Starting with macOS 12.2, AltTab only grabs windows in active spaces

[skyzyx]

Describe the bug

• I work with 2 monitors
• I work almost exclusively in full-screen mode

I updated to macOS 12.2 Beta (21D5039d) this morning, and since then, AltTab only grabs the front-most full-screen app window from each of my displays — ignoring the full-screen windows that are not front-most.

I know that the full-screen support is buggy because this app has to use private APIs, etc., but I wanted to bring this situation to the attention of the developers as a known issue.

Usually when AltTab is missing windows, I can quit and re-launch the app to get it to pick up the current state of my environment. However, even this action no longer works as of this morning's macOS beta update.

Screenshots / video

http://s3.ryanparman.com.s3.amazonaws.com/alttab-bug-1.mp4

[dnivi3]

Seeing the same on macOS 12.2 (21D49), the production version of macOS 12.2.

[kaatt]

likely related to kasper/phoenix#289 and ianyh/Amethyst#1192

[dnivi3]

Looks like Amethyst has fixed this in ianyh/Amethyst#1184

[lwouis]

@dnivi3 the code change you linked to is this:

Changing the order remove -> add to add -> remove. AltTab already does add -> remove:

[dnivi3]

@lwouis yeah, I realised my layman non-technical understanding of this isn't helpful. Is there any I can help or contribute towards this getting fixed?

[lwouis]

@dnivi3 i'm afraid only code contributions would help. Please see #1179

[lwouis]

Related: #1351

[stevetodd]

Just to add the datapoint, the issue persists in the newly released macOS 12.3.

[radaczynski]

This behaviour is repeatable. I have 3 desktops. When restarting alt-tab, windows from the active one get detected correctly, the switcher works just as expected, while on the other desktops only the active window is shown in the switcher. Restarting the apps/reopening the windows causes them to be shown in the switcher. Macos 12.3.1 here.

[kaatt]

Allowing screen recording permissions to the app should fix this.

[radaczynski]

@kaatt - were you refering to my comment? It does not fix this issue - AltTab had the permission to record screen all the time. Windows from the current desktop are detected just fine after restart of AltTab, but on other desktops only one window is detected (+ all the windows that are created after AltTab is launched).

[lwouis]

It seems that we could simply replace the call to CGSAddWindowsToSpaces with a call to CGSMoveWindowsToManagedSpace.

Can anyone confirm this would work?

[lwouis]

I experimented with replacing CGSAddWindowsToSpaces with CGSMoveWindowsToManagedSpace. It's not a 1-to-1 replacement. It doesn't move fullscreen windows. It successfully moves regular windows, and moves them back, but it doesn't do anything for fullscreen windows, thus AltTab doesn't see them.

[dnivi3]

@lwouis glad to hear it solves for regular windows, but shame with fullscreen ones. Selfishly, this solves for my use cases. Is there a branch I can build from to test this?

[lwouis]

Is there a branch I can build from to test this?

i'm sorry, there isn't

[J-Siu]

I just notice this recently. And the strange part is, it is inconsistent between apps.

I have two steam games, "Undead Hord 2" and "Nova Drift". I play both in full screen. When I cmd+tad out of the game, I can see both in the task list. However, from desktop, when I try to cmd-tab back to the game, "Nova Drift" shows, while "Undead Hord 2" won't.