🚀 go-pugleaf

In article <1992Dec18.012228.3908@hplabsz.hpl.hp.com>, yefchak@hplabsz.hpl.hp.com (George Yefchak) writes:
|> Are the second opinions on that?  I think I've seen software
|> which does seem to be able to distinguish between single
|> and double clicks as described above.  (Actually, I've
|> wanted to know how to do that too...)  In particular,
|> on the Mac you have only one button, so this ability seems
|> pretty important there.

The problem is that you will always get a WM_LBUTTONDOWN/WM_LBUTTONUP
combination before getting the WM_LBUTTONDBLCLK message -- likewise for
controls like a listbox you will always get the LBN_SELCHANGE before
you get the LBN_DBLCLK notification.

The only way I can think to really distinguish between single and double
clicks would be to set a timer when you get the first click and if you
_don't_ get a double click notification within some period of time then
you assume it must have been a single click and only then take the
appropriate action for a single click.

Just thinking about trying to make this work properly for all cases and 
users makes me feel slightly nauseated though.  A double click should
only perform an action that is an extension of whatever a single click
does, anything else would be confusing and cause endless annoyance.  I'm
not a Mac user, but I'll bet that even there it is a very rare case where
a double click does something completely unrelated to a single click.

I think the suggestion that modifier keys (CTRL, ALT, SHIFT) be used to
distinguish between different actions on a click is the best way to go
unless you want to introduce "mouse modes" in your application where the
current mode determines the action of a click.


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PE Nelson Systems       |                                  ... I got better"
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