What do you think about supporting Qt backend?

[groggily]

On Linux, the backend is GTK3. Adding a Qt backend will allow people to choose the backend they prefer. I know some people prefer to use Qt even on Windows.

[frang75]

Hi @groggily!
Yes. That would be great. I have a small PoC in my private repo. It's entirely possible to create a Qt backend. However, it's laborious. NAppGUI's current functionality is extensive. Not just the widgets, but the entire vector drawing API implemented on top of Cairo. I also have GTK4/GTK2 backends in mind.

[groggily]

GTK4 is understandable. But GTK2?

[frang75]

GTK2 is a robust and stable library. It's still included in modern distributions (Ubuntu-24). I'm also a big fan of legacy systems. I'd like to run NAppGUI on Ubuntu 10 and earlier.

[rubyFeedback]

GTK2 is fairly easy to implement (or, rather, add support for) since the API is smaller than GTK4 and well-known.

Here is an example of ffi gir bindings for ruby via gtk2:

https://github.com/mvz/gir_ffi-gtk

See the first example code there.

For simple stuff, simple GUIs, this works quite ok-ish (hello world example, getting user input
via gtk-entry and so forth - all works in ruby-gtk2); for more advanced things it can be a bit
burdensome, but it's not that much work via ffi/fir/gobject-introspection.

GTK4 is a bit strange. They added things but also removed it and they already plan
to remove even more in GTK5, including xorg-server support. I stopped using GTK
as a result of the developers not caring about any other platform than GNOME.
GTK4 is basically now a GNOMEY-toolkit only.

With regard to qt: it would be nice if a prototype could be supported, say only a
minmal subset:

• buttons
• text / label
• textarea / entry (whatever is needed to get user input)

These three would be pretty nice to have, so we can do quite a bit with this. For
instance, on windows I can use ruby-libui-ng bindings and have a commandline
ruby shell actually, which I use after starting cmd.exe via admin-rights. Then I
can use that simple GUI to use or simulate a simple GUI shell. I can then batch
install stuff or do anything I can do via a shell e. g. create directories, download
stuff and so forth. So it would be nice if we could get a minimal qt-implementation.

If that works then perhaps at a later time it can be extended.

Qt is pretty large, and supporting all of it may be too much work. There used to
be ruby bindings to qt4 but when qt5 emerged, things died down and the
old maintainers of ruby-qt4 quit. That's why I think keeping it simple and small
should suffice, hence my suggestion for three widgets support initially only.