flutter_screenshot_detector

A Flutter plugin that emits an event when the user takes a screenshot of your app.

Features

• Android 14+ screenshot detection through the platform screen-capture callback.
• Android 13 and older configurable fallback modes.
• iOS screenshot detection through UIApplication.userDidTakeScreenshotNotification.
• Simple Dart stream API.
• Built with Flutter 3.44 and Dart 3.12 compatibility.

Usage

import 'dart:async';

import 'package:flutter_screenshot_detector/flutter_screenshot_detector.dart';

late final StreamSubscription<ScreenshotEvent> subscription;

void startListening() {
  subscription = FlutterScreenshotDetector.instance.onScreenshot.listen((event) {
    // React after the screenshot is taken.
    print('Screenshot detected on ${event.platform} at ${event.timestamp}');
  });
}

Future<void> stopListening() => subscription.cancel();

Android 13 and Older Mode

Android 14 and newer always use the native screen-capture callback. On Android 13 and older, choose one of two fallback modes before listening:

await FlutterScreenshotDetector.instance.configure(
  androidLegacyMode: AndroidLegacyMode.focusHeuristic,
);

focusHeuristic is the default. It does not require media permission, but it can report false positives when system UI briefly steals focus. It waits for a quick false -> true focus cycle, then emits after a short delay.

await FlutterScreenshotDetector.instance.configure(
  androidLegacyMode: AndroidLegacyMode.mediaStore,
);

mediaStore is more accurate, but your host app must declare and request media or storage read permission.

Android setup

The plugin declares the required Android permissions in its manifest:

<uses-permission android:name="android.permission.DETECT_SCREEN_CAPTURE" />

If you use AndroidLegacyMode.mediaStore, add the relevant permissions to your app manifest and request them at runtime:

<uses-permission
  android:name="android.permission.READ_EXTERNAL_STORAGE"
  android:maxSdkVersion="32" />
<uses-permission
  android:name="android.permission.READ_MEDIA_IMAGES"
  android:maxSdkVersion="33" />

iOS setup

iOS does not require additional permissions. The event is emitted after the system posts UIApplication.userDidTakeScreenshotNotification.

Limitations

• Detection happens after the screenshot is taken.
• iOS does not expose the screenshot file path.
• Android 13 and older focusHeuristic mode can miss screenshots on some devices and may report false positives for other quick system focus changes.
• Android 13 and older mediaStore mode depends on media access permission and device screenshot naming conventions.