ComboBox: Horizontal scrollbar on Combobox dropdown causes vertical scrollbar to show up

[leannek]

This is a similar issue to #4134.

When the contents in the dropdown is too wide, a horizontal scrollbar will be shown. The scrollbar was placed on top of the dropdown covering the last item in the list. A vertical scrollbar is hence created to allow scrolling down to reveal the last item.

The fix for #4134 (in ​10489) is to extend the width of the popup. A similar trick applying on the height should fix this problem.

However, one thing I have noticed when playing around with the fix was that increasing the dimension of the popup might cause the page scrollbar to appear. This might not be desirable.

[bill]

Hmm, can you attach a test case using the attach file button? Are you saying that the drop down is really wide, wider than your viewport?

[leannek]

My dropdown wasn't really that wide. It's just located close to the right edge of the page :)

Test case attached.

Test 1: Maximize the browser, then click on the dropdown arrow. The vertical scrollbar appears unnecessarily while the popup panel could have its height extended to accommodate the horizontal scrollbar. (Just spotted another thing - If you scroll right on the popup panel, you will notice that the background color of the panel is not rendered properly.)

Test 2: Resize the browser so that the viewport is shorter than the fully expanded popup list. Now click on the dropdown arrow again. Vertical and horizontal scrollbars are appearing on the viewport (as well as on the popup panel, as expected).

[bill]

Thanks for the test case. Actually #8948 might help some of this, but anyway I'll try to look at this for 1.4.

[Douglas Hays]

I could not recreate this problem.

[bill]

OK, let's assume that this is fixed by #8948, unless of course the drop down is wider than the viewport itself, but that doesn't seem worth worrying about.