Flutter: Receiving Shared Data from other Apps

AndroidManifest.xml

<activity
  android:name=".MainActivity"
  android:launchMode="singleTop"
  android:theme="@style/LaunchTheme"
  android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density"
  android:hardwareAccelerated="true"
  android:windowSoftInputMode="adjustResize">
  <!-- Add This intent-filter -->
  <intent-filter>
    <action android:name="android.intent.action.SEND" />
    <category android:name="android.intent.category.DEFAULT" />
    <data android:mimeType="text/plain" />
  </intent-filter>
</activity>

main.dart

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void main() => runApp(new MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'App Name',
      theme: new ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: new MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key}) : super(key: key);

  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  // Set up the channel
  MethodChannel _channel = const MethodChannel("app.channel.shared.data");
  String dataShared = "No data";

  @override
  void initState() {
    super.initState();
    // Set up the event listener
    _channel.setMethodCallHandler(_handleMethod);
  }

  // Receive event when Android receives shared content
  Future<dynamic> _handleMethod(MethodCall call) async {
    switch (call.method) {
      case "onSharedIntent":
        setState(() => dataShared = call.arguments.toString());
        return call.arguments;
    }
  }

  @override
  Widget build(BuildContext context) {
    return Text(dataShared);
  }
}

MainActivity.java

package com.example.videonotesapp;

import android.os.Bundle;
import io.flutter.app.FlutterActivity;
import io.flutter.plugins.GeneratedPluginRegistrant;

// Add Imports
import android.content.Intent;
import java.nio.ByteBuffer;
import io.flutter.plugin.common.ActivityLifecycleListener;
import io.flutter.plugin.common.MethodCall;
import io.flutter.plugin.common.MethodChannel;
import io.flutter.plugins.GeneratedPluginRegistrant;
import io.flutter.plugin.common.MethodChannel.MethodCallHandler;
import io.flutter.plugin.common.MethodChannel.Result;

public class MainActivity extends FlutterActivity {
  private String sharedText;
  private MethodChannel channel;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    GeneratedPluginRegistrant.registerWith(this);
    // Set up the channel
    channel = new MethodChannel(getFlutterView(), "app.channel.shared.data");
    Intent intent = getIntent();
    handleIntent(intent);
  }

  // This handles the case where the app is paused and user has shared an intent
  @Override
  protected void onNewIntent(Intent intent) {
    handleIntent(intent);
    super.onNewIntent(intent);
  }

  // Handles the intent coming in and calls Flutter EventListener
  protected void handleIntent(Intent intent) {
    String action = intent.getAction();
    System.out.println(action);
    String type = intent.getType();
    System.out.println(type);

    if (Intent.ACTION_SEND.equals(action) && type != null) {
      System.out.println("Action");
      if ("text/plain".equals(type)) {
        channel.invokeMethod("onSharedIntent", intent.getStringExtra(Intent.EXTRA_TEXT));
      }
    }
  }
}