Bug 279882

Summary:	Starting any KDE application changes Windows' cursor blink rate setting.
Product:	[Unmaintained] kde-windows	Reporter:	peter.orchard
Component:	general	Assignee:	KDE-Windows <kde-windows>
Status:	RESOLVED FIXED
Severity:	normal	CC:	kill.more.bugs, ps_ml
Priority:	NOR
Version:	4.5
Target Milestone:	---
Platform:	Microsoft Windows
OS:	Microsoft Windows
Latest Commit:	http://commits.kde.org/kdelibs/caf186f6c6b2c741798e41a9c78cfc3a0f66b01f	Version Fixed In:
Sentry Crash Report:

Description peter.orchard 2011-08-11 12:58:49 UTC

Version:           4.5 (using KDE 4.5.4) 
OS:                MS Windows

Whenever I start a KDE application, my cursor blink rate setting in Windows changes. At present, I have to manually reset the blink rate every time I start a KDE app.


Reproducible: Always

Steps to Reproduce:
1. Open the keyboard settings in the control panel.
2. At the bottom is a slider for the blink rate setting. Move it fully to the left (no blinking).
3. Click OK to close the dialog.
4. Open any KDE on windows app, eg Amarok.
5. Reopen the keyboard settings. The blink rate in now maximum (slider fully right).
6. Close the keyboard settings dialog.
7. Open another KDE app (or close and reopen the same one).
8. Reopen the keyboard settings. The blink rate has changed again, now to a mid-range value.


Actual Results:  
Cursor blink rate changed as described above.


Expected Results:  
KDE applications should not change the blink rate setting unless the user requests it.


While KDE apps are running, the blink rate doesn't change. It is only when an app is started. If the pdf reader is already running, opening another pdf does change the blink rate - presumably because another instance of the application is started.

This bug is not serious for apps that are started infrequently. But it is frustrating to have to reset the blink rate every time I open a pdf, for example.

I am running Windows 7.

Comment 1 Christoph Feck 2011-08-12 00:25:55 UTC

I guess on Windows the cursor blink setting should not be visible in KDE System Settings, and not touched by KDE. Instead, the user should change it via the Windows Control Panel.

Comment 2 peter.orchard 2011-08-12 11:20:40 UTC

(In reply to comment #1)
> I guess on Windows the cursor blink setting should not be visible in KDE System
> Settings, and not touched by KDE.

As far as I can see, there is no setting for blink rate in the KDE system settings. I now recall that in Linux, the blink rate is defined by qt, and can be set using the qtconfig application. Web searches suggest that qt on windows provides no config utility, but takes its values from Windows' settings. So this might be a bug in qt for Windows. Hopefully someone more familiar with these things can pinpoint the problem.

Comment 3 peter.orchard 2011-08-12 15:09:50 UTC

I also note that I do not experience the problem with other (non-KDE) QT-based applications on Windows.

Comment 4 Patrick Spendrin 2012-04-30 07:29:53 UTC

*** Bug 299079 has been marked as a duplicate of this bug. ***

Comment 5 Patrick Spendrin 2012-04-30 07:32:26 UTC

thanks for reporting this, and sorry for not looking into this earlier. I could reproduce this and it looks as if the native cursor setting is overwritten by the default: if you set it to off (-1) and start the application, it will go to the default again, if you restart the app a second time, it will go to the highest possible again.

Comment 6 peter.orchard 2012-04-30 07:57:00 UTC

Until this is fixed, others may be interested in my workaround. I keep a perl script on my desktop, and run it after starting a KDE application. The perl script contains these lines:

use Win32::API;
$SetCaretBlinkTime = new Win32::API('user32', 'SetCaretBlinkTime', 'I', 'I');
$SetCaretBlinkTime->Call(-1);

Comment 7 Patrick Spendrin 2012-04-30 09:58:41 UTC

Git commit caf186f6c6b2c741798e41a9c78cfc3a0f66b01f by Patrick Spendrin.
Committed on 30/04/2012 at 11:55.
Pushed by sengels into branch 'KDE/4.8'.

disable setting the cursor blink rate from within KDE, since this is totally broken in Qt itself.

M  +4    -1    kdeui/kernel/kglobalsettings.cpp

http://commits.kde.org/kdelibs/caf186f6c6b2c741798e41a9c78cfc3a0f66b01f