Install Gtk3 theme versioned

[TingPing]

This allows multiple Gtk versions to be installed and themed properly.

On a side note this manually calling cp to install everything is awful, would you mind me completely redoing all of that (and possibly moving around some files)?

[horst3180]

I see some problem with this:

• GTK 3.14 doesn't support versioned directories. From what I see, this patch hasn't been backported to 3.14. This means the theme for GTK 3.14 has to be installed to gtk-3.0.
• You'll have to run the installation process multiple times to install multiple version.
• gnome-tweak-tool doesn't recognize themes without gtk-3.0 directory, so you won't be able to select it.

I'd appreciate improvements to the build system, though. Maybe open an issue were we discuss the details?

[TingPing]

You'll have to run the installation process multiple times to install multiple version.

I planned a second patch to solve this.

gnome-tweak-tool doesn't recognize themes without gtk-3.0 directory, so you won't be able to select it.

I can look into fixing that upstream.

GTK 3.14 doesn't support versioned directories. From what I see, this patch hasn't been backported to 3.14. This means the theme for GTK 3.14 has to be installed to gtk-3.0.

I'll fix that.

[TingPing]

https://bugzilla.gnome.org/show_bug.cgi?id=764114

[horst3180]

It seems I missed the notification that you updated this :D.

Do you know if that gnome-tweak-tool patch will be backported to 3.16 and 3.18? I can't merge this until the patched tweak tool is available to distros, because I really don't want to break the theme selection.

I thought about a slightly different approach:

• By default install all available versions of the GTK 3 theme into versioned directories, with the 3.14 version going into gtk-3.0 and completely ignore GNOME_VERSION for the GTK 3 installation.
• If the --with-gnome=... option is set, only install the corresponding GTK 3 theme to gtk-3.0, i.e. it should override GNOME_VERSION like before and change the GTK 3 installation routine to only install common/gtk-3.0/$GNOME_VERSION to $themedirectory/gtk-3.0.

This way gnome-tweak-tool will always recognize the theme and multi version support can still be disabled. I don't think we need to add the option to disable certain GTK 3 versions specifically.

[horst3180]

Or to make things even simpler, we could always install all GTK 3 versions and leave the rest as it is. It'll add less than 1MB to the installed size.
I can't see any downsides in this apart from a slightly larger install size (which shouldn't matter at all nowadays).

[TingPing]

I pushed it to the older branches; I imagine another 3.16 release is unlikely though I don't really know his release policy.

If the --with-gnome=... option is set, only install the corresponding GTK 3 theme to gtk-3.0

Seems reasonable for a short term solution until tweak tool catches up.

By default install all available versions of the GTK 3 theme into versioned directories, with the 3.14 version going into gtk-3.0 and completely ignore GNOME_VERSION for the GTK 3 installation.

I don't think 3.14 should be installed in this situation, it could create a problem where it loads that version on a newer release.

[horst3180]

The loading part is entirely up to GTK itself. It'll only use gtk-3.0 if it doesn't find any newer versions (https://git.gnome.org/browse/gtk+/tree/gtk/gtkcssprovider.c#n2007)

[TingPing]

The loading part is entirely up to GTK itself. It'll only use gtk-3.0 if it doesn't find any newer versions

I know and that could lead to a poor UX. User upgrades gnome version and suddenly they are on the 3.14 version which looks broken. Falling back to Adwaita because there is no new version is a much clearer issue and leaves the applications usable.

[horst3180]

I'm not sure if I understand this correctly.
Let's say a user upgrades from 3.20 to 3.22 in the future, but the theme only has gtk-3.0, gtk-3.16, ..., gtk-3.20 directories. In that case GTK will always use gtk-3.20, regardless if gtk-3.0 exists or not.

[TingPing]

Oh sorry it was me who misunderstood.

[chewi]

I just had a user file a Gentoo bug report because of this. Could we please make it happen?

[HEXcube]

gnome-tweak-tool doesn't recognize themes without gtk-3.0 directory, so you won't be able to select it

@horst3180 GNOME Tweak Tool 3.20 fixed the issue and is now able to load versioned themes that don't contain a gtk-3.0 directory. This fix got backported to v3.18 too. However, the official tarballs are still at 3.18.1 😞

But, this issue can be workarounded by renaming/symlinking the lowest version gtk-3.xx theme as gtk-3.0. Tweak Tool just needs to see a gtk-3.0 directory in the theme for it to be selectable. GTK'll still load theme from gtk-3.18 if it's present.

[horst3180]

@HEXcube Yeah, that's not a problem. I'll have to put the 3.14 theme into gtk-3.0 either way, because GTK 3.14 doesn't support multi version.
I just have to figure out how to exactly implement it. If possible I want a build option to disable multi version.

[HEXcube]

I'll have to put the 3.14 theme into gtk-3.0 either way, because GTK 3.14 doesn't support multi version.

@horst3180 Maybe keep a separate gtk-3.14 folder to be consistent with gtk-3.16, gtk-3.18 and those higher version folders, and then place gtk-3.0 as a symlink to it? 🤔

[TingPing]

@HEXcube No reason to over-complicate it.