| 1 | import { computed, ref } from 'vue' |
| 2 | |
| 3 | export async function startScreenshotSession(width: number, height: number) { |
| 4 | const canvas = document.createElement('canvas') |
| 5 | canvas.width = width |
| 6 | canvas.height = height |
| 7 | const context = canvas.getContext('2d')! |
| 8 | const video = document.createElement('video') |
| 9 | video.width = width |
| 10 | video.height = height |
| 11 | |
| 12 | const captureStream = ref<MediaStream | null>(await navigator.mediaDevices.getDisplayMedia({ |
| 13 | video: { |
| 14 | // Use a rather small frame rate |
| 15 | frameRate: 10, |
| 16 | // @ts-expect-error missing types |
| 17 | cursor: 'never', |
| 18 | }, |
| 19 | selfBrowserSurface: 'include', |
| 20 | preferCurrentTab: true, |
| 21 | })) |
| 22 | captureStream.value!.addEventListener('inactive', dispose) |
| 23 | |
| 24 | video.srcObject = captureStream.value! |
| 25 | video.play() |
| 26 | |
| 27 | function screenshot(element: HTMLElement) { |
| 28 | if (!captureStream.value) |
| 29 | throw new Error('captureStream inactive') |
| 30 | context.clearRect(0, 0, width, height) |
| 31 | const { left, top, width: elWidth } = element.getBoundingClientRect() |
| 32 | context.drawImage( |
| 33 | video, |
| 34 | left * window.devicePixelRatio, |
| 35 | top * window.devicePixelRatio, |
| 36 | elWidth * window.devicePixelRatio, |
| 37 | elWidth / width * height * window.devicePixelRatio, |
| 38 | 0, |
| 39 | 0, |
| 40 | width, |
| 41 | height, |
| 42 | ) |
| 43 | return canvas.toDataURL('image/png') |
| 44 | } |
| 45 | |
| 46 | function dispose() { |
| 47 | captureStream.value?.getTracks().forEach(track => track.stop()) |
| 48 | captureStream.value = null |
| 49 | } |
| 50 | |
| 51 | return { |
| 52 | isActive: computed(() => !!captureStream.value), |
| 53 | screenshot, |
| 54 | dispose, |
| 55 | } |
| 56 | } |
| 57 | |
| 58 | export type ScreenshotSession = Awaited<ReturnType<typeof startScreenshotSession>> |
| 59 | |
| 60 | const chromeVersion = window.navigator.userAgent.match(/Chrome\/(\d+)/)?.[1] |
| 61 | export const isScreenshotSupported = chromeVersion ? Number(chromeVersion) >= 94 : false |
| 62 |