refactor(theme-{classic,common}): refactor ColorModeToggle + useColorMode() hook (#6930)

Co-authored-by: Joshua Chen <sidachen2003@gmail.com>
Co-authored-by: sebastienlorber <lorber.sebastien@gmail.com>
Co-authored-by: Sébastien Lorber <slorber@users.noreply.github.com>

packages/docusaurus-theme-classic/src/theme-classic.d.ts

@@ -746,12 +746,16 @@ declare module '@theme/TOCCollapsible' {
 }
 
 declare module '@theme/ColorModeToggle' {
-  import type {SyntheticEvent} from 'react';
+  import type {ColorMode} from '@docusaurus/theme-common';
 
   export interface Props {
     readonly className?: string;
-    readonly checked: boolean;
-    readonly onChange: (e: SyntheticEvent) => void;
+    readonly value: ColorMode;
+    /**
+     * The parameter represents the "to-be" value. For example, if currently in
+     * dark mode, clicking the button should call `onChange("light")`
+     */
+    readonly onChange: (colorMode: ColorMode) => void;
   }
 
   export default function Toggle(props: Props): JSX.Element;

packages/docusaurus-theme-classic/src/theme/ColorModeToggle/index.tsx

@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import React, {useState, useRef, useEffect} from 'react';
+import React from 'react';
 import type {Props} from '@theme/ColorModeToggle';
 import useIsBrowser from '@docusaurus/useIsBrowser';
 import {translate} from '@docusaurus/Translate';
@@ -15,56 +15,18 @@ import IconDarkMode from '@theme/IconDarkMode';
 import clsx from 'clsx';
 import styles from './styles.module.css';
 
-function ColorModeToggle({
-  className,
-  checked: defaultChecked,
-  onChange,
-}: Props): JSX.Element {
+function ColorModeToggle({className, value, onChange}: Props): JSX.Element {
   const isBrowser = useIsBrowser();
-  const [checked, setChecked] = useState(defaultChecked);
-  const [focused, setFocused] = useState(false);
-  const inputRef = useRef<HTMLInputElement>(null);
 
-  useEffect(() => {
-    setChecked(defaultChecked);
-  }, [defaultChecked]);
-
-  return (
-    <div
-      className={clsx(
-        styles.toggle,
-        className,
-        checked && styles.toggleChecked,
-        focused && styles.toggleFocused,
-        !isBrowser && styles.toggleDisabled,
-      )}>
-      {/* eslint-disable-next-line jsx-a11y/click-events-have-key-events */}
-      <div
-        className={styles.toggleButton}
-        role="button"
-        tabIndex={-1}
-        onClick={() => inputRef.current?.click()}>
-        <IconLightMode
-          className={clsx(styles.toggleIcon, styles.lightToggleIcon)}
-        />
-        <IconDarkMode
-          className={clsx(styles.toggleIcon, styles.darkToggleIcon)}
-        />
-      </div>
-
-      <input
-        ref={inputRef}
-        checked={checked}
-        type="checkbox"
-        className={styles.toggleScreenReader}
-        aria-label={translate(
+  const title = translate(
     {
       message: 'Switch between dark and light mode (currently {mode})',
       id: 'theme.colorToggle.ariaLabel',
       description: 'The ARIA label for the navbar color mode toggle',
     },
     {
-            mode: checked
+      mode:
+        value === 'dark'
           ? translate({
               message: 'dark mode',
               id: 'theme.colorToggle.ariaLabel.mode.dark',
@@ -76,17 +38,28 @@ function ColorModeToggle({
               description: 'The name for the light color mode',
             }),
     },
+  );
+
+  return (
+    <div className={clsx(styles.toggle, className)}>
+      <button
+        className={clsx(
+          'clean-btn',
+          styles.toggleButton,
+          !isBrowser && styles.toggleButtonDisabled,
         )}
-        onChange={onChange}
-        onClick={() => setChecked(!checked)}
-        onFocus={() => setFocused(true)}
-        onBlur={() => setFocused(false)}
-        onKeyDown={(e) => {
-          if (e.key === 'Enter') {
-            inputRef.current?.click();
-          }
-        }}
+        type="button"
+        onClick={() => onChange(value === 'dark' ? 'light' : 'dark')}
+        disabled={!isBrowser}
+        title={title}
+        aria-label={title}>
+        <IconLightMode
+          className={clsx(styles.toggleIcon, styles.lightToggleIcon)}
         />
+        <IconDarkMode
+          className={clsx(styles.toggleIcon, styles.darkToggleIcon)}
+        />
+      </button>
     </div>
   );
 }

