Re: Binding a command to the down-event of a toolbar button

[Richard Stallman]

    I'm trying to add tool-bar buttons for "fast forward" and "rewind" in my
    MPC.el package, and the way I expected it would work is that down-mouse-1 on
    those buttons would start the ffwd/rewind and the up event would stop it.

Is such behavior normal in tool bars in other user interfaces?
If not, I think we should not do it.