Make methods non static

lib/permission_handler.dart

@@ -5,19 +5,34 @@ import 'dart:convert';
 import 'dart:io';
 import 'dart:io';
 
 
 import 'package:flutter/services.dart';
 import 'package:flutter/services.dart';
+import 'package:meta/meta.dart';
 
 
 part 'package:permission_handler/permission_enums.dart';
 part 'package:permission_handler/permission_enums.dart';
 part 'package:permission_handler/utils/codec.dart';
 part 'package:permission_handler/utils/codec.dart';
 
 
 /// Provides a cross-platform (iOS, Android) API to request and check permissions.
 /// Provides a cross-platform (iOS, Android) API to request and check permissions.
 class PermissionHandler {
 class PermissionHandler {
-  static const MethodChannel _channel =
-      const MethodChannel('flutter.baseflow.com/permissions/methods');
+  factory PermissionHandler() {
+    if (_instance == null) {
+      final MethodChannel methodChannel =
+          const MethodChannel('flutter.baseflow.com/permissions/methods');
+
+      _instance = new PermissionHandler.private(methodChannel);
+    }
+    return _instance;
+  }
+
+  @visibleForTesting
+  PermissionHandler.private(this._methodChannel);
+
+  static PermissionHandler _instance;
+
+  final MethodChannel _methodChannel;
 
 
   /// Returns a [Future] containing the current permission status for the supplied [PermissionGroup].
   /// Returns a [Future] containing the current permission status for the supplied [PermissionGroup].
-  static Future<PermissionStatus> checkPermissionStatus(
+  Future<PermissionStatus> checkPermissionStatus(
       PermissionGroup permission) async {
       PermissionGroup permission) async {
-    final dynamic status = await _channel.invokeMethod(
+    final dynamic status = await _methodChannel.invokeMethod(
         'checkPermissionStatus', Codec.encodePermissionGroup(permission));
         'checkPermissionStatus', Codec.encodePermissionGroup(permission));
 
 
     return Codec.decodePermissionStatus(status);
     return Codec.decodePermissionStatus(status);
@@ -26,19 +41,19 @@ class PermissionHandler {
   /// Open the App settings page.
   /// Open the App settings page.
   ///
   ///
   /// Returns [true] if the app settings page could be opened, otherwise [false] is returned.
   /// Returns [true] if the app settings page could be opened, otherwise [false] is returned.
-  static Future<bool> openAppSettings() async {
-    final bool hasOpened = await _channel.invokeMethod('openAppSettings');
+  Future<bool> openAppSettings() async {
+    final bool hasOpened = await _methodChannel.invokeMethod('openAppSettings');
     return hasOpened;
     return hasOpened;
   }
   }
 
 
   /// Request the user for access to the supplied list of permissiongroups.
   /// Request the user for access to the supplied list of permissiongroups.
   ///
   ///
   /// Returns a [Map] containing the status per requested permissiongroup.
   /// Returns a [Map] containing the status per requested permissiongroup.
-  static Future<Map<PermissionGroup, PermissionStatus>> requestPermissions(
+  Future<Map<PermissionGroup, PermissionStatus>> requestPermissions(
       List<PermissionGroup> permissions) async {
       List<PermissionGroup> permissions) async {
     final String jsonData = Codec.encodePermissionGroups(permissions);
     final String jsonData = Codec.encodePermissionGroups(permissions);
     final dynamic status =
     final dynamic status =
-        await _channel.invokeMethod('requestPermissions', jsonData);
+        await _methodChannel.invokeMethod('requestPermissions', jsonData);
 
 
     return Codec.decodePermissionRequestResult(status);
     return Codec.decodePermissionRequestResult(status);
   }
   }
@@ -47,13 +62,13 @@ class PermissionHandler {
   ///
   ///
   /// This method is only implemented on Android, calling this on iOS always
   /// This method is only implemented on Android, calling this on iOS always
   /// returns [false].
   /// returns [false].
-  static Future<bool> shouldShowRequestPermissionRationale(
+  Future<bool> shouldShowRequestPermissionRationale(
       PermissionGroup permission) async {
       PermissionGroup permission) async {
     if (!Platform.isAndroid) {
     if (!Platform.isAndroid) {
       return false;
       return false;
     }
     }
 
 
-    final bool shouldShowRationale = await _channel.invokeMethod(
+    final bool shouldShowRationale = await _methodChannel.invokeMethod(
         'shouldShowRequestPermissionRationale',
         'shouldShowRequestPermissionRationale',
         Codec.encodePermissionGroup(permission));
         Codec.encodePermissionGroup(permission));