[Typescript SimpleEvents] Base Event

This is the base interface that all the others provided event types use.

One could also use this to create one's own event type.

export class BaseEvent<D, R> {
    protected add(callback: (data: D) => R): number;
    protected remove(handle: number): void;
    protected removeAll(): void;
    protected getCallbacks(): ((data: D) => R)[];
    protected getResult(data: D, defaultValueOfCallback: R | undefined = undefined): R | undefined;
}

• <D>: data type of the event data;

• <R>: data type of the event result;

• add: adds a callback to the invoke list and returns its handle;

• remove: removes a callback from the invoke list based on its handle;

• removeAll: clears the invoke list;

• getCallbacks: returns the current invoke list;

• getResult: calls the invoke list in order returning the first valid (as in not null, not undefined, not 0 and not false) result; if the invoke list is empty this method returns undefined; if the invoke list is not empty but no callback returns a valid value it will return defaultValueOfCallback.