Null safety support

example/pubspec.lock

@@ -1,13 +1,20 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
+  characters:
+    dependency: transitive
+    description:
+      name: characters
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.0"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.14.11"
+    version: "1.15.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -26,7 +33,7 @@ packages:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.6"
+    version: "1.3.0"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -38,13 +45,13 @@ packages:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.6"
+    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.8"
+    version: "2.1.0"
 sdks:
-  dart: ">=2.2.2 <3.0.0"
+  dart: ">=2.12.0 <3.0.0"

example/pubspec.yaml

@@ -3,7 +3,7 @@ description: A new Flutter project.
 version: 1.0.0+1
 
 environment:
-  sdk: ">=2.1.0 <3.0.0"
+  sdk: ">=2.12.0 <3.0.0"
 
 dependencies:
   flutter:

lib/geopattern_flutter.dart

@@ -9,8 +9,7 @@ class FullPainter extends CustomPainter {
   Color background;
   Pattern pattern;
 
-  FullPainter({@required this.pattern, @required this.background})
-      : assert(pattern != null && background != null);
+  FullPainter({required this.pattern, required this.background});
 
   @override
   void paint(Canvas canvas, Size size) {

lib/patterns/chevrons.dart

@@ -13,11 +13,11 @@ class Chevrons extends Pattern {
   final Color strokeColor;
 
   Chevrons(
-      {@required this.side,
-      @required this.nx,
-      @required this.ny,
-      @required this.fillColors,
-      @required this.strokeColor})
+      {required this.side,
+      required this.nx,
+      required this.ny,
+      required this.fillColors,
+      required this.strokeColor})
       : assert(fillColors.length == nx * ny);
 
   Chevrons.fromHash(String hash)

lib/patterns/concentric_circles.dart

@@ -16,12 +16,12 @@ class ConcentricCircles extends Pattern {
   final List<Color> fillColors;
 
   ConcentricCircles(
-      {@required this.radius,
-      @required this.strokeWidth,
-      @required this.nx,
-      @required this.ny,
-      @required this.strokeColors,
-      @required this.fillColors})
+      {required this.radius,
+      required this.strokeWidth,
+      required this.nx,
+      required this.ny,
+      required this.strokeColors,
+      required this.fillColors})
       : assert(strokeColors.length == nx * ny),
         assert(fillColors.length == nx * ny);
 

lib/patterns/diamonds.dart

@@ -16,12 +16,12 @@ class Diamonds extends Pattern {
   final Color strokeColor;
 
   Diamonds(
-      {@required this.w,
-      @required this.h,
-      @required this.nx,
-      @required this.ny,
-      @required this.fillColors,
-      @required this.strokeColor})
+      {required this.w,
+      required this.h,
+      required this.nx,
+      required this.ny,
+      required this.fillColors,
+      required this.strokeColor})
       : assert(fillColors.length == nx * ny);
 
   Diamonds.fromHash(String hash)

lib/patterns/hexagons.dart

@@ -18,11 +18,11 @@ class Hexagons extends Pattern {
   final double _hexHeight;
 
   Hexagons(
-      {@required this.side,
-      @required this.nx,
-      @required this.ny,
-      @required this.fillColors,
-      @required this.strokeColor})
+      {required this.side,
+      required this.nx,
+      required this.ny,
+      required this.fillColors,
+      required this.strokeColor})
       : assert(fillColors.length == nx * ny),
         _hexWidth = side * 2,
         _hexHeight = side * sqrt(3);

lib/patterns/mosaic_squares.dart

@@ -13,11 +13,11 @@ class MosaicSquares extends Pattern {
   final Color strokeColor;
 
   MosaicSquares(
-      {@required this.side,
-      @required this.nx,
-      @required this.ny,
-      @required this.fillColors,
-      @required this.strokeColor})
+      {required this.side,
+      required this.nx,
+      required this.ny,
+      required this.fillColors,
+      required this.strokeColor})
       : assert(fillColors.length == 2 * nx * ny);
 
   MosaicSquares.fromHash(String hash)

lib/patterns/nested_squares.dart

@@ -15,11 +15,11 @@ class NestedSquares extends Pattern {
   final List<Color> strokeColors;
 
   NestedSquares(
-      {@required this.side,
-      @required this.outerside,
-      @required this.nx,
-      @required this.ny,
-      @required this.strokeColors})
+      {required this.side,
+      required this.outerside,
+      required this.nx,
+      required this.ny,
+      required this.strokeColors})
       : assert(strokeColors.length == nx * ny),
         assert(outerside > side);
 

lib/patterns/octagons.dart

@@ -15,11 +15,11 @@ class Octagons extends Pattern {
   final Color strokeColor;
 
