[Gambas-user] Program going off the rails in a way I can't explain. Help?

[Benoît Minisini]

> Benoît Minisini wrote:
> >> I've got a really weird problem going on.  I've been working on this
> >> project for about a month, and today I decided to make some major
> >> changes to the user interface operates.  I moved some code around and
> >> delete some code, and now when I run it in the IDE, it randomly jumps
> >> into the sub that handles the click event for a combo-box control called
> >> cbBedList_Click().  The routine "Populate_cbBedList()" gets called by
> >> "Form_Open", and reads values from a database to populate the
> >> Combo-box.  As far as I can remember, I haven't changed the code for
> >> this form at all, but seemingly for no reason, when it hits line "178
> >> cbBedList.Clear" in the Populate sub, it starts executing the code in
> >> cbBedList_Click!   This generates an error because the cbBedList.index
> >> value isn't set, since it wasn't actually clicked.  If I remark out the
> >> contents of the Click event, the Populate routine finishes, although I
> >> still see the debug statement from line 169.  If I remark out everything
> >> from 168-173, it still runs fine (although obviously I don't get click
> >> events handled for the combo-box any longer!).  I'm pulling my hair
> >> out.  The stack backtrace shows:
> >>
> >> FMain.cbBedList_Click.169
> >> (native code)
> >> FMain.Populate_cbBedList.178
> >> FMain.Form_Open.26
> >>
> >> Setting a breakpoint at 178 and single-stepping shows exactly what the
> >> backtrace does; the next line to be executed after 178 is 169!  ANY
> >> ideas???  Please?
> >>
> >> ===
> >>
> >>
> >> 168 PUBLIC SUB cbBedList_Click()
> >> 169 DEBUG "We're in cbBedList_Click()!"
> >> 170 '  BedNum = BedList[cbBedList.index + 1]
> >> 171 '  DrawPlots($db, BedNum)
> >> 172
> >> 173 END
> >> 174
> >> 175 PUBLIC SUB Populate_cbBedList()
> >> 176  DIM sql AS String
> >> 177  'populate the bed selection listbox
> >> 178  cbBedList.Clear
> >> 179  sql = "select bedname, bednum from Beds"
> >> 180 $res = $db.Exec(sql)
> >> 181  DEBUG "$res.Count=" & $res.Count
> >> 182  FOR EACH $res
> >> 183    DEBUG "$res!BedName=" & $res!BedName
> >> 184    cbBedList.Add($res!BedName)
> >> 185    DEBUG "cbBedList.count=" & cbBedList.Count
> >> 186    DEBUG "$res!BedNum=" & $res!BedNum
> >> 187    BedList[cbBedList.count] = $res!BedNum
> >> 188  NEXT
> >> 189 END
> >
> > Which version of Gambas do you use? With which GUI component? On which
> > desktop?
> 
> Gambas 2.7, gb.gui, Ubuntu Linux  2.6.27-16-generic, Gnome 2.24.1

The ComboBox.Clear() method should not raise Click event. This is an old bug 
that has been fixed since Gambas 2.7. You should upgrade Gambas, or handle 
that specific case in your code by hand (i.e. by using a global variable as a 
lock).

Regards,


-- 
Benoît Minisini