erratic behavior with touch on submenus in qt related apps

[Don Nguyen]

Short video clip of bug here: https://www.youtube.com/watch?v=BAJo-jwuFW8

If I tap the touch screen on a menu item that brings up a submenu in qt related apps, the submenu will appear for about one second, and then disappear. However, if instead of tapping and releasing on the menu item, I tap on the menu item and move in any other direction just a tiny bit, and then release, the submenu will appear and stay like normal behavior.

Below are specific examples and the pattern seems to be with qt related apps:
QtCreator - Tap on the Tools menu. Then tap on the Git menu. The submenu will appear, and then disappear after 1 second. If instead of tapping on the Git menu, you tap and drag a few pixels to the right, the submenu will appear and stay.
Dolphin file manager - Tap on "Control". Then tap on "View Mode". The submenu will appear, and then disappear after 1 second. If instead of tapping on "View Mode", you tap and drag a few pixels to the right, the submenu will appear and stay.
Kate text editor - Tap on the "Tools" menu. Then tap on "Mode". The submenu will appear, and then disappear after 1 second. If instead of tapping on "Mode", you tap and drag a few pixels to the right, the submenu will appear and stay.

Description: Ubuntu 16.04.1 LTS
Release: 16.04

Expected Behavior: The submenu should stay until I make a selection or cancel.

What happened: The submenu appears only for 1 second and disappears. However, if I "trick it" by tapping and dragging on the menu item, the submenu will stay as normal.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1658550/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Don Nguyen (infinityx78)]

I uninstalled libgrail6 and libgeis and the problem still persists so the problem is not related to grail or geis. It's probably related to Qt.