x11-wm/xfce4-panel: Disable GTK2 support by default

[woodsb02]

Summary

x11-wm/xfce4-panel: Disable GTK2 support by default

Test Plan

poudriere bulk -j 13amd64 x11-wm/xfce4 x11/xfce4-goodies - ok

[madpilot]

This change would prevent any panel built with gtk2 from working, and, I am almost sure, would cause them to also fail to compile, so breaking the built of such components present in the tree.

The GTK2 support in panel does not mean that panel actually uses GTK2, in fact panel unconditionally depends in GTK3 and now uses that for itself. The GTK2 option means if the panel should support docking GTK2 plugins. I'd rather leave this on, since we have a few in out ports tree.

[woodsb02]

Yep, agreed.

[woodsb02]

Hi madpilot,

It looks like the latest release of Xfce4-panel 4.15 has dropped support for Gtk2 plugins:
https://mail.xfce.org/pipermail/xfce-announce/2019-October/000794.html

What are your thoughts on the migration path for FreeBSD ports?

[madpilot]

In D21919#482764, @woodsb02 wrote:

Hi madpilot,

It looks like the latest release of Xfce4-panel 4.15 has dropped support for Gtk2 plugins:
https://mail.xfce.org/pipermail/xfce-announce/2019-October/000794.html

4.15 is a development release, so the port is not going to be updated to that, just like 4.13 was the development for 4.14.

So nothing needs to be done right away.

I was thinking to start early with a github repository to keep development ports of thee development versions though. Just like what I did with 4.13.

What are your thoughts on the migration path for FreeBSD ports?

As said nothing needs to be done right away, we will be tracking 4.14.x versions with bugfixes for now.

XFCE project published a blog post today describing what they plan for 4.16, and are starting to implement in 4.15:

https://simon.shimmerproject.org/2019/10/19/xfce-4-15-development-phase-starting/

So, with XFCE 4.16, when it will come out, GTK2 support will have to die and ports depending on XFCE not being adapted will need to be marked broken and removed, I don't see any other option.

I'll try to setup a repository for XFCE 4.15 ports to be used as an overlay or with portshaker like I did with 4.13 so such changes can be tested. Just give me a little to set things up.

[madpilot]

In D21919#482777, @madpilot wrote:

So, with XFCE 4.16, when it will come out, GTK2 support will have to die and ports depending on XFCE not being adapted will need to be marked broken and removed, I don't see any other option.

BTW, since 4.16 is at least one year away (but I bet it will take longer) while we have time, maybe we could start deprecating GTK2 components at some point in the future, and disable GTK2 support by default. Id just wait a little longer when we are nearer to the 4.16 release.