Update underlying color with setting alpha and opacity, and re-structure as library.

lib/color_extension.dart → lib/src/color_extension.dart

@@ -1,13 +1,13 @@
 import 'package:flutter/painting.dart';
 import 'tinycolor.dart';
 
-/// Extends the Color class to allow direct TinyColor manipulation nativly
+/// Extends the Color class to allow direct TinyColor manipulation natively
 extension TinyColorExtension on Color {
   /// Converts standard Color to TinyColor object
   TinyColor toTinyColor() => TinyColor(this);
 
   HSVColor toHsv() => TinyColor(this).toHsv();
-  
+
   HslColor toHsl() => TinyColor(this).toHsl();
 
   /// Lighten the color a given amount, from 0 to 100. Providing 100 will always return white.
@@ -26,7 +26,8 @@ extension TinyColorExtension on Color {
   Color shade([int amount = 10]) => TinyColor(this).shade(amount).color;
 
   /// Desaturate the color a given amount, from 0 to 100. Providing 100 will is the same as calling greyscale.
-  Color desaturate([int amount = 10]) => TinyColor(this).desaturate(amount).color;
+  Color desaturate([int amount = 10]) =>
+      TinyColor(this).desaturate(amount).color;
 
   /// Saturate the color a given amount, from 0 to 100.
   Color saturate([int amount = 10]) => TinyColor(this).saturate(amount).color;
@@ -53,5 +54,6 @@ extension TinyColorExtension on Color {
   Color get compliment => TinyColor(this).complement().color;
 
   /// Blends the color with another color a given amount, from 0 - 100, default 50.
-  Color mix(Color toColor, [int amount = 50]) => TinyColor(this).mix(input: toColor, amount: amount).color;
+  Color mix(Color toColor, [int amount = 50]) =>
+      TinyColor(this).mix(input: toColor, amount: amount).color;
 }

lib/tinycolor.dart → lib/src/tinycolor.dart

@@ -57,12 +57,12 @@ class TinyColor {
   }
 
   TinyColor setAlpha(int alpha) {
-    _color.withAlpha(alpha);
+    _color = _color.withAlpha(alpha);
     return this;
   }
 
   TinyColor setOpacity(double opacity) {
-    _color.withOpacity(opacity);
+    _color = _color.withOpacity(opacity);
     return this;
   }
 

lib/tinycolor2.dart

@@ -0,0 +1,7 @@
+library tinycolor2;
+
+export 'src/color_extension.dart';
+export 'src/conversion.dart';
+export 'src/hsl_color.dart';
+export 'src/tinycolor.dart';
+export 'src/util.dart';

test/tinycolor_test.dart

@@ -0,0 +1,27 @@
+import 'dart:ui';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:tinycolor2/tinycolor2.dart';
+
+void main() {
+  test(
+    "setAlpha updates alpha value of color",
+    () {
+      TinyColor color = TinyColor(Color(0xFFFFFFFF));
+      color.setAlpha(0x00);
+      expect(color.color.alpha, 0x00);
+    },
+  );
+
+  test(
+    "setOpacity updates opacity value of color",
+    () {
+      TinyColor color = TinyColor(Color(0xFFFFFFFF).withOpacity(1.0));
+      color.setOpacity(0.5);
+
+      // underlying dart implementation converts the opacity value to an 
+      // int, then back into a double. Thus some precision is loss.
+      expect(color.color.opacity, moreOrLessEquals(0.5, epsilon: 1e-2));
+    },
+  );
+}

test/util_test.dart

@@ -1,6 +1,5 @@
 import 'package:flutter_test/flutter_test.dart';
-//import 'package:test/test.dart';
-import 'package:tinycolor/util.dart';
+import 'package:tinycolor2/tinycolor2.dart';
 
 void main() {
   test("bound01 values", () {