Hi Florian,

>> But especially what Florian said about there being 1 item to few
>> set me on a track. Is there also a horizontal scrollbar? I had this
>> problem half a year ago: the drop down list was too narrow for the
>> data, so a horizontal scrollbar was automatically added. This
>> reduces the vertical space by roughly 1 item.
>
> Setting the DropDownWidth to a high enough value actually solves the
> problem, it must have been the one property I have not played with.
> However, it is peculiar that the described effect only occurs the
> very first time the combo is dropped down, after that until the
> application is closed everthing works just fine.

For me it works differently: if it goes wrong, it keeps going wrong
all the time. So at least I have consistent behaviour :-)

By the way: that this happens at all is not surprising (although it
may be irritating): TIB_LookupCombo is not a descendant of the VCL's
TComboBox, and its drop down list, far from being a simple box, is a
complete TIB_CustomGrid. Of course a grid doesn't resize itself if it
finds out it has to add in a scrollbar.

The default drop down list for TIB_LookupCombo is a TIB_LookupList (a
TIB_CustomGrid descendant). But you can also assign your own grid to
act as drop down list - that's what the CustomPopup property is for.


To fix the problem in IBO itself, we have to look at
TIB_ComboBox.DropDown and TIB_CustomGrid.HeightForGridRows (called by
the former) in the IBO sources. But having taken a glance at them,
it's clear that this isn't the kind of thing you're gonna solve in
half an hour...


Greetings,
Paul Vinkenoog