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-   -   Qt programs get no keyboard input (https://www.linuxquestions.org/questions/slackware-14/qt-programs-get-no-keyboard-input-4175478325/)

guanx 09-24-2013 05:12 AM
[BUG] Qt programs get no keyboard input
 
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 (Post 5034330)
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 (Post 5034591)
(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 (Post 5034591)
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/


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