improved the code and null safety

Author: Shrutimahajan

lib/google_places_flutter.dart

@@ -13,19 +13,19 @@ import 'package:rxdart/rxdart.dart';
 
 class GooglePlaceAutoCompleteTextField extends StatefulWidget {
   InputDecoration inputDecoration;
-  ItemClick itmClick;
-  GetPlaceDetailswWithLatLng getPlaceDetailWithLatLng;
+  ItemClick? itmClick;
+  GetPlaceDetailswWithLatLng? getPlaceDetailWithLatLng;
   bool isLatLngRequired = true;
 
   TextStyle textStyle;
   String googleAPIKey;
   int debounceTime = 600;
-  List<String> countries = List();
+  List<String>? countries = [];
   TextEditingController textEditingController = TextEditingController();
 
   GooglePlaceAutoCompleteTextField(
-      {@required this.textEditingController,
-      @required this.googleAPIKey,
+      {required this.textEditingController,
+      required this.googleAPIKey,
       this.debounceTime: 600,
       this.inputDecoration: const InputDecoration(),
       this.itmClick,
@@ -43,8 +43,8 @@ class GooglePlaceAutoCompleteTextField extends StatefulWidget {
 class _GooglePlaceAutoCompleteTextFieldState
     extends State<GooglePlaceAutoCompleteTextField> {
   final subject = new PublishSubject<String>();
-  OverlayEntry _overlayEntry;
-  List<Prediction> alPredictions = new List();
+  OverlayEntry? _overlayEntry;
+  List<Prediction> alPredictions = [];
 
   TextEditingController controller = TextEditingController();
   final LayerLink _layerLink = LayerLink();
@@ -71,8 +71,8 @@ class _GooglePlaceAutoCompleteTextFieldState
     if (widget.countries != null) {
       // in
 
-      for (int i = 0; i < widget.countries.length; i++) {
-        String country = widget.countries[i];
+      for (int i = 0; i < widget.countries!.length; i++) {
+        String country = widget.countries![i];
 
         if (i == 0) {
           url = url + "&components=country:$country";
@@ -90,21 +90,21 @@ class _GooglePlaceAutoCompleteTextFieldState
 
     if (text.length == 0) {
       alPredictions.clear();
-      this._overlayEntry.remove();
+      this._overlayEntry!.remove();
       return;
     }
 
     isSearched = false;
-    if (subscriptionResponse.predictions.length > 0) {
+    if (subscriptionResponse.predictions!.length > 0) {
       alPredictions.clear();
-      alPredictions.addAll(subscriptionResponse.predictions);
+      alPredictions.addAll(subscriptionResponse.predictions!);
     }
 
     //if (this._overlayEntry == null)
 
     this._overlayEntry = null;
     this._overlayEntry = this._createOverlayEntry();
-    Overlay.of(context).insert(this._overlayEntry);
+    Overlay.of(context)!.insert(this._overlayEntry!);
     //   this._overlayEntry.markNeedsBuild();
   }
 
@@ -120,9 +120,9 @@ class _GooglePlaceAutoCompleteTextFieldState
     getLocation(text);
   }
 
-  OverlayEntry _createOverlayEntry() {
+  OverlayEntry? _createOverlayEntry() {
     if (context != null && context.findRenderObject() != null) {
-      RenderBox renderBox = context.findRenderObject();
+      RenderBox renderBox = context.findRenderObject() as RenderBox;
       var size = renderBox.size;
       var offset = renderBox.localToGlobal(Offset.zero);
       return OverlayEntry(
@@ -144,7 +144,7 @@ class _GooglePlaceAutoCompleteTextFieldState
                           return InkWell(
                             onTap: () {
                               if (index < alPredictions.length) {
-                                widget.itmClick(alPredictions[index]);
+                                widget.itmClick!(alPredictions[index]);
                                 if (!widget.isLatLngRequired) return;
 
