This parameter (see parameters) gets or installs the current event dispatch handler. The event dispatch handler is called by an eventspace's handler thread for every queue-based event to be processed in the eventspace. The only argument to the handler is the eventspace in which an event should be dispatched. The event dispatch handler gives the programmer control over the timing of event disptaching, but not the order in which events are dispatched within a single eventspace.
An event dispatch handler must ultimately call the primitive event dispatch handler. If an event dispatch handler returns without calling the primitive handler, then the primitive handler is called directly by the eventspace handler thread.
Returns the current handler.
Sets the current handler.