This assert is incorrect if Xwayland is enabled and an Override Redirect
window steals the keyboard focus from the parent surface.
It also seems likely to be hit if a Wayland client attempts to use a
pointer constraint on a subsurface. I don't think a pointer constraint
on a subsurface is likely to work entirely correctly and I don't know of
any Wayland clients that try such a thing. We can't let them crash river
by trying though.
It is possible for the assertion in PointerConstraint.confine() to fail
if a view with an active pointer constraint is, for example, resized
using a keybinding such that the pointer is outside the constraint
region.
Handle this edge case by deactivating the constraint. The other option
would be to warp the pointer to the nearest point still inside the
constraint region. Deactivating the constraint is far simpler however
and I don't expect this to be a UX pain point.
Now with 50% less pointer warping!
The new implementation requires the user to move the cursor into the
constraint region before the constraint is activated in order to keep
behavior more predictable.
This implementation as it stands is incomplete/buggy and will make
updating to wlr_scene more complex.
It will be reimplemented after updating to wlr_scene is complete.
Currently the implementation treats the x/y coordinates of
View.State.box as layout coordinates instead of output-relative. This
causes issues when using an output not at 0,0.
