import 'package:flutter/foundation.dart';
import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/services.dart';

Widget buildHybridAndroidView(BuildContext context, String viewType, Map<String, dynamic> creationParams) {
  return PlatformViewLink(
    viewType: viewType,
    surfaceFactory: (context, controller) {
      return AndroidViewSurface(
        controller: controller as AndroidViewController,
        gestureRecognizers: const <Factory<OneSequenceGestureRecognizer>>{},
        hitTestBehavior: PlatformViewHitTestBehavior.opaque,
      );
    },
    onCreatePlatformView: (params) {
      return PlatformViewsService.initSurfaceAndroidView(
        id: params.id,
        viewType: viewType,
        layoutDirection: TextDirection.ltr,
        creationParams: creationParams,
        creationParamsCodec: const StandardMessageCodec(),
        onFocus: () {
          params.onFocusChanged(true);
        },
      )
        ..addOnPlatformViewCreatedListener(params.onPlatformViewCreated)
        ..create();
    },
  );
}

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

Widget buildTextureAndroidView(BuildContext context, String viewType, Map<String, dynamic> creationParams) {
  return AndroidView(
    viewType: viewType,
    layoutDirection: TextDirection.ltr,
    creationParams: creationParams,
    creationParamsCodec: const StandardMessageCodec(),
  );
}

package dev.flutter.example

import android.content.Context
import android.graphics.Color
import android.view.View
import android.widget.TextView
import io.flutter.embedding.android.FlutterActivity
import io.flutter.embedding.engine.FlutterEngine
import io.flutter.plugin.common.StandardMessageCodec
import io.flutter.plugin.platform.PlatformView
import io.flutter.plugin.platform.PlatformViewFactory

// 1. Define the View
internal class NativeView(context: Context, id: Int, creationParams: Map<String?, Any?>?) : PlatformView {
    private val textView: TextView = TextView(context).apply {
        textSize = 72f
        setBackgroundColor(Color.rgb(255, 255, 255))
        text = "Rendered on a native Android view (id: $id)"
    }
    override fun getView(): View = textView
    override fun dispose() {}
}

// 2. Define the Factory
class NativeViewFactory : PlatformViewFactory(StandardMessageCodec.INSTANCE) {
    override fun create(context: Context, viewId: Int, args: Any?): PlatformView {
        val creationParams = args as Map<String?, Any?>?
        return NativeView(context, viewId, creationParams)
    }
}

// 3. Register in MainActivity
class MainActivity : FlutterActivity() {
    override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
        super.configureFlutterEngine(flutterEngine)
        flutterEngine
            .platformViewsController
            .registry
            .registerViewFactory("<platform-view-type>", NativeViewFactory())
    }
}

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

Widget buildIosView(BuildContext context, String viewType, Map<String, dynamic> creationParams) {
  return UiKitView(
    viewType: viewType,
    layoutDirection: TextDirection.ltr,
    creationParams: creationParams,
    creationParamsCodec: const StandardMessageCodec(),
  );
}

import Flutter
import UIKit

// 1. Define the View
class FLNativeView: NSObject, FlutterPlatformView {
    private var _view: UIView

    init(frame: CGRect, viewIdentifier viewId: Int64, arguments args: Any?, binaryMessenger messenger: FlutterBinaryMessenger?) {
        _view = UIView()
        super.init()
        createNativeView(view: _view)
    }

    func view() -> UIView { return _view }

    func createNativeView(view _view: UIView){
        _view.backgroundColor = UIColor.blue
        let nativeLabel = UILabel()
        nativeLabel.text = "Native text from iOS"
        nativeLabel.textColor = UIColor.white
        nativeLabel.textAlignment = .center
        nativeLabel.frame = CGRect(x: 0, y: 0, width: 180, height: 48.0)
        _view.addSubview(nativeLabel)
    }
}

// 2. Define the Factory
class FLNativeViewFactory: NSObject, FlutterPlatformViewFactory {
    private var messenger: FlutterBinaryMessenger

    init(messenger: FlutterBinaryMessenger) {
        self.messenger = messenger
        super.init()
    }

    func create(withFrame frame: CGRect, viewIdentifier viewId: Int64, arguments args: Any?) -> FlutterPlatformView {
        return FLNativeView(frame: frame, viewIdentifier: viewId, arguments: args, binaryMessenger: messenger)
    }

    public func createArgsCodec() -> FlutterMessageCodec & NSObjectProtocol {
          return FlutterStandardMessageCodec.sharedInstance()
    }
}

