Created attachment 122281 [details] LO in Ubuntu subj. make as in ubuntu-unity and in OS X
This is possible, but not trivial and it would require conceptual changes to LO behavior circumventing the Windows Desktop Environment defaults. We generally do not do that. In MS Windows the frame holding the Title is referred to as the "non-client area", an it includes the title bar, icon, window border, caption buttons. It is controlled by the MS Desktop Windows Manager (DWM) APIs. This MSDN article describes what would need to be done. https://msdn.microsoft.com/en-us/library/bb688195.aspx So, yes we could replace the standard frame with a custom frame, and populate the frame with our standard menu--which would be visually cool. But the project would then be responsible for replicating the Windows DWM controls that we've removed with our custom frame. We'll also have to support HiDPI graphics with whatever we implement. So, while visually appealing, it would expose the project to ill-will and a bad UX if we make the UI unstable. Additionally, we'd need to be sure we could maintain this over the long term, or we'd be faced with complaints of non-compliant UI as with support of OS X Aqua. If this were easy/reliable more cross platform projects would implement it on Windows.
KDE has also an appmenu (http://www.webupd8.org/2013/02/how-to-enable-new-kde-410-appmenu-title.html), probably not fully ported yet to Plasma 5. But, as Stuart said, those options are clearly related to the OS; and Libreoffice aims to fit into the default system style. So I close this bug as invalid. Anyway, thanks for sharing the idea.
Why is this desirable anyway? I see that GNOME's CSD initiative links this (https://wiki.gnome.org/Initiatives/CSD#:~:text=Status-,libreoffice,-VCL%2BGTK3) but I genuinely don't see why this would be an improvement, at the least unless entirely optional.