packages/docusaurus-theme-classic/src/theme/ColorModeToggle/styles.module.css

@@ -6,28 +6,11 @@
  */
 
 .toggle {
-  position: relative;
-  width: 32px;
-  height: 32px;
-}
-
-.toggleScreenReader {
-  border: 0;
-  clip: rect(0 0 0 0);
-  height: 1px;
-  margin: -1px;
-  overflow: hidden;
-  position: absolute;
-  width: 1px;
-}
-
-.toggleDisabled {
-  cursor: not-allowed;
+  width: 2rem;
+  height: 2rem;
 }
 
 .toggleButton {
-  cursor: pointer;
-  user-select: none;
   -webkit-tap-highlight-color: transparent;
   align-items: center;
   display: flex;
@@ -35,17 +18,18 @@
   width: 100%;
   height: 100%;
   border-radius: 50%;
+  transition: background var(--ifm-transition-fast);
 }
 
 .toggleButton:hover {
-  background-color: #00000010;
-}
-
-[data-theme='dark'] .toggleButton:hover {
-  background-color: #ffffff20;
+  background: var(--ifm-color-emphasis-200);
 }
 
 [data-theme='light'] .darkToggleIcon,
 [data-theme='dark'] .lightToggleIcon {
   display: none;
 }
+
+.toggleButtonDisabled {
+  cursor: not-allowed;
+}

packages/docusaurus-theme-classic/src/theme/Navbar/index.tsx

@@ -88,12 +88,12 @@ function useColorModeToggle() {
   const {
     colorMode: {disableSwitch},
   } = useThemeConfig();
-  const {isDarkTheme, setLightTheme, setDarkTheme} = useColorMode();
-  const toggle = useCallback(
-    (e) => (e.target.checked ? setDarkTheme() : setLightTheme()),
-    [setLightTheme, setDarkTheme],
-  );
-  return {isDarkTheme, toggle, disabled: disableSwitch};
+  const {colorMode, setColorMode} = useColorMode();
+  return {
+    value: colorMode,
+    onChange: setColorMode,
+    disabled: disableSwitch,
+  };
 }
 
 function useSecondaryMenu({
@@ -173,8 +173,8 @@ function NavbarMobileSidebar({
         {!colorModeToggle.disabled && (
           <ColorModeToggle
             className={styles.navbarSidebarToggle}
-            checked={colorModeToggle.isDarkTheme}
-            onChange={colorModeToggle.toggle}
+            value={colorModeToggle.value}
+            onChange={colorModeToggle.onChange}
           />
         )}
         <button
@@ -279,8 +279,8 @@ export default function Navbar(): JSX.Element {
           {!colorModeToggle.disabled && (
             <ColorModeToggle
               className={styles.toggle}
-              checked={colorModeToggle.isDarkTheme}
-              onChange={colorModeToggle.toggle}
+              value={colorModeToggle.value}
+              onChange={colorModeToggle.onChange}
             />
           )}
           {!hasSearchNavbarItem && <SearchBar />}

packages/docusaurus-theme-classic/src/theme/ThemedImage/index.tsx

@@ -16,12 +16,13 @@ import styles from './styles.module.css';
 
 export default function ThemedImage(props: Props): JSX.Element {
   const isBrowser = useIsBrowser();
-  const {isDarkTheme} = useColorMode();
+  const {colorMode} = useColorMode();
   const {sources, className, alt, ...propsRest} = props;
 
   type SourceName = keyof Props['sources'];
 
