Allow resizing timeline layers heights
@jeff
Submitted by Jeff F.T.
Description
I have finally found a reason for needing to be able to drag a layer to make it "taller": keyframe curves.
Indeed, I find myself very limited with audio curves when I need to make precise adjustments. When I have a quiet voice recording and a loud music track, I need to be able to lower the music volume a lot (while still not muting it completely) to let the voice be heard.
With the current layer height of ~100px, this is very hard to accomplish, because you have to be precise to the pixel in your mouse movements.
Being able to blow up the size of a layer (and fold/unfold layers to "compact vs expanded" sizes, while we're at it) would allow me to have a much greater zone to work in vertically and make my adjustments.
Imported from https://bugzilla.gnome.org/show_bug.cgi?id=600969