Description
From @jcunhafonte #4620 (comment):
When there are many traces the information gets hidden. Any hint or suggestion to have the legend with scroll or above the graph?
That's a good point - it would be tricky to have this scroll since you can't in general mouse over it; and we don't really want to overflow the graph container, that could have all sorts of negative repercussions.
One possibility that occurs to me is perhaps when the box is cut off we use the vertical position of the cursor as the scroll bar: when the cursor is near the top of the subplot you see the top of the label, when it's near the bottom you see the bottom.
Another possibility is to find the trace closest to the cursor and make sure the entry for that particular trace is visible; but that would be jittery and anyway if you have two traces exactly on top of each other, you might never be able to see the label for the bottom one. So I think I prefer the first option.