Hello,

We are facing an issue with the scrollbar of the Listbox component, as described below.

Consider a simple page with a listbox component with one column :

<listbox id="listbox" width="100%" rows="10">
  <listhead>
    <listheader label="Label" sort="auto" />
  </listhead>
</listbox>

and the following attributes enabled (ROD, checkmarks, ...).

 
listbox.setMultiple(true);
listbox.setCheckmark(true);
listbox.setAttribute("org.zkoss.zul.listbox.rod", true);

The listbox is filled with about 1000 items.

When no item or only few items are selected, the scrollbar works as expected.
But when many items or all items are selected, a strange behaviour happens : the slider doesn't stop at the point the mouse drops it, but instead the slider either goes up or down, or even goes up permanently until it reaches the top of the scrollbar.
In other words, when the user scrolls the scrollbar never remains stable once the slider is released.

Please see the file attached, containing the following files :

• ZUL file
• Java file (zul controller)
• A video capture showing the issue

Best Regards,
Saad Benbouzid