// 3. Register in AppDelegate
@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
    override func application(
        _ application: UIApplication,
        didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]?
    ) -> Bool {
        GeneratedPluginRegistrant.register(with: self)
        guard let pluginRegistrar = self.registrar(forPlugin: "plugin-name") else { return false }
        
        let factory = FLNativeViewFactory(messenger: pluginRegistrar.messenger())
        pluginRegistrar.register(factory, withId: "<platform-view-type>")
        
        return super.application(application, didFinishLaunchingWithOptions: launchOptions)
    }
}

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

Widget buildMacOsView(BuildContext context, String viewType, Map<String, dynamic> creationParams) {
  return AppKitView(
    viewType: viewType,
    layoutDirection: TextDirection.ltr,
    creationParams: creationParams,
    creationParamsCodec: const StandardMessageCodec(),
  );
}

import Cocoa
import FlutterMacOS

// 1. Define the View
class NativeView: NSView {
  init(viewIdentifier viewId: Int64, arguments args: Any?, binaryMessenger messenger: FlutterBinaryMessenger?) {
    super.init(frame: CGRect(x: 0, y: 0, width: 200, height: 200))
    wantsLayer = true
    layer?.backgroundColor = NSColor.systemBlue.cgColor
    createNativeView(view: self)
  }
  required init?(coder nsCoder: NSCoder) { super.init(coder: nsCoder) }

  func createNativeView(view _view: NSView) {
    let nativeLabel = NSTextField()
    nativeLabel.frame = CGRect(x: 0, y: 0, width: 180, height: 48.0)
    nativeLabel.stringValue = "Native text from macOS"
    nativeLabel.isEditable = false
    nativeLabel.sizeToFit()
    _view.addSubview(nativeLabel)
  }
}

// 2. Define the Factory
class NativeViewFactory: NSObject, FlutterPlatformViewFactory {
  private var messenger: FlutterBinaryMessenger
  init(messenger: FlutterBinaryMessenger) {
    self.messenger = messenger
    super.init()
  }
  func create(withViewIdentifier viewId: Int64, arguments args: Any?) -> NSView {
    return NativeView(viewIdentifier: viewId, arguments: args, binaryMessenger: messenger)
  }
  public func createArgsCodec() -> (FlutterMessageCodec & NSObjectProtocol)? {
    return FlutterStandardMessageCodec.sharedInstance()
  }
}

// 3. Register in MainFlutterWindow.swift
class MainFlutterWindow: NSWindow {
  override func awakeFromNib() {
    let registrar = flutterViewController.registrar(forPlugin: "plugin-name")
    let factory = NativeViewFactory(messenger: registrar.messenger)
    registrar.register(factory, withId: "<platform-view-type>")
    super.awakeFromNib()
  }
}

_flutter.loader.load({
  onEntrypointLoaded: async function onEntrypointLoaded(engineInitializer) {
    let engine = await engineInitializer.initializeEngine({
      multiViewEnabled: true, // Enables embedded mode.
    });
    let app = await engine.runApp();
    
    // Add a view to a specific host element
    let viewId = app.addView({
      hostElement: document.querySelector('#flutter-host-element'),
      initialData: { greeting: 'Hello from JS!' }
    });
  }
});

import 'dart:ui' show FlutterView;
import 'package:flutter/widgets.dart';

void main() {
  // MUST use runWidget, not runApp, for multi-view web embedding.
  runWidget(
    MultiViewApp(
      viewBuilder: (BuildContext context) => const MyEmbeddedWidget(),
    ),
  );
}

class MultiViewApp extends StatefulWidget {
  const MultiViewApp({super.key, required this.viewBuilder});
  final WidgetBuilder viewBuilder;

  @override
  State<MultiViewApp> createState() => _MultiViewAppState();
}

class _MultiViewAppState extends State<MultiViewApp> with WidgetsBindingObserver {
  Map<Object, Widget> _views = <Object, Widget>{};

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
    _updateViews();
  }

  @override
  void didChangeMetrics() {
    _updateViews();
  }

  void _updateViews() {
    final Map<Object, Widget> newViews = <Object, Widget>{};
    for (final FlutterView view in WidgetsBinding.instance.platformDispatcher.views) {
      final Widget viewWidget = _views[view.viewId] ?? _createViewWidget(view);
      newViews[view.viewId] = viewWidget;
    }
    setState(() {
      _views = newViews;
    });
  }

  Widget _createViewWidget(FlutterView view) {
    return View(
      view: view,
      child: Builder(builder: widget.viewBuilder),
    );
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return ViewCollection(views: _views.values.toList(growable: false));
  }
}

class MyEmbeddedWidget extends StatelessWidget {
  const MyEmbeddedWidget({super.key});

  @override
  Widget build(BuildContext context) {
    // Retrieve the viewId to handle specific logic if needed
    final int viewId = View.of(context).viewId;
    return Directionality(
      textDirection: TextDirection.ltr,
      child: Center(child: Text('Rendered in View ID: $viewId')),
    );
  }
}