Add sound null safety

demo/lib/animated_input.dart

@@ -6,7 +6,7 @@ class AnimatedInput extends StatefulWidget {
   final String text;
   final InputBuilder builder;
 
-  AnimatedInput({this.text, this.builder});
+  AnimatedInput({required this.text, required this.builder});
 
   @override
   _AnimatedInputState createState() => _AnimatedInputState();
@@ -16,7 +16,7 @@ class _AnimatedInputState extends State<AnimatedInput>
     with SingleTickerProviderStateMixin {
   String _input = '';
 
-  AnimationController _controller;
+  late AnimationController _controller;
 
   @override
   void initState() {

demo/lib/sync_demo.dart

@@ -17,7 +17,7 @@ class _SyncDemoState extends State<SyncDemo>
     with SingleTickerProviderStateMixin {
   double _scale = 0;
   var group = AutoSizeGroup();
-  AnimationController _controller;
+  late AnimationController _controller;
 
   @override
   void initState() {
@@ -52,8 +52,8 @@ class _SyncDemoState extends State<SyncDemo>
 
   @override
   Widget build(BuildContext context) {
-    var group = AutoSizeGroup();
-    var text =
+    final group = AutoSizeGroup();
+    const text =
         'These AutoSizeTexts fit the available space and synchronize their '
         'text sizes.';
     return Column(

demo/lib/text_card.dart

@@ -4,7 +4,7 @@ class TextCard extends StatelessWidget {
   final String title;
   final Widget child;
 
-  TextCard({this.title, this.child});
+  TextCard({required this.title, required this.child});
 
   @override
   Widget build(BuildContext context) {

demo/pubspec.yaml

@@ -4,7 +4,7 @@ description: AutoSizeText Demo App
 version: 1.0.0+2
 
 environment:
-  sdk: ">=2.10.0 <3.0.0" 
+  sdk: '>=2.12.0-0 <3.0.0'
 
 dependencies:
   flutter:

example/pubspec.yaml

@@ -1,10 +1,10 @@
 name: example
-description: AutoSizeText Example
+description: AutoSizeText example
 
 version: 1.0.0
 
 environment:
-  sdk: ">=2.10.0 <3.0.0"
+  sdk: '>=2.12.0-0 <3.0.0'
 
 dependencies:
   flutter:

lib/src/auto_size_text.dart

@@ -12,8 +12,8 @@ class AutoSizeText extends StatefulWidget {
   /// If the [style] argument is null, the text will use the style from the
   /// closest enclosing [DefaultTextStyle].
   const AutoSizeText(
-    this.data, {
-    Key key,
+    String this.data, {
+    Key? key,
     this.textKey,
     this.style,
     this.strutStyle,
@@ -32,15 +32,13 @@ class AutoSizeText extends StatefulWidget {
     this.textScaleFactor,
     this.maxLines,
     this.semanticsLabel,
-  })  : assert(data != null,
-            'A non-null String must be provided to a AutoSizeText widget.'),
-        textSpan = null,
+  })  : textSpan = null,
         super(key: key);
 
   /// Creates a [AutoSizeText] widget with a [TextSpan].
   const AutoSizeText.rich(
-    this.textSpan, {
-    Key key,
+    TextSpan this.textSpan, {
+    Key? key,
     this.textKey,
     this.style,
     this.strutStyle,
@@ -59,32 +57,30 @@ class AutoSizeText extends StatefulWidget {
     this.textScaleFactor,
     this.maxLines,
     this.semanticsLabel,
-  })  : assert(textSpan != null,
-            'A non-null TextSpan must be provided to a AutoSizeText.rich widget.'),
-        data = null,
+  })  : data = null,
         super(key: key);
 
   /// Sets the key for the resulting [Text] widget.
   ///
   /// This allows you to find the actual `Text` widget built by `AutoSizeText`.
-  final Key textKey;
+  final Key? textKey;
 
   /// The text to display.
   ///
   /// This will be null if a [textSpan] is provided instead.
-  final String data;
+  final String? data;
 
   /// The text to display as a [TextSpan].
   ///
   /// This will be null if [data] is provided instead.
-  final TextSpan textSpan;
+  final TextSpan? textSpan;
 
   /// If non-null, the style to use for this text.
   ///
   /// If the style's "inherit" property is true, the style will be merged with
   /// the closest enclosing [DefaultTextStyle]. Otherwise, the style will
   /// replace the closest enclosing [DefaultTextStyle].
-  final TextStyle style;
+  final TextStyle? style;
 
   // The default font size if none is specified.
   static const double _defaultFontSize = 14;
@@ -99,7 +95,7 @@ class AutoSizeText extends StatefulWidget {
   /// a font size.
   ///
   /// See [StrutStyle] for details.
-  final StrutStyle strutStyle;
+  final StrutStyle? strutStyle;
 
   /// The minimum text size constraint to be used when auto-sizing text.
   ///
@@ -125,17 +121,17 @@ class AutoSizeText extends StatefulWidget {
   /// Predefines all the possible font sizes.
   ///
   /// **Important:** PresetFontSizes have to be in descending order.
-  final List<double> presetFontSizes;
+  final List<double>? presetFontSizes;
 
