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Comment by albertzeyer | Hacker News Reader

I find it a bit weird that Gimp does not use the latest GTK (i.e. GTK4, which was considered stable since 2020), even though GTK originates in the Gimp project itself. It actually seems to be quite a bit behind: This is now the first release of Gimp which started to use GTK3, i.e. before, it even still used GTK2 (reached end-of-life in 2020)?

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Having had to migrate a very simple project from GTK2 to GTK3, I don't think it's all that weird. The migration was utterly difficult, in the areas that hit me seemingly no effort was made to give proper migration paths. Only with some later published documentation (+ help from chatgpt) was it possible to restore some functionality later, after the initial migration. Finally that even meant calling the xlib directly.

And note that the software used wxWidgets, so most of the changes were encapsulated there. Only a very small part of GDK/GTK was used directly, with wnck already used as a helper layer (but the functionality in question broke there as well).

So even if GTK came from GIMP, if the later development in GTK was not made specifically for and by the GIMP project, the migration must have been a nightmare. Especially in a project that had so many other things to worry about, non-destructive editing alone.

And to repeat such a migration now again for GTK4 will not be very enticing.

From what I've heard surrounding this, GTK3 to GTK4 isn't as big of a jump as GTK2 to GTK3 was. The GTK3 port was finished first because there was already work in place for that, but we can expect a GTK4 port to be faster. That said, I haven't seen many apps that aren't specifically GNOME apps start using GTK4 in the first place, and as such I'm currently not using any GTK4 applications. I expect it to take a while before more things move to GTK4.

GTK stands for "Gnome first every other user literally does not matter break them hard, break them often, make them give up ToolKit" these days, and has for quite a while.

The funniest thing is that GTK used to stand for "Gimp toolkit". How times fly.

GTK4 removed a bunch of APIs for stupid reasons and GIMPs move to 3 started before 4 even existed. Had 4 at least tried to maintain some degree of compatibility then switching from 3 to 4 near the end would have been feasible. But that's not the case.

If you aren't Gnome, GTK is not for you.

Guess what the "G" in GTK stands for historically

That was before GNOME took over, as it was supposed to be the answer against KDE and original Qt license.

And here we are, having written articles about Gtkmm to The C/C++ Users Journal, I no longer care and run systems from Microsoft/Apple/Google instead.

I think Harmony was the Qt replacement but I don’t think it lasted very long.

That was after Nokia acquisition from Trolltech.

https://blogs.kde.org/2009/01/14/cute-harmony-qt-goes-lgpl/

Development ceased at the end of 2000, when Qt was released under the GPL, removing the perceived need for the Harmony Project to exist. In January 2009 Qt itself was made available under the GNU LGPL, along with the previous license options.

I feel this. I tried using GTK4 a little while ago and almost immediately switched library when I realised it's simply incapable of doing certain things I needed, usually because either Wayland can't do it or GNOME doesn't need it.

Would you care to actually list those things?

Might as well port the next version of Gimp to Qt - they seem to be much more reasonable as API providers.

Qt also introduces some messy changes between major versions but they tend to be a lot more reasonable than what GTK does. Since Qt4 at least there's usually some attempt at providing alternatives for each deprecated function or class (the alternatives are shown in the error messages) and sometimes full-on compatibility layers for missing features are provided like with Qt5Compat.

Not sure Gimp devs would be willing to switch to C++ for Qt though.

True but the leap from GTK2 to GTK3 is a lot bigger than from GTK3 to GTK4. I'm not sure when the "port" to GTK3 started, but if it was from before GTK4 was a thing, it makes sense that they wanted to finish the GTK3 stuff first.

> I'm not sure when the "port" to GTK3 started

Probably more than 10 years ago.

GTK 3.0 was released in 2011 and it was announced a few years before that, probably in 2009. So whoever down voted, the 90s weren't 10 years ago...

From the second paragraph of the article:

> GTK 4 has been available for a few years now, and is on the project's radar, but the plan was always to finish the GTK 3 work first.

Maybe so, but did you actually open that "on the radar" link? It was closed WONTFIX because moving to the latest release of their bespoke library was considered "tech debt" :-/ https://gitlab.gnome.org/GNOME/gimp/-/issues/6440#note_12726... I actually think it was terribly disingenuous of LWN to use "on the radar" language pointing at a closed issue. Maybe there is another issue (hiding in the 12,000 issues) that is actively tracking the Gtk4 migration, but that one ain't it

We actually had a Google Summer of Code project this summer that explored porting one of our main GTK3 widgets to be compatible with GTK4. It's definitely on our radar, but it's not a major focus at this point.

Do you have the correct issue that one could follow since 6440 isn't it?

Also, since you're here: is it just a matter of glucose, and thus if someone were to port it to GTK4 that patch would be accepted, or it's quite literally "no user cares about library versions"?

If someone submitted a patch that ported everything in GIMP to GTK4, I'm quite sure it'd be accepted after review. The trouble is that GTK4 deprecates or breaks a number of things as well. For instance, while the icon scaling system is much more flexible in GTK4, it's different than in GTK3 so all that work would have to be redone. GtkTreeViews are also becoming obsolete, and since GIMP relies on that for the layer/path/channel views, it'll be another big change.

At the moment, new development is encouraged to follow the GTK3 -> GTK4 migration guidelines (e.g. use gtk_widget_set_visible () rather than gtk_widget_show (), don't use gtk_widget_destroy () since it's been removed, etc). I don't know a specific issue tracking GTK4 at the moment, but I can check.

GTK has become the Gnome toolkit , and the Gnome developers don't care about developers outside their umbrella.

> I find it a bit weird that Gimp does not use the latest GTK

Which is ? GTK 6 ? GTK is a moving target (like a lot of libraries those days). /s

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