禁用/启用jQuery在拖放时可拖动

Question

Demo: http://jsfiddle.net/py3DE/

$(".source .item").draggable({ revert: "invalid", appendTo: 'body', helper: 'clone',
    start: function(ev, ui){ ui.helper.width($(this).width()); }                    // ensure helper width
});

$(".target .empty").droppable({ tolerance: 'pointer', hoverClass: 'highlight',
    drop: function(ev, ui){
        var item = ui.draggable;
        if (!ui.draggable.closest('.empty').length) item = item.clone().draggable();// if item was dragged from the source list - clone it
        this.innerHTML = '';                                                        // clean the placeholder
        item.css({ top: 0, left: 0 }).appendTo(this);                                // append item to placeholder
    }
});

$(".target").on('click', '.closer', function(){
    var item = $(this).closest('.item');
    item.fadeTo(200, 0, function(){ item.remove(); })
});

My goal here is when an item is taken from .source and dropped on to .target, I want to disable the draggable that was dropped so that I can only have a single instance of an item from .source end up in .target. Conversely, I am also trying to re-enable the item once it is removed from .target.

Answer 1

Given that your creating a clone of the original you need to track this and be able to tie back to the original when you close the clone.

var mapOrig = [];

$(".source .item:not(.added)").draggable({ revert: "invalid", appendTo: 'body', helper: 'clone',
    start: function(ev, ui){ ui.helper.width($(this).width()); }                    // ensure helper width
});

$(".target .empty").droppable({ tolerance: 'pointer', hoverClass: 'highlight',
    drop: function(ev, ui){
        var item = ui.draggable;
        if (!ui.draggable.closest('.empty').length) {
            var orig = item;           
            item = item.clone().draggable();// if item was dragged from the source list - clone it
            orig.draggable('disable');
            mapOrig.push({item: item, orig: orig});
        }
        this.innerHTML = ''; // clean the placeholder
        item.css({ top: 0, left: 0 }).appendTo(this);                                // append item to placeholder
    }
});

$(".target").on('click', '.closer', function(){
    var item = $(this).closest('.item');
    for(var i = 0; i < mapOrig.length; ++i){
        if(item.is(mapOrig[i].item)){
            mapOrig[i].orig.draggable('enable');
            mapOrig.splice(i, 1);
        }
    }
    item.fadeTo(200, 0, function(){ item.remove(); })
});

I've created an updated fiddle at http://jsfiddle.net/xmltechgeek/FCj2a/ that show a way to do this using a tracking array for your old item when you create the clone. You can just use the enable/disable functionality from jquery for the actual task of enabling or disabling.

Answer 2

use this code inside droppable -

    deactivate: function( event, ui ) {
    var item = ui.draggable;
    item.draggable('disable');
    }

Demo Fiddle