jQuery UI Draggable set drag length without containment property

Question

I have a div without any parent element and I want the draggable DIV to drag to top and bottom but not all the way. I have done the top using,

drag: function (event, ui) {
      if(ui.position.top < 50)
      ui.position.top = 50;
},

However, I can't figure out a way to do this to bottom. When the element is dragged to the bottom I need to prevent it dragging from a certain position.

JSFIDDLE

HTML

<div id="draggable" class="ui-widget-content">
<p>Drag me around</p>
</div>

Jquery

$( "#draggable" ).draggable({
        axis: 'y',
    containment: 'window',
        scroll: false,
    cancel: false,
    drag: function (event, ui) {
          if(ui.position.top < 50)
          ui.position.top = 50;
    },

});

Answer 1

You need the parent/container's height to calculate the bottom offset:

$("#draggable").draggable({
  axis: 'y',
  containment: 'window',
  scroll: false,
  cancel: false,
  drag: function (event, ui) {
    var offset = 50;
    var maxHeight = (window.innerHeight - this.offsetHeight - offset);

    if (ui.position.top < offset) {
      ui.position.top = offset;
      return false;
    } 
    else if (ui.position.top > maxHeight) {
      ui.position.top = maxHeight;
      return false;
    }
  }    
});

Returning false might be required for canceling or basically "releasing" the dragging effect when it goes outside of the boundaries.

---

Here's your fiddle with the above changes:

 $("#draggable").draggable({ axis: 'y', containment: 'window', scroll: false, cancel: false, drag: function(event, ui) { var offset = 50; var maxHeight = (window.innerHeight - this.offsetHeight - offset); if (ui.position.top < offset) { ui.position.top = offset; //return false; } else if (ui.position.top > maxHeight) { ui.position.top = maxHeight; //turn false; } }, }); 

 html { overflow: hidden; } .ui-widget-content { width: 100%; padding: 15px; } 

 <link href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.18/themes/overcast/jquery-ui.css" rel="stylesheet"/> <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/jqueryui/1.12.1/jquery-ui.js"></script> <div id="draggable" class="ui-widget-content"> <p>Drag me around</p> </div> 

Answer 2

Considering your div has no parent and you want to drag this across the entire document, you should add this to your code

$( "#draggable" ).draggable({
        axis: 'y',
    containment: 'window',
        scroll: false,
    cancel: false,
    drag: function (event, ui) {
          if(ui.position.top < 50)
          ui.position.top = 50;
          if(ui.position.top > $(document).height() - 50)
          ui.position.top = $(document).height() - 50;
    },

});