Comment 2 for bug 1157213

After the current stages of analysis, it seems that there might be no changes to Qt5 required at all. At the first stages, I thought we'll have to introduce some upstream modifications to Qt5 - but after discussing with some of the Qt5 developers, it seems we can make use of the QPlatformThemeFactory framework and build everything in the separate appmenu-qt5 package.

I'm working on a related blueprint, it's attached to this bug. Architectural plans will be mentioned there.
https://blueprints.launchpad.net/appmenu-qt/+spec/qt5-qpa-appmenu