implement shims

shims/electron/remote/theme.js

@@ -0,0 +1,60 @@
+// Shim for remote.nativeTheme
+// Obsidian uses: shouldUseDarkColors, on('updated', cb)
+
+const listeners = [];
+
+const darkQuery = typeof window !== 'undefined'
+  ? window.matchMedia('(prefers-color-scheme: dark)')
+  : null;
+
+if (darkQuery?.addEventListener) {
+  darkQuery.addEventListener('change', () => {
+    for (const fn of listeners) {
+      fn();
+    }
+  });
+}
+
+export const themeShim = {
+  get shouldUseDarkColors() {
+    return darkQuery ? darkQuery.matches : true;
+  },
+
+  get themeSource() {
+    return 'system';
+  },
+
+  set themeSource(val) {
+    // No-op in browser; theme is controlled by OS
+  },
+
+  on(event, callback) {
+    if (event === 'updated') {
+      listeners.push(callback);
+    }
+    return themeShim;
+  },
+
+  once(event, callback) {
+    if (event === 'updated') {
+      const wrapped = () => {
+        const idx = listeners.indexOf(wrapped);
+        if (idx >= 0) listeners.splice(idx, 1);
+        callback();
+      };
+      listeners.push(wrapped);
+    }
+    return themeShim;
+  },
+
+  removeListener(event, callback) {
+    const idx = listeners.indexOf(callback);
+    if (idx >= 0) listeners.splice(idx, 1);
+    return themeShim;
+  },
+
+  removeAllListeners() {
+    listeners.length = 0;
+    return themeShim;
+  },
+};