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I'm trying to understand the rationale behind the vertical scroll bar in the 'List All Tabs' dropdown in Firefox (15.0.1);

  • All the tabs are listed here, so it gives the wrong impression of the list containing more elements than can be listed.
  • It's not grab-able by the mouse pointer
  • It's not location specific. Selected a tab in the middle of the list, and the scrollbar will still be set hard against either the top or bottom (whatever was last selected).

I was wondering what other people think? Is there a logical to this, I am missing? Or is it a bug/inconsistency?

Firefox 'List All Tabs' dropdown scrollbar

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up vote 6 down vote accepted

It's actually not a scroll bar. It's an indicator to show which of the tabs are currently visible in the browser tab bar. The ones in the list outside the grey indicator are also outside the tab bar in the browser.

It's there to make it easier for users to orientate and look among the tabs that are currently not shown in the browser.

Try and use the < and > and navigate in the tab bar and you'll see that the bar has shifted place.

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Probably not a great design, though - it does look like a type of scrollbar common on the web. I wonder if it would have been better to show only the tabs that weren't being displayed (after all, the real use of this control is to grab tabs that aren't being shown). – Jimmy Breck-McKye Sep 28 '12 at 8:39
I see, it wasn't immediately obvious but now I understand. – wonea Sep 28 '12 at 8:40
@JimmyBreck-McKye Showing only the tabs that weren't being displayed is a possible answer, and could work better as a metaphor. In a sense of the drop down tabs list could be an overflow for what couldn't be displayed, I have seen that behavior in Microsoft Visual Studio 2010 – wonea Sep 28 '12 at 8:43
Or perhaps they could annotate the vertical scroll bar (view indicator) with a little message ("Current View") ? – wonea Sep 28 '12 at 8:45
I think this is a great, poorly-executed idea. They could probably use something like section highlighting or graying out, or what have you. But a scroll bar is the wrong kind of indicator here simply because so many people have a different idea as to its purpose. – Phong Oct 3 '12 at 20:09

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