feat(editor): improve html content color mapping (#15516)

fix #15514

#### PR Dependency Tree


* **PR #15516** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Bug Fixes**
  * Improved color handling when importing HTML content.
* Added support for hex, RGB/RGBA, percentage, alpha, transparent,
named, and HSL color values.
  * Correctly maps supported colors to the app’s color themes.
* Prevents invalid, translucent, or unsuitable colors from being
applied.
  * Preserves style values containing additional colons during import.
* Improved imported text formatting for supported and unsupported
colors.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

blocksuite/affine/all/src/__tests__/adapters/markdown.unit.spec.ts

@@ -3929,48 +3929,40 @@ describe('markdown to snapshot', () => {
     });
   });
 
-  test('html inline color span imports to nearest supported text color', async () => {
-    const markdown = `<span style="color: #00afde;">Hello</span>`;
-    const blockSnapshot: BlockSnapshot = {
-      type: 'block',
-      id: 'matchesReplaceMap[0]',
-      flavour: 'affine:note',
-      props: {
-        xywh: '[0,0,800,95]',
-        background: DefaultTheme.noteBackgrounColor,
-        index: 'a0',
-        hidden: false,
-        displayMode: NoteDisplayMode.DocAndEdgeless,
-      },
-      children: [
-        {
-          type: 'block',
-          id: 'matchesReplaceMap[1]',
-          flavour: 'affine:paragraph',
-          props: {
-            type: 'text',
-            text: {
-              '$blocksuite:internal:text$': true,
-              delta: [
-                {
-                  insert: 'Hello',
-                  attributes: {
-                    color: 'var(--affine-v2-text-highlight-fg-blue)',
-                  },
-                },
-              ],
-            },
-          },
-          children: [],
-        },
-      ],
-    };
-
+  test.each([
+    ['#00afde', 'blue'],
+    ['rgb(0 175 222 / 100%)', 'blue'],
+    ['#c83030', 'red'],
+    ['red', 'red'],
+    ['hsl(0, 100%, 50%)', 'red'],
+    ['#db7123', 'orange'],
+    ['#ac7400', 'yellow'],
+    ['#04b745', 'green'],
+    ['#0e4841', 'teal'],
+    ['#7c3aed', 'purple'],
+    ['#7a7a7a', 'grey'],
+    ['rgb(26, 26, 26)', null],
+    ['#333', null],
+    ['#fff', null],
+    ['rgba(0, 175, 222, 0.5)', null],
+  ])('maps supported HTML color %s conservatively', async (color, mapped) => {
     const mdAdapter = new MarkdownAdapter(createJob(), provider);
     const rawBlockSnapshot = await mdAdapter.toBlockSnapshot({
-      file: markdown,
+      file: `<span style="color: ${color};">Hello</span>`,
+    });
+    expect(rawBlockSnapshot.children[0]?.props.text).toEqual({
+      '$blocksuite:internal:text$': true,
+      delta: [
+        mapped
+          ? {
+              insert: 'Hello',
+              attributes: {
+                color: `var(--affine-v2-text-highlight-fg-${mapped})`,
+              },
+            }
+          : { insert: 'Hello' },
+      ],
     });
-    expect(nanoidReplacement(rawBlockSnapshot)).toEqual(blockSnapshot);
   });
 
   test('paragraph', async () => {

blocksuite/affine/inlines/preset/package.json

@@ -23,6 +23,7 @@
     "@blocksuite/affine-shared": "workspace:*",
     "@blocksuite/std": "workspace:*",
     "@blocksuite/store": "workspace:*",
+    "@ctrl/tinycolor": "^4.1.0",
     "@toeverything/theme": "^1.1.23",
     "@types/hast": "^3.0.4",
     "collapse-white-space": "^2.1.0",

blocksuite/affine/inlines/preset/src/adapters/html/color-utils.ts

@@ -1,9 +1,16 @@
-import { parseStringToRgba } from '@blocksuite/affine-components/color-picker';
+import { TinyColor } from '@ctrl/tinycolor';
 import { cssVarV2, darkThemeV2, lightThemeV2 } from '@toeverything/theme/v2';
 
