[Interest] What for does qt5gui need OpenGL?

[Bo Thorsen]

Den 07-11-2013 07:40, Uwe Rathmann skrev:
> On Wed, 06 Nov 2013 08:03:47 -0800, Thiago Macieira wrote:
>
>>> Shouldn't they be in Qt5OpenGL.dll?
>>
>> No, they are where they were supposed to be. That's by design.
>
> With some nasty consequences for us users:
>
> Our applications run on several pieces of embedded hardware, where one of
> them had been designed 7 years ago with a graphic chip, where only OpenGL
> ES 1.1 is supported. This board needs to be supported and updated for
> many, many years - no way to exchange it by something more recent.
>
> Even if we don't need OpenGL ( using widgets only ) we are stuck with Qt
> 4 forever, because Qt5 has this unnecessary OpenGL dependency. So far
> this had been no big problem - Qt4 is pretty fine - and there are some
> backports of new Qt5 features ( by the way: it would be nice to add the
> json classes to Qt 4.9 ), but sooner or later this will become an issue.
>
> There are reasons why Qt 4.8 is still the platform, where most users are,
> and one of them is because of such a design decision.

After the switch from Qt 3 to 4, there were a bunch of companies that 
had to stay on Qt 3. A few even use it today.

The reason is that Qt progressed into something that didn't work well 
for their platform. For whatever reason.

With a 7 year old board, this is what you can expect to start hitting. 
It's so old, that you just can't expect brand new software to run on it. 
It's nice if it does, and recompiling Qt without GL might be your 
solution. But in general, there are some who will be hit when software 
moves on.

This sucks for those who get hit. But there's no way the community can 
support every piece of legacy hardware used with Qt 3 or 4. Of course, 
the trick is to annoy as few as possible. But annoying some is inevitable.

I don't think you will see a Qt 4.9. I might be wrong, but I doubt it. 
What you could do instead is to start a backport library for 4.8 where 
you put stuff like the JSON class in. Make it public in github, you're 
not going to be the only one stuck on Qt 4. There might be others who 
will contribute other classes to this.

For Qt4 JSON support, I've used Eeli Reilins QtJSON and been very happy 
with it: https://github.com/da4c30ff/qt-json. I recommend it.

Bo.

-- 
Bo Thorsen, European Engineering Manager, ICS
Integrated Computer Solutions. Delivering World-Class Applications
http://ics.com/services