Linux's Display Brightness/Backlight Interface Is Finally Being Overhauled

[unis_torvalds]

Sure windows should move if a monitor is removed.

But the issue in question is when a monitor is added/connected.

[Anux]

Sure windows should move if a monitor is removed. Maybe one could create a virtual desktop for each monitor and keep the virtual desktop after removal with all it's windows. But virtual desktops are not connected as in having windows spann between them.

[unis_torvalds]

But then if you eg unplug your laptop with a monitor plugged in to work elsewhere, you can't access or move the windows that were open on the other monitor.

Then that would be my problem, wouldn't it. Nevertheless, even if I choose to move a window to monitor 3 and then turn off monitor 3, the OS has no business second-guessing my intent. A computer should always defer to the user's input/instructions.

And to speak specifics, we are talking about Cinnamon DE here, so I can simply right click on an app in the taskbar and select "move to other monitor" or hit ctl+alt+up-arrow and drag my windows between screen buffers with the mouse. So nobody's screwed if a window gets marooned on a disconnected monitor.

And furthermore, the behaviour you have described (relocating windows on a monitor disconnect) is not the behaviour we are griping about. What is actually happening is some windows jump to new positions when a new monitor is connected (or powered on). Which serves no practical purpose and is rather clearly a bug not a feature.

EDIT: I wonder if different signals are sent in the event of a monitor disconnect (i.e. the signal cable is unplugged) and a monitor power cycling (i.e. monitor is powered off or power cable unplugged). I take your point that, in the case of a laptop, it's convenient to re-arrange the workspace when you unplug from an external monitor. I'm on a desktop workstation with shared monitors in different arrangements, so power cycling happens often and the random teleporting windows drives me nuts (also because I work with many many floating windows). They should damn well stay where I put them.

[hamishmb]

I disagree. A window manager should not randomly and unexpectedly re-arrange my windows. Windows should only move when I (the user) move them.

But then if you eg unplug your laptop with a monitor plugged in to work elsewhere, you can't access or move the windows that were open on the other monitor.

[unis_torvalds]

Moving windows to other displays that still exist is good behavior. As you noted about the extension, the real problem is that DEs/WMs aren't always smart about moving them back when that display comes back.

I disagree. A window manager should not randomly and unexpectedly re-arrange my windows. Windows should only move when I (the user) move them.

[pWe00Iri3e7Z9lHOX2Qx]

Me too. It's infuriating.
But I always thought it was a Muffin/Mutter issue. Could it be lower level than that?

EDIT: I just discovered a Cinnamon extension by nathan818fr called "Back to Monitor" which solves this issue! hamishmb you might want to try it out!

Moving windows to other displays that still exist is good behavior. As you noted about the extension, the real problem is that DEs/WMs aren't always smart about moving them back when that display comes back.

[Anux]

On KDE power cycling may cause Plasma desktop to crash. I think it also once happened to me with XFCE a long time ago.

I'm on XFCE and never had a problem with standby or power cycling of my monitor. I regularly turn it off manually. Only thing that bothers me is some error in EDID detection (need a modeline for 144 Hz), but that is an xorg problem.

Also turning of a second monitor in windows puts all programs on the running screen and not automatically back if switched on again. Not sure how it could be done better, no one knows if the second monitor will ever come back and if you want all the programs automatically moved back.

[Snaipersky]

Off topic for the article, but relevant to the comments, I would think enumerating a default display buffer, and either flushing to a display if attached, or discarding when detached, would solve the plug/unplug/power/disconnect on sleep headaches. Set said buffer to whatever the last combined display resolution was on last GPU power off, and update based on EDID/current modesetting during use.

[unis_torvalds]

My windows move around when I power cycle monitors on Cinnamon (X11). It's a multi monitor setup.

Me too. It's infuriating.
But I always thought it was a Muffin/Mutter issue. Could it be lower level than that?

EDIT: I just discovered a Cinnamon extension by nathan818fr called "Back to Monitor" which solves this issue! hamishmb you might want to try it out!

[user1]

This isn't the way Windows works at all. It's always monitoring for display change events. The "Detect" button is only there as a manual fallback if the system didn't automatically detect the event. If you turn off the power to your primary display in a multi-monitor setup, it will move your primary display to another display. If you leave your display settings open and start power cycling or unplugging / plugging displays, you'll see it updating the display layout in real time (slowly as it deals with reconfiguring things). On Windows this event handling may be a function of the display driver itself.

Thanks for the insight. A long time ago I had to press "detect display" on Windows when I changed to another monitor, so that's why I thought it works like this.