From 4ae51209aa579c21d848c2067fae1f1c5ce0626c Mon Sep 17 00:00:00 2001
From: Eric Liu <ericyl.us@gmail.com>
Date: Sun, 12 Jan 2020 12:55:21 -0800
Subject: [PATCH] docs(palimpsest): support dark mode, local storage for
 theming

---
 palimpsest/src/components/ThemePicker.svelte | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/palimpsest/src/components/ThemePicker.svelte b/palimpsest/src/components/ThemePicker.svelte
index 95ea2c7a..4f4ed797 100644
--- a/palimpsest/src/components/ThemePicker.svelte
+++ b/palimpsest/src/components/ThemePicker.svelte
@@ -1,9 +1,26 @@
 <script>
   export let inline = false;
 
+  import { onMount, afterUpdate } from 'svelte';
   import { Select, SelectItem } from 'carbon-components-svelte';
   import { theme } from '../store';
 
+  onMount(() => {
+    let currentTheme = localStorage.getItem('theme');
+
+    if (currentTheme) {
+      theme.set(currentTheme);
+    } else {
+      if (window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches) {
+        theme.set('g90');
+      }
+    }
+  });
+
+  afterUpdate(() => {
+    localStorage.setItem('theme', $theme);
+  });
+
   $: {
     document.documentElement.setAttribute('carbon-theme', $theme);
   }