[Interest] Direction of Qt [Was: Re: QML Runtime]

Bo Thorsen bo at fioniasoftware.dk
Fri Feb 1 09:37:13 CET 2013

Den 01-02-2013 09:06, Mark Summerfield skrev:
> Hi Shawn,
> On Wed, 30 Jan 2013 12:50:53 +0000
> Rutledge Shawn <Shawn.Rutledge at digia.com> wrote:
> [snip]
>>>>> - Would this mean that QML would be able to access all or most of
>>>>> the Qt C++ APIs (e.g., QFile, etc.)?
>>>> No, adding new QtQuick APIs is still more work that needs to be done.
>>> That's a decision I've seen debated a few times here. On one hand, QML
>>> feels like a limited tool if you don't have access to the full Qt API
>>> or at least a much larger subset of it. OTOH, ATM all non-trivial QML
>>> apps need a C++ side anyway, so why not let people code the C++
>>> instead of trying to wrap everything.
>>> The javascript side also has a lot of limitations. Especially because
>>> there is no available framework to do real work. JS is pretty much
>>> restricted to manipulate the QML objects.
>>> As the situation is right now, I don't see the point in making it
>>> possible to run a QML only app. The environment is too weak for this
>>> to make sense. Sure, there are probably a few apps you can do. But the
>>> overwhelming amount of QML apps will need C++ coding as well.
>> Yeah but it should get better over time.
> ISTM that many people will want to create pure QML/JavaScript apps. Some
> for rapid prototyping; some because their developer costs are more
> important than runtime efficiency; and some---perhaps most---because
> they want rapid development & are willing to resolve any efficiency
> problems by dropping down to C++ when necessary.
> Is this where Qt is headed? Or will the Qt devs "hold the line" and
> insist on the need for C++? FWIW I don't have any axe to grind either
> way, I just want to know where things are going.

You probably won't get an answer to this, because I doubt anyone really 
know where this is heading. It's a HUGE task to expose the entire Qt API 
to QML, and it might not make sense or even map 1:1 to the QML code 
model, so no one will commit to this.

I take a fairly laid back approach to this. If it happens, I might use 
this option. If not, I'll just do as I do right now, which is to always 
have C++ layers as well.

Personally, I think this is one of the cases where it's better to let 
the project evolve than try to make a decision on what should be the 

Bo Thorsen.

Fionia Software - Qt experts for hire.

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