QWidget / QWindow title bar: custom look, native feel (similar to Chrome)

Question

I know how to make a QWidget (in Qt4 or Qt5) / QWindow (since Qt5) borderless, draw a custom title bar and manually implement mouse dragging to move the window on the screen by simply tracking the mouse position with some mouseMoveEvent and updating the window position.

However, this movement behaves different than the native one as implemented by the window manager. For example, moving the window near the screen's border can be interpreted as "fullscreen" or "split screen"; or windows snap to each other's borders, depending on the system / window manager. These things don't work if you implement the window movement like above.

Google Chrome / Chromium is only one example for an application which implements a custom window title bar and border, while still adapting to the native behavior of the window manager. I'm wondering whether Chrome implements these by itself (and detects the window manager and its configuration) or if there is some functionality in most window managers (clearly, this is still highly platform-dependent) for telling "start native window movement" and "stop native window movement" or similar.

Is something like that possible in Qt? If not, maybe using some other libraries like Qxt?

FYI: I'm mainly targeting Windows and Linux, where I see the difficulty that the user can have any window manager installed.

Answer 1

Based on attempting the same with Qt4 recently, I fear the answer is, you need to tune this per-platform / per-window-manager. I expect patches to QWindow to improve the behaviour in this area would be accepted, but I'm not aware of any standard hook to tell the OS/window-manager what you're trying to achieve.

Equally Qt should be not be 'getting in the way' of solving this, it's simply an area where it can't do anything to help you in a generic way.