                                 getPlaceDetailsFromPlaceId(
@@ -155,7 +155,7 @@ class _GooglePlaceAutoCompleteTextFieldState
                             },
                             child: Container(
                                 padding: EdgeInsets.all(10),
-                                child: Text(alPredictions[index].description)),
+                                child: Text(alPredictions[index].description!)),
                           );
                         },
                       )),
@@ -168,12 +168,12 @@ class _GooglePlaceAutoCompleteTextFieldState
     alPredictions.clear();
     this._overlayEntry = this._createOverlayEntry();
     if (context != null) {
-      Overlay.of(context).insert(this._overlayEntry);
-      this._overlayEntry.markNeedsBuild();
+      Overlay.of(context)!.insert(this._overlayEntry!);
+      this._overlayEntry!.markNeedsBuild();
     }
   }
 
-  Future<Response> getPlaceDetailsFromPlaceId(Prediction prediction) async {
+  Future<Response?> getPlaceDetailsFromPlaceId(Prediction prediction) async {
     //String key = GlobalConfiguration().getString('google_maps_key');
 
     var url =
@@ -184,10 +184,10 @@ class _GooglePlaceAutoCompleteTextFieldState
 
     PlaceDetails placeDetails = PlaceDetails.fromJson(response.data);
 
-    prediction.lat = placeDetails.result.geometry.location.lat.toString();
-    prediction.lng = placeDetails.result.geometry.location.lng.toString();
+    prediction.lat = placeDetails.result!.geometry!.location!.lat.toString();
+    prediction.lng = placeDetails.result!.geometry!.location!.lng.toString();
 
-    widget.getPlaceDetailWithLatLng(prediction);
+    widget.getPlaceDetailWithLatLng!(prediction);
 
 //    prediction.latLng = new LatLng(
 //        placeDetails.result.geometry.location.lat,
@@ -196,11 +196,11 @@ class _GooglePlaceAutoCompleteTextFieldState
 }
 
 PlacesAutocompleteResponse parseResponse(Map responseBody) {
-  return PlacesAutocompleteResponse.fromJson(responseBody);
+  return PlacesAutocompleteResponse.fromJson(responseBody as Map<String, dynamic>);
 }
 
 PlaceDetails parsePlaceDetailMap(Map responseBody) {
-  return PlaceDetails.fromJson(responseBody);
+  return PlaceDetails.fromJson(responseBody as Map<String, dynamic>);
 }
 
 typedef ItemClick = void Function(Prediction postalCodeResponse);

lib/model/place_details.dart

@@ -1,6 +1,6 @@
 class PlaceDetails {
-  Result result;
-  String status;
+  Result? result;
+  String? status;
 
   PlaceDetails({this.result, this.status});
 
@@ -14,29 +14,29 @@ class PlaceDetails {
     final Map<String, dynamic> data = new Map<String, dynamic>();
 
     if (this.result != null) {
-      data['result'] = this.result.toJson();
+      data['result'] = this.result!.toJson();
     }
     data['status'] = this.status;
     return data;
   }
 }
 
 class Result {
-  List<AddressComponents> addressComponents;
-  String adrAddress;
-  String formattedAddress;
-  Geometry geometry;
-  String icon;
-  String name;
-  List<Photos> photos;
-  String placeId;
-  String reference;
-  String scope;
-  List<String> types;
-  String url;
-  int utcOffset;
-  String vicinity;
-  String website;
+  List<AddressComponents>? addressComponents;
+  String? adrAddress;
+  String? formattedAddress;
+  Geometry? geometry;
+  String? icon;
+  String? name;
+  List<Photos>? photos;
+  String? placeId;
+  String? reference;
+  String? scope;
+  List<String>? types;
+  String? url;
+  int? utcOffset;
+  String? vicinity;
+  String? website;
 
