1. lists & widgets
My dear fellow incorruptible dos dinosaurs,
I have whipped up a treat for you: widgets, basic dos GUI elements.
They are not designed to compete with Bill's Great $cheme, or David's
interpretation of that monstrosity, but if you need a button or two, a
simple menu, or even a file selector, you are welcome to them.
Why? And why about three years too late?
Well, why not? - Initially I was provoked by the recent outbreak of OO
accidents. To the simple, uninitiated mind, like mine, they all looked
like either a conglomeration of spelling mistakes or a ghastly result
of some terrible java(nese) affliction. I thought there had to be a
simpler, better way. So I revamped my old associative lists code, and
when I was quite happy with it, I was searching for an nice example, a
worthwhile demo. Then I spotted my old widgets, with a three year dust
layer on them. Soon enough they just took over my life, for the
following couple of weeks anyway... - And after going so far, I
decided I
might just as well share it!
Btw, associative lists, sometimes also called dictionaries, or keyed
lists, are quite powerful, and at the same time very intuitive
devices. And as long as the current namespace nightmare continues,
they are probably the best antidote. They can, for example, easily
simulate flexible structures. Sensibly combined with ordinary
sequences, (see the widgets 
, or with hashed or sorted lists, they
can also be used in creating very interesting database schemes. They
are, of course, somewhat slower than ordinary sequences, but even in
comparison with say btrees, they looked quite respectable. They do not
suffer, not to the same degree anyway, from indexing overheads of deep
nested trees.
I have just sent a couple of bundles to Rob. In case he decides not to
have such retrograde material on his site, you can also fetch it off
my own page.
Enjoy. jiri
http: homepages.paradise.net.nz/~jbabor/euphoria.html
2. Re: lists & widgets
Jiri wrote:
> I have whipped up a treat for you: widgets, basic
> dos GUI elements.
Nice stuff. A couple of nits to ignore:
1. Traditionally, a radio button represents an exclusive choice - you can
only select one option from the group. Your rbuttons seem to act like
checkboxes.
2. It would be nice if the label were part of the clickable area of
checkboxes and radio buttons, otherwise you're limited to clicking a fairly
small graphic.
3. The vlist has me a bit puzzled. In the demo, choosing clicking the
up/down arrows didn't move the thumb. By the way, I really like the
next-style scrolls, with the arrows stuck together.
4. The behavior of the lists is a bit disconcerting. I expected clicking the
list to set focus on an item, not to choose an item. The lack of visible
feedback makes me unsure as to which item I've actually selected.
5. It would be nice if the sle changed appearance to show that it was in
edit mode - perhaps drawing a thick border around the box. The I-beam is a
bit thin, especially if I have my glasses off.
> Btw, associative lists
I'm quite font of associative lists myself, and your implementation is
typically clever. I had used a similar mechanism in Llama to try avoiding
the namespace mess, but the overhead of using strings as keys turned out to
be significant.
I was thinking that, since Euphoria is optimized to append data elements, it
might be faster to store the keys and values like so:
{ key list, value list }
This might make the appending of new values onto the list slightly cheaper,
although that's not a frequent operation.
Again, very nice - almost enough to make me go back to the portable GUI
project.
-- David Cuny
3. Re: lists & widgets
----- Original Message -----
From: jiri babor <jbabor at PARADISE.NET.NZ>
To: <EUPHORIA at LISTSERV.MUOHIO.EDU>
Sent: Sunday, March 05, 2000 8:59 AM
Subject: lists & widgets
> My dear fellow incorruptible dos dinosaurs,
>
> I have whipped up a treat for you: widgets, basic dos GUI elements.
> They are not designed to compete with Bill's Great $cheme, or David's
> interpretation of that monstrosity, but if you need a button or two, a
> simple menu, or even a file selector, you are welcome to them.
Jiri:
Nice job - especially the selector(s).
It would be good to add an event handler, which could, among other things,
re-order the 'pile' so as to bring a clicked-upon widget to the foreground.
Regards,
Irv
4. Re: lists & widgets
David wrote:
> 1. Traditionally, a radio button represents an exclusive choice -
> you can only select one option from the group. Your rbuttons seem to
> act like checkboxes.
David, you obviously did not notice, I have both. Under misleadingly
similar names. rbutton is really a checkbox in disguise, and rbuttons
is a cluster widget with the behavior you want. Run the other example
and you will see.
> 2. It would be nice if the label were part of the clickable area of
> checkboxes and radio buttons, otherwise you're limited to clicking a
> fairly small graphic.
You are quite right, it is a standard requirement. But this is just
the first cut...
