Can I implement client side decoration?

[Yujeonja]

I want to implement complete client side decoration with Qt. It means, it has title bar with window move, window frame for resize, and drop shadow which is not take any inputs. The drop shadow should transparent for input, so when I click the shadow area, window should not be activated but just select another window below the shadow.
I found Qt::WindowTransparentForInput window flag which is similar what I want. But the problem is when this flag is set, the entire window turns transparent for input. In Wayland client, there is wl_surface_set_input_region function to make a surface is valid only given region so the out of region is still visible but not interact with mouse input or compositor's window snap feature.
Is there any way to implement this in Qt?