   Result(
       {this.addressComponents,
@@ -57,9 +57,9 @@ class Result {
 
   Result.fromJson(Map<String, dynamic> json) {
     if (json['address_components'] != null) {
-      addressComponents = new List<AddressComponents>();
+      addressComponents = [];
       json['address_components'].forEach((v) {
-        addressComponents.add(new AddressComponents.fromJson(v));
+        addressComponents!.add(new AddressComponents.fromJson(v));
       });
     }
     adrAddress = json['adr_address'];
@@ -70,9 +70,9 @@ class Result {
     icon = json['icon'];
     name = json['name'];
     if (json['photos'] != null) {
-      photos = new List<Photos>();
+      photos =[];
       json['photos'].forEach((v) {
-        photos.add(new Photos.fromJson(v));
+        photos!.add(new Photos.fromJson(v));
       });
     }
     placeId = json['place_id'];
@@ -89,17 +89,17 @@ class Result {
     final Map<String, dynamic> data = new Map<String, dynamic>();
     if (this.addressComponents != null) {
       data['address_components'] =
-          this.addressComponents.map((v) => v.toJson()).toList();
+          this.addressComponents!.map((v) => v.toJson()).toList();
     }
     data['adr_address'] = this.adrAddress;
     data['formatted_address'] = this.formattedAddress;
     if (this.geometry != null) {
-      data['geometry'] = this.geometry.toJson();
+      data['geometry'] = this.geometry!.toJson();
     }
     data['icon'] = this.icon;
     data['name'] = this.name;
     if (this.photos != null) {
-      data['photos'] = this.photos.map((v) => v.toJson()).toList();
+      data['photos'] = this.photos!.map((v) => v.toJson()).toList();
     }
     data['place_id'] = this.placeId;
     data['reference'] = this.reference;
@@ -114,9 +114,9 @@ class Result {
 }
 
 class AddressComponents {
-  String longName;
-  String shortName;
-  List<String> types;
+  String? longName;
+  String? shortName;
+  List<String>? types;
 
   AddressComponents({this.longName, this.shortName, this.types});
 
@@ -136,8 +136,8 @@ class AddressComponents {
 }
 
 class Geometry {
-  Location location;
-  Viewport viewport;
+  Location? location;
+  Viewport? viewport;
 
   Geometry({this.location, this.viewport});
 
@@ -153,18 +153,18 @@ class Geometry {
   Map<String, dynamic> toJson() {
     final Map<String, dynamic> data = new Map<String, dynamic>();
     if (this.location != null) {
-      data['location'] = this.location.toJson();
+      data['location'] = this.location!.toJson();
     }
     if (this.viewport != null) {
-      data['viewport'] = this.viewport.toJson();
+      data['viewport'] = this.viewport!.toJson();
     }
     return data;
   }
 }
 
 class Location {
-  double lat;
-  double lng;
+  double? lat;
+  double? lng;
 
   Location({this.lat, this.lng});
 
@@ -182,8 +182,8 @@ class Location {
 }
 
 class Viewport {
-  Location northeast;
-  Location southwest;
+  Location? northeast;
+  Location? southwest;
 
   Viewport({this.northeast, this.southwest});
 
@@ -199,20 +199,20 @@ class Viewport {
   Map<String, dynamic> toJson() {
     final Map<String, dynamic> data = new Map<String, dynamic>();
     if (this.northeast != null) {
-      data['northeast'] = this.northeast.toJson();
+      data['northeast'] = this.northeast!.toJson();
     }
     if (this.southwest != null) {
-      data['southwest'] = this.southwest.toJson();
+      data['southwest'] = this.southwest!.toJson();
     }
     return data;
   }
 }
 
 class Photos {
-  int height;
-  List<String> htmlAttributions;
-  String photoReference;
-  int width;
+  int? height;
+  List<String>? htmlAttributions;
+  String? photoReference;
+  int? width;
 
   Photos({this.height, this.htmlAttributions, this.photoReference, this.width});