   Octagons(
-      {@required this.side,
-      @required this.nx,
-      @required this.ny,
-      @required this.fillColors,
-      @required this.strokeColor})
+      {required this.side,
+      required this.nx,
+      required this.ny,
+      required this.fillColors,
+      required this.strokeColor})
       : assert(fillColors.length == nx * ny);
 
   Octagons.fromHash(String hash)

lib/patterns/overlapping_circles.dart

@@ -11,12 +11,12 @@ class OverlappingCircles extends Pattern {
   final int ny;
   final List<Color> fillColors;
 
-  OverlappingCircles(
-      {@required this.radius,
-      @required this.nx,
-      @required this.ny,
-      @required this.fillColors})
-      : assert(fillColors.length == nx * ny);
+  OverlappingCircles({
+    required this.radius,
+    required this.nx,
+    required this.ny,
+    required this.fillColors,
+  }) : assert(fillColors.length == nx * ny);
 
   OverlappingCircles.fromHash(String hash)
       : assert(hash.length == 40),

lib/patterns/overlapping_rings.dart

@@ -13,11 +13,11 @@ class OverlappingRings extends Pattern {
   final List<Color> strokeColors;
 
   OverlappingRings(
-      {@required this.radius,
-      @required this.strokeWidth,
-      @required this.nx,
-      @required this.ny,
-      @required this.strokeColors})
+      {required this.radius,
+      required this.strokeWidth,
+      required this.nx,
+      required this.ny,
+      required this.strokeColors})
       : assert(strokeColors.length == nx * ny);
 
   OverlappingRings.fromHash(String hash)

lib/patterns/plaid.dart

@@ -16,12 +16,12 @@ class Plaid extends Pattern {
   final int _ny;
 
   Plaid(
-      {@required this.horizontalOffsets,
-      @required this.verticalOffsets,
-      @required this.horizontalSizes,
-      @required this.verticalSizes,
-      @required this.horizontalFillColors,
-      @required this.verticalFillColors})
+      {required this.horizontalOffsets,
+      required this.verticalOffsets,
+      required this.horizontalSizes,
+      required this.verticalSizes,
+      required this.horizontalFillColors,
+      required this.verticalFillColors})
       : _nx = horizontalSizes.length,
         _ny = verticalSizes.length,
         assert(horizontalFillColors.length == horizontalSizes.length),

lib/patterns/plus_signs.dart

@@ -15,11 +15,11 @@ class PlusSigns extends Pattern {
   final double _midh;
 
   PlusSigns(
-      {@required this.side,
-      @required this.nx,
-      @required this.ny,
-      @required this.fillColors,
-      @required this.strokeColor})
+      {required this.side,
+      required this.nx,
+      required this.ny,
+      required this.fillColors,
+      required this.strokeColor})
       : assert(fillColors.length == nx * ny),
         _midl = side / 3,
         _midh = 2 * side / 3;

lib/patterns/sine_waves.dart

@@ -18,11 +18,11 @@ class SineWaves extends Pattern {
   final double _xoff;
 
   SineWaves(
-      {@required this.period,
-      @required this.amplitude,
-      @required this.strokeOffsets,
-      @required this.strokeWidth,
-      @required this.strokeColors})
+      {required this.period,
+      required this.amplitude,
+      required this.strokeOffsets,
+      required this.strokeWidth,
+      required this.strokeColors})
       : _xoff = (period / 4) * .7,
         assert(strokeOffsets.length == strokeColors.length);
 

lib/patterns/squares.dart

@@ -15,11 +15,11 @@ class Squares extends Pattern {
   final Color strokeColor;
 
   Squares(
-      {@required this.side,
-      @required this.nx,
-      @required this.ny,
-      @required this.fillColors,
-      @required this.strokeColor})
+      {required this.side,
+      required this.nx,
+      required this.ny,
+      required this.fillColors,
+      required this.strokeColor})
       : assert(fillColors.length == nx * ny);
 
   Squares.fromHash(String hash)

lib/patterns/triangles.dart

@@ -16,11 +16,11 @@ class Triangles extends Pattern {
   final double _trih;
 
   Triangles(
-      {@required this.side,
-      @required this.nx,
-      @required this.ny,
-      @required this.fillColors,
-      @required this.strokeColor})
+      {required this.side,
+      required this.nx,
+      required this.ny,
+      required this.fillColors,
+      required this.strokeColor})
       : assert(fillColors.length == nx * ny),
         _trih = sqrt(3) * side / 2;