Subject: Odd Delphi 1.02=>2.01 bug(?)
   Date: Mon, 03 Feb 1997 23:04:09 -0500
   From: imti@panix.com
     To: r.p.sterkenburg@dataweb.nl

Reinier:
    Before getting started, I'd just like to say I think you're doing a
great job with the Delphi Bug List website -- invaluable resource!  May it
continue until the very last bug is swatted...whenever that may be.
    Anyhow, here's a problem I ran into porting an app in 1.02 to 2.01.
It's based on (stolen from, more like it) something in the first edition of
Pacheco & Teixeira's DELPHI DEVELOPER'S GUIDE, a section titled "Subclassing
Forms" that begins on p. 540, if you have your copy handy.  Basically, the
idea is to create "fake" notebook pages out of forms, bringing them up so
they fill the area of a panel on your main form.  The only essential
difference between the book's approach and mine is that they create all
their child forms at the beginning and store them in an array of TForm,
whereas I, because of the great number of forms involved in the app (too
many to admit!), create and free them as needed.
    So, the module they call MPGLOBAL.PAS I use unaltered as CHILDFRM.PAS.
I've attached as simplified a version of all this as I can come up with.
The problem is that, although this works just fine under 1.02, when compiled
with 2.01 some strange things happen:
    (1)  The form only appears on ALTERNATE clicks of my activating button.
    (2)  Actually, (1) is true only if you change the code NOT to disable
the button after clicking, which makes sense when the app is working
correctly, OR you change the FormChild.Show call to either FormChild.Visible
:= True by itself or FormChild.BringToFront and then FormChild.Visible :=
True (note the odd order).
    (3) So again, the Show method no longer works.
    (4) Ah, but when it DOES appear, the child form has ignored the
SetBounds call and appears too high on the main form!
    (5) One fix for that seems to be omitting the line assigning the child
form's parent to be the panel on the main form: then the child form appears
in the right position.
    (6) But alas, it also allows the child form to disappear if you do an
Alt+Tab to something else and then return to the app -- not a good feature.
    In short, then, something(s) got quite screwed up in the translation
from 16 to 32 bits, and I haven't a clue as to what it is or what the best
way around it might be; and part of the reason I've letting you in on this
now is that neither does Borland technical support, and they've been looking
at it (??) for a week or so.
    If you or the Bug List's readers can figure out what's going on, I'd
certainly be thankful -- and it's probably a terrific bug, too!
    Regards,
    Michael
    imti@panix.com