Bug 176765

Created attachment 29006 [details]
Screenshot example of the problem

Just to provide some further info for this:
* All windows are maximised or clearly on one page only (ie they are not partially appearing on both screens)
* Moving a window from the left screen to the right causes its entry to move from the right to the left panel, so it will always be in the wrong location. 
* Removing the applets and placing them back on does not correct the problem. The order they are placed on (ie right then left or left then right) also makes no difference

Same here
I'm running the 4.1.96 packages from Arch Linux

I have 2 screens:
On the left I have my notebook, right of it is the external TFT
The Intel graphics chip numbers the external monitor as output 1 (primary), while the built-in display is output 2.

If I change the position of the screens via xrandr (xrandr --output LVDS --right-of TMDS-1), the task manager starts showing the correct windows.

This leads me to the assumption that the task manager is making incorrect assumptions/guesses which screen is which.

I have the same problem, with the addition that if I move a window between two screens it will *not* move from one taskbar to the other. So if I move every window to the oposite screen of where it started, the taskbars get the correct window list...

This is with KDE 4.1.96 installed using gentoo ebuilds. KDE 4.1.3 worked correctly.

I have the same problem in KDE 4.2.0 final. I have notebook (LVDS) + VGA with a panel and taskbar on each of them. I have these settings on both of them:
Don't group
Don't sort
Only show tasks from curr. desktop
Only show tasks from curr. screen

The tasks from a screen appear on the taskbar which is on the other screen.

*** This bug has been confirmed by popular vote. ***

Created attachment 30961 [details]
Screenshot displaying problem

I have the same problem. Note in the screen shot that adept is on the left monitor while it is displayed in the task manager from the right monitor. Additionally there seems to be corruption which looks like two task managers overlapping on the left monitor. I was able to correct this once by swapping the panels on each monitor, but eventually the problem returns.

Same here. Reproduced with both Debian experimental as well as Kubuntu packages.

The bug is still present in the 4.2.1 Kubuntu experimental packages. The task manager code between 4.2.1 and 4.1.4 seems identical with regard to screen numbers, and the QT function checking whether two rectangles overlap seems correct as well. Something I haven't been able to check is whether KDE some sets its screen geometry wrongly. Anybody?

An extremely ugly but effective hack that worked for me is to patch kdebase-workspace-x.y.z/libs/taskmanager/taskmanager.cpp with the following patch:

--- taskmanager.cpp.old 2009-03-06 16:13:35.000000000 +0100
+++ taskmanager.cpp     2009-03-06 13:51:41.000000000 +0100
@@ -511,7 +511,7 @@
     QRect window = wi.frameGeometry();
     QRect desktop = QApplication::desktop()->screenGeometry(screen);
     desktop.adjust(5, 5, -5, -5);
-    return window.intersects(desktop);
+    return !window.intersects(desktop);
 }

 int TaskManager::currentDesktop() const

As I said, it's ugly :) And I imagine it could cause problems in monitor setups with > 2 monitors.

This is fixed in trunk, problem was the use of QDesktopWidget, which doesnt share the same screen-ids as kephal which is used in plasma.

SVN commit 942882 by asommer:

Backport 937005.

Query screen-geometry from kephal instead of QDesktopWidget, this makes "only 
current screen"-setting work as expected.
BUG:176765

 M  +4 -0      CMakeLists.txt  
 M  +3 -1      taskmanager.cpp  


WebSVN link: http://websvn.kde.org/?view=rev&revision=942882