gala-xy

A small plugin for Gala, the window manager behind elementaryOS's Pantheon desktop.

Right now all it does is draw a highlighted border around the focused window, so you can always tell which window has focus at a glance. It does not move, resize, or reorder anything.

It started as a PaperWM-style horizontal tiling plugin. That layer caused more trouble than it was worth and has been removed for now while the layout model gets rethought — see the git history if you want it back.

What it does

• The focused window gets a highlighted border, coloured to match your System Settings → Appearance accent colour, updating live if you change it.
• Panels, docks, and similar chrome don't get a border (see below).

Excluding windows

Wingpanel and Plank are excluded by default, matched by a substring in their window title; anything else can be added the same way, or by GTK application ID if the app has more than one window and only some should be excluded — either via System Settings → Tiling, or with gsettings:

gsettings set org.pantheon.desktop.gala.plugins.xy excluded-title-keywords "['wingpanel', 'plank', 'some-substring']"
gsettings set org.pantheon.desktop.gala.plugins.xy excluded-app-ids "['com.vandragt.sidewing', 'some.other.app']"

Installing

Requires libgala-dev and a Gala source checkout (for libmutter-14.vapi, which Ubuntu's Mutter packages don't ship separately — point gala_vapi_dir at yours if it's not at the default path in meson_options.txt).

make install

(equivalent to meson setup build && ninja -C build && sudo ninja -C build install)

Then log out and back in to pick it up. Don't use gala --replace or systemctl --user kill to reload in place — both are known to trigger an unrelated, pre-existing Mutter crash (meta_x11_barriers_free assertion on teardown) that's confusing to debug around if you don't know it's coming.

Uninstalling

make uninstall

Then log out and back in the same as above.

Known limitations

• Built and tested against Gala 8.5.1 / Mutter 46 (elementaryOS 8-era). Other versions may need adjusting the HAS_MUTTER* defines in meson.build.
• The border's corner radius is an approximation of the common Granite/GTK default — a window's real client-side radius isn't queryable from a plugin.
• This is a young, unofficial plugin, not an elementary/Gala project. If Gala crashes after installing it, remove the .so from the plugins directory and reload Gala to get back to a stock session.