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Comment by mega-tux | Hacker News Reader

I do not know exactly what all that means but does it needs to be desktop wide or just inside a specific app window?

Neither way works in Wayland. A program can know where it was clicked but not where the pointer was immediately before that. For that matter Wayland doesn't have a concept of "the" pointer; there may be multiple pointers.

I don't think this is true. As per wayland protocol docs (https://wayland-book.com/seat/pointer.html):

> Using the wl_seat.get_pointer request, clients may obtain a wl_pointer object. The server will send events to it whenever the user moves their pointer, presses mouse buttons, uses the scroll wheel, etc — whenever the pointer is over one of your surfaces. [...] The server sends this event when the pointer moves over one of our surfaces, and specifies both the surface that was "entered", as well as the surface-local coordinates (from the top-left corner) that the pointer is positioned over.

So the program should know the pointer's local coordinates.

Surely programs can know where the pointer is as long as it is over a window that belongs to the program. Otherwise hover wouldn't work.

Hover is done by the client telling the compositor it would like the cursor to change its shape if it is over a certain area the client is drawing. But the client does not know where the cursor is or where on the screen the client is (or even if the client is visible at all).

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