如何为触摸和鼠标（拖动）事件制作可拖动元素

Question

我有以下用于拖放应用程序的代码，该代码在桌面上可以正常工作，但是当我想在移动设备上使用该应用程序时，拖动事件无法正常工作。我知道需要触摸事件，但是我不确定如何设置它们并实现功能。

<style>
    .objects {
        display:inline-block;
        background-color: #FFF3CC;
        border: #DFBC6A 1px solid;
        width: 50px;
        height: 50px;
        margin: 10px;
        padding: 8px;
        font-size: 18px;
        text-align: center;
        box-shadow: 2px 2px 2px #999;
        cursor: move;
    }
    #drop_zone {
        background-color: #EEE;
        border: #999 1px solid;
        width: 280px;
        height: 200px;
        padding: 8px;
        font-size: 18px;
    }
    </style>

  <h2 id="app_status">App status...</h2>
  <h1>Drop Zone</h1>
  <div id="drop_zone" ondragenter="drag_enter(event)" ondrop="drag_drop(event)" ondragover="return false" ondragleave="drag_leave(event)" ></div>
  <div id="object1" class="objects" draggable="true" ondragstart="drag_start(event)" ondragend="drag_end(event)">object 1</div>
  <div id="object2" class="objects" draggable="true" ondragstart="drag_start(event)" ondragend="drag_end(event)">object 2</div>
  <div id="object3" class="objects" draggable="true" ondragstart="drag_start(event)" ondragend="drag_end(event)">object 3</div>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.0.3/jquery.min.js"></script>
<script>
    function _(id){
       return document.getElementById(id);
    }
    var droppedIn = false;
    function drag_start(event) {
        _('app_status').innerHTML = "Dragging the "+event.target.getAttribute('id');
        event.dataTransfer.dropEffect = "move";
        event.dataTransfer.setData("text", event.target.getAttribute('id') );
    }
    function drag_enter(event) {
        _('app_status').innerHTML = "You are dragging over the "+event.target.getAttribute('id');
    }
    function drag_leave(event) {
        _('app_status').innerHTML = "You left the "+event.target.getAttribute('id');
    }
    function drag_drop(event) {
        event.preventDefault(); /* Prevent undesirable default behavior while dropping */
        var elem_id = event.dataTransfer.getData("text");
        _('app_status').innerHTML = "Dropped "+elem_id+" into the "+event.target.getAttribute('id');
        droppedIn = true;
          // Create our XMLHttpRequest object
          var hr = new XMLHttpRequest();
          // Create some variables we need to send to our PHP file
          var url = "jqueryserver.php";
          var vars = "value= "+elem_id;

          hr.open("POST", url, true);

          // Set content type header information for sending url encoded variables in the request
          hr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
          // Access the onreadystatechange event for the XMLHttpRequest object
          hr.onreadystatechange = function() {
            if(hr.readyState == 4 && hr.status == 200) {
              var return_data = hr.responseText;
            document.getElementById("app_status").innerHTML = return_data;
            }
          }
          // Send the data to PHP now... and wait for response to update the status div
          hr.send(vars); // Actually execute the request
          document.getElementById("app_status").innerHTML = event.target.getAttribute('id')+"processing...";
        }

    function drag_end(event) {
        if(droppedIn == false){
            _('app_status').innerHTML = "You let the "+event.target.getAttribute('id')+" go.";
        }
        droppedIn = false;
    }

</script>