Xlib backend

[Thiago Milczarek Sayão]

Kevin,

Sure, I was hoping for the question.

"The focus of GTK has moved away from being a “meta toolkit” that other
toolkits can use as a “backend”."

Quoted from
https://discourse.gnome.org/t/gtk4-migration-window-management-functions-gone/7542/4

The first attempt I have made is the logical one, gtk4:
https://github.com/openjdk/jfx-sandbox/tree/tsayao_gtk4_playground

Then I have discovered it's not possible to use gtk4 without Xlib and that
many window management functions are gone (see the quotation link).
In addition to this:
- Gtk4 cannot draw directly on the window or set the background without
gtk4 css;
- It cannot even move the window, just tell the compositor it started a
move.

I also have played plenty with gtk3, it breaks a lot of things thru the 3.x
release cycle, such as DND.

So, I see no reason to use Gtk if Xlib fits better as a glass backend (has
all the needed functions) and Gtk would use Xlib anyway and hide much
needed functionality.

Current glass Gtk backend already touches a lot of Xlib.

Wayland is fully compatible with Xlib, so we can work on "both worlds" with
it. Someday on the future a pure Wayland backend would be nice.

I'm happy to answer any further questions.

-- Thiago.




Em seg., 11 de abr. de 2022 às 12:41, Kevin Rushforth <
kevin.rushforth at oracle.com> escreveu:

> Can you say more about the motivation for doing this? Given the eventual
> direction for Wayland support, even in X11 compatibility mode, I would
> expect more use of gtk and less use of Xlib, not the other way around.
>
> -- Kevin
>
> On 4/10/2022 2:43 PM, Thiago Milczarek Sayão wrote:
> > Hi,
> >
> > I got simple samples running on the pure Xlib port of the Gtk backend.
> >
> > It still has gtk code, but mainly uses Xlib by now. Don't judge the code,
> > I'm porting it gradually.
> >
> > https://github.com/openjdk/jfx-sandbox/tree/tsayao_xlib
> >
> > java @build/run.args -cp apps/toys/Hello/dist/Hello.jar
> hello.HelloCursors
> >
> > Window coordinates and sizes are still off a bit, so you might have to
> > resize the window to redraw.
> >
> > -- Thiago.
>
>