Fix null DataList issue + other null-safety concerns

.gitignore

@@ -15,4 +15,9 @@ res/
 android/
 
 lib/selectable_tags_back.dart
+lib/generated_plugin_registrant.dart
+
 example/lib/main_back.dart
+example/android/local.properties
+example/android/app/src/main/java/*
+example/ios/Flutter/*

example/ios/Flutter/flutter_export_environment.sh

@@ -5,6 +5,8 @@ export "FLUTTER_APPLICATION_PATH=D:\Android\Flutter\package\flutter_tags\example
 export "FLUTTER_TARGET=lib\main.dart"
 export "FLUTTER_BUILD_DIR=build"
 export "SYMROOT=${SOURCE_ROOT}/../build\ios"
+export "OTHER_LDFLAGS=$(inherited) -framework Flutter"
+export "FLUTTER_FRAMEWORK_DIR=C:\flutter\bin\cache\artifacts\engine\ios"
 export "FLUTTER_BUILD_NAME=1.0.0"
 export "FLUTTER_BUILD_NUMBER=1"
 export "DART_OBFUSCATION=false"

example/test/widget_test.dart

@@ -1,3 +1 @@
-import 'package:flutter/material.dart';
-
 void main() {}

lib/src/item_tags.dart

@@ -149,19 +149,21 @@ class _ItemTagsState extends State<ItemTags> {
     _dataListInherited = DataListInherited.of(context);
 
     // set List length
-    if (_dataListInherited!.list!.length < _dataListInherited!.itemCount!)
+    if (_dataListInherited!.itemCount != null &&
+        _dataListInherited!.list!.length < _dataListInherited!.itemCount!) {
       _dataListInherited!.list!.length = _dataListInherited!.itemCount!;
+    }
 
     if (_dataListInherited!.list!.length > (widget.index + 1) &&
         _dataListInherited!.list!.elementAt(widget.index) != null &&
-        _dataListInherited!.list!.elementAt(widget.index).title !=
+        _dataListInherited!.list!.elementAt(widget.index)!.title !=
             widget.title) {
       // when an element is removed from the data source
       _dataListInherited!.list!.removeAt(widget.index);
 
       // when all item list changed in data source
       if (_dataListInherited!.list!.elementAt(widget.index) != null &&
-          _dataListInherited!.list!.elementAt(widget.index).title !=
+          _dataListInherited!.list!.elementAt(widget.index)!.title !=
               widget.title)
         _dataListInherited!.list!
             .removeRange(widget.index, _dataListInherited!.list!.length);
@@ -415,16 +417,15 @@ class _ItemTagsState extends State<ItemTags> {
       case MainAxisAlignment.spaceBetween:
       case MainAxisAlignment.start:
         return TextAlign.start;
-        break;
+
       case MainAxisAlignment.end:
         return TextAlign.end;
-        break;
+
       case MainAxisAlignment.spaceAround:
       case MainAxisAlignment.spaceEvenly:
       case MainAxisAlignment.center:
         return TextAlign.center;
     }
-    return null;
   }
 
   ///TextStyle
@@ -438,9 +439,9 @@ class _ItemTagsState extends State<ItemTags> {
   void _singleItem(DataListInherited dataSetIn, DataList? dataSet) {
     dataSetIn.list!
         .where((tg) => tg != null)
-        .where((tg) => tg.active)
+        .where((tg) => tg!.active)
         .where((tg2) => tg2 != dataSet)
-        .forEach((tg) => tg.active = false);
+        .forEach((tg) => tg!.active = false);
   }
 }
 

lib/src/suggestions_textfield.dart

@@ -14,8 +14,7 @@ typedef OnSubmittedCallback = void Function(String string);
 class SuggestionsTextField extends StatefulWidget {
   SuggestionsTextField(
       {required this.tagsTextField, this.onSubmitted, Key? key})
-      : assert(tagsTextField != null),
-        super(key: key);
+      : super(key: key);
 
   final TagsTextField tagsTextField;
   final OnSubmittedCallback? onSubmitted;

lib/src/tags.dart

@@ -1,8 +1,8 @@
 import 'package:flutter/material.dart';
+import 'package:flutter_tags/src/suggestions_textfield.dart';
 
 import '../flutter_tags.dart';
 import 'util/custom_wrap.dart';
-import 'package:flutter_tags/src/suggestions_textfield.dart';
 
 ///ItemBuilder
 typedef Widget ItemBuilder(int index);
@@ -25,11 +25,6 @@ class Tags extends StatefulWidget {
       this.textField,
       Key? key})
       : assert(itemCount >= 0),
-        assert(alignment != null),
-        assert(runAlignment != null),
-        assert(direction != null),
-        assert(verticalDirection != null),
-        assert(textDirection != null),
         super(key: key);
 
   ///specific number of columns
@@ -87,9 +82,9 @@ class TagsState extends State<Tags> {
   Orientation _orientation = Orientation.portrait;
   double _width = 0;
 
-  final List<DataList> _list = [];
+  final List<DataList?> _list = [];
 
-  List<Item> get getAllItem => _list.toList();
+  List<Item?> get getAllItem => _list.toList();
 
   //get the current width of the screen
   void _getWidthContext() {
@@ -164,11 +159,11 @@ class TagsState extends State<Tags> {
               tagsTextField: widget.textField!,
               onSubmitted: (String str) {
                 if (!widget.textField!.duplicates) {
-                  final List<DataList> lst =
+                  final List<DataList?> lst =
                       _list.where((l) => l != null && l.title == str).toList();
 
                   if (lst.isNotEmpty) {
-                    lst.forEach((d) => d.showDuplicate = true);
+                    lst.forEach((d) => d!.showDuplicate = true);
                     return;
                   }
                 }
@@ -240,7 +235,7 @@ class DataListInherited extends InheritedWidget {
       required Widget child})
       : super(key: key, child: child);
 
