[SOLVED] Qt programs get no keyboard input

guanx · 09-24-2013, 05:12 AM

After the "Fri Sep 20 00:38:57 UTC 2013" update I sometimes (suddenly) cannot type any letters in Qt based applications. Not only KDE apps but also Qt apps not using KDE.

Switching to another GUI window and then back makes input possible again. For apps with multiple tabs, such as konsole, I could also switch to another tab and back, then the problem is also gone.

Because I have no longer the packages before this update, I cannot easily test which package caused the problem.

NoStressHQ · 09-24-2013, 09:37 PM

Which WM to you use ? It sounds like an input focus problem.

(Also versions of Slackware, used WM and X11 would help...)

guanx · 09-25-2013, 01:52 AM

The slackware version is the "Fri Sep 20 00:38:57 UTC 2013" snapshot of -current.
The DE is KDE and the WM is kwin.

NoStressHQ · 09-25-2013, 09:19 AM

Quote:

Originally Posted by guanx

The slackware version is the "Fri Sep 20 00:38:57 UTC 2013" snapshot of -current.
The DE is KDE and the WM is kwin.

Well you don't name the versions of KDE neither WM (ie: I don't have current)...

You don't say which full version of slackware you're using (32 ? 64bit? )

Giving a date requires the one to help you reading the changelog... Give us some hint or you will struggle to get any help...

And for what I see, the version of X11 and KWin is crucial (it's up to them to handle input focus...).

jon lee · 09-25-2013, 09:30 AM

Both kde-4.11.0 and kde-4.11.1 have had some bugs. Plasma is buggy in both versions. 4.11.1 had a double click taskbar bug (that was fixed in the latest git of kde-runtime)... so they've been playing with input code.

guanx · 09-25-2013, 12:11 PM

Quote:

Originally Posted by NoStressHQ

(ie: I don't have current)...

Sorry, I didn't know that. It was KDE 4.10.5 / kwin 4.10.5. And I repeat it was the "Fri Sep 20 00:38:57 UTC 2013" snapshot of slackware-current lest someone jumping directly to here missed the information in the original post.

It was not slackware64-current.

Quote:

Originally Posted by NoStressHQ

Giving a date requires the one to help you reading the changelog... Give us some hint or you will struggle to get any help...

I think the ChangeLog gives more information than if I list all my software versions because the change on that specific date mentioned above narrows the problem down to very few packages.

NoStressHQ · 09-25-2013, 12:14 PM

Finding solution is all about "narrowing the problem"

guanx · 09-25-2013, 12:18 PM

I know a solution is to revert to the "Thu Sep 19 06:48:59 UTC 2013" snapshot. Unfortunately I don't have it anymore ...

guanx · 09-30-2013, 09:51 AM

How I found a way to reproduce this bug easily.

Open konsole
Start something in konsole, e.g. okular
Move okular to the upper left corner of screen
Close okular
Now cannot type anything in konsole but mouse works.
Switch to any other window, or switch to another tab in the same konsole, then switch back, keyboard works again

I am sure I got this problem after the "Fri Sep 20 00:38:57 UTC 2013" update but I didn't keep a snapshot of slackware-current before that. So I cannot fix it by reverting the changes by the "Fri Sep 20 00:38:57 UTC 2013" update.

guanx · 09-30-2013, 11:06 AM

Another way to reproduce it is to receive a message from skype (skype then pops up a message window in the lower-right corner of the screen). Then after the message disappears, I lose keyboard input to my foreground Qt window.

Mouse input works perfectly fine at the same time. Only keyboard input is lost.

guanx · 10-14-2013, 04:49 AM

Changed "~/.kde/Autostart/scim.sh" from

Code:

#!/bin/sh

if [ -x /usr/bin/scim ]; then
    /usr/bin/scim -d &
fi

to

Code:

#!/bin/sh

if [ -x /usr/bin/scim ]; then
    (sleep 30; /usr/bin/scim -d) &
fi

Until now this problem did not appear again. Looks like starting scim too early when KDE is restoring last session causes problems.

This workaround is too ugly, and the problem did not appear until the X updates on 20.Sep.2013, so I will not mark this thread as solved at present.
.
EDIT: No. The problem re-appeared after some time.

guanx · 10-25-2013, 05:23 AM

Solved:
http://www.linuxquestions.org/questi...qt-4175482102/