Auto light/dark theme and button toggle to change theme

web/themeSwitcher.js

@@ -0,0 +1,82 @@
+/*!
+ * Color mode toggler for Bootstrap's docs (https://getbootstrap.com/)
+ * Copyright 2011-2023 The Bootstrap Authors
+ * Licensed under the Creative Commons Attribution 3.0 Unported License.
+ */
+(() => {
+  "use strict";
+  const getStoredTheme = () => localStorage.getItem("theme");
+  const setStoredTheme = (theme) => localStorage.setItem("theme", theme);
+
+  const getPreferredTheme = () => {
+    const storedTheme = getStoredTheme();
+    if (storedTheme) {
+      return storedTheme;
+    }
+
+    return window.matchMedia("(prefers-color-scheme: dark)").matches
+      ? "dark"
+      : "light";
+  };
+
+  const setTheme = (theme) => {
+    if (
+      theme === "auto" &&
+      window.matchMedia("(prefers-color-scheme: dark)").matches
+    ) {
+      document.documentElement.setAttribute("data-bs-theme", "dark");
+    } else {
+      document.documentElement.setAttribute("data-bs-theme", theme);
+    }
+  };
+
+  setTheme(getPreferredTheme());
+
+  const showActiveTheme = (theme, focus = false) => {
+    const themeSwitcher = document.querySelector("#bd-theme");
+
+    if (!themeSwitcher) {
+      return;
+    }
+
+    const themeSwitcherText = document.querySelector("#bd-theme-text");
+    const btnToActive = document.querySelector(
+      `[data-bs-theme-value="${theme}"]`
+    );
+
+    document.querySelectorAll("[data-bs-theme-value]").forEach((element) => {
+      element.classList.remove("active");
+      element.setAttribute("aria-pressed", "false");
+    });
+
+    btnToActive.classList.add("active");
+    btnToActive.setAttribute("aria-pressed", "true");
+    themeSwitcher.textContent = `Theme (${btnToActive.dataset.bsThemeValue})`;
+
+    if (focus) {
+      themeSwitcher.focus();
+    }
+  };
+
+  window
+    .matchMedia("(prefers-color-scheme: dark)")
+    .addEventListener("change", () => {
+      const storedTheme = getStoredTheme();
+      if (storedTheme !== "light" && storedTheme !== "dark") {
+        setTheme(getPreferredTheme());
+      }
+    });
+
+  window.addEventListener("DOMContentLoaded", () => {
+    showActiveTheme(getPreferredTheme());
+
+    document.querySelectorAll("[data-bs-theme-value]").forEach((toggle) => {
+      toggle.addEventListener("click", () => {
+        const theme = toggle.getAttribute("data-bs-theme-value");
+        setStoredTheme(theme);
+        setTheme(theme);
+        showActiveTheme(theme, true);
+      });
+    });
+  });
+})();

web/timeseries.html

@@ -15,6 +15,7 @@
       integrity="sha384-9ndCyUaIbzAi2FUVXJi0CjmCapSmO7SnpJef0486qhLnuZ2cdeRhO02iuK6FUUVM"
       crossorigin="anonymous"
     />
+    <script src="./themeSwitcher.js"></script>
     <script
       src="https://kit.fontawesome.com/f6cc126dcc.js"
       crossorigin="anonymous"
@@ -249,29 +250,49 @@
               >
             </li>
             <li class="nav-item">
-              <a class="nav-link" href="https://github.com/blaylockbk/Herbie">🏁 Herbie</a>
+              <a class="nav-link" href="https://github.com/blaylockbk/Herbie"
+                >🏁 Herbie</a
+              >
             </li>
             <li class="nav-item">
-              <a class="nav-link" href="https://github.com/blaylockbk/goes2go">🌎 GOES-2-go</a>
+              <a class="nav-link" href="https://github.com/blaylockbk/goes2go"
+                >🌎 GOES-2-go</a
+              >
             </li>
             <li class="nav-item">
-              <a class="nav-link" href="https://github.com/blaylockbk/SynopticPy">🌡️ SynopticPy</a>
+              <a
+                class="nav-link"
+                href="https://github.com/blaylockbk/SynopticPy"
+                >🌡️ SynopticPy</a
+              >
             </li>
           </ul>
         </div>
         <!-- Title -->
         <a class="navbar-brand"
           ><h2 style="display: inline">Station Timeseries</h2></a
         >
-        <!-- README button; trigger modal -->
-        <button
-          type="button"
-          class="btn btn-outline-info"
-          data-bs-toggle="modal"
-          data-bs-target="#exampleModal"
-        >
-          README
-        </button>
+        <div class="d-flex gap-2">
+          <div class="dropdown">
+            <button class="btn btn-outline-light dropdown-toggle" type="button" data-bs-toggle="dropdown" aria-expanded="false" id="bd-theme">
+              Theme
+            </button>
+            <ul class="dropdown-menu">
+              <li><button class="dropdown-item" data-bs-theme-value="auto">Auto</button></li>
+              <li><button class="dropdown-item" data-bs-theme-value="light">Light</li>
+              <li><button class="dropdown-item" data-bs-theme-value="dark">Dark</li>
+            </ul>
+          </div>
+          <!-- README button; trigger modal -->
+          <button
+            type="button"
+            class="btn btn-outline-info"
+            data-bs-toggle="modal"
+            data-bs-target="#exampleModal"
+          >
+            README
+          </button>
+        </div>
       </div>
     </nav>
 
@@ -877,7 +898,9 @@ <h2 class="accordion-header">
                   value="english"
                   checked
                 />
-                <label class="btn btn-outline-dark btn-sm" for="unitsRadio1"
+                <label
+                  class="btn btn-outline-secondary btn-sm"
+                  for="unitsRadio1"
                   >English Units</label
                 >
                 <input
@@ -888,7 +911,9 @@ <h2 class="accordion-header">
                   autocomplete="off"
                   value="metric"
                 />
-                <label class="btn btn-outline-dark btn-sm" for="unitsRadio2"
+                <label
+                  class="btn btn-outline-secondary btn-sm"
+                  for="unitsRadio2"
                   >Metric Units</label
                 >
               </div>
@@ -908,7 +933,9 @@ <h2 class="accordion-header">
                   value="local"
                   checked
                 />
-                <label class="btn btn-outline-dark btn-sm" for="timezoneRadio1"
+                <label
+                  class="btn btn-outline-secondary btn-sm"
+                  for="timezoneRadio1"
                   >Local Time</label
                 >
                 <input
@@ -919,7 +946,9 @@ <h2 class="accordion-header">
                   autocomplete="off"
                   value="utc"
                 />
-                <label class="btn btn-outline-dark btn-sm" for="timezoneRadio2"
+                <label
+                  class="btn btn-outline-secondary btn-sm"
+                  for="timezoneRadio2"
                   >UTC Time</label
                 >
               </div>