 type Rgb = { r: number; g: number; b: number };
+type Oklab = { l: number; a: number; b: number; chroma: number; hue: number };
+
+const ACHROMATIC_CHROMA_THRESHOLD = 0.02;
+const DEFAULT_TEXT_LIGHTNESS_MIN = 0.4;
+const DEFAULT_TEXT_LIGHTNESS_MAX = 0.9;
+const MAX_COLOR_DISTANCE = 0.18;
+const MAX_CHROMA_DISTANCE = 0.12;
+const MAX_HUE_DISTANCE = 45;
 
-const COLOR_DISTANCE_THRESHOLD = 90;
 const supportedTextColorNames = [
   'red',
   'orange',
@@ -15,68 +22,81 @@ const supportedTextColorNames = [
   'grey',
 ] as const;
 
-const supportedTextColors = supportedTextColorNames.map(name => ({
-  name,
-  cssVar: cssVarV2(`text/highlight/fg/${name}`),
-  light: lightThemeV2[`text/highlight/fg/${name}`],
-  dark: darkThemeV2[`text/highlight/fg/${name}`],
-}));
+export const parseCssColor = (value: string) => {
+  const parsed = new TinyColor(value);
+  if (!parsed.isValid) return null;
+  const { r, g, b, a } = parsed.toRgb();
+  return { r, g, b, alpha: a };
+};
 
-const hexToRgb = (value: string): Rgb | null => {
-  const hex = value.replace('#', '');
-  if (![3, 4, 6, 8].includes(hex.length)) {
-    return null;
-  }
-  const normalized =
-    hex.length === 3 || hex.length === 4
-      ? hex
-          .slice(0, 3)
-          .split('')
-          .map(c => c + c)
-          .join('')
-      : hex.slice(0, 6);
-  const intVal = Number.parseInt(normalized, 16);
-  if (Number.isNaN(intVal)) {
-    return null;
-  }
+const srgbToLinear = (channel: number) => {
+  const value = channel / 255;
+  return value <= 0.04045
+    ? value / 12.92
+    : Math.pow((value + 0.055) / 1.055, 2.4);
+};
+
+const rgbToOklab = ({ r, g, b }: Rgb): Oklab => {
+  const red = srgbToLinear(r);
+  const green = srgbToLinear(g);
+  const blue = srgbToLinear(b);
+  const l = Math.cbrt(
+    0.4122214708 * red + 0.5363325363 * green + 0.0514459929 * blue
+  );
+  const m = Math.cbrt(
+    0.2119034982 * red + 0.6806995451 * green + 0.1073969566 * blue
+  );
+  const s = Math.cbrt(
+    0.0883024619 * red + 0.2817188376 * green + 0.6299787005 * blue
+  );
+  const result = {
+    l: 0.2104542553 * l + 0.793617785 * m - 0.0040720468 * s,
+    a: 1.9779984951 * l - 2.428592205 * m + 0.4505937099 * s,
+    b: 0.0259040371 * l + 0.7827717662 * m - 0.808675766 * s,
+  };
   return {
-    r: (intVal >> 16) & 255,
-    g: (intVal >> 8) & 255,
-    b: intVal & 255,
+    ...result,
+    chroma: Math.hypot(result.a, result.b),
+    hue: (Math.atan2(result.b, result.a) * 180) / Math.PI,
   };
 };
 
-export const parseCssColor = (value: string): Rgb | null => {
-  const trimmed = value.trim();
-  if (!trimmed) {
-    return null;
-  }
-  if (trimmed.startsWith('#')) {
-    return hexToRgb(trimmed);
-  }
-  if (/^rgba?\(/i.test(trimmed)) {
-    const rgba = parseStringToRgba(trimmed);
-    return {
-      r: Math.round(rgba.r * 255),
-      g: Math.round(rgba.g * 255),
-      b: Math.round(rgba.b * 255),
-    };
-  }
-  return null;
-};
+const supportedTextColors = supportedTextColorNames.map(name => ({
+  name,
+  cssVar: cssVarV2(`text/highlight/fg/${name}`),
+  references: [
+    lightThemeV2[`text/highlight/fg/${name}`],
+    darkThemeV2[`text/highlight/fg/${name}`],
+  ].flatMap(color => {
+    const parsed = parseCssColor(color);
+    return parsed ? [rgbToOklab(parsed)] : [];
+  }),
+}));
 