-  const clientThemes: SourceName[] = isDarkTheme ? ['dark'] : ['light'];
+  const clientThemes: SourceName[] =
+    colorMode === 'dark' ? ['dark'] : ['light'];
 
   const renderedSourceNames: SourceName[] = isBrowser
     ? clientThemes

packages/docusaurus-theme-common/src/hooks/usePrismTheme.ts

@@ -11,10 +11,10 @@ import {useThemeConfig} from '../utils/useThemeConfig';
 
 export default function usePrismTheme(): typeof defaultTheme {
   const {prism} = useThemeConfig();
-  const {isDarkTheme} = useColorMode();
+  const {colorMode} = useColorMode();
   const lightModeTheme = prism.theme || defaultTheme;
   const darkModeTheme = prism.darkTheme || lightModeTheme;
-  const prismTheme = isDarkTheme ? darkModeTheme : lightModeTheme;
+  const prismTheme = colorMode === 'dark' ? darkModeTheme : lightModeTheme;
 
   return prismTheme;
 }

packages/docusaurus-theme-common/src/index.ts

@@ -140,7 +140,12 @@ export {
   PluginHtmlClassNameProvider,
 } from './utils/metadataUtilsTemp';
 
-export {useColorMode, ColorModeProvider} from './utils/colorModeUtils';
+export {
+  useColorMode,
+  ColorModeProvider,
+  type ColorMode,
+} from './utils/colorModeUtils';
+
 export {
   useTabGroupChoice,
   TabGroupChoiceProvider,

packages/docusaurus-theme-common/src/utils/colorModeUtils.tsx

@@ -21,77 +21,80 @@ import {createStorageSlot} from './storageUtils';
 import {useThemeConfig} from './useThemeConfig';
 
 type ColorModeContextValue = {
+  readonly colorMode: ColorMode;
+  readonly setColorMode: (colorMode: ColorMode) => void;
+
+  // TODO legacy APIs kept for retro-compatibility: deprecate them
   readonly isDarkTheme: boolean;
   readonly setLightTheme: () => void;
   readonly setDarkTheme: () => void;
 };
 
-const ThemeStorageKey = 'theme';
-const ThemeStorage = createStorageSlot(ThemeStorageKey);
+const ColorModeStorageKey = 'theme';
+const ColorModeStorage = createStorageSlot(ColorModeStorageKey);
 
-const themes = {
+const ColorModes = {
   light: 'light',
   dark: 'dark',
 } as const;
 
-type Themes = typeof themes[keyof typeof themes];
+export type ColorMode = typeof ColorModes[keyof typeof ColorModes];
 
-// Ensure to always return a valid theme even if input is invalid
-const coerceToTheme = (theme?: string | null): Themes =>
-  theme === themes.dark ? themes.dark : themes.light;
+// Ensure to always return a valid colorMode even if input is invalid
+const coerceToColorMode = (colorMode?: string | null): ColorMode =>
+  colorMode === ColorModes.dark ? ColorModes.dark : ColorModes.light;
 
-const getInitialTheme = (defaultMode: Themes | undefined): Themes => {
+const getInitialColorMode = (defaultMode: ColorMode | undefined): ColorMode => {
   if (!ExecutionEnvironment.canUseDOM) {
-    return coerceToTheme(defaultMode);
+    return coerceToColorMode(defaultMode);
   }
-  return coerceToTheme(document.documentElement.getAttribute('data-theme'));
+  return coerceToColorMode(document.documentElement.getAttribute('data-theme'));
 };
 
