How can I prevent body scrollbar and shifting when twitter bootstrap modal dialog is loaded?

Question 1

Marko,

I just had the same problem. It appears that Bootstrap 3.0.0 adds a class to <body>, modal-open, when the modal first shows. This class adds margin-right: 15px to the body to account for a scrollbar, which is there on longer pages. This is great, except for shorter pages when a scrollbar isn't on the body. In the no scrollbar case, the margin-right causes the body to shift left on modal open.

I was able to solve this by adding some short Javascript and a little CSS:

CSS:

/* override bootstrap 3 class to remove scrollbar from modal backdrop
   when not necessary */
.modal {
  overflow-y: auto;
}
/* custom class to override .modal-open */
.modal-noscrollbar {
    margin-right: 0 !important;
}

JS:

(function($) {

$(document)
    .on( 'hidden.bs.modal', '.modal', function() {
        $(document.body).removeClass( 'modal-noscrollbar' );
    })
    .on( 'show.bs.modal', '.modal', function() {
        // Bootstrap adds margin-right: 15px to the body to account for a
        // scrollbar, but this causes a "shift" when the document isn't tall
        // enough to need a scrollbar; therefore, we disable the margin-right
        // when it isn't needed.
        if ( $(window).height() >= $(document).height() ) {
            $(document.body).addClass( 'modal-noscrollbar' );
        }
    });

})(window.jQuery);

These combined permit the margin-right scrollbar fix to work for long pages, yet is disabled for shorter pages (when document height <= window height). I hope this helps!

Bootstrap 3.0.1+ (tested up to 3.1.1) is a different story. Try the following:

CSS:

/* override bootstrap 3 class to remove scrollbar from modal backdrop
   when not necessary */
.modal {
  overflow-y: auto;
}
/* custom class to add space for scrollbar */
.modal-scrollbar {
    margin-right: 15px;
}

JS:

(function($) {

$(document)
    .on( 'hidden.bs.modal', '.modal', function() {
        $(document.body).removeClass( 'modal-scrollbar' );
    })
    .on( 'show.bs.modal', '.modal', function() {
        // Bootstrap's .modal-open class hides any scrollbar on the body,
        // so if there IS a scrollbar on the body at modal open time, then
        // add a right margin to take its place.
        if ( $(window).height() < $(document).height() ) {
            $(document.body).addClass( 'modal-scrollbar' );
        }
    });

})(window.jQuery);

EDIT:

In light of Mac eliminating scrollbars from inhabiting window render width, here's a more portable solution (3.0.1+) if you don't mind some feature detection. Reference: http://davidwalsh.name/detect-scrollbar-width

CSS:

.scrollbar-measure {
    height: 100px;
    overflow: scroll;
    position: absolute;
    top: -9999px;
}

JS:

window.jQuery(function() {
  // detect browser scroll bar width
  var scrollDiv = $('<div class="scrollbar-measure"></div>')
        .appendTo(document.body)[0],
      scrollBarWidth = scrollDiv.offsetWidth - scrollDiv.clientWidth;

  $(document)
    .on('hidden.bs.modal', '.modal', function(evt) {
      // use margin-right 0 for IE8
      $(document.body).css('margin-right', '');
    })
    .on('show.bs.modal', '.modal', function() {
      // When modal is shown, scrollbar on body disappears.  In order not
      // to experience a "shifting" effect, replace the scrollbar width
      // with a right-margin on the body.
      if ($(window).height() < $(document).height()) {
        $(document.body).css('margin-right', scrollBarWidth + 'px');
      }
    });
});

Question 2

For me only the combination of two answers worked.

css:

body {
    padding-right:0px !important;
    margin-right:0px !important;
}

body.modal-open {
    overflow: auto;
}

stylus:

body
  padding-right:0px !important
  margin-right:0px !important
  &.modal-open
    overflow: auto

Question 3

Try this

body.modal-open {
overflow: auto;
}

Question 4

Mine is easy there it is (CSS Only):

body {
padding-right:0px !important;
margin-right:0px !important;
}

The fact is the !important is overlapping bootstrap from changing padding and margin with the modal-open class and styles.

Question 5

I had the same issue with the scroll bar disappearing, and the body shifting to the left when opening a bootstrap modal.

I've found out an easy fix:

.modal
{
    overflow-y: auto !important;
}

.modal-open
{
   overflow:auto !important;
   overflow-x:hidden !important;
   padding-right: 0 !important;
}

Good luck to all!

Question 6

body {
    /*prevent modal background jumping*/
    padding-right:0px !important;
    margin-right:0px !important;
}

/*prevent modal background jumping*/
body.modal-open {
    overflow: auto;
}

Question 7

the best way is:

to add to BODY overflow-y: scroll
and remove 4 functions from bootstrap.js: checkScrollbar, setScrollbar, resetScrollbar, and measureScrollbar.

Question 8

I added this to my CSS and seemed to work when adding a 'fixed' overlay to view

.modal-open {
    margin-right: 15px;
}

Question 9

You should try this. this is working fine.

$j(document).ready(function() {
    $('.modal').on('show.bs.modal', function () {
      if ($(document).height() <= $(window).height()) {
        $('body').css('margin-right','0','!important');
      }
      else { 
       $('body').removeAttr('style');
      }
    })
    $('.modal').on('hide.bs.modal', function () {
        $('body').removeAttr('style');
    })
  })

Question 10

Try this simple javascript:

$j(document).ready(function() {
     if ($(document).height() <= $(window).height()) {
         $('body').css('margin-right','0','!important');
      }      
 });

Question 11

The following inclusion to my .css file fixed my centered content page from moving or resizing when the popup modal shows.

I did not need any Javascript, just the css code below. This fixed it for content with or without a vertical or horizontal scrollbar.

.modal
{
    overflow-y: auto !important;
}

.modal-open {
    overflow: auto !important;
    overflow-x: hidden !important;
    padding-right: 15px !important;
}

I'm using bootstrap 3.3.7.