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From: engber@gumball.ils.nwu.edu (Mike Engber)
Newsgroups: comp.sys.mac.programmer
Subject: PopUp CDEFs
Summary: are there any standards?
Message-ID: <5355@accuvax.nwu.edu>
Date: 19 Mar 90 19:59:11 GMT
Sender: news@accuvax.nwu.edu
Reply-To: engber@gumball (Mike Engber)
Organization: ^
Lines: 44

Is there any official way to implement PopUp menu's a controls?
Alternatively, is anyone particulary proud of the way they`ve done it
and/or willing to share some source or ideas?

I looked at the DTS example of a PopUp user item and it seems to me a
control would be a lot cleaner. I also looked at Plamondon`s article in
MacTutor (Sept '88) and wasn't so happy with his implementation (no
clean way to line up a group of PopUp menus as shown in IM V p. 25)

Anyway, unless someone sends me source, I'm going to take a hack at my
own version and I'm soliciting suggestions on my ideas.

1) After creating the control, the CDEF user would store a handle the
the menu (to be popped) in the contrlRfCon.

2) contrlValue will contain the currently selected item.

3) the menu title will be used as the PopUp menu`s title

And now the hard part...

4) how to display it. Obviously you want it all to fit in contrlRect,
but the you want the title right justified against a left justified
Pop-up box. Since everything must fit in contrlRect, you have to divide
it up between the title and the Pop-up box.

The approach Plamondon took was to give the title as much as it needed
and the rest to the pop-up box. However, as he points out, this method
doesn`t let you line up several pop-up menus (as shown on IM V p. 25 )

The only idea I`ve come up with is to split the contrlRect in half;
right justify the title in the left half and left justify the pop-up
box in the right half. This means you`ll need excessively large
contrlRects when there is a big difference in the width of the title
and the largest menu item, but I think it should be reasonable in most
cases.

If you have any ideas/suggestion pleas let me know. I don't want to
re-invent the wheel if I don't have to. Unless I`m overlooking something
implementing this shouldn't be hard and I plan to share my source.

Please respond via email if possible.

-ME