Hovering over ribbonbar buttons spikes CPU

I'm seeing that hovering over the ribbon bar buttons of the demo apps (as well as my own tests) produce a CPU spike of 20% on my machine, and a delayed animation of the hover state. I compared this to Microsoft Office's Ribbon bar and saw no such spike.

Can anyone from Developer Machines speak to this and suggest how to make this faster? it seems like a bug in the source code, there's no reason such a simple animation state should cause a 20% CPU spike and a delay in animation. I'm on Windows 7 Ultimate with a Core 5 Intel chip and 2GB of ram.

Please provide more information about your investigation of this problem.
1) Does you Windows 7 has AIR feature enabled while you testing?
2) Are you trying setFrameThemeEnabled() or without it?
3) What Ribbon theme do you use (Office 2007 or Office 2010)?
4) Do you see gaps in performance if you run a standard Qt application with the standard QToolBar (from Qt demo for example)?

Thanks so much for responding. Here are the answers, I also emailed them to you:


1) Does you Windows 7 has AIR feature enabled while you testing?

Yes. And I’m running on a Lenovo Thinkpad X201, my RAM usage is at around 1.8GB of 2GB available, so it’s a bit tight, but that shouldn’t be causing it. The machine has a simple HW graphics renderer in it that accelerates the Windows desktop, it’s part of Intel’s integrated i5 CPU package, and is quite capable, so again I doubt it’s a machine resource issue.

2) Are you trying setFrameThemeEnabled() or without it?

I call setFrameThemeEnabled(true) in the constructor of my RibbonMainWindow derived window class.

3) What Ribbon theme do you use (Office 2007 or Office 2010)?

Office 2010 Silver.

4) Do you see gaps in performance if you run a standard Qt application with the standard QToolBar (from Qt demo for example)?

I ran all of the Main Window demo examples from the Qt Examples and Demos app that ships with the commercial version of Qt 4.8.1 (32 bit) and while there are only a few simple toolbars in there, I saw no spike in CPU or delay in rendering.

Ok. Descussed by email. The problem was confirmed.