-const colorDistance = (a: Rgb, b: Rgb) => {
-  const dr = a.r - b.r;
-  const dg = a.g - b.g;
-  const db = a.b - b.b;
-  return Math.sqrt(dr * dr + dg * dg + db * db);
+const colorDistance = (a: Oklab, b: Oklab) =>
+  Math.hypot(a.l - b.l, a.a - b.a, a.b - b.b);
+
+const hueDistance = (a: number, b: number) => {
+  const distance = Math.abs(a - b) % 360;
+  return Math.min(distance, 360 - distance);
 };
 
 export const resolveNearestSupportedColor = (color: string): string | null => {
-  const target = parseCssColor(color);
-  if (!target) {
+  const parsed = parseCssColor(color);
+  if (!parsed || parsed.alpha < 1) {
     return null;
   }
+
+  const target = rgbToOklab(parsed);
+  const achromatic = target.chroma < ACHROMATIC_CHROMA_THRESHOLD;
+  if (
+    achromatic &&
+    (target.l < DEFAULT_TEXT_LIGHTNESS_MIN ||
+      target.l > DEFAULT_TEXT_LIGHTNESS_MAX)
+  ) {
+    return null;
+  }
+
   let nearest:
     | {
         cssVar: string;
@@ -85,21 +105,26 @@ export const resolveNearestSupportedColor = (color: string): string | null => {
     | undefined;
 
   for (const supported of supportedTextColors) {
-    const light = parseCssColor(supported.light);
-    const dark = parseCssColor(supported.dark);
-    for (const ref of [light, dark]) {
-      if (!ref) continue;
-      const distance = colorDistance(target, ref);
+    if (achromatic !== (supported.name === 'grey')) {
+      continue;
+    }
+    for (const reference of supported.references) {
+      const distance = colorDistance(target, reference);
+      if (
+        distance > MAX_COLOR_DISTANCE ||
+        (!achromatic &&
+          (Math.abs(target.chroma - reference.chroma) > MAX_CHROMA_DISTANCE ||
+            hueDistance(target.hue, reference.hue) > MAX_HUE_DISTANCE))
+      ) {
+        continue;
+      }
       if (!nearest || distance < nearest.distance) {
         nearest = { cssVar: supported.cssVar, distance };
       }
     }
   }
 
-  if (nearest && nearest.distance <= COLOR_DISTANCE_THRESHOLD) {
-    return nearest.cssVar;
-  }
-  return null;
+  return nearest?.cssVar ?? null;
 };
 
 export const extractColorFromStyle = (
@@ -110,10 +135,11 @@ export const extractColorFromStyle = (
   }
   const declarations = style.split(';');
   for (const declaration of declarations) {
-    const [rawKey, rawValue] = declaration.split(':');
-    if (!rawKey || !rawValue) continue;
-    if (rawKey.trim().toLowerCase() === 'color') {
-      return rawValue.trim();
+    const colon = declaration.indexOf(':');
+    if (colon === -1) continue;
+    const key = declaration.slice(0, colon).trim().toLowerCase();
+    if (key === 'color') {
+      return declaration.slice(colon + 1).trim();
     }
   }
   return null;

yarn.lock

@@ -2795,6 +2795,7 @@ __metadata:
     "@blocksuite/affine-shared": "workspace:*"
     "@blocksuite/std": "workspace:*"
     "@blocksuite/store": "workspace:*"
+    "@ctrl/tinycolor": "npm:^4.1.0"
     "@toeverything/theme": "npm:^1.1.23"
     "@types/hast": "npm:^3.0.4"
     collapse-white-space: "npm:^2.1.0"