on Class — svelte Architecture

Source Code

packages/svelte/types/index.d.ts lines 2808–2868

declare module 'svelte/events' {
	// Once https://github.com/microsoft/TypeScript/issues/59980 is fixed we can put these overloads into the JSDoc comments of the `on` function

	/**
	 * Attaches an event handler to the window and returns a function that removes the handler. Using this
	 * rather than `addEventListener` will preserve the correct order relative to handlers added declaratively
	 * (with attributes like `onclick`), which use event delegation for performance reasons
	 */
	export function on<Type extends keyof WindowEventMap>(
		window: Window,
		type: Type,
		handler: (this: Window, event: WindowEventMap[Type] & { currentTarget: Window }) => any,
		options?: AddEventListenerOptions | undefined
	): () => void;
	/**
	 * Attaches an event handler to the document and returns a function that removes the handler. Using this
	 * rather than `addEventListener` will preserve the correct order relative to handlers added declaratively
	 * (with attributes like `onclick`), which use event delegation for performance reasons
	 */
	export function on<Type extends keyof DocumentEventMap>(
		document: Document,
		type: Type,
		handler: (this: Document, event: DocumentEventMap[Type] & { currentTarget: Document }) => any,
		options?: AddEventListenerOptions | undefined
	): () => void;
	/**
	 * Attaches an event handler to an element and returns a function that removes the handler. Using this
	 * rather than `addEventListener` will preserve the correct order relative to handlers added declaratively
	 * (with attributes like `onclick`), which use event delegation for performance reasons
	 */
	export function on<Element extends HTMLElement, Type extends keyof HTMLElementEventMap>(
		element: Element,
		type: Type,
		handler: (this: Element, event: HTMLElementEventMap[Type] & { currentTarget: Element }) => any,
		options?: AddEventListenerOptions | undefined
	): () => void;
	/**
	 * Attaches an event handler to an element and returns a function that removes the handler. Using this
	 * rather than `addEventListener` will preserve the correct order relative to handlers added declaratively
	 * (with attributes like `onclick`), which use event delegation for performance reasons
	 */
	export function on<Element extends MediaQueryList, Type extends keyof MediaQueryListEventMap>(
		element: Element,
		type: Type,
		handler: (this: Element, event: MediaQueryListEventMap[Type] & { currentTarget: Element }) => any,
		options?: AddEventListenerOptions | undefined
	): () => void;
	/**
	 * Attaches an event handler to an element and returns a function that removes the handler. Using this
	 * rather than `addEventListener` will preserve the correct order relative to handlers added declaratively
	 * (with attributes like `onclick`), which use event delegation for performance reasons
	 */
	export function on(
		element: EventTarget,
		type: string,
		handler: EventListener,
		options?: AddEventListenerOptions | undefined
	): () => void;

	export {};
}