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

[Stefan Monnier <monnier@iro.umontreal.ca>]

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.

But looking at the tool-bar bindings (I wasn't familiar with the tool-bar
until recently), I see that I can not distinguish a "down" event from
any other.  Basically, I can only bind a command to a "click".

Am I missing something?  If not, should we add a note anout it in the
TODO file?  I'd expect each button to not have just a command associated
with it, but a complete keymap instead (I wouldn't necessarily try to
support non-mouse bindings in those keymaps, tho) so I could have different
bindings for clicks, double clicks, mouse-1, mouse-2, ...


        Stefan