Window scroll bar disappearing.

[ermish]

When opening a dropdown, the window scrollbar is disappearing.

The paper-dropdown-menu demo shows the issue.

[solomongracio]

+1

[dhineshdhanapal]

+1

[SamMaier]

Can reproduce here: http://jsbin.com/qukawalura/edit?html,output - however demo no longer shows the issue.

[ianbitts]

I was able to create a hacky work-around that suits my needs. Perhaps it will help other as well.

In your css...

body {
     overflow: auto !important;
}
body.noscroll {
       position: fixed;
       overflow-y: scroll !important;
       width: 100%;
}

In your app.js...

window.addEventListener('paper-dropdown-open', function () {
      var body = document.querySelector('body');
      // If the window's scroll bar would be visible, add the noscroll class.
      if (body.scrollHeight > body.clientHeight) {
          body.classList.add('noscroll');
      }
  });
  window.addEventListener('paper-dropdown-close', function () {
      document.querySelector('body').classList.remove('noscroll');
  });

Essentially, the css prevents Polymer from hiding the scroll bars when the dropdown is opened. The javascript and .noscroll class prevent the screen from being scrolled when the dropdown is open, but keep the scrollbar visible.