Bootstrap 3 modal fires and causes page to shift to the left momentarily / browser scroll bar problems

Question

I am working on a site using Bootstrap 3.1.0.

You\'ll notice when the modal window opens, the browser scroll bar just disappears for a split second, then comes back.

Answer 1

My page needed a modified version of Agni Pradharma's code to keep it from shifting when the modal was shown. I have a fixed nav header and some pages with scroll, some without. Demo here: http://jsbin.com/gekenakoki/1/

I used both the css:

.modal {
    overflow-y: auto;
}

.modal-open {
    overflow: auto;
} 

and the script:

$(document.body)
.on('show.bs.modal', function () {
    if (this.clientHeight <= window.innerHeight) {
        return;
    }
    // Get scrollbar width
    var scrollbarWidth = getScrollBarWidth();
    if (scrollbarWidth) {
        $(document.body).css('padding-left', scrollbarWidth); 
    }
})
.on('hidden.bs.modal', function () {
    $(document.body).css('padding-left', 0);
});

function getScrollBarWidth () {
    var inner = document.createElement('p');
    inner.style.width = "100%";
    inner.style.height = "200px";

    var outer = document.createElement('div');
    outer.style.position = "absolute";
    outer.style.top = "0px";
    outer.style.left = "0px";
    outer.style.visibility = "hidden";
    outer.style.width = "200px";
    outer.style.height = "150px";
    outer.style.overflow = "hidden";
    outer.appendChild (inner);

    document.body.appendChild (outer);
    var w1 = inner.offsetWidth;
    outer.style.overflow = 'scroll';
    var w2 = inner.offsetWidth;
    if (w1 == w2) w2 = outer.clientWidth;

    document.body.removeChild (outer);

    return (w1 - w2);
};