Introduction

Traditionally, event-driven applications use a central event-loop:

      while waiting for events:
            get ready events
            handle events

Event handling may get complicated:
Every new event type requires special handling.

      while waiting for events:
            for each ready event:
                if event is of type A:
                    handle event type A
                if event is of type B:
                    handle event type B
                if event is of type C:
                    handle event type C
                ...