Bug 299079

Compiling LaTeX source in Kile and/or forwarding the output (DVI or PDF) to Okular changes the stored cursor blink rate setting in both 32-bit Vista and 64-bit Windows 7. The same problem can also occur when either program starts, and accordingly (since I rarely run other KDE programs on Windows) this may be a duplicate of the unresolved/unconfirmed Bug 279882 (https://bugs.kde.org/show_bug.cgi?id=279882).


Details:

By the "cursor blink rate setting" or CBR in Windows, I mean the value of the registry key
[HKEY_CURRENT_USER\Control Panel\Desktop] "CursorBlinkRate".
CBR can also be changed via a slider in the Control Panel > Keyboard menu. According to http://www.sevenforums.com/tutorials/208107-cursor-blink-rate-set.html and http://www.jurta.org/en/prog/noblink CBR is an integer between 200 and 800 (inclusive) or -1. If 200 <= CBR <= 800, the cursor in Windows alternates between being visible and invisible every CBR milliseconds. The cursor remains constantly visible if CBR = -1, and this is the setting I try to maintain.

When I run "Quick Build" (defined as PDFLaTeX followed by ForwardPDF, the latter forwarding to Okular) after making changes to a LaTeX source file, CBR is set to roughly 200 (making the cursor flicker rapidly until the setting is changed).

I find this really distracting, and wind up having to keep the Keyboard Properties window opened while typesetting documents (so basically at all times). This is even more frustrating since the setting change that occurs during compilation (or possibly previewing in Okular) isn't reflected in the Keyboard Properties screen (meaning to change the setting back to CBR=0, I have to change it to some other CBR, apply the change, then change it to CBR = 0, and once again apply changes); it's not the most accessible menu in Windows; and the only way I'm aware of (or remember) interacting with this setting in the menu is via mouse. (Using a couple .reg files and a batch file to enable and then disable cursor blinking via the above registry key also doesn't work (and would still be a nuisance to run every time I want to preview a document). If a solution like this exists, I'm assuming it involves refreshing some component of the Windows UI.)


Steps to Reproduce:
0. Set CBR = 0 by moving the "cursor blink rate" slider in the Control Panel > Keyboard menu as far to the left as possible.
1. Open a LaTeX document in Kile
2. Make some changes to the source code (so that your LaTeX compiler actually recreates the PDF/DVI file)
3. Run Quick Build as defined above. My LaTeX compiler is MikTeX (either the current or previous minor version will do), and ForwardPDF runs Okular in the default manner.
4. Return to Kile or any other program where cursor blink rate is determined by the CBR setting. Frequently, the cursor will now be blinking.

Other Information:
The bug affects every version of Kile/Okular on 32- and 64-bit Windows Vista/7 that I can remember using on Windows in the past two years (so those in the KDE 4.5 and 4.7 builds in particular). I have only tried this with MikTeX as a LaTeX backend, but MikTeX does not seem responsible; compiling LaTeX source in other frontends doesn't change the CBR setting. However, this could also be because the other frontends I've tried do not use Windows's default cursor settings.

The information at http://www.jurta.org/en/prog/noblink is usually reliable when one wishes to disable cursor blink rate for applications on Linux, and it mentions that KDE's qt-based applications rely on a setting that can be changed using the qtconfig application. I'm unaware of how to install qtconfig on Windows, and even if it's possible, Kile/Okular changing the built-in Windows CBR setting might be independent of qt settings.


Relevant Links:
http://forum.kde.org/viewtopic.php?f=59&t=101838 (original forum post re. this bug)
https://bugs.kde.org/show_bug.cgi?id=279882 (related bug)
http://www.jurta.org/en/prog/noblink (Changing cursor blink rate settings for applications in Linux)