Buttons on GTK3 scrollbars

To disable the "auto-hide" feature of GTK3 scrollbars, add the following environment variable to your .profile, .bash_profile, or wherever you put your customized environment variables.

export GTK_OVERLAY_SCROLLING=0

Note: If you are running a display manager, consult your display manager's documentation. Some display managers source .profile; some don't. Personally, I prefer to use startx to launch a graphical session, so .bash_profile is loaded when I login.

One more thing is missing: the up and down buttons.

Create the file ~/.config/gtk-3.0/gtk.css:

* {
    -GtkScrollbar-has-backward-stepper: true;
    -GtkScrollbar-has-forward-stepper: true;
    /* -GtkScrollbar-has-secondary-backward-stepper: false; */
    /* -GtkScrollbar-has-secondary-forward-stepper: false; */
}

Uncomment and set the has-secondary-*-stepper properties if you desire to configure a scrollbar that has both up/down buttons on a single corner (e.g. old KDE style).

If you changed the GTK_OVERLAY_SCROLLING environment variable, log out and log back in so that the change takes effect globally. If you created or modified gtk.css, restart all GTK3 applications.

It's hard to say anything about UI design without starting a flame war, so I will keep it simple:

This is my workbench, dammit, it's not a pretty box to impress people with graphics and sounds. When I work at this system up to 12 hours a day, I'm profoundly uninterested in what user interface a novice user would prefer.

– Erik Naggum, 1997-02-16

• Reddit thread

Reddit user sdeklight points out other locations to store environment variables:

Why not just use /etc/environment, /etc/security/pam_env.conf or ~/.pam_environment to store your variables? Those are loaded by pam on login independently of shells and WMs.

Reddit user AnSpailpinFanach suggests using ~/.xsessionrc:

On Debian the recommended place to put them is ~/.xsessionrc. In that way they are available only in an X session. Example:

$ cat .xsessionrc
export QT_STYLE_OVERRIDE=gtk
export GTK_OVERLAY_SCROLLING=0

The file is sourced, not executed, on starting a session so it doesn't need to be executable.

Reddit user SomeGenericUsername gives some helpful troubleshooting advice:

Depending on your setup and how the dbus session daemon is started, you might also need to run dbus-update-activation-environment GTK_OVERLAY_SCROLLING after setting the environment variable for this to work with applications that are started via dbus activation (e.g. gedit) and inherit their environment variables from the dbus session.

Reddit user __konrad links to an additional trick to remove the dashed lines.

Thank you to all for reviewing and providing feedback!