React's mouseEvent doesn't have offsetX/offsetY
Solution 1:
Oh, well, I see.
I get it from e.nativeEvent.offsetX. Is it right approach?
Solution 2:
I have found that evt.nativeEvent.offsetX was causing me problems with my component flashing a lot and being sort of weird, I haven't fully debugged it, but I switched to using
React.createRef or React.useRef on the parent container, and then using event.clientX - ref.current.getBoundingClientRect().left and found this works better for me