Bug 255848

Summary:	menu option not always launched on mouse button release
Product:	[I don't know] kde	Reporter:	S. Christian Collins <s_chriscollins>
Component:	general	Assignee:	Unassigned bugs <unassigned-bugs-null>
Status:	RESOLVED UPSTREAM
Severity:	normal	CC:	cfeck
Priority:	NOR
Version First Reported In:	4.5
Target Milestone:	---
Platform:	Ubuntu
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description S. Christian Collins 2010-11-02 03:37:27 UTC

Version:           4.5 (using KDE 4.5.1) 
OS:                Linux

The easiest way to understand this glitch is to watch the attached video.

** Bug Description **
Clicking and holding down a mouse button to open a menu and then releasing the mouse button over the desired menu item doesn't always activate the menu item. The cause of failure seems to be related to the presence of a sub-menu adjacent to the desired menu item. When the user's cursor crosses over a sub-menu (which causes it to be briefly opened), passes on to the desired menu item adjacent to the submenu, then the user releases the mouse button, the menu will not open unless the mouse has moved a sufficient number of pixels while on the selected menu item.

This bug seems easiest to reproduce using the QtCurve engine, second-easiest with Oxygen, animations disabled, and a bit harder with Oxygen, animations enabled.

I initially filed this bug with Qt, but the Qt guys don't believe it is a Qt problem and suggested I file as a KDE bug.  Here is the original Qt bug report:
http://bugreports.qt.nokia.com/browse/QTBUG-14034

Reproducible: Always

Steps to Reproduce:
see attached video



** My System **
Motherboard: MSI K9N SLI Platinum (nForce 570 SLI chipset)
CPU: AMD Athlon(tm) 64 Processor 4000+ (2.6 GHz)
RAM: 2GB DDR2
Video: Dell NVIDIA GeForce 7800 GTX w/ 256 MB RAM (PCI Express)
OS: Kubuntu 10.04 i386 w/ KDE SC 4.5.1 from Kubuntu PPA
Linux Kernel: 2.6.32-24-lowlatency
NVIDIA driver: 260.19.06
Screen Resolution: 1280 x 960
X.org: 7.5
Qt: 4.7.0

Comment 1 S. Christian Collins 2010-11-02 03:43:31 UTC

Attachment was too large, so here's a link to the video:
http://www.schristiancollins.com/temp/menu_mouse_button_release_glitch.ogv

Comment 2 Christoph Feck 2010-11-03 13:32:52 UTC

I could reproduce it on a Qt-only application (Arora), so it is a Qt bug.

Comment 3 Christoph Feck 2010-11-03 13:36:52 UTC

Additional comment, since the reporter seems to indicate it depends on the used style: I could reproduce using Plastique Qt style.

Comment 4 Christoph Feck 2010-11-03 13:39:23 UTC

And one final comment: Trolls don't believe that Qt handles the "press-move-release" menu item selection at all, they believe it must be "click-move-click".

See http://bugreports.qt.nokia.com/browse/QTBUG-6632