Merge pull request #8 from kc3hack/generate_color_schema

Generate_color_schema

Author: Chika0221

lib/main.dart

@@ -29,4 +29,4 @@ class MitakaApp extends HookConsumerWidget {
       routerConfig: goRouter,
     );
   }
-}
+}

lib/theme/custom_color_schema.dart

@@ -0,0 +1,93 @@
+// Flutter imports:
+import 'package:flutter/material.dart';
+
+final class CustomColorSchema {
+  const CustomColorSchema(this.value);
+
+  final double value;
+
+  double get _v => value.clamp(-1.0, 1.0);
+
+  Color get seedColor {
+    final v = _v;
+
+    // v < 0: 寒色 -> ニュートラル
+    if (v < 0) {
+      final t = v + 1.0;
+      return _lerpStops(const [Colors.cyan, Colors.purple, Colors.grey], t);
+    }
+
+    // v >= 0: ニュートラル -> 暖色
+    final t = v;
+    return _lerpStops(const [
+      Colors.grey,
+      Colors.yellow,
+      Colors.deepOrange,
+      Colors.pink,
+    ], t);
+  }
+
+  ColorScheme toColorScheme({Brightness brightness = Brightness.light}) {
+    print("seedColor: ${seedColor.toARGB32().toRadixString(16)}");
+    if (seedColor == Color(0xFF9E9E9E)) {
+      return grayColorScheme(brightness: brightness);
+    }
+    return ColorScheme.fromSeed(seedColor: seedColor, brightness: brightness);
+  }
+
+  static Color _lerpStops(List<Color> colors, double t) {
+    assert(colors.length >= 2);
+    final clampedT = t.clamp(0.0, 1.0);
+    final scaled = clampedT * (colors.length - 1);
+    final index = scaled.floor();
+
+    if (index >= colors.length - 1) {
+      return colors.last;
+    }
+
+    final localT = scaled - index;
+    return Color.lerp(colors[index], colors[index + 1], localT)!;
+  }
+
+  static ColorScheme schemeFor(
+    double value, {
+    Brightness brightness = Brightness.light,
+  }) {
+    return CustomColorSchema(value).toColorScheme(brightness: brightness);
+  }
+
+  ColorScheme grayColorScheme({Brightness brightness = Brightness.light}) {
+    return grayLightColorScheme;
+  }
+}
+
+final ColorScheme grayLightColorScheme = ColorScheme(
+  brightness: Brightness.light,
+  primary: Colors.grey.shade900,
+  onPrimary: Colors.white,
+  primaryContainer: Colors.grey.shade200,
+  onPrimaryContainer: Colors.grey.shade900,
+  secondary: Colors.grey.shade800,
+  onSecondary: Colors.white,
+  secondaryContainer: Colors.grey.shade100,
+  onSecondaryContainer: Colors.grey.shade900,
+  tertiary: Colors.grey.shade700,
+  onTertiary: Colors.white,
+  tertiaryContainer: Colors.grey.shade100,
+  onTertiaryContainer: Colors.grey.shade900,
+  error: Colors.red.shade700,
+  onError: Colors.white,
+  errorContainer: Colors.red.shade100,
+  onErrorContainer: Colors.red.shade900,
+  surface: Colors.grey.shade50,
+  onSurface: Colors.grey.shade900,
+  surfaceContainerHighest: Colors.grey.shade100,
+  onSurfaceVariant: Colors.grey.shade700,
+  outline: Colors.grey.shade400,
+  outlineVariant: Colors.grey.shade200,
+  shadow: Colors.black,
+  scrim: Colors.black,
+  inverseSurface: Colors.grey.shade900,
+  onInverseSurface: Colors.grey.shade50,
+  inversePrimary: Colors.grey.shade200,
+);