Accept a Drop

$('.draggable').hqyDraggable({
  proxy: 'clone'
});

$('.droppable').hqyDroppable({
  accept:'#a,#c',
  onDragEnter:function(e,source){
    $(this).html('enter').addClass('over');
  },
  onDragLeave: function(e,source){
    $(this).html('leave').removeClass('over');
  },
  onDrop: function(e,source){
    $(this).html($(source).html() + ' dropped').removeClass('over');
  }
});

<style type="text/css">
.draggable{
  height: 60px;
  width: 60px;
  line-height: 60px;
  text-align: center;
  color: #fff;
  font-size: 24px;
  margin-bottom: 10px;
  z-index: 10;
}

.droppable{
  height: 300px;
  line-height: 300px;
  text-align: center;
  font-size: 24px;
}
</style>

<div class="row">
  <div class="col-xs-4">
    <div id="a" class="draggable bg-red">A</div>
    <div id="b" class="draggable bg-green">B</div>
    <div id="c" class="draggable bg-pink">C</div>
  </div>
  <div class="col-xs-8">
    <div style="background: #f5f5f5;">
      <div class="droppable">Drop here</div>
    </div>
  </div>
</div>