I had an app on my dsi a while back called Flipnote studio. I remember there was a feature which allowed you to hold right to skim through frames and draw freely leading to a pretty cool looking line that would flow around the screen. I was looking for a way to do the same with Animate but it doesn't seem to like the idea of you drawing over the playback.
Is there any way to do this? I imagined that if a DS could do it way back in 2010 then there should be a way of achieving this in animate?
i don't know what your trying to describe but if you want to (make it appear that you) animate a line, draw the line and then create shape that animates (shape tweens usually work well to automate this) to cover the line and use the shape to mask the line.