Flutter - Native Platform Interactions - Code for the youtube video.

AppDelegate.m

#include "AppDelegate.h"
#include "GeneratedPluginRegistrant.h"

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    [GeneratedPluginRegistrant registerWithRegistry:self];
    // Override point for customization after application launch.
    
    FlutterViewController* controller = (FlutterViewController*)self.window.rootViewController;
    
    FlutterMethodChannel* channel = [FlutterMethodChannel
                                     methodChannelWithName:@"demo.gawkat.com/info"
                                     binaryMessenger:controller];
    
    [channel setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
        
        NSString *from = call.arguments[@"from"];
        
        if ([@"getMessage" isEqualToString:call.method]) {
            //NSString *message = @"iOS says greetings";
            //NSString *returnMessage = [message stringByAppendingString:from];
            
            //result(returnMessage);
            
            UIApplication *mySafari = [UIApplication sharedApplication];
            NSURL *myURL = [[NSURL alloc]initWithString:@"https://flutter.io"];
            [mySafari openURL:myURL];
        }
        
    }];
    
    return [super application:application didFinishLaunchingWithOptions:launchOptions];
}

@end

main.dart

import 'dart:async';

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: 'Flutter Demo',
      theme: new ThemeData(
        primarySwatch: Colors.lightGreen,
      ),
      home: new MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  static const platform = const MethodChannel('demo.gawkat.com/info');

  String _message = "No messages yet...";

  @override
  void initState() {
    // fetch and change the message from the platform

    _getMessage().then((String message) {
      setState(() {
       _message = message;
      });
    });

    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text("Home"),
      ),
      body: new ListView(
        children: <Widget>[
          new ListTile(
            title: new Text(_message),
          )
        ],
      ),
    );
  }

  Future<String> _getMessage() async {
    var sendMap = <String, dynamic> {
      'from' : 'Brandon',
    };

    String value;

    try {
      value = await platform.invokeMethod('getMessage', sendMap);
    } catch (e) {
      print(e);
    }

    return value;
  }
}

MainActivity.java

package com.gawkat.flutterplatforminteractions;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;

import java.util.Map;

import io.flutter.app.FlutterActivity;
import io.flutter.plugin.common.MethodCall;
import io.flutter.plugin.common.MethodChannel;
import io.flutter.plugins.GeneratedPluginRegistrant;

public class MainActivity extends FlutterActivity {
    private static final String CHANNEL = "demo.gawkat.com/info";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        GeneratedPluginRegistrant.registerWith(this);

        new MethodChannel(getFlutterView(), CHANNEL).setMethodCallHandler(new MethodChannel.MethodCallHandler() {
            @Override
            public void onMethodCall(MethodCall methodCall, MethodChannel.Result result) {

                final Map<String, Object> arguments = methodCall.arguments();

                if (methodCall.method.equals("getMessage")) {

//                    String from = (String) arguments.get("from");
//
//                    String message = "Android say hi " + from;
//
//                    result.success(message);


                   openWebPage("https://flutter.io");
                }

            }
        });
    }

    public void openWebPage(String url) {
        Uri webpage = Uri.parse(url);
        Intent intent = new Intent(Intent.ACTION_VIEW, webpage);
        if (intent.resolveActivity(getPackageManager()) != null) {
            startActivity(intent);
        }
    }
}

The video that covered this source: https://youtu.be/0nJrGKyRlPQ