Added dart support code

lib/modal_progress_hud_nsn.dart

@@ -1,7 +1,14 @@
-library modal_progress_hud;
+library modal_progress_hud_nsn;
 
-import 'package:flutter/material.dart';
-import 'dart:ui';
+import "modal_progress_hud_nsn_platform_interface.dart";
+import "package:flutter/material.dart";
+import "dart:ui";
+
+class ModalProgressHudNsn {
+  Future<String?> getPlatformVersion() {
+    return ModalProgressHudNsnPlatform.instance.getPlatformVersion();
+  }
+}
 
 ///
 /// Wrap around any widget that makes an async call to show a modal progress
@@ -32,7 +39,7 @@ class ModalProgressHUD extends StatelessWidget {
   /// A [Widget] which should be the the widget to be shown behind the loading barrier.
   final Widget child;
 
-  /// A [double] value specifying the amount of background blur of the progress.
+  /// A [double] value specifying the amount of background blur when progress hud is active.
   final double blur;
 
   const ModalProgressHUD({
@@ -56,9 +63,9 @@ class ModalProgressHUD extends StatelessWidget {
       layOutProgressIndicator = Center(child: progressIndicator);
     } else {
       layOutProgressIndicator = Positioned(
-        child: progressIndicator,
         left: offset!.dx,
         top: offset!.dy,
+        child: progressIndicator,
       );
     }
 
@@ -68,8 +75,8 @@ class ModalProgressHUD extends StatelessWidget {
         BackdropFilter(
           filter: ImageFilter.blur(sigmaX: blur, sigmaY: blur),
           child: Opacity(
-            child: ModalBarrier(dismissible: dismissible, color: color),
             opacity: opacity,
+            child: ModalBarrier(dismissible: dismissible, color: color),
           ),
         ),
         layOutProgressIndicator,

lib/modal_progress_hud_nsn_method_channel.dart

@@ -0,0 +1,17 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter/services.dart';
+
+import 'modal_progress_hud_nsn_platform_interface.dart';
+
+/// An implementation of [ModalProgressHudNsnPlatform] that uses method channels.
+class MethodChannelModalProgressHudNsn extends ModalProgressHudNsnPlatform {
+  /// The method channel used to interact with the native platform.
+  @visibleForTesting
+  final methodChannel = const MethodChannel('modal_progress_hud_nsn');
+
+  @override
+  Future<String?> getPlatformVersion() async {
+    final version = await methodChannel.invokeMethod<String>('getPlatformVersion');
+    return version;
+  }
+}

lib/modal_progress_hud_nsn_platform_interface.dart

@@ -0,0 +1,29 @@
+import 'package:plugin_platform_interface/plugin_platform_interface.dart';
+
+import 'modal_progress_hud_nsn_method_channel.dart';
+
+abstract class ModalProgressHudNsnPlatform extends PlatformInterface {
+  /// Constructs a ModalProgressHudNsnPlatform.
+  ModalProgressHudNsnPlatform() : super(token: _token);
+
+  static final Object _token = Object();
+
+  static ModalProgressHudNsnPlatform _instance = MethodChannelModalProgressHudNsn();
+
+  /// The default instance of [ModalProgressHudNsnPlatform] to use.
+  ///
+  /// Defaults to [MethodChannelModalProgressHudNsn].
+  static ModalProgressHudNsnPlatform get instance => _instance;
+
+  /// Platform-specific implementations should set this with their own
+  /// platform-specific class that extends [ModalProgressHudNsnPlatform] when
+  /// they register themselves.
+  static set instance(ModalProgressHudNsnPlatform instance) {
+    PlatformInterface.verifyToken(instance, _token);
+    _instance = instance;
+  }
+
+  Future<String?> getPlatformVersion() {
+    throw UnimplementedError('platformVersion() has not been implemented.');
+  }
+}

lib/modal_progress_hud_nsn_web.dart

@@ -0,0 +1,26 @@
+// In order to *not* need this ignore, consider extracting the "web" version
+// of your plugin as a separate package, instead of inlining it in the same
+// package as the core of your plugin.
+// ignore: avoid_web_libraries_in_flutter
+import 'dart:html' as html show window;
+
+import 'package:flutter_web_plugins/flutter_web_plugins.dart';
+
+import 'modal_progress_hud_nsn_platform_interface.dart';
+
+/// A web implementation of the ModalProgressHudNsnPlatform of the ModalProgressHudNsn plugin.
+class ModalProgressHudNsnWeb extends ModalProgressHudNsnPlatform {
+  /// Constructs a ModalProgressHudNsnWeb
+  ModalProgressHudNsnWeb();
+
+  static void registerWith(Registrar registrar) {
+    ModalProgressHudNsnPlatform.instance = ModalProgressHudNsnWeb();
+  }
+
+  /// Returns a [String] containing the version of the platform.
+  @override
+  Future<String?> getPlatformVersion() async {
+    final version = html.window.navigator.userAgent;
+    return version;
+  }
+}