[DUG] Embarcadero article

[Jolyon Smith]

|> I just don't see it working unless it is possible to take
|> sophisticated applications using the current VCL (ie VCL32) and 
|> with some effort but not a complete rewrite <snip> modify the 
|> code using ifdefs etc so that you have single source that can compile
|> to either platform.

I disagree.  This is exactly the approach that Borland tried to take with
VCL.NET with disastrous results.  Even in that case, where the GUI "toolkit"
was essentially the same, a simple "recompile for this platform" approach
results in an application that is not well suited for the platform at all.
Far from it.

In the case of the Mac and Linux, those platforms are also quite visually
different and in the case of the Mac in particular provide a quite different
interaction with the user in many cases.  How would you single-source VCL
apps that assume a regular 3 button mouse with chording support when running
on a 1 button Mac or even a Mighty Mouse equipped Mac?

It's not necessarily a simple question of $ifdef'ing some event handling
code - the different user input devices (and the difference in available
user input/interaction controls, if you wish to exploit the "native" look
and feel of the respective platforms) mean that you will almost certainly
need to implement a quite different GUI on each version.

Either that or dumb your GUI down to the lowest common denominator,
resulting in an app that is unacceptably retarded in the UI department to be
considered appealing on any of the platforms you choose to support.

(for simple apps this might be viable, but you specifically referenced
"sophisticated" applications, and this is my area of interest also).

Any NON-visual code should be easily single-source'able, but the V part of
the VCL really has to be different for each platform.  "Visual" classes
will, by definition, need to be different from platform to platform because,
visually, those platforms ARE different.


Didn't CLX try to achieve single source cross platform support?

How did that work out again?  ;)


--
 "Smile", they said "it could be worse!"
 So I did.  And it was.