anki/ts/lib/events.ts

// Copyright: Ankitects Pty Ltd and contributors
// License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html

type EventTargetToMap<A extends EventTarget> = A extends HTMLElement
    ? HTMLElementEventMap
    : A extends Document
    ? DocumentEventMap
    : A extends Window
    ? WindowEventMap
    : A extends FileReader
    ? FileReaderEventMap
    : A extends Element
    ? ElementEventMap
    : A extends Animation
    ? AnimationEventMap
    : A extends EventSource
    ? EventSourceEventMap
    : A extends AbortSignal
    ? AbortSignalEventMap
    : A extends AbstractWorker
    ? AbstractWorkerEventMap
    : never;

export function on<T extends EventTarget, K extends keyof EventTargetToMap<T>>(
    target: T,
    eventType: Exclude<K, symbol | number>,
    handler: (this: T, event: EventTargetToMap<T>[K]) => void,
    options?: AddEventListenerOptions,
): () => void {
    target.addEventListener(eventType, handler as EventListener, options);
    return () =>
        target.removeEventListener(eventType, handler as EventListener, options);
}

export function preventDefault(event: Event): void {
    event.preventDefault();
}