-const storeTheme = (newTheme: Themes) => {
-  ThemeStorage.set(coerceToTheme(newTheme));
+const storeColorMode = (newColorMode: ColorMode) => {
+  ColorModeStorage.set(coerceToColorMode(newColorMode));
 };
 
 function useColorModeContextValue(): ColorModeContextValue {
   const {
     colorMode: {defaultMode, disableSwitch, respectPrefersColorScheme},
   } = useThemeConfig();
-  const [theme, setTheme] = useState(getInitialTheme(defaultMode));
+  const [colorMode, setColorModeState] = useState(
+    getInitialColorMode(defaultMode),
+  );
 
-  const setLightTheme = useCallback(() => {
-    setTheme(themes.light);
-    storeTheme(themes.light);
-  }, []);
-  const setDarkTheme = useCallback(() => {
-    setTheme(themes.dark);
-    storeTheme(themes.dark);
+  const setColorMode = useCallback((newColorMode: ColorMode) => {
+    setColorModeState(newColorMode);
+    storeColorMode(newColorMode);
   }, []);
 
   useEffect(() => {
-    document.documentElement.setAttribute('data-theme', coerceToTheme(theme));
-  }, [theme]);
+    document.documentElement.setAttribute(
+      'data-theme',
+      coerceToColorMode(colorMode),
+    );
+  }, [colorMode]);
 
   useEffect(() => {
     if (disableSwitch) {
       return undefined;
     }
     const onChange = (e: StorageEvent) => {
-      if (e.key !== ThemeStorageKey) {
+      if (e.key !== ColorModeStorageKey) {
         return;
       }
       try {
-        const storedTheme = ThemeStorage.get();
-        if (storedTheme !== null) {
-          setTheme(coerceToTheme(storedTheme));
+        const storedColorMode = ColorModeStorage.get();
+        if (storedColorMode !== null) {
+          setColorMode(coerceToColorMode(storedColorMode));
         }
       } catch (err) {
         console.error(err);
       }
     };
     window.addEventListener('storage', onChange);
-    return () => {
-      window.removeEventListener('storage', onChange);
-    };
-  }, [disableSwitch, setTheme]);
+    return () => window.removeEventListener('storage', onChange);
+  }, [disableSwitch, setColorMode]);
 
   // PCS is coerced to light mode when printing, which causes the color mode to
   // be reset to dark when exiting print mode, disregarding user settings. When
@@ -109,19 +112,45 @@ function useColorModeContextValue(): ColorModeContextValue {
         previousMediaIsPrint.current = window.matchMedia('print').matches;
         return;
       }
-      setTheme(matches ? themes.dark : themes.light);
+      setColorMode(matches ? ColorModes.dark : ColorModes.light);
     };
     mql.addListener(onChange);
-    return () => {
-      mql.removeListener(onChange);
-    };
-  }, [disableSwitch, respectPrefersColorScheme]);
+    return () => mql.removeListener(onChange);
+  }, [setColorMode, disableSwitch, respectPrefersColorScheme]);
 
-  return {
-    isDarkTheme: theme === themes.dark,
-    setLightTheme,
-    setDarkTheme,
-  };
+  return useMemo(
+    () => ({
+      colorMode,
+      setColorMode,
+      get isDarkTheme() {
+        if (process.env.NODE_ENV === 'development') {
+          console.error(
+            '`useColorMode().isDarkTheme` is deprecated. Please use `useColorMode().colorMode === "dark"` instead.',
+          );
+        }
+        return colorMode === ColorModes.dark;
+      },
+      setLightTheme() {
+        if (process.env.NODE_ENV === 'development') {
+          console.error(
+            '`useColorMode().setLightTheme` is deprecated. Please use `useColorMode().setColorMode("light")` instead.',
+          );
+        }
+        setColorMode(ColorModes.light);
+        storeColorMode(ColorModes.light);
+      },
+      setDarkTheme() {
+        if (process.env.NODE_ENV === 'development') {
+          console.error(
+            '`useColorMode().setDarkTheme` is deprecated. Please use `useColorMode().setColorMode("dark")` instead.',
+          );
+        }
+        setColorMode(ColorModes.dark);
+        storeColorMode(ColorModes.dark);
+      },
+    }),
+    [colorMode, setColorMode],
+  );
 }
 
