@flare-engine/share

Cross-platform screenshot capture (Skia makeImageSnapshot) + share-sheet orchestration with pluggable transports. captureScreenshot(source, opts?) returns { bytes, base64, format, width, height }. ShareManager cascades through registered transports — first one whose canShare(payload) returns true wins. Built-in transports cover Web Share API, Web Clipboard fallback, native RN Share, and expo-sharing (image files, for Android screenshots). createScreenshotScene wires a one-shot capture scene for store-asset workflows.

Install

bun add @flare-engine/share

Usage

import { Share } from 'react-native';
import { captureScreenshot, ShareManager, createNativeShareTransport,
         createWebShareTransport, createWebClipboardTransport } from '@flare-engine/share';
import type { CaptureSource } from '@flare-engine/share';

declare const source: CaptureSource;

const shot = captureScreenshot(source, { format: 'png' });

const share = new ShareManager()
  .register(createNativeShareTransport(Share))
  .register(createWebShareTransport(navigator, File))
  .register(createWebClipboardTransport(navigator));

if (shot) {
  await share.share({ message: 'New high score! https://example.com', screenshot: shot });
}

Platform notes:

• createWebShareTransport attaches the screenshot as a File when the browser's navigator.canShare({ files }) accepts it.
• createNativeShareTransport attaches it on iOS as a data:image/<format>;base64,… URL, only when url is unset — an explicit url wins and no image is attached then. Android's RN Share forwards only title and message, so put a link in message; the image is not attached there, and a payload with a screenshot but no message opens an empty sheet that still reports dispatched: true.
• createWebClipboardTransport copies message and url text only.
• createExpoShareTransport shares the screenshot as an image file; see below.

Android screenshots

RN's Share cannot attach an image on Android. createExpoShareTransport(sharing, files) writes the screenshot to a file and hands its URI to expo-sharing. Register it before the RN transport: its canShare is true only when the payload has a screenshot, so screenshot payloads reach expo-sharing and text-only payloads fall through to RN Share.

import { Share } from 'react-native';
import * as Sharing from 'expo-sharing';
import { File, Paths } from 'expo-file-system';
import { createExpoShareTransport, createNativeShareTransport, ShareManager } from '@flare-engine/share';
import type { ShareFileWriterLike } from '@flare-engine/share';

const files: ShareFileWriterLike = {
  async writeBase64File(name, base64) {
    const f = new File(Paths.cache, name);
    await f.write(base64, { encoding: 'base64' });
    return f.uri;
  },
};

const share = new ShareManager()
  .register(createExpoShareTransport(Sharing, files))
  .register(createNativeShareTransport(Share));

files is one callback that writes base64 data to a file and resolves to its URI. The adapter above uses the File API of expo-file-system 58, where write creates the file or overwrites it. With the expo-file-system/legacy entry, write it this way instead:

import { cacheDirectory, writeAsStringAsync } from 'expo-file-system/legacy';
import type { ShareFileWriterLike } from '@flare-engine/share';

const files: ShareFileWriterLike = {
  async writeBase64File(name, base64) {
    const uri = `${cacheDirectory}${name}`;
    await writeAsStringAsync(uri, base64, { encoding: 'base64' });
    return uri;
  },
};

Limits:

• expo-sharing shares one file and no text. The screenshot goes out alone: message and url are dropped, and title becomes the chooser's dialogTitle.
• The file is always named screenshot.<format>, so each share overwrites the previous one.
• The result is { dispatched: true, via: 'native' } once the sheet has opened; expo-sharing does not say whether the user finished the share. When isAvailableAsync() resolves false, nothing is written and the result is { dispatched: false, via: 'native' }. A failed write or a rejected shareAsync rejects the share() promise.

See API spec.

License

Apache-2.0