Prevent BODY from scrolling when a modal is opened

Question

I want my body to stop scrolling when using the mousewheel while the Modal (from http://twitter.github.com/bootstrap) on my website is opened.

I've tried to call the piece of javascript below when the modal is opened but without success

$(window).scroll(function() { return false; });

AND

$(window).live('scroll', function() { return false; });

Please note our website dropped support for IE6, IE7+ needs to be compatible though.

Answer 1

/* =============================
 * Disable / Enable Page Scroll
 * when Bootstrap Modals are
 * shown / hidden
 * ============================= */

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

function theMouseWheel(e) {
  preventDefault(e);
}

function disable_scroll() {
  if (window.addEventListener) {
      window.addEventListener('DOMMouseScroll', theMouseWheel, false);
  }
  window.onmousewheel = document.onmousewheel = theMouseWheel;
}

function enable_scroll() {
    if (window.removeEventListener) {
        window.removeEventListener('DOMMouseScroll', theMouseWheel, false);
    }
    window.onmousewheel = document.onmousewheel = null;  
}

$(function () {
  // disable page scrolling when modal is shown
  $(".modal").on('show', function () { disable_scroll(); });
  // enable page scrolling when modal is hidden
  $(".modal").on('hide', function () { enable_scroll(); });
});

Answer 2

Hiding the overflow and fixing the position does the trick however with my fluid design it would fix it past the browsers width, so a width:100% fixed that.

body.modal-open{overflow:hidden;position:fixed;width:100%}

Answer 3

Many suggest "overflow: hidden" on the body, which will not work (not in my case at least), since it will make the website scroll to the top.

This is the solution that works for me (both on mobile phones and computers), using jQuery:

    $('.yourModalDiv').bind('mouseenter touchstart', function(e) {
        var current = $(window).scrollTop();
        $(window).scroll(function(event) {
            $(window).scrollTop(current);
        });
    });
    $('.yourModalDiv').bind('mouseleave touchend', function(e) {
        $(window).off('scroll');
    });

This will make the scrolling of the modal to work, and prevent the website from scrolling at the same time.

Answer 4

My solution for Bootstrap 3:

.modal {
  overflow-y: hidden;
}
body.modal-open {
  margin-right: 0;
}

because for me the only overflow: hidden on the body.modal-open class did not prevent the page from shifting to the left due to the original margin-right: 15px.

Answer 5

I am using this vanilla js function to add "modal-open" class to the body. (Based on smhmic's answer)

function freezeScroll(show, new_width)
{
    var innerWidth = window.innerWidth,
        clientWidth = document.documentElement.clientWidth,
        new_margin = ((show) ? (new_width + innerWidth - clientWidth) : new_width) + "px";

    document.body.style.marginRight = new_margin;
    document.body.className = (show) ? "modal-open" : "";
};

Answer 6

If modal are 100% height/width "mouseenter/leave" will work to easily enable/disable scrolling. This really worked out for me:

var currentScroll=0;
function lockscroll(){
    $(window).scrollTop(currentScroll);
} 
$("#myModal").mouseenter(function(){
    currentScroll=$(window).scrollTop();
    $(window).bind('scroll',lockscroll); 
}).mouseleave(function(){
    currentScroll=$(window).scrollTop();
    $(window).unbind('scroll',lockscroll); 
});