Please integrate/review this one. In the context of replacing the current event handling mechanism, for the new Event-Model using announcements, i found out that the UserInterruptHandler is somehow treated as a global. See InputEventSensor>>installEventSensorFramework: fetcherClass. â¦. "Register the interrupt handler" UserInterruptHandler new registerIn: InputEventFetcher default. â¦â¦. What if you want to replace the user interrupt handler for another? It cant be done transparently. I've added the userInterruptHandler as an ivar of the current Sensor, so when it registers and unregisters, it takes care of registering and unregistering its user interrupt handler. So you can plug different user interrupt handlers to the current sensor. Fernando