   /// Synchronizes the size of multiple [AutoSizeText]s.
   ///
   /// If you want multiple [AutoSizeText]s to have the same text size, give all
   /// of them the same [AutoSizeGroup] instance. All of them will have the
   /// size of the smallest [AutoSizeText]
-  final AutoSizeGroup group;
+  final AutoSizeGroup? group;
 
   /// How the text should be aligned horizontally.
-  final TextAlign textAlign;
+  final TextAlign? textAlign;
 
   /// The directionality of the text.
   ///
@@ -150,20 +146,20 @@ class AutoSizeText extends StatefulWidget {
   /// its left.
   ///
   /// Defaults to the ambient [Directionality], if any.
-  final TextDirection textDirection;
+  final TextDirection? textDirection;
 
   /// Used to select a font when the same Unicode character can
   /// be rendered differently, depending on the locale.
   ///
   /// It's rarely necessary to set this property. By default its value
   /// is inherited from the enclosing app with `Localizations.localeOf(context)`.
-  final Locale locale;
+  final Locale? locale;
 
   /// Whether the text should break at soft line breaks.
   ///
   /// If false, the glyphs in the text will be positioned as if there was
   /// unlimited horizontal space.
-  final bool softWrap;
+  final bool? softWrap;
 
   /// Whether words which don't fit in one line should be wrapped.
   ///
@@ -174,11 +170,11 @@ class AutoSizeText extends StatefulWidget {
   /// How visual overflow should be handled.
   ///
   /// Defaults to retrieving the value from the nearest [DefaultTextStyle] ancestor.
-  final TextOverflow overflow;
+  final TextOverflow? overflow;
 
   /// If the text is overflowing and does not fit its bounds, this widget is
   /// displayed instead.
-  final Widget overflowReplacement;
+  final Widget? overflowReplacement;
 
   /// The number of font pixels for each logical pixel.
   ///
@@ -190,7 +186,7 @@ class AutoSizeText extends StatefulWidget {
   /// The value given to the constructor as textScaleFactor. If null, will
   /// use the [MediaQueryData.textScaleFactor] obtained from the ambient
   /// [MediaQuery], or 1.0 if there is no [MediaQuery] in scope.
-  final double textScaleFactor;
+  final double? textScaleFactor;
 
   /// An optional maximum number of lines for the text to span, wrapping if necessary.
   /// If the text exceeds the given number of lines, it will be resized according
@@ -203,7 +199,7 @@ class AutoSizeText extends StatefulWidget {
   /// an explicit number for its [DefaultTextStyle.maxLines], then the
   /// [DefaultTextStyle] value will take precedence. You can use a [RichText]
   /// widget directly to entirely override the [DefaultTextStyle].
-  final int maxLines;
+  final int? maxLines;
 
   /// An alternative semantics label for this text.
   ///
@@ -217,7 +213,7 @@ class AutoSizeText extends StatefulWidget {
   /// ```dart
   /// AutoSizeText(r'$$', semanticsLabel: 'Double dollars')
   /// ```
-  final String semanticsLabel;
+  final String? semanticsLabel;
 
   @override
   _AutoSizeTextState createState() => _AutoSizeTextState();
@@ -228,9 +224,7 @@ class _AutoSizeTextState extends State<AutoSizeText> {
   void initState() {
     super.initState();
 
-    if (widget.group != null) {
-      widget.group._register(this);
-    }
+    widget.group?._register(this);
   }
 
   @override
@@ -249,10 +243,10 @@ class _AutoSizeTextState extends State<AutoSizeText> {
       final defaultTextStyle = DefaultTextStyle.of(context);
 
       var style = widget.style;
-      if (widget.style == null || widget.style.inherit) {
+      if (widget.style == null || widget.style!.inherit) {
         style = defaultTextStyle.style.merge(widget.style);
       }
-      if (style.fontSize == null) {
+      if (style!.fontSize == null) {
         style = style.copyWith(fontSize: AutoSizeText._defaultFontSize);
       }
 
@@ -267,21 +261,21 @@ class _AutoSizeTextState extends State<AutoSizeText> {
       Widget text;
 
       if (widget.group != null) {
-        widget.group._updateFontSize(this, fontSize);
-        text = _buildText(widget.group._fontSize, style, maxLines);
+        widget.group!._updateFontSize(this, fontSize);
+        text = _buildText(widget.group!._fontSize, style, maxLines);
       } else {
         text = _buildText(fontSize, style, maxLines);
       }
 
       if (widget.overflowReplacement != null && !textFits) {
-        return widget.overflowReplacement;
+        return widget.overflowReplacement!;
       } else {
         return text;
       }
     });
   }
 
