[Development] Question about Qt's future

[Steve Gold]

I have been reading the discussions about Qt’s future and strongly feel that 
it's full of promise. Last year I used a different application framework but 
the company went bankrupt without notifying its users. I then tried several 
other frameworks but wasn’t happy with any of them. Then I came across 
Cosos2d-x and Qt and briefly tried both. I quickly came to the conclusion 
that QML (with JavaScript) was an extremely powerful way to develop systems 
and that I was able to use C++ if I needed to access existing libraries or 
required critical performance. IMHO, this one-two punch in some ways sets Qt 
above the fray and enable developers to create and deploy a wide range of 
applications, including complex and highy performant ones. QML can be used 
when it is appropriate and C++ can be used when it is appropriate.

When I last counted the QML types and C++ classes I found that the C++ 
classed outnumbered the QML typed by approximately 3:1. I’m certainly not 
suggesting that the ratio be close to 1:1 but there is some room here for 
improvement. I like that many of the new features of Qt 5.3 and some of its 
immediate predecessors allow users to access functionality in C++ or QML and 
hope that this trend continues. There are certainly several aspects of Qt 
that can be improved, like the Qt Creator editor for one, but Qt is an open 
source project and everyone has an opportunity to contribute by comments, 
suggestions or even code.

BTW, I agree with the statement "I do not really care about .ui file 
support." I would, however, like to see some improvement in the Qt Creator 
design functionality, especially since the older Qt Designer appears to have 
more capability than the newer Qt Quick Designer. However, I personally 
disagree that "100% C++ GUI is fine." QML provides a MUCH better vehicle for 
GUI than C++ and after using C++ and Java for many years I can see 
tremendous benefit in QML. If someone wants to spend the time and effort to 
create GUIs in C++, then I wish him or her luck. I've experienced some pain 
with this in the past and I don't want to do it again. It's just my 
preference and may not be right for everyone.

To Qt's bright future,

Steve

-----Original Message----- 
From: md at rpzdesign.com
Sent: Monday, April 21, 2014 12:55 PM
To: Thiago Macieira ; development at qt-project.org
Subject: Re: [Development] Question about Qt's future

Thiago:

I really appreciate your and Intel's participation in the open source Qt
project.

I think you misunderstood what I was talking about and forcefully
rejected that which I did not ask.

I want the "pattern" brought forward, but we should not try to bring the
code forward. Let sleeping dogs lie.

After reading these:

http://qt-project.org/doc/qt-5/topics-graphics.html
http://qt-project.org/doc/qt-5/qtquick-visualcanvas-scenegraph.html
http://qt-project.org/doc/qt-5/qtquick-visualcanvas-scenegraph.html#scene-graph-and-rendering

What I think would be a solution is to create a starting point
where Qt Widget 2.0 development could begin anew again based on the
QQuickPaintedItem class.

I think the notion of a Window with child custom controls is not too far
fetched.

My suggestion is basically to provide an early off ramp for QQuickWindow
to allow for 100% C++ projects.

This may even serve as the foundation for custom controls in QML as
well, don't know enough right now to be dangerous.

It would definitely provide current Qt Widget users a sense of ease
that the Widget option is still available even though QtQuickWindow is
the future focus.

QML and QTWidget would then both use the same dual GUI/render thread
foundation, but it would be good to have an early C++ jumping off point
for QQuickWindow based projects.

I do not really care about .ui file support.  For all I can see, 100%
C++ GUI is fine.

What do you think?

Cheers,

md


On 4/21/2014 12:19 PM, Thiago Macieira wrote:
> Em seg 21 abr 2014, às 10:59:43, md at rpzdesign.com escreveu:
>> Can Qt Widgets design pattern be brought forward using the same OpenGL
>> foundation
>> that QML uses to instantiate controls?
>
> Short answer: no.
>
> Long answer: if you want it working in other platforms, without glitches 
> and
> regressions, the effort required for this is enormous. It basically 
> requires
> rewriting all or almost all widgets from scratch so that they work in a
> retained-mode OpenGL scene graph, instead of imperative-mode raster buffer
> painting. It's a complete paradigm change.
>
> Since this requires a rewrite, instead of doing it in QtWidgets and 
> risking
> regressions that users will not accept, the idea was instead to do it in a
> different module, one where we can experiment and at the same time clean 
> up
> some of the mistakes that exist in QtWidgets and can't be cleaned up 
> without
> annoying someone.
>
> That's the Qt Quick Components.
>
_______________________________________________
Development mailing list
Development at qt-project.org
http://lists.qt-project.org/mailman/listinfo/development