-  final List<DataList>? list;
+  final List<DataList?>? list;
   final bool? symmetry;
   final int? itemCount;
 

lib/src/util/custom_wrap.dart

@@ -1,4 +1,5 @@
 import 'dart:math' as math;
+
 import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 
@@ -104,13 +105,7 @@ class CustomRenderWrap extends RenderBox
     WrapCrossAlignment crossAxisAlignment = WrapCrossAlignment.start,
     TextDirection? textDirection,
     VerticalDirection verticalDirection = VerticalDirection.down,
-  })  : assert(direction != null),
-        assert(alignment != null),
-        assert(spacing != null),
-        assert(runAlignment != null),
-        assert(runSpacing != null),
-        assert(crossAxisAlignment != null),
-        _column = column,
+  })  : _column = column,
         _symmetry = symmetry,
         _direction = direction,
         _alignment = alignment,
@@ -142,7 +137,6 @@ class CustomRenderWrap extends RenderBox
   Axis get direction => _direction;
   Axis _direction;
   set direction(Axis value) {
-    assert(value != null);
     if (_direction == value) return;
     _direction = value;
     markNeedsLayout();
@@ -151,7 +145,6 @@ class CustomRenderWrap extends RenderBox
   WrapAlignment get alignment => _alignment;
   WrapAlignment _alignment;
   set alignment(WrapAlignment value) {
-    assert(value != null);
     if (_alignment == value) return;
     _alignment = value;
     markNeedsLayout();
@@ -160,7 +153,6 @@ class CustomRenderWrap extends RenderBox
   double get spacing => _spacing;
   double _spacing;
   set spacing(double value) {
-    assert(value != null);
     if (_spacing == value) return;
     _spacing = value;
     markNeedsLayout();
@@ -169,7 +161,6 @@ class CustomRenderWrap extends RenderBox
   WrapAlignment get runAlignment => _runAlignment;
   WrapAlignment _runAlignment;
   set runAlignment(WrapAlignment value) {
-    assert(value != null);
     if (_runAlignment == value) return;
     _runAlignment = value;
     markNeedsLayout();
@@ -178,7 +169,6 @@ class CustomRenderWrap extends RenderBox
   double get runSpacing => _runSpacing;
   double _runSpacing;
   set runSpacing(double value) {
-    assert(value != null);
     if (_runSpacing == value) return;
     _runSpacing = value;
     markNeedsLayout();
@@ -187,7 +177,6 @@ class CustomRenderWrap extends RenderBox
   WrapCrossAlignment get crossAxisAlignment => _crossAxisAlignment;
   WrapCrossAlignment _crossAxisAlignment;
   set crossAxisAlignment(WrapCrossAlignment value) {
-    assert(value != null);
     if (_crossAxisAlignment == value) return;
     _crossAxisAlignment = value;
     markNeedsLayout();
@@ -202,20 +191,17 @@ class CustomRenderWrap extends RenderBox
     }
   }
 
-  VerticalDirection get verticalDirection => _verticalDirection;
-  VerticalDirection _verticalDirection;
-  set verticalDirection(VerticalDirection value) {
+  VerticalDirection? get verticalDirection => _verticalDirection;
+  VerticalDirection? _verticalDirection;
+
+  set verticalDirection(VerticalDirection? value) {
     if (_verticalDirection != value) {
       _verticalDirection = value;
       markNeedsLayout();
     }
   }
 
   bool get _debugHasNecessaryDirections {
-    assert(direction != null);
-    assert(alignment != null);
-    assert(runAlignment != null);
-    assert(crossAxisAlignment != null);
     if (firstChild != null && lastChild != firstChild) {
       // i.e. there's more than one child
       switch (direction) {
@@ -415,7 +401,6 @@ class CustomRenderWrap extends RenderBox
       case Axis.vertical:
         return child.size.height;
     }
-    return 0.0;
   }
 
   double _getCrossAxisExtent(RenderBox child) {
@@ -425,7 +410,6 @@ class CustomRenderWrap extends RenderBox
       case Axis.vertical:
         return child.size.width;
     }
-    return 0.0;
   }
 
   Offset _getOffset(double mainAxisOffset, double crossAxisOffset) {
@@ -435,7 +419,6 @@ class CustomRenderWrap extends RenderBox
       case Axis.vertical:
         return Offset(crossAxisOffset, mainAxisOffset);
     }
-    return Offset.zero;
   }
 
   double _getChildCrossAxisOffset(bool flipCrossAxis, double runCrossAxisExtent,
@@ -449,7 +432,6 @@ class CustomRenderWrap extends RenderBox
       case WrapCrossAlignment.center:
         return freeSpace / 2.0;
     }
-    return 0.0;
   }
 
   bool _hasVisualOverflow = false;
@@ -463,7 +445,7 @@ class CustomRenderWrap extends RenderBox
       size = constraints.smallest;
       return;
     }
-    BoxConstraints? childConstraints;
+    BoxConstraints childConstraints;
     double mainAxisLimit = 0.0;
     bool flipMainAxis = false;
     bool flipCrossAxis = false;
@@ -481,8 +463,6 @@ class CustomRenderWrap extends RenderBox
         if (textDirection == TextDirection.rtl) flipCrossAxis = true;
         break;
     }
-    assert(childConstraints != null);
-    assert(mainAxisLimit != null);
     final double spacing = this.spacing;
     final double runSpacing = this.runSpacing;
     final List<_RunMetrics> runMetrics = <_RunMetrics>[];