We received a feature request idea from one of our faculty members about the scroll bars within SpeedGrader/Canvas DocViewer.
"There is a vertical scroll bar between the document view and the rubric/comment section, but this one is somewhat constant and does not move. Further inside the document view is the vertical scroll bar for the document itself. At the top are two sets of menus for SpeedGrader tools. The scroll bar goes under these menus, so when it is scrolled all the way to the top, you can't select the scroller and you can't see its scroll bar."
I have also attached a screenshot illustrating how the top of the scroll bar is hidden under the Canvas DocViewer tools menu.
If a student submits a paper with a large number of pages, it can make the length of the scroll bar shorter. This could potentially be harder to grab to scroll down the page. It would be more convenient if the scroll bar was not hidden behind the menu area.
Also, it doesn't appear that there is a need for the scroll bar in the middle that remains constant. It may be less confusing to remove that bar entirely.