feat: 深色模式基础设施 (system theme + 跟随系统)

2026-07-08 11:33:09 +08:00
parent a88c4da361
commit c43f1d7389
6 changed files with 88 additions and 4 deletions
@@ -0,0 +1,49 @@
+/**
+ * 系统深色模式监听 — 提供初始值与变更回调
+ * 旧设备 wx.onThemeChange 失败时退化为只读一次
+ */
+
+const STORAGE_KEY = 'dark_mode_pref'
+
+function _readSystemTheme() {
+  try {
+    const info = wx.getSystemInfoSync()
+    return info.theme === 'dark' ? true : false
+  } catch (e) {
+    return false
+  }
+}
+
+function getInitialDarkMode() {
+  const pref = wx.getStorageSync(STORAGE_KEY) || 'system'
+  if (pref === 'system') return _readSystemTheme()
+  return pref === 'dark'
+}
+
+function getPref() {
+  return wx.getStorageSync(STORAGE_KEY) || 'system'
+}
+
+function setPref(value) {
+  if (!['system', 'light', 'dark'].includes(value)) return
+  wx.setStorageSync(STORAGE_KEY, value)
+}
+
+function watchDarkMode(onChange) {
+  if (typeof wx.onThemeChange !== 'function') return
+  try {
+    wx.onThemeChange(({ theme }) => {
+      const pref = getPref()
+      if (pref === 'system') onChange(theme === 'dark')
+    })
+  } catch (e) {
+    // 旧设备不支持,忽略
+  }
+}
+
+module.exports = {
+  getInitialDarkMode,
+  getPref,
+  setPref,
+  watchDarkMode
+}