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From: oster@dewey.soe.berkeley.edu (David Phillip Oster)
Newsgroups: comp.sys.mac.programmer
Subject: Re: ModalDialog filterprocs
Message-ID: <33391@ucbvax.BERKELEY.EDU>
Date: 28 Dec 89 16:06:11 GMT
References: <10125@saturn.ucsc.edu> <33385@ucbvax.BERKELEY.EDU> <10132@saturn.ucsc.edu>
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Reply-To: oster@dewey.soe.berkeley.edu.UUCP (David Phillip Oster)
Organization: School of Education, UC-Berkeley
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Here are some more things your filterProc should do, that mine does, that
I forgot in my previous message:
12.) supress and ignore Cut/Copy/Clear commanas if nothing is selected.
13.) change the mouse cursor to an I-Beam if it is over a edittext field, and
	back to an arrow when it leaves it.
14.) When you start typing, the dialog manager does an ObscureCursor(). If
you terminate the dialog by using a button equivalent, the cursor is still
obscured.Your filter proc should  force the cursor visible on dialog
exit.
15.) if I have scrollbars or ListManager items in a dialog, pass them
Activate & Deactivate events.
16.) filter invisible control characters out of the input stream so they
won't get into editText items.

Another area where I have to improve:
) Beep if a keystroke is inappropriate for the type of an editText entry,
for example trying to type 'A'..'Z' in a numeric only field.

">" is sirkm@ssyx.ucsc.edu (Greg Anderson)
">>" is me
>>5.) On synonyms for Edit commands, flash the word "Edit" on the menu bar.

Don't forget: (like ACTA forgets) ignore Cut/Copy/&Clear commands if no
text is selected.  It is obnoxious to simply empty the clipboard, placing
nothing there.

>>4.) handle <Shift>Tab to tab backwards  through the fields.
>How should that be done?  Forge a mouseDown event inside the appropriate
>editable text field?
if your filter proc sees <Shift>Tab, it just does a SelIText() of the
appropriate field, and changes the "what" of the event record to
nullEvent, so the dialog manager will do no more with it. It ususally
group all the EditText items in a dialog as one contiguous group of items.
Since I sometimes gray out editable text items, I don't make the
<shift>Tab function completely automatic: I have a generic filterproc that
is called with extra arguments from each specific dialog's filterproc, so
I can customize the behavior of the filterproc while reusing as much code
as possible.

>My filterProc is being called from a dialog box that is invoked from a
>desk accessory, so I can't use globals in the usual way (I have a Handle
>that holds all of the global data, & pass that from routine to routine).
>Any suggestions on how I might pass this handle into the filterProc?

There are two issues here, since there are two kinds of "global" data. One
is true globals, the other is per-window globals. (A dialog might start a
second dialog, for example, an error message dialog. Since you have two
dialogs on the screen, you can't depend on a single set of filterproc
variables.)  Use SetWRefCon(theDialog, (long) winVarHandle) to stash the
gloabls handle, and GetWRefCon(theDialog) to retrieve it. That is what the
refCon is for.  I would make a field in my window variables be a reference
to my application globals.

>How do you determine if the user is clicking in a scrollbar?  Use a custom
>filterProc for each dialog that 'knows' (via hard-coding) which items have
>scrollbars?

Well scrollbars are userItems. You detect clicks on an item by calling
FindDItem() (I.M.V4). If your porgram maintains 64K ROM compatibility,
you'll need to write your own version of this routine, but it si simple.
My filterproc needs to call this so it can track the cursor to handle
changing it to an iBeam as appropriate.  i don't try to write one
completely general filterProc, instead, I write a simple, single, short
one for each dialog, that calls MyGenericFilterProc() to do most of the
work.

Does MacApp miss any of the subtle user interface points I catch? What
does it do along these lines that I don't? 
THINK C Class Library doesn't seem to have much filterproc support, or am
I missing something there?

> The mac is a detour in the inevitable march of mediocre computers.
> drs@bnlux0.bnl.gov (David R. Stampf)
--- David Phillip Oster          -master of the ad hoc odd hack. 
Arpa: oster@dewey.soe.berkeley.edu 
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