@Pafrape: in system settings > Colors & Themes > Window Decorations select "Material".

Then click on "configure buttons on titlebar" and drag the application menu on the titlebar

@guiodic It seems it works now ^^

@TechniKris

It is likely that the version under development has changed something; in fact, I use a private API on X11. Can you report the bug on GitHub?

EDIT: I removed the direct use of kwin's X11Window. Can you try again?

It seems the package fails to build now:

[ 88%] Building CXX object src/CMakeFiles/materialdecoration.dir/InternalSettings.cpp.o
[ 90%] Building CXX object src/CMakeFiles/materialdecoration.dir/Decoration.cc.o
[ 93%] Built target materialdecoration_kcm
In file included from /usr/include/kwin/x11window.h:19,
                 from /home/user/.cache/paru/clone/material-kwin-decoration-git/src/material-kwin-decoration/src/Decoration.cc:45:
/usr/include/kwin/utils/xcbutils.h: In member function ‘KWin::Xcb::GeometryHints::NormalHints::SizeHints* KWin::Xcb::GeometryHints::NormalHints::sizeHints()’:
/usr/include/kwin/utils/xcbutils.h:1061:65: error: ‘class std::optional<std::span<KWin::Xcb::GeometryHints::NormalHints::SizeHints, 18446744073709551615> >’ has no member named ‘transform’
 1061 |             return array<SizeHints>(32, XCB_ATOM_WM_SIZE_HINTS).transform([](std::span<SizeHints> span) {
      |                                                                 ^~~~~~~~~
make[2]: *** [src/CMakeFiles/materialdecoration.dir/build.make:192: src/CMakeFiles/materialdecoration.dir/Decoration.cc.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:455: src/CMakeFiles/materialdecoration.dir/all] Error 2
make: *** [Makefile:146: all] Error 2
==> ERROR: A failure occurred in build().
    Aborting...

The issue spotted while using KDE-unstable repos.

@Pafrape: in system settings > Colors & Themes > Window Decorations select "Material".

Then click on "configure buttons on titlebar" and drag the application menu on the titlebar

Thanks to this module, the menu button appears perfectly in the title bar and works perfectly. However, how can I make the menu bar appear in the title bar? Thank you for your help.

I generated it using extra-x86_64-build, it didn't make any difference,

Does it work on Wayland or only on X11?