I took a look at this and discovered that UNIFIED doesn’t really work on any platform. It was never supported on Linux, the Mac implementation doesn’t really unify anything, and Windows is broken (see JDK-8154847 <https://bugs.openjdk.java.net/browse/JDK-8154847>). In that bug report it’s suggested that UNIFIED be deprecated.
I don’t think the UNIFIED API was ever complete. For example, I don’t see a way of querying the system to discover the location of the OS window controls so you can position your JavaFX controls appropriately. Getting this right on the Mac would require some plumbing. We would need an API so we know which JavaFX controls are supposed to be in the unified title bar area so we can get the hit-testing right to enable dragging, title bar double-clicks, etc. I could imagine a new control that you could wrap around an existing control (like a Toolbar) that would handle the hit-testing and positioning correctly. I’m fuzzier on what it would take on Windows and there’s still the drawing problems to sort out. Would be nice to have, the unified look is ascendant.
