input/pointer: Support wl_pointer.warp in MotionEvent

[ids1024]

Description

Based on #2108.

cosmic-comp needs to be updated with this to test properly with pointer constraints, then it needs testing in XWayland/etc. This is meant to replace the motion/relative_motion code in pop-os/cosmic-comp@dda2d14832.

As far as I understand, it should be correct to use .motion on older versions of the protocol, and .warp on newer versions. If the .relative_pointer event with a delta of 0 is just a workaround for the lack of a "warp" in earlier versions of the protocol, it presumably isn't necessary to send with newer versions? In which case, handling here seems appropriate.

Checklist

• I agree to smithay's Developer Certificate of Origin.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 12.92135% with 155 lines in your changes missing coverage. Please review.
✅ Project coverage is 17.39%. Comparing base (20061c1) to head (82808ef).
⚠️ Report is 9 commits behind head on master.

Files with missing lines	Patch %	Lines
src/wayland/seat/pointer.rs	5.55%	34 Missing ⚠️
src/wayland/relative_pointer.rs	3.03%	32 Missing ⚠️
src/wayland/pointer_gestures.rs	27.27%	16 Missing ⚠️
src/input/pointer/mod.rs	6.66%	14 Missing ⚠️
src/backend/input/mod.rs	40.00%	9 Missing ⚠️
src/input/tablet/tool/mod.rs	0.00%	9 Missing ⚠️
src/input/keyboard/mod.rs	0.00%	8 Missing ⚠️
anvil/src/input_handler.rs	0.00%	6 Missing ⚠️
src/wayland/seat/keyboard.rs	0.00%	6 Missing ⚠️
anvil/src/focus.rs	25.00%	3 Missing ⚠️
... and 9 more

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2137      +/-   ##
==========================================
- Coverage   17.41%   17.39%   -0.02%     
==========================================
  Files         187      187              
  Lines       30976    31172     +196     
==========================================
+ Hits         5393     5422      +29     
- Misses      25583    25750     +167     

Flag	Coverage Δ
wlcs-buffer	15.08% <0.56%> (-0.08%)	⬇️
wlcs-core	14.66% <0.56%> (-0.08%)	⬇️
wlcs-output	6.53% <0.56%> (-0.03%)	⬇️
wlcs-pointer-input	16.37% <12.92%> (-0.01%)	⬇️

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[YaLTeR]

Hm. What about cases like the new logic in ClickGrab that updates the focus start data? I guess it doesn't need any explicit handling because if the compositor changes the location of the surface without a pointer event, it will send is_warp: true, which will pass through ClickGrab correctly, and if it's coincided with an input event, then the compositor will send is_warp: false, which will also be correct?