Bug 408281

Created attachment 120554 [details]
Screencast showing the problematic behavior with Kate

SUMMARY

When a menu (a pull down menu, or an RMB menu) is opened, if it shows under the mouse cursor then attempts to use keyboard arrow keys to navigate it are frustrated by some kind of mouse selector refresh that happens every second.

This problem *always* manifests itself when one uses the mouse right button to open a context menu then tries to use the keyboard to navigate the created menu (without first moving the mouse away). 

It also happens 100% of the time in:
- Klipper's "open at mouse position" entry selection menu.
- Konsole's context menu when opened using the menu key on the keyboard (the menu always appears under the mouse cursor regardless where it is, even not on the Konsole window)

Additionally this problem can be easily reproduced in all KDE applications when using the keyboard to open an application's pull down menu with the keyboard while the mouse pointer happens to be in a location where the menu renders underneath it. The attached screencast shows how to reproduce the issue in Kate.

STEPS TO REPRODUCE
1. Cause a menu to appear under the mouse cursor. The summary above offers some surefire ways to cause it to happen.
2. without moving the mouse, use up/down arrows and the ENTER key to select an entry.

OBSERVED RESULT

If the user cannot choose and select the menu entry in less than 1 second, the menu selector disappears. 

Using the ENTER key at this point produces unexpected results that are application dependent. Often the menu closes without any action, but not in all cases - for example in Konsole it causes the first enabled menu item to be selected immediately but not activated.

EXPECTED RESULT

As long as the mouse isn't moved, the menu selector should not change position (other through the continued use of the keyboard arrows) or disappear.

For comparison, please see any GTK+ application.


SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 5.16.80
KDE Frameworks Version: 5.59.0
Qt Version: 5.12.2

ADDITIONAL INFORMATION

Packages installed from KCI staging PPA.

As mentioned above, this behavior is in contrast to how non-KDE/non-Qt applications are behaving, for example GTK+ applications - such as Firefox - work fine.

I'm not sure this is the right product for this report, and it is also very likely that this is a Qt issue that cannot be solved by KDE - I have a ticket opened in the Qt bug tracker that is basically the same problem just less well analyzed and demonstrated: https://bugreports.qt.io/browse/QTBUG-67723 , which haven't seen any attention in the last year, so part of the reason for this report is to see if KDE devs are interested in pushing this issue as it has a large effect on KDE software behavior.