Context

#385

In Xwayland and xdg_output protocol, the positions of clients and outputs in the layout coordinate system are already defined in the 2D space. So we cannot omit the concept that the displays are aligned in the 2D space.

So I permit zn_screen, a zen component, to have a layout position.

Summary

• Add layout_position member to zn_screen.
• Use layout coordinate position for wlr_xwayland_surface_configure.

How to check the behavior

Open xeyes in a display and another X app in another display.
When the cursor hovers the X app, you can confirm the the X eyes knows the layout coordinate system from its eye movement.