Re: Air traffic control system in Java

["Vinzent Hoefler" <0439279208b62c95f1880bf0f8776eeb@t-domaingrabbing.de>]

Shark8 wrote:

> On Mar 5, 12:15 am, "Vinzent Hoefler"
> <0439279208b62c95f1880bf0f8776...@t-domaingrabbing.de> wrote:
>> Shark8 wrote:
>> > On Mar 4, 10:15 pm, "Vinzent Hoefler"
>> > <0439279208b62c95f1880bf0f8776...@t-domaingrabbing.de> wrote:
>>
>> > Interesting you should mention Oberon; I just installed it into a VM
>> > to play with.
>> > {VirtualPC is free now, so if you're using Windows there is little
>> > disincentive
>> > to throwing odd/interesting OSes into a VM.}
>>
>> I'm happy user of VirtualBox sind a couple of major versions. ;)
>
> And that diminishes my pointing out that VirtualPC is free how?

Not at all. Just wanted to point out cross-platform alternatives. ;)

> {You're just making my point that it is *easy*/*cheap* to have VMs.}

Precisely.

>> > Delphi's VCL is actually one of the best GUI-builders I've seen...
>> > there was
>> > also the Kylix port of the VCL to the Linux environs which fizzled
>> > out, but
>> > iy *WAS* there.
>>
>> Well, FreePascal has Lazarus, that's probably more cross-platform. :)
>
> Possibly, Though I wasn't able to get it to work last time I tried it.

I hear that a lot. Never used it and there are people actually using it,
so it must work under certain conditions.

>> > Given that the VCL is basically an object-oriented wrapper of the
>> > Windows [graphics] API
>>
>> And still, a lot of regular users are /not/ satisfied with what the VCL
>> offers. And it's already huge (thus, nothing I would put in a standards
>> document).
>
> I didn't say we should enshrine the VCL as a standard. I *DID* say
> that the VCL presents us with an intriguing possible opportunity to
> implement a GUI hierarchy.

So did Turbo-Vision. ;)

>> Yes, it is surely *possible*. But it also means that you probably have to
>> trade look-and-feel against the portability. And that means, users of
>> your Ada-GUI will complain about the differences, will not use it or
>> "patch" it according to their specific needs.
>
> True enough. However, the lack-of-GUI may be more weighty than a
> GUI-I-Have-To-Tweak, especially in the minds of Ada-newbies.

So use GtkAda? It may not be in the ISO-standard (neither is Qt which a
lot of C++ programmers seem to prefer), yet it is _available_. And I
think, especially "newbies" care less about standard than we oldtimers
(although for an Ada programmer, I'm probably one of the younger ones.)

>> IMO, there's no point in standardizing such a beast, if you can't get it
>> right.
>
> Ah, but I believe that you *can* "get it right."
> Scroll-bars should scroll; edit-boxes should be editable; spin-edits
> should
> constrain themselves to valid [numeric] values which are modified by
> the
> attached arrow-buttons.

Yes, they should. Unfortunately, the precise semantics one might require
for one particular control can not be standardized without trading it for
implementation effort or portability.

Minor example, but I remember a simple progress bar (pygtk). It was cross-
platform in the sense, that it worked on ever supported system. Yet, its
precise look depended on the window manager/platform. On one only the
progress bar was shown, on another one the percentage was shown inside
the bar, on the other one below it.

We could live with those differences, yet many users won't like it.

>> Wasn't there a standard GUI description language (based on XML?) a couple
>> of years ago? What happened to it?
>
> Hopefully it died a slow and horrid death.

I didn't think the basic idea of having a standard GUI description languge
was stupid. And before they invent another language just for that purpose,
I'd rather see an XML description for it.

>> And as mentioned above. To put something like that into a language standard,
>> you have to keep minimalistic (remember that the vendors need to implement
>> it and cost of implementation is also an issue in terms of standardization).
>> But being minimalistic also means, that nobody will use it due to lack of
>> (necessary) features.
>
> That's where the beauty of the VCL shines: a 'minimal' implementation
> may
> be extended as needed. {And these extensions are how more complex
> types are
> introduced/elaborated to the user.}

Have you ever taken a look at a GUI class hierarchy. Even a minimal one
would be quite large, I'd say.

>> IME, if a minimalistic GUI is needed, embed a webserver into your application
>> and let it start up the browser. This served me well so far. Virtually everybody
>> knows how to use a browser, and in the days of Web 2.0 such an approach is
>> probably even "en vogue".
>
> I think Ada could get the upper hand if a) the embedded webserver was
> standard,

Hmm. Standardizing a thing like AWS might turn out to be easier than standardizing
a whole cross-platform GUI library.

> b) the events [server-side] were easy-to-handle,

I don't think that's a problem once you solved the issue of getting the events
back to the server.

> and c) Ada programmers encouraged/evangelized the method.

Well, I'd do that. I have always been bad when it came to GUI design,
but spitting out XHTML was easy. :)


Vinzent.

-- 
A C program is like a fast dance on a newly waxed dance floor by people carrying
razors.
     --  Waldi Ravens