 const ColorModeContext = React.createContext<ColorModeContextValue | undefined>(
@@ -133,11 +162,7 @@ export function ColorModeProvider({
 }: {
   children: ReactNode;
 }): JSX.Element {
-  const {isDarkTheme, setLightTheme, setDarkTheme} = useColorModeContextValue();
-  const contextValue = useMemo(
-    () => ({isDarkTheme, setLightTheme, setDarkTheme}),
-    [isDarkTheme, setLightTheme, setDarkTheme],
-  );
+  const contextValue = useColorModeContextValue();
   return (
     <ColorModeContext.Provider value={contextValue}>
       {children}

website/docs/api/themes/theme-configuration.md

@@ -901,9 +901,9 @@ import {useColorMode} from '@docusaurus/theme-common';
 
 const Example = () => {
   // highlight-next-line
-  const {isDarkTheme, setLightTheme, setDarkTheme} = useColorMode();
+  const {colorMode, setColorMode} = useColorMode();
 
-  return <h1>Dark mode is now {isDarkTheme ? 'on' : 'off'}</h1>;
+  return <h1>Dark mode is now {colorMode === 'dark' ? 'on' : 'off'}</h1>;
 };
 ```
 

website/src/components/ColorGenerator/index.tsx

@@ -35,7 +35,10 @@ function wcagContrast(foreground: string, background: string) {
 }
 
 export default function ColorGenerator(): JSX.Element {
-  const {isDarkTheme, setDarkTheme, setLightTheme} = useColorMode();
+  const {colorMode, setColorMode} = useColorMode();
+
+  const isDarkTheme = colorMode === 'dark';
+
   const DEFAULT_PRIMARY_COLOR = isDarkTheme
     ? DARK_PRIMARY_COLOR
     : LIGHT_PRIMARY_COLOR;
@@ -131,13 +134,7 @@ export default function ColorGenerator(): JSX.Element {
         <button
           type="button"
           className="clean-btn button button--primary margin-left--md"
-          onClick={() => {
-            if (isDarkTheme) {
-              setLightTheme();
-            } else {
-              setDarkTheme();
-            }
-          }}>
+          onClick={() => setColorMode(isDarkTheme ? 'light' : 'dark')}>
           <Translate
             id="colorGenerator.inputs.modeToggle.label"
             values={{

website/src/components/Zoom/index.tsx

@@ -15,11 +15,13 @@ export default function Zoom({
 }: {
   children: React.ReactNode;
 }): JSX.Element {
-  const {isDarkTheme} = useColorMode();
+  const {colorMode} = useColorMode();
   return (
     <BasicZoom
       overlayBgColorEnd={
-        isDarkTheme ? 'rgba(0, 0, 0, 0.95)' : 'rgba(255, 255, 255, 0.95)'
+        colorMode === 'dark'
+          ? 'rgba(0, 0, 0, 0.95)'
+          : 'rgba(255, 255, 255, 0.95)'
       }>
       {children}
     </BasicZoom>

website/src/theme/ColorModeToggle.tsx

@@ -28,9 +28,9 @@ export default function ColorModeToggle(props: Props): JSX.Element {
   return (
     <OriginalToggle
       {...props}
-      onChange={(e) => {
-        props.onChange(e);
-        const isDarkMode = e.target.checked;
+      onChange={(colorMode) => {
+        props.onChange(colorMode);
+        const isDarkMode = colorMode === 'dark';
         const storage = isDarkMode ? darkStorage : lightStorage;
         const colorState: ColorState = JSON.parse(storage.get() ?? 'null') ?? {
           baseColor: isDarkMode ? DARK_PRIMARY_COLOR : LIGHT_PRIMARY_COLOR,