javascript - 如果可拖动元素通过其容器，它们将被隐藏

Question

我在左侧菜单中有一些可拖动元素，我需要将其放入右侧容器 #mainDiv。拖放工作正常，但是当我开始拖动时，元素在通过其容器时被隐藏。我知道，这是因为父级可拖动元素设置了 position: relative;。如果我删除它，一切正常，但我需要它有 position: relative; 因为其他目的。如何解决可见性问题并保持 position 属性设置？这是 fiddle :

https://jsfiddle.net/vaxobasilidze/02g2ggt9/2/

拖动“item 1”和“item 2”，它们是隐藏的，因为它们的容器设置了position: relative;，但是如果你拖动“item 3”和“item 4”，它们是可见的，因为他们应该是。如何在不删除 position 属性的情况下在拖动时使所有这些元素可见？

$('#deviceName li').draggable({
                helper: 'clone',
                revert: 'invalid'
            });
            $('#interface li').draggable({
                helper: 'clone',
                revert: 'invalid'
            });
            $('#display li').draggable({
                helper: 'clone',
                revert: 'invalid'
            });
            $('#output li').draggable({
                helper: 'clone',
                revert: 'invalid'
            });
            $('#streams li').draggable({
                helper: 'clone',
                revert: 'invalid'
            });
            function foo(){
                $('.foo').each(function() {
                    $(this).draggable({
                        stack: '.foo'
                    });
                });
            }
            var fooCount = $('.foo').length;
            $('#mainDiv').droppable({
                drop: function(event, ui) {
                    if (!ui.draggable.hasClass('foo')) {
                        var Class = ui.draggable.attr("class");
                        var title = ui.draggable.text().trim();
                        var item = $('<table class="foo elementTable ' + Class + '" name="' + title + '" id="'+(fooCount+1)+'"><tr class="tableHeader"><th class="thClass"><button class="settings">set</button>' + title + '<span class="close">x</span></th></tr><tr><td class="add"><span class="addList">Add new link</span></td></tr></table>');
                        $(this).append(item);
                        fooCount += 1;
                        foo();
                    }
                }
            });

html {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    background: #2c2c2c;
    background: url(data:image/svg+xml;base64,PD94bWwgdmVyc2lvbj0iMS4wIiA/Pgo8c3ZnIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgd2lkdGg9IjEwMCUiIGhlaWdodD0iMTAwJSIgdmlld0JveD0iMCAwIDEgMSIgcHJlc2VydmVBc3BlY3RSYXRpbz0ibm9uZSI+CiAgPGxpbmVhckdyYWRpZW50IGlkPSJncmFkLXVjZ2ctZ2VuZXJhdGVkIiBncmFkaWVudFVuaXRzPSJ1c2VyU3BhY2VPblVzZSIgeDE9IjAlIiB5MT0iMCUiIHgyPSIxMDAlIiB5Mj0iMCUiPgogICAgPHN0b3Agb2Zmc2V0PSIwJSIgc3RvcC1jb2xvcj0iIzJjMmMyYyIgc3RvcC1vcGFjaXR5PSIxIi8+CiAgICA8c3RvcCBvZmZzZXQ9IjM3JSIgc3RvcC1jb2xvcj0iIzNkM2QzZCIgc3RvcC1vcGFjaXR5PSIxIi8+CiAgICA8c3RvcCBvZmZzZXQ9IjY2JSIgc3RvcC1jb2xvcj0iIzM1MzUzNSIgc3RvcC1vcGFjaXR5PSIxIi8+CiAgICA8c3RvcCBvZmZzZXQ9IjY2JSIgc3RvcC1jb2xvcj0iIzM1MzUzNSIgc3RvcC1vcGFjaXR5PSIxIi8+CiAgICA8c3RvcCBvZmZzZXQ9IjEwMCUiIHN0b3AtY29sb3I9IiMxMzEzMTMiIHN0b3Atb3BhY2l0eT0iMSIvPgogIDwvbGluZWFyR3JhZGllbnQ+CiAgPHJlY3QgeD0iMCIgeT0iMCIgd2lkdGg9IjEiIGhlaWdodD0iMSIgZmlsbD0idXJsKCNncmFkLXVjZ2ctZ2VuZXJhdGVkKSIgLz4KPC9zdmc+);
    background: -moz-linear-gradient(left, #2c2c2c 0%, #3d3d3d 37%, #353535 66%, #353535 66%, #131313 100%);
    background: -webkit-gradient(linear, left top, right top, color-stop(0%, #2c2c2c), color-stop(37%, #3d3d3d), color-stop(66%, #353535), color-stop(66%, #353535), color-stop(100%, #131313));
    background: -webkit-linear-gradient(left, #2c2c2c 0%, #3d3d3d 37%, #353535 66%, #353535 66%, #131313 100%);
    background: -o-linear-gradient(left, #2c2c2c 0%, #3d3d3d 37%, #353535 66%, #353535 66%, #131313 100%);
    background: -ms-linear-gradient(left, #2c2c2c 0%, #3d3d3d 37%, #353535 66%, #353535 66%, #131313 100%);
    background: linear-gradient(to right, #2c2c2c 0%, #3d3d3d 37%, #353535 66%, #353535 66%, #131313 100%);
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#2c2c2c', endColorstr='#131313', GradientType=1);
}

body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    color: #b8c0c8;
    background: rgba(0, 0, 0, 0.3);
}