> 3. The vlist has me a bit puzzled. In the demo, choosing clicking
> the up/down arrows didn't move the thumb. By the way, I really like
> the next-style scrolls, with the arrows stuck together.
I think you mean the vscroll control. My example is poor. Generally,
vscroll is a bit of a dilemma for me. How much do I move the thumb
slider, when the arrow is clicked? Just a pixel and adjust the list
display accordingly? That's not terribly satisfactory with both
relatively short and relatively long lists. So I basically postpone
the decision until the list size is known and then move the list one
line up or down per click. I have experimented with continuous
movement while the rat button remains pressed, but for that I need
better timer resolution than 18 ticks per second, and unfortunately
tick_rate() does not seem to work properly at all in NT dos windows...
> 4. The behavior of the lists is a bit disconcerting. I expected
> clicking the list to set focus on an item, not to choose an item.
> The lack of visible feedback makes me unsure as to which item I've
> actually selected.
I originally had an inverted display there, then removed it when I
used it for the file selector (where it is superfluous) and forgot to
put it back in. Next time.
> 5. It would be nice if the sle changed appearance to show that it
> was in edit mode - perhaps drawing a thick border around the box.
> The I-beam is a bit thin, especially if I have my glasses off.
Changed appearance is a good idea. The cursor is just one pixel wide
xor-ed vertical line, built into my prompt in font.e. I'll change it
to three pixels, because the speed is not of real importance in this
case anyway.
> Btw, associative lists
>
> I'm quite font of associative lists myself, and your implementation
> is typically clever. I had used a similar mechanism in Llama to try
> avoiding the namespace mess, but the overhead of using strings as
> keys turned out to be significant.
That's what I thought too, but when I ran even more complex widgets on
my old 50 MHz 486 for comparison, I did not see any performance
degradation at all.
> I was thinking that, since Euphoria is optimized to append data
> elements, it might be faster to store the keys and values like so:
>
> { key list, value list }
This is exactly what I used for a number of years, as I mentioned in
my previous note. I think I called it 'parallel sequences' scheme.
There is not much in it, but indexing of a 1d sequence is obviously
faster than indexing of a 2d sequence.
> Again, very nice - almost enough to make me go back to the portable
> GUI project.
Don't you even think about it! You have enough on your plate as it is.
Thanks, David.
Irv wrote:
> Nice job - especially the selector(s).
> It would be good to add an event handler, which could, among other
> things, re-order the 'pile' so as to bring a clicked-upon widget to
> the foreground.
Thank you very much too, Irv.
I thought about it and even played with it. As it turns out, it is
fairly simple to implement, but eventually I decided to keep it as
simple as possible, initially, and wait for the feedback - if any.
Generally, if no one else is going to use it, I do not have to worry
about proper documentation, easy formats, updates, additional widgets
and comments, etc. So it's up to you guys...
jiri
5. lists & widgets
My dear fellow incorruptible dos dinosaurs,
I have whipped up a treat for you: widgets, basic dos GUI elements.
They are not designed to compete with Bill's Great $cheme, or David's
interpretation of that monstrosity, but if you need a button or two, a
simple menu, or even a file selector, you are welcome to them.
Why? And why about three years too late?
Well, why not? - Initially I was provoked by the recent outbreak of OO
accidents. To the simple, uninitiated mind, like mine, they all looked
like either a conglomeration of spelling mistakes or a ghastly result
of some terrible java(nese) affliction. I thought there had to be a
simpler, better way. So I revamped my old associative lists code, and
when I was quite happy with it, I was searching for an nice example, a
worthwhile demo. Then I spotted my old widgets, with a three year dust
layer on them. Soon enough they just took over my life, for the
following couple of weeks anyway... - And after going so far, I
decided I
might just as well share it!
Btw, associative lists, sometimes also called dictionaries, or keyed
lists, are quite powerful, and at the same time very intuitive
devices. And as long as the current namespace nightmare continues,
they are probably the best antidote. They can, for example, easily
simulate flexible structures. Sensibly combined with ordinary
sequences, (see the widgets , or with hashed or sorted lists, they
can also be used in creating very interesting database schemes. They
are, of course, somewhat slower than ordinary sequences, but even in
comparison with say btrees, they looked quite respectable. They do not
suffer, not to the same degree anyway, from indexing overheads of deep
nested trees.
I have just sent a couple of bundles to Rob. In case he decides not to
have such retrograde material on his site, you can also fetch it off
my own page.
Enjoy. jiri
http: homepages.paradise.net.nz/~jbabor/euphoria.html
Robert Stanton
Plessey Asia Pacific Pty Ltd
mailto: rstanton at plessey.com.au
