This adds support for copy/move in the piano roll using the mouse for pen and both selection tools.
I added TODO comments to indicate where further improvements are possible, but I think this can be merged as-is and the other stuff can be fixed later on.
This adds support for copy/move in the piano roll using the mouse for pen and both selection tools.
I added TODO comments to indicate where further improvements are possible, but I think this can be merged as-is and the other stuff can be fixed later on.