On Sat, 4 Mar 2023 13:21:08 -0500
Hendrik Boom <hendrik@???> wrote:

> When a window gets opened,
> it often ends up on the now invisible part of the extended screen. I
> have to reach out with my mouse by dead reckoning, click on it while
> holding the alt key down, and drag it back from the unseen land. It
> sometimes takes several tries befor I manage to fish it out.

I use Openbox, and I believe that's a part of lxqt. For it, I'm pretty
sure there's a configuration feature to force new windows from an
application to appear on the monitor which has the mouse. More on that
after.

Regarding the window opening in the wrong screen, you might have
success by changing the second screen to be mirrored (and not extended)
before disconnecting.

If it helps, for a window which is trapped in another monitor or a
strange space, I've used <alt-space> <m> and held down cursor keys to
move the window over. This works for Openbox, and I've needed to use
it for claws-mail before. I'm not sure what pulls up the
window-context menu for lxqt, and your default hotkeys may vary. Try
alt-space and see if you get a menu.

-

For Openbox, you can make changes here:

$HOME/.config/openbox/rc.xml

(sometimes the xml file is called something else like lubuntu-rc.xml)

To apply changes without restarting Openbox, do:

openbox --reconfigure


Simplified, it is:

<openbox_config xmlns="http://openbox.org/3.4/rc">

[... lots of stuff ...]

<placement>
    <policy>UnderMouse</policy>
    <monitor>Mouse</monitor>
    <primaryMonitor>Mouse</primaryMonitor>
</placement>

</openbox_config>

My advice:

0. make a back up of your rc.xml
1. Edit the rc.xml file
2. copy/paste that <placement> block right near the bottom, before
</openbox_config>
3. openbox --reconfigure
(If an error occurs, restore your back up and double-check your
changes. XML is an exact science.)
4. re-test