Prevent scrolling of parent element when inner element scroll position reaches top/bottom? [duplicate]

Answer 1

There are tons of questions like this out there, with many answers, but I could not find a satisfactory solution that did not involve events, scripts, plugins, etc. I wanted to keep it straight in HTML and CSS. I finally found a solution that worked, although it involved restructuring the markup to break the event chain.

---

1. Basic problem

Scrolling input (i.e.: mousewheel) applied to the modal element will spill over into an ancestor element and scroll it in the same direction, if some such element is scrollable:

(All examples are meant to be viewed on desktop resolutions)

https://jsfiddle.net/ybkbg26c/5/

HTML:

<div id="parent">
  <div id="modal">
    This text is pretty long here.  Hope fully, we will get some scroll bars.
  </div>
</div>

CSS:

#modal {
  position: absolute;
  height: 100px;
  width: 100px;
  top: 20%;
  left: 20%;
  overflow-y: scroll;
}
#parent {
  height: 4000px;
}

---

2. No parent scroll on modal scroll

The reason why the ancestor ends up scrolling is because the scroll event bubbles and some element on the chain is able to handle it. A way to stop that is to make sure none of the elements on the chain know how to handle the scroll. In terms of our example, we can refactor the tree to move the modal out of the parent element. For obscure reasons, it is not enough to keep the parent and the modal DOM siblings; the parent must be wrapped by another element that establishes a new stacking context. An absolutely positioned wrapper around the parent can do the trick.

The result we get is that as long as the modal receives the scroll event, the event will not bubble to the "parent" element.

It should typically be possible to redesign the DOM tree to support this behavior without affecting what the end user sees.

https://jsfiddle.net/0bqq31Lv/3/

HTML:

<div id="context">
  <div id="parent">
  </div>
</div>
<div id="modal">
  This text is pretty long here.  Hope fully, we will get some scroll bars.
</div>

CSS (new only):

#context {
  position: absolute;
  overflow-y: scroll;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
}

---

3. No scroll anywhere except in modal while it is up

The solution above still allows the parent to receive scroll events, as long as they are not intercepted by the modal window (i.e. if triggered by mousewheel while the cursor is not over the modal). This is sometimes undesirable and we may want to forbid all background scrolling while the modal is up. To do that, we need to insert an extra stacking context that spans the whole viewport behind the modal. We can do that by displaying an absolutely positioned overlay, which can be fully transparent if necessary (but not visibility:hidden).

https://jsfiddle.net/0bqq31Lv/2/

HTML:

<div id="context">
  <div id="parent">
  </div>
</div>
<div id="overlay">  
</div>
<div id="modal">
  This text is pretty long here.  Hope fully, we will get some scroll bars.
</div>

CSS (new on top of #2):

#overlay {
  background-color: transparent;
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
}

Answer 2

Angular JS Directive

I had to wrap an angular directive. The following is a Mashup of the other answers here. tested on Chrome and Internet Explorer 11.

var app = angular.module('myApp');

app.directive("preventParentScroll", function () {
    return {
        restrict: "A",
        scope: false,
        link: function (scope, elm, attr) {
            elm.bind('mousewheel', onMouseWheel);
            function onMouseWheel(e) {
                elm[0].scrollTop -= (e.wheelDeltaY || (e.originalEvent && (e.originalEvent.wheelDeltaY || e.originalEvent.wheelDelta)) || e.wheelDelta || 0);
                e.stopPropagation();
                e.preventDefault();
                e.returnValue = false;
            }
        }
    }
});

Usage

<div prevent-parent-scroll>
    ...
</div>

---

Hopes this helps the next person that gets here from a Google search.

Answer 3

my jQuery plugin:

$('.child').dontScrollParent();

$.fn.dontScrollParent = function()
{
    this.bind('mousewheel DOMMouseScroll',function(e)
    {
        var delta = e.originalEvent.wheelDelta || -e.originalEvent.detail;

        if (delta > 0 && $(this).scrollTop() <= 0)
            return false;
        if (delta < 0 && $(this).scrollTop() >= this.scrollHeight - $(this).height())
            return false;

        return true;
    });
}

Answer 4

I know it's quite an old question, but since this is one of top results in google... I had to somehow cancel scroll bubbling without jQuery and this code works for me:

function preventDefault(e) {
  e = e || window.event;
  if (e.preventDefault)
    e.preventDefault();
  e.returnValue = false;  
}

document.getElementById('a').onmousewheel = function(e) { 
  document.getElementById('a').scrollTop -= e. wheelDeltaY; 
  preventDefault(e);
}

Answer 5

There's also a funny trick to lock the parent's scrollTop when mouse hovers over a scrollable element. This way you don't have to implement your own wheel scrolling.

Here's an example for preventing document scroll, but it can be adjusted for any element.

scrollable.mouseenter(function ()
{
  var scroll = $(document).scrollTop();
  $(document).on('scroll.trap', function ()
  {
    if ($(document).scrollTop() != scroll) $(document).scrollTop(scroll);
  });
});

scrollable.mouseleave(function ()
{
  $(document).off('scroll.trap');
});

Answer 6

Check out Leland Kwong's code.

Basic idea is to bind the wheeling event to the child element, and then use the native javascript property scrollHeight and the jquery property outerHeight of the child element to detect the end of the scroll, upon which return false to the wheeling event to prevent any scrolling.

var scrollableDist,curScrollPos,wheelEvent,dY;
$('#child-element').on('wheel', function(e){
  scrollableDist = $(this)[0].scrollHeight - $(this).outerHeight();
  curScrollPos = $(this).scrollTop();
  wheelEvent = e.originalEvent;
  dY = wheelEvent.deltaY;
  if ((dY>0 && curScrollPos >= scrollableDist) ||
      (dY<0 && curScrollPos <= 0)) {
    return false;
  }
});