Host · interface

Lifecycle

Focus, and the end of the process.

interface Lifecycle

import type { Lifecycle } from '@driftengine/core';

In depth

The engine needs to know when it stopped being looked at — a paused simulation, a muted mixer — and a shell additionally needs to be told to close. A browser cannot close its own tab, so requestQuit warns rather than silently doing nothing: a silent no-op reads as a working call, which is the failure AGENTS.md names where an unimplemented capability returns a plausible answer instead of a defined one.

Every subscription returns its own unsubscribe. Nothing here is called per frame.

Properties

Name	Type	Description
`canQuit`readonly	`boolean`	Whether `requestQuit` will actually end the process. More This is what an exit button should be drawn from. A browser cannot close its own tab and iOS applications do not exit programmatically, so a menu that always shows Exit has a button that does nothing on two of the platforms a game ships to — and a game that instead branches on "am I in a shell" has hard-coded an assumption that stops being true. Ask the capability.

Methods

`onFocusChange`

onFocusChange(handler: (focused: boolean) => void): () => void

Parameter	Type	Description
`handler`	`(focused: boolean) => void`

`onQuitRequest`

onQuitRequest(handler: () => void): () => void

The shell is closing and the game may finish what it is doing.

Parameter	Type	Description
`handler`	`() => void`

A shell calls the handler on a window-close request and waits; a browser never calls it, because a tab closing gives nothing that can be waited on.

`requestQuit`

requestQuit(): void