At a glance, there seems to be some duplication (as well as things on top).

See:

• https://github.com/scijava/scijava-common/tree/scijava-common-2.50.0/src/main/java/org/scijava/input
• https://github.com/scijava/scijava-common/tree/scijava-common-2.50.0/src/main/java/org/scijava/display/event/input
• https://github.com/scijava/scijava-common/tree/scijava-common-2.50.0/src/main/java/org/scijava/display/event/window