#leftDiv {
    display: inline-block;
    width: 15%;
    height: 100%;
    border-right: 3px solid rgba(0,0,0,0.2);
    box-sizing: border-box;
    float: left;
    margin: 0;
    padding: 0;
    overflow: auto;
    text-shadow: 1px 1px 1px rgba(0,0,0,0.33);
}

#deviceInfo {
    min-height: auto;
    border-bottom: 3px solid rgba(0,0,0,0.2);
    padding: 3px;
    resize: vertical;
    overflow: auto;
}

#menu {
    padding: 0;
    margin: 0;
    margin-bottom: 5px;
    list-style-type: none;
}

#menu li {
    list-style: none;
    padding: 2px;
    border-radius: 4px;
    margin-top: 1px;
}

#menu li span {
    display: block;
    width: 100%;
    min-height: 20px;
    line-height: 20px;
    text-align: center;
    box-shadow: 0 2px 2px rgba(0,0,0,0.26);
    -webkit-box-shadow: 0 2px 2px rgba(0,0,0,0.26);
    -moz-box-shadow: 0 2px 2px rgba(0,0,0,0.26);
    cursor: pointer;
}

#menu li ul {
    padding: 0;
    list-style-type: none;
    overflow: hidden;
}

#menu li ul li {
    width: 100%;
    max-width: 250px;
    text-align: center;
    min-height: 20px;
    line-height: 20px;
    margin: auto;
    border-bottom: 1px solid rgba(0,0,0,0.3);
    cursor: move;
}

#menu li ul li:first-child {
    margin-top: 2px;
    border-top-left-radius: 4px;
    border-top-right-radius: 4px;
}

#menu li ul li:last-child {
    border-bottom-left-radius: 4px;
    border-bottom-right-radius: 4px;
    border-bottom: none;
}

#settingsDiv {
    margin: 0;
    width: 100%;
    min-height: 10px;
    box-sizing: border-box;
    margin: 0;
    padding: 3px;
    overflow: auto;
}
#mainDiv {
    display: inline-block;
    width: 85%;
    min-height: 100%;
    box-sizing: border-box;
    position: relative;
    float: left;
    margin: 0;
    overflow: auto;
    padding: 3px;
}

.foo {
    min-width: 250px;
    width: auto;
    text-align: center;
    min-height: 30px;
    border: 1px solid #515151;
    border-radius: 6px;
    position: absolute;
    padding: 0;
    overflow: hidden;
    text-shadow: 1px 1px 1px rgba(0,0,0,0.33);
    box-shadow: 5px 5px rgba(0,0,0, 0.1);
}

.thClass {
    display: block;
    min-width: 150px;
    width: 102%;
    margin-left: -3px;
    text-align: center;
    box-shadow: 0 2px 2px rgba(0,0,0,0.26);
    -webkit-box-shadow: 0 2px 2px rgba(0,0,0,0.26);
    -moz-box-shadow: 0 2px 2px rgba(0,0,0,0.26);
    margin-top: -2px;
    min-height: 30px;
    line-height: 30px;
    font-size: 19px;
    cursor: move;
}

.header{
    margin-left: 17px;
}

.tableBody {
    display: block;
    min-height: 25px;
    text-align: center;
    width: 102%;
    margin-left: -2px;
    cursor: default;
}

.foo tbody tr td {
    display: block;
    line-height: 25px;
    text-align: center;
    border-bottom: 1px solid rgba(0,0,0,0.2);
}

.addList{
    width: 100px;
    cursor: pointer;
}

.addList:hover{
    text-decoration: underline;
    color: antiquewhite;
}

.devInfo {
    max-height: 150px;
    overflow-y: auto !important;
}

#deviceName {
  position: relative;
}

#interface {
  position: relative;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<head runat="server">
    <title>Test</title>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.4/jquery-ui.min.js"></script>
<!DOCTYPE html>
<head runat="server">
    <title>Test</title>
    <script src="jquery-3.2.1.js"></script>
    <script src="jquery-ui.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jsPlumb/2.1.8/jsPlumb.js"></script>
    <style>
        .jsplumb-endpoint {
            z-index: 10;
        }
    </style>
</head>
<body>
    
    <div id="leftDiv">
        <div id="deviceInfo">
            <ul id="menu">
            <li>Device Name
                <ul id="deviceName">
                    <li>
                      item 1
                    </li>
                </ul>
            </li>
            <li>Interface
                <ul id="interface">
                    <li>
                      item 2
                    </li>
                </ul>
            </li>
            <li>Display
                <ul id="display">
                    <li>
                      item 3
                    </li>
                </ul>
            </li>
            <li>Output
                <ul id="output">
                    <li>
                      item 4
                    </li>
                </ul>
            </li>
        </ul>
        </div>
        <div id="settingsDiv">
            
        </div>
    </div>
    <div id="mainDiv">
        
    </div>

Answer 1

我找到了解决方案:

$('#widget li').draggable({
      helper: 'clone',
      revert: 'invalid',
      start: function(e, ui) {
        $('.draggableItems').css({
          'position': '' //Disable position property when user starts dragging
        });
        $('.ui-draggable-dragging').removeClass('.ui-draggable-dragging');
      },
      stop: function() {
        $('.draggableItems').css({
          'position': 'relative' //Setting potion relative back again after user drops item
        });
      },
      drag: function() {
        $(this).css({
          'z-index': '1500'
        });
      }
    });

我只是删除了拖动时的位置属性，稍后再添加。