Using alt-tab to switch between two windows (Gwenview and Firefox) and every once in a while it will switch to an open window that I haven't used for a long time (minutes or hours.) For example, I've switching back and forth between Gwenview and Firefox and after a dozen switches or so it will switch me to a VLC window that's open, which I haven't used since I launched it an hour ago. The problem seems worse with multiple windows open of the same application (like LibreOffice Calc). I have no grouping set on the task bar, and the Task Switcher is set to Recently Used Sort Order, the shortcuts are the defaults (Alt Tab set to Forward.)

Any ideas to troubleshoot this issue? I doubt there's a list of what windows it's been using and what order it switches, so there's no real way to log this behavior.

Using KDE 4.10 on Kubuntu.

Thanks.

The window switcher (Alt + Tab) is part of KWin, so i've moved this to the KWin forum. Is this issue a one off event, or does it constantly occur once triggered until KWin is restarted?

The issue occurs randomly despite everything I do. I'm also troubled recently by random Kwin crashes (since updating to KDE 4.10), but the alt-tab problem has been happening for a couple of months.

Does this happen with all kinds of "dead" clients or (predominantly) vlc?
Judging from the code a client will bump itself in the focus chain by a maprequest or similar "here! i'm important, take me! here! me!" calls.

Interesting. It happens with other untouched open applications, including LibreOffice Calc and a Citrix client I have open. The problem seems to be worse with multiple open windows of the same application - for instance I usually have two Calc windows open with different spreadsheets and the problem seems to occur more often, between both open windows that I haven't touched recently. I have also see a Dolphin window enter into the Alt-Tab queue, despite being untouched for a while.

Can you explain a bit more about the maprequests or other calls that may be causing the problem? Is there any way to identify their occurence?

Thanks!

you can "xev -id <winid>" and obtain the winid eg. with xwininfo.
A maprequest is just what the window yells when it wants to be on screen (what does not necessarily mean it is not already) if this or a focus request occurs and is denied (eg. because the window is on another virtual desktop) the taskbar item will usually start to flash.

The multiple window situation refers to "you've two calc windows untouched for a long time but one of them raises nevertheless" not "you've a dead and a living calc window and the dead one raises in the focus chain"?

Could just be a bug in the list maintainace, but i've not seen such myself.

The taskbar settings are irrelevant, but what focus policy do you use? (click to focus?)

Definitely "you've two calc windows untouched for a long time but one of them raises nevertheless". My policy is Click to Focus. I'll poke around some more and see what xev shows. It happens randomly enough to interrupt a good groove of working back and forth between two apps.