have brain lock - need help

it has been so long since i have done a gui that
i have forgotten almost everything i ever knew
about them, which was not much to begin with.

i am looking for the dolphin widget which will
continuously select from a list of strings as you
type more characters. iow, when you type 'm',
the list narrows to entries beginning with 'm'. then
when you type 'a', the list narrows further to
entries beginning with 'ma'.

thanks in advance.

Donald

You wrote in message news:aloshe$m99$[hidden email]...
You are talking about the sort of widget used for an "auto-completion" list
right? Hmmm, maybe that is slightly different. Either way there is,
unfortunately, no standard component to do that, so unless someone has
something (or knows of an Active-X control) you'll have to roll your own.

I am not an expert in the use of MVP, but it seems to me that this is a
"view" issue, and ought therefore to be implemented as a specialised kind of
list that plugs into the standard ChoicePresenter. One possible approach
would be to subclass ListView and add a "filter" to it that restricts what
the list displays. If the ListView is operating in "virtual" mode (the
default) changing the filter could be made pretty efficient, as it is only
necessary to tell the list how many items to display, with the content being
determined dynamically at paint time. This hypothetical "narrowing" list
view would override the #lvnFindItem: notification and use it to configure
the filter, rather than to perform an incremental search. This would involve
applying the filter to work out how many items would be in the revised list,
and then just setting the new number of items with #lvmSetItemCount:. It
would probably pay to cache the filtered list for better repaint
performance, as otherwise you'll end up rebuilding the filtered list as each
cell (row and column) is repainted.

Maybe some kind soul would be willing to help you with a NarrowingListView,
or perhaps has a better idea? If not I'll have a bash at when I get a spare
moment, as it seems like it might be quite an interesting and useful little
project.

Regards

Blair

Donald,

> i am looking for the dolphin widget which will
> continuously select from a list of strings as you
> type more characters.

A listview has the builtin capability you may be looking for (though it
doesn't actually narrow down the items in the list, as Blair was talking
about).  Methods can also be added to listbox and combobox to do the same
thing.

-- Louis

Donald MacQueen <[hidden email]> wrote in message
news:aloshe$m99$[hidden email]...
...
> i am looking for the dolphin widget which will
> continuously select from a list of strings as you
> type more characters. iow, when you type 'm',
> the list narrows to entries beginning with 'm'. then
> when you type 'a', the list narrows further to
> entries beginning with 'ma'.

I am not aware of a control that does this automatically.  A combo box will
assist with a selection based on typing the first few characters of a
string, but does not limit the list.

I happen to have created a behavior similar to what you are asking for in my
CJD Lookup tool http://www.mitchellscientific.com/smalltalk/CJDLookUp.htm .
Look at the screen shot of the method selection dialog.  It dynamically
filters based on a partial string.  Feel free to use this code as an
example.  I have a new (unreleased at the moment) version with much faster
filter code, but the basic approach is the same.

Chris