feat(theme): add Material You tonal palette

src/features/theme/services/MaterialYouPalette.test.ts

@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) Contributors to the Suwayomi project
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+import assert from 'node:assert/strict';
+import { describe, it } from 'node:test';
+import { createMaterialYouScheme, MATERIAL_YOU_STABLE_SEED } from './MaterialYouPalette.ts';
+
+describe('createMaterialYouScheme', () => {
+    it('creates a deterministic stable blue light scheme', () => {
+        const first = createMaterialYouScheme(MATERIAL_YOU_STABLE_SEED, 'light');
+        const second = createMaterialYouScheme(MATERIAL_YOU_STABLE_SEED, 'light');
+
+        assert.deepEqual(first, second);
+        assert.equal(first.seed, '#5B74EF');
+        assert.equal(first.onSurface, '#171B2C');
+        assert.notEqual(first.surface, first.surfaceContainer);
+    });
+
+    it('orders dark tonal surfaces from darkest to lightest', () => {
+        const scheme = createMaterialYouScheme('#8F7CF7', 'dark');
+
+        assert.deepEqual(
+            [scheme.surface, scheme.surfaceContainer, scheme.surfaceContainerHigh],
+            ['#11131A', '#191B23', '#24262F'],
+        );
+        assert.equal(scheme.onSurface, '#E4E6F0');
+    });
+
+    it('uses true black only for the base pure-black surface', () => {
+        const scheme = createMaterialYouScheme('#5B74EF', 'dark', true);
+
+        assert.equal(scheme.surface, '#000000');
+        assert.notEqual(scheme.surfaceContainer, '#000000');
+        assert.notEqual(scheme.primary, scheme.onPrimary);
+    });
+
+    it('normalizes invalid seeds to the stable seed', () => {
+        assert.deepEqual(createMaterialYouScheme('not-a-color', 'dark'), createMaterialYouScheme('#5B74EF', 'dark'));
+    });
+});

src/features/theme/services/MaterialYouPalette.ts

@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) Contributors to the Suwayomi project
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+import { hsl, parseToHsl } from 'polished';
+import { coerceIn } from '@/lib/HelperFunctions.ts';
+
+export const MATERIAL_YOU_STABLE_SEED = '#5B74EF';
+
+export type MaterialYouScheme = {
+    seed: string;
+    primary: string;
+    onPrimary: string;
+    primaryContainer: string;
+    onPrimaryContainer: string;
+    secondary: string;
+    onSecondary: string;
+    tertiary: string;
+    surface: string;
+    surfaceContainer: string;
+    surfaceContainerHigh: string;
+    surfaceVariant: string;
+    onSurface: string;
+    onSurfaceVariant: string;
+    outline: string;
+    outlineVariant: string;
+};
+
+const toUpperHex = (color: string): string => color.toUpperCase();
+
+const normalizeSeed = (seed: string): string => {
+    try {
+        const parsed = parseToHsl(seed);
+        return toUpperHex(hsl(parsed.hue, parsed.saturation, parsed.lightness));
+    } catch {
+        return MATERIAL_YOU_STABLE_SEED;
+    }
+};
+
+const tone = (seed: string, lightness: number, saturationDelta: number = 0): string => {
+    const parsed = parseToHsl(seed);
+
+    return toUpperHex(hsl(parsed.hue, coerceIn(parsed.saturation + saturationDelta, 0.25, 0.92), lightness));
+};
+
+const shiftedTone = (seed: string, hueDelta: number, lightness: number): string => {
+    const parsed = parseToHsl(seed);
+
+    return toUpperHex(hsl((parsed.hue + hueDelta + 360) % 360, coerceIn(parsed.saturation * 0.58, 0.28, 0.62), lightness));
+};
+
+export const createMaterialYouScheme = (
+    requestedSeed: string,
+    mode: 'light' | 'dark',
+    pureBlack: boolean = false,
+): MaterialYouScheme => {
+    const seed = normalizeSeed(requestedSeed);
+
+    if (mode === 'dark') {
+        return {
+            seed,
+            primary: tone(seed, 0.78, -0.08),
+            onPrimary: tone(seed, 0.2, -0.12),
+            primaryContainer: tone(seed, 0.3, -0.1),
+            onPrimaryContainer: tone(seed, 0.9, -0.14),
+            secondary: shiftedTone(seed, 24, 0.76),
+            onSecondary: shiftedTone(seed, 24, 0.2),
+            tertiary: shiftedTone(seed, 62, 0.78),
+            surface: pureBlack ? '#000000' : '#11131A',
+            surfaceContainer: '#191B23',
+            surfaceContainerHigh: '#24262F',
+            surfaceVariant: '#2D303A',
+            onSurface: '#E4E6F0',
+            onSurfaceVariant: '#C4C6D0',
+            outline: '#8E909A',
+            outlineVariant: '#454751',
+        };
+    }
+
+    return {
+        seed,
+        primary: tone(seed, 0.43, -0.03),
+        onPrimary: '#FFFFFF',
+        primaryContainer: tone(seed, 0.9, -0.13),
+        onPrimaryContainer: tone(seed, 0.2, -0.1),
+        secondary: shiftedTone(seed, 24, 0.42),
+        onSecondary: '#FFFFFF',
+        tertiary: shiftedTone(seed, 62, 0.43),
+        surface: '#F9F9FF',
+        surfaceContainer: '#F0F1FA',
+        surfaceContainerHigh: '#E8E9F2',
+        surfaceVariant: '#E1E2EC',
+        onSurface: '#171B2C',
+        onSurfaceVariant: '#444752',
+        outline: '#757781',
+        outlineVariant: '#C5C6D0',
+    };
+};