the line tool is shift
im having trouble uploading simulations,
i dont know how
Hmm.... LINE TOOL IS FOR LINES INSTEAD OF PAINTING!!!
Copy/paste work on windows at least, I'm not sure if mac has that support yet. Any place you can type in supports copy/paste.
EDIT: Mac and linux only have copy support, not paste.
Line tool is a useful tool to draw lines with. To use press 'shift' and drag then you should have made a line of the selected element. To make a straighter line use Alt Shift drag.