-  void _validateProperties(TextStyle style, int maxLines) {
+  void _validateProperties(TextStyle style, int? maxLines) {
     assert(widget.overflow == null || widget.overflowReplacement == null,
         'Either overflow or overflowReplacement must be null.');
     assert(maxLines == null || maxLines > 0,
@@ -306,12 +300,13 @@ class _AutoSizeTextState extends State<AutoSizeText> {
             'MaxFontSize must be a multiple of stepGranularity.');
       }
     } else {
-      assert(widget.presetFontSizes.isNotEmpty,
+      assert(widget.presetFontSizes!.isNotEmpty,
           'PresetFontSizes must not be empty.');
     }
   }
 
-  List _calculateFontSize(BoxConstraints size, TextStyle style, int maxLines) {
+  List _calculateFontSize(
+      BoxConstraints size, TextStyle? style, int? maxLines) {
     final span = TextSpan(
       style: widget.textSpan?.style ?? style,
       text: widget.textSpan?.text ?? widget.data,
@@ -325,11 +320,11 @@ class _AutoSizeTextState extends State<AutoSizeText> {
     int left;
     int right;
 
-    final presetFontSizes = widget.presetFontSizes?.reversed?.toList();
+    final presetFontSizes = widget.presetFontSizes?.reversed.toList();
     if (presetFontSizes == null) {
-      final defaultFontSize =
-          style.fontSize.clamp(widget.minFontSize, widget.maxFontSize);
-      final defaultScale = defaultFontSize * userScale / style.fontSize;
+      final num defaultFontSize =
+          style!.fontSize!.clamp(widget.minFontSize, widget.maxFontSize);
+      final defaultScale = defaultFontSize * userScale / style.fontSize!;
       if (_checkTextFits(span, defaultScale, maxLines, size)) {
         return <Object>[defaultFontSize * userScale, true];
       }
@@ -346,9 +341,9 @@ class _AutoSizeTextState extends State<AutoSizeText> {
       final mid = (left + (right - left) / 2).floor();
       double scale;
       if (presetFontSizes == null) {
-        scale = mid * userScale * widget.stepGranularity / style.fontSize;
+        scale = mid * userScale * widget.stepGranularity / style!.fontSize!;
       } else {
-        scale = presetFontSizes[mid] * userScale / style.fontSize;
+        scale = presetFontSizes[mid] * userScale / style!.fontSize!;
       }
       if (_checkTextFits(span, scale, maxLines, size)) {
         left = mid + 1;
@@ -373,7 +368,7 @@ class _AutoSizeTextState extends State<AutoSizeText> {
   }
 
   bool _checkTextFits(
-      TextSpan text, double scale, int maxLines, BoxConstraints constraints) {
+      TextSpan text, double scale, int? maxLines, BoxConstraints constraints) {
     if (!widget.wrapWords) {
       final words = text.toPlainText().split(RegExp('\\s+'));
 
@@ -384,7 +379,7 @@ class _AutoSizeTextState extends State<AutoSizeText> {
         ),
         textAlign: widget.textAlign ?? TextAlign.left,
         textDirection: widget.textDirection ?? TextDirection.ltr,
-        textScaleFactor: scale ?? 1,
+        textScaleFactor: scale,
         maxLines: words.length,
         locale: widget.locale,
         strutStyle: widget.strutStyle,
@@ -402,7 +397,7 @@ class _AutoSizeTextState extends State<AutoSizeText> {
       text: text,
       textAlign: widget.textAlign ?? TextAlign.left,
       textDirection: widget.textDirection ?? TextDirection.ltr,
-      textScaleFactor: scale ?? 1,
+      textScaleFactor: scale,
       maxLines: maxLines,
       locale: widget.locale,
       strutStyle: widget.strutStyle,
@@ -415,10 +410,10 @@ class _AutoSizeTextState extends State<AutoSizeText> {
         textPainter.width > constraints.maxWidth);
   }
 
-  Widget _buildText(double fontSize, TextStyle style, int maxLines) {
+  Widget _buildText(double fontSize, TextStyle style, int? maxLines) {
     if (widget.data != null) {
       return Text(
-        widget.data,
+        widget.data!,
         key: widget.textKey,
         style: style.copyWith(fontSize: fontSize),
         strutStyle: widget.strutStyle,
@@ -433,7 +428,7 @@ class _AutoSizeTextState extends State<AutoSizeText> {
       );
     } else {
       return Text.rich(
-        widget.textSpan,
+        widget.textSpan!,
         key: widget.textKey,
         style: style,
         strutStyle: widget.strutStyle,
@@ -442,7 +437,7 @@ class _AutoSizeTextState extends State<AutoSizeText> {
         locale: widget.locale,
         softWrap: widget.softWrap,
         overflow: widget.overflow,
-        textScaleFactor: fontSize / style.fontSize,
+        textScaleFactor: fontSize / style.fontSize!,
         maxLines: maxLines,
         semanticsLabel: widget.semanticsLabel,
       );
@@ -456,7 +451,7 @@ class _AutoSizeTextState extends State<AutoSizeText> {
   @override
   void dispose() {
     if (widget.group != null) {
-      widget.group._remove(this);
+      widget.group!._remove(this);
     }
     super.dispose();
   }