Page Visibility API

Page Visibility API 用于反馈当前文档的可见性

读取可见性

Document 接口的 visibilityState 属性返回一个 string，代表当前文档的可见性，值为 visible 或 hidden

Document 接口的 hidden 属性返回一个 boolean，代表当前文档是否隐藏

document.hidden
document.visibilityState

监视可见性改变

Document 接口的 visibilitychange 事件在当前文档的可见性改变时触发，返回一个 Event

document.addEventListener('visibilitychange', () => {
  //
})

类型

interface Document {
  readonly hidden: boolean
  readonly visibilityState: DocumentVisibilityState
  onvisibilitychange: ((this: Document, ev: Event) => any) | null
}

type DocumentVisibilityState = 'hidden' | 'visible'

链接

• https://developer.mozilla.org/en-US/docs/Web/API/Page_Visibility_API
• https://html.spec.whatwg.org/multipage/interaction.html#page-visibility