid black;
 }
 li.s1 {
     background-color: #FFE5E5;
 }
 li.s2 {
     background-color: #C6D4FF;
 }
 li.s3 {
     background-color: #C6FFE3;
 }

Edit: The following script also has sorting added to it. I have not stress tested this example and it may not perform under certain conditions.

(function ($, undefined) {
    // document ready function
    $(function () {
        init();

        $('ul.select-list,ul.drop-list').on({
            'dragstart': dragstart,
                'dragend': dragend
        }, 'li.object').on('dragenter dragover', listDragover);

        $('ul.drop-list').on({
            'dragenter dragover': dragover,
                'dragleave': dragleave,
                'drop': drop
        }, 'li.dropzone');
    });

    // Initializes the lists
    function init() {
        $('ul.select-list').find('li').not('[class="header"]').each(function () {
            var height = getSlotHeight() * $(this).data('slots');
            $(this).height(height);
        }).attr('draggable', true).addClass('object');

        $('ul.drop-list').find('li').each(function () {
            $(this).height(getSlotHeight());
        }).addClass('dropzone');
    }

    // Get the height of the grid
    function getSlotHeight() {
        return 20;
    }

    /**
     * Checks whether target is a kompatible dropzone
     * A dropzone needs the dropzone class
     * and needs to have enough consequent slots to drop the object into
     */
    function isDropZone(target, draggedObj) {
        var isDropZone = true;
        var slots = draggedObj.data('slots');
        for (var i = 1; i < slots; i++) {
            target = target.next('li');
            if (target.size() == 0 || !target.hasClass('dropzone')) {
                if (!target.is(draggedObj)) {
                    isDropZone = false;
                    break;
                } else {
                    i--;
                }
            }
        }
        return isDropZone;
    }

    // dragstart event handler
    function dragstart(e) {
        e.stopPropagation();
        var dt = e.originalEvent.dataTransfer;
        dt.effectAllowed = 'move';
        dt.setData('text/html', ''); 
        $('ul.select-list').data({
            draggedObj: $(this)
        });        
    }

    // dragover list event handler
    function listDragover(e) {
        e.preventDefault();
        e.stopPropagation();
        e.originalEvent.dataTransfer.dropEffect = 'none';
        var data = $('ul.select-list').data();
        if (data.draggedObj) {
            var item = data.draggedObj;
            item.hide();
            if (data.draggedObj.closest('ul').is('ul.drop-list')) {
                var slots = item.data('slots');
                for (var i = 0; i < slots; i++) {
                    item = item.next('li').show();
                }
            }
        }
        return false;
    }

    // dragover event handler
    function dragover(e) {
        e.preventDefault();
        e.stopPropagation();
        var data = $('ul.select-list').data();
        if (!data.draggedObj || !isDropZone($(this), data.draggedObj)) {
            e.originalEvent.dataTransfer.dropEffect = 'none';
            return;
        }
        e.originalEvent.dataTransfer.dropEffect = 'move';
        var item = $(this).addClass('dragover');
        var slots = data.draggedObj.data('slots');
        for (var i = 1; i < slots; i++) {
            item = item.next('li');
            if (!item.is(data.draggedObj)) {
                item.addClass('dragover');
            } else {
                i--;
            }
        }
        return false;
    }

    // dragleave event handler
    function dragleave(e) {
        e.preventDefault();
        e.stopPropagation();
        var data = $('ul.select-list').data();
        if (!data.draggedObj || !isDropZone($(this), data.draggedObj)) {
            return;
        }
        var item = $(this).removeClass('dragover');
        var slots = data.draggedObj.data('slots');
        for (var i = 1; i < slots; i++) {
            item = item.next('li');
            if (!item.is(data.draggedObj)) {
                item.removeClass('dragover');
            } else {
                i--;
            }
        }
        return false;
    }

    // drop event handler
    function drop(e) {
        e.stopPropagation();
        e.preventDefault();
        var data = $('ul.select-list').data();
        if (data.draggedObj || !isDropZone($(this), data.draggedObj)) {
            data.target = $(this);
            data.draggedObj.trigger('dragend');
        }
        return false;
    }

    // dragend event handler
    function dragend(e) {
        var data = $('ul.select-list').data();
        var target = data.target;
        if (data.draggedObj && !target && data.draggedObj.closest('ul').is('ul.drop-list')) {
            target = data.draggedObj.next('li');
        }
        if (data.draggedObj && target && isDropZone(target, data.draggedObj)) {
            data.draggedObj = data.draggedObj.insertBefore(target);
            var item = target.hide();
            var slots = data.draggedObj.data('slots');
            for (var i = 1; i < slots; i++) {
                item = item.next('li').hide();
            }
        }
        if (data.draggedObj) {
            data.draggedObj.show();
        }
        data.target = undefined;
        data.draggedObj = undefined;
        $('ul.drop-list').find('li').removeClass('dragover');
    }
}(jQuery));