From b36ebadcb87897e01b314b4a696a281d299085f5 Mon Sep 17 00:00:00 2001
From: pengzhanbo <volodymyr@foxmail.com>
Date: Sun, 10 Nov 2024 00:13:43 +0800
Subject: [PATCH] feat(theme): optimize appearance transition, close #325
 (#333)

---
 docs/notes/theme/config/主题配置.md           |  7 +-
 .../client/components/VPSwitchAppearance.vue  | 92 ++++++++++++++++++-
 theme/src/client/composables/dark-mode.ts     |  9 +-
 theme/src/shared/base.ts                      |  4 +-
 4 files changed, 101 insertions(+), 11 deletions(-)

diff --git a/docs/notes/theme/config/主题配置.md b/docs/notes/theme/config/主题配置.md
index 2b2ec3ad..e94436f3 100644
--- a/docs/notes/theme/config/主题配置.md
+++ b/docs/notes/theme/config/主题配置.md
@@ -711,10 +711,11 @@ interface SidebarItem {
      */
     postList?: boolean
     /**
-     * 是否启用 深色/浅色 模式切换过渡动画
-     * @default true
+     * 是否启用 深色/浅色 模式切换过渡动画，
+     * 或配置过渡动画类型
+     * @default 'fade'
      */
-    appearance?: boolean
+    appearance?: boolean | 'fade' | 'circle-clip' | 'horizontal-clip' | 'vertical-clip' | 'skew-clip'
   }
   ```
 
diff --git a/theme/src/client/components/VPSwitchAppearance.vue b/theme/src/client/components/VPSwitchAppearance.vue
index 0e74f163..ff2c2163 100644
--- a/theme/src/client/components/VPSwitchAppearance.vue
+++ b/theme/src/client/components/VPSwitchAppearance.vue
@@ -1,13 +1,79 @@
 <script lang="ts" setup>
 import VPSwitch from '@theme/VPSwitch.vue'
-import { inject, ref, watchPostEffect } from 'vue'
-import { useData } from '../composables/index.js'
+import { computed, inject, nextTick, ref, watchPostEffect } from 'vue'
+import { enableTransitions, useData } from '../composables/index.js'
 
 const checked = ref(false)
 const { theme, isDark } = useData()
 
-const toggleAppearance = inject('toggle-appearance', () => {
-  isDark.value = !isDark.value
+const transitionMode = computed(() => {
+  const transition = theme.value.transition
+  const options = typeof transition === 'object' ? transition : {}
+  if (transition === false || options.appearance === false)
+    return false
+
+  return typeof options.appearance === 'string' ? options.appearance : 'fade'
+})
+
+const toggleAppearance = inject('toggle-appearance', async ({ clientX: x, clientY: y }: MouseEvent) => {
+  if (!enableTransitions() || transitionMode.value === false) {
+    isDark.value = !isDark.value
+    return
+  }
+
+  await document.startViewTransition(async () => {
+    isDark.value = !isDark.value
+    await nextTick()
+  }).ready
+
+  const keyframes: PropertyIndexedKeyframes = {}
+  const mode = transitionMode.value
+  let duration = 400
+
+  if (mode === 'circle-clip') {
+    const clipPath = [
+      `circle(0px at ${x}px ${y}px)`,
+      `circle(${Math.hypot(
+        Math.max(x, innerWidth - x),
+        Math.max(y, innerHeight - y),
+      )}px at ${x}px ${y}px)`,
+    ]
+    keyframes.clipPath = isDark.value ? clipPath.reverse() : clipPath
+  }
+  else if (mode === 'horizontal-clip') {
+    const clipPath = [
+      `inset(0px ${innerWidth}px 0px 0px)`,
+      `inset(0px 0px 0px 0px)`,
+    ]
+    keyframes.clipPath = isDark.value ? clipPath.reverse() : clipPath
+  }
+  else if (mode === 'vertical-clip') {
+    const clipPath = [
+      `inset(0px 0px ${innerHeight}px 0px)`,
+      `inset(0px 0px 0px 0px)`,
+    ]
+    keyframes.clipPath = isDark.value ? clipPath.reverse() : clipPath
+  }
+  else if (mode === 'skew-clip') {
+    const clipPath = [
+      'polygon(0px 0px, 0px 0px, 0px 0px)',
+      `polygon(0px 0px, ${innerWidth * 2}px 0px, 0px ${innerHeight * 2}px)`,
+    ]
+    keyframes.clipPath = isDark.value ? clipPath.reverse() : clipPath
+  }
+  else {
+    keyframes.opacity = isDark.value ? [1, 0] : [0, 1]
+    duration = 300
+  }
+
+  document.documentElement.animate(
+    keyframes,
+    {
+      duration,
+      easing: 'ease-in',
+      pseudoElement: `::view-transition-${isDark.value ? 'old' : 'new'}(root)`,
+    },
+  )
 })
 
 const switchTitle = ref('')
@@ -52,3 +118,21 @@ watchPostEffect(() => {
   transform: translateX(18px);
 }
 </style>
+
+<style>
+::view-transition-old(root),
+::view-transition-new(root) {
+  mix-blend-mode: normal;
+  animation: none;
+}
+
+::view-transition-old(root),
+[data-theme="dark"]::view-transition-new(root) {
+  z-index: 1;
+}
+
+::view-transition-new(root),
+[data-theme="dark"]::view-transition-old(root) {
+  z-index: 9999;
+}
+</style>
diff --git a/theme/src/client/composables/dark-mode.ts b/theme/src/client/composables/dark-mode.ts
index b3a658b8..a1b14f80 100644
--- a/theme/src/client/composables/dark-mode.ts
+++ b/theme/src/client/composables/dark-mode.ts
@@ -9,13 +9,18 @@ export const darkModeSymbol: InjectionKey<DarkModeRef> = Symbol(
   __VUEPRESS_DEV__ ? 'darkMode' : '',
 )
 
+export function enableTransitions() {
+  return 'startViewTransition' in document
+    && window.matchMedia('(prefers-reduced-motion: no-preference)').matches
+}
+
 export function setupDarkMode(app: App): void {
   const theme = useThemeData()
 
   const transition = theme.value.transition
-  const disableTransition = typeof transition === 'object'
+  const disableTransition = enableTransitions() || (typeof transition === 'object'
     ? transition.appearance === false
-    : transition === false
+    : transition === false)
 
   const appearance = theme.value.appearance
   const isDark
diff --git a/theme/src/shared/base.ts b/theme/src/shared/base.ts
index d16bc593..b244e25e 100644
--- a/theme/src/shared/base.ts
+++ b/theme/src/shared/base.ts
@@ -63,7 +63,7 @@ export interface ThemeTransition {
   postList?: boolean
   /**
    * 是否启用 深色/浅色 模式切换过渡动画
-   * @default true
+   * @default 'fade'
    */
-  appearance?: boolean
+  appearance?: boolean | 'fade' | 'circle-clip' | 'horizontal-clip' | 'vertical-clip' | 'skew-clip'
 }