[Qt-interest] Qt for the iPad?

[Jason H]

Well, clearly, Apple has the upper hand (people develop for that first) and they don't want leakage of apps to other platforms. That article I read this week about one runtime for all platforms (AIR) would seem to be in violation of the agreement,ut I would not expect Qt to be classified as the same kind of thing for reasons below. Nokia does not have the upper hand in the smart phone market, so I would expect them to be pushing Qt as a disruptive technology, which would result in more apps for Nokia phones. 

You do raise a point about static linking. As a binary that if they ran ldd against it, it would only show Apple-supplied-library linkages. Will they question the size and inspect further? Could they even tell if we stripped symbols? Would they just assume that its too big and reject it under suspicion? Given that Googletalk is still "under review", who knows?

"Applications that link to Documented APIs through an 
intermediary translation or compatibility layer or tool are 
prohibited"

This here is to ban Flash and Java from the platform.  Flash binaries require the use of a "projector" which provides a run-time translation of the Flash app's bundle. The part about compatibilty layer I would take to be something like Cygwin or equivalent. While Qt provides a good degree of compatability across platforms, it is not its only function. We aren't about to argue that POSIX interfaces and IFDEFs aren't allowed are we? I think the "compatibility" clause is to prevent the platform slipping away from Apple. Imagine if there was a non-Apple toolkit (AIR, JAVA) that developers adopted that was maintained differently from the OS. Apple would lose control and users would have linkage problems, QA and the expereince would go down. A statically linked Qt app ensures that every app depends only on itself, its bugs (from Qt) are its own and won't fry a dozen apps at a time. Furthermore, both JAVA and AIR require an interpreted file. How do you sign and
 police that? It is useless to sign the JAVA binary. A statically linked Qt app can be signed, so there is accountability. 

I think Qt just skirts the clause.






----- Original Message ----
From: Andre Somers <andre at familiesomers.nl>
To: qt-interest at trolltech.com
Sent: Fri, April 9, 2010 4:36:06 AM
Subject: Re: [Qt-interest] Qt for the iPad?

On 9-4-2010 10:11, Oliver.Knoll at comit.ch wrote:
> Werner Van Belle wrote on Friday, April 09, 2010 9:36 AM:
>
>    
>> ... Nowhere do I see
>> this 'explicit prohibition' of yours ? Or is there something I don't
>> understand here ?
>>      
> "Applications that link to Documented APIs through an intermediary translation or compatibility layer or tool are prohibited."
>
> Your app: whatever
> Compatibility layer: Qt
>
> So your app would not directly target the "Documented API" (but the Qt API instead) ->  Apple forbids this, at it seems.
>
> That is how I understand it.
>
> Cheers, Oliver
>    

I would understand it like that as well, but the situation is not 100% 
clear. Would that separation still really be there if you'd link Qt 
statically in your app? I guess it depends how Apple interprets it's own 
rules. The problem is: Apple makes the rules as well as judges if apps 
fit them. If they do, but they don't want the apps to fit them, they 
simply change the rules.

I understand that a firm like Nokia is not enthousiastic about investing 
into such an uncertain market where your whole investment could be wiped 
away by a third party at any time. I would not.

I also agree with an earlier post that stated that you should not 
overestimate the usefulness of Qt on that platform. I think the UI 
warrants separate code on a platform like apples, but there may be a 
market for a solid base in terms of the core Qt, networking and similar 
API's. This would enable you to easily port over the core of an 
application, and develop a UI that really fits the platform on top of 
that. An intermidiary GUI layer like QtGUI is very nice on the desktop 
(and even there there are problems of fitting into the platform 
properly), but I think that on mobile devices, this gap is just a bit 
too wide. But perhaps the Trolls can amaze us all once again :-)

André

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