feat(easel): add localization

static/src/theme.ts

@@ -0,0 +1,76 @@
+(() => {
+  const getStoredTheme = () => localStorage.getItem("theme");
+  const setStoredTheme = (theme: string) => 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: string) => {
+    if (theme === "auto") {
+      document.documentElement.setAttribute(
+        "data-bs-theme",
+        window.matchMedia("(prefers-color-scheme: dark)").matches ? "dark" : "light",
+      );
+    } else {
+      document.documentElement.setAttribute("data-bs-theme", theme);
+    }
+  };
+
+  setTheme(getPreferredTheme());
+
+  const showActiveTheme = (theme: string, focus = false) => {
+    const themeSwitcher = document.querySelector("#bd-theme");
+
+    if (!themeSwitcher) {
+      return;
+    }
+
+    const themeSwitcherText = document.querySelector("#bd-theme-text");
+    const activeThemeIcon = document.querySelector(".theme-icon-active");
+    const btnToActive = document.querySelector(`[data-bs-theme-value="${theme}"]`);
+    const activeThemeIconClass = btnToActive.querySelector("i.bi").className.match(/bi-[\w-]+/)[0];
+
+    document.querySelectorAll("[data-bs-theme-value]").forEach((element) => {
+      element.classList.remove("active");
+      element.setAttribute("aria-pressed", "false");
+    });
+
+    btnToActive.classList.add("active");
+    btnToActive.setAttribute("aria-pressed", "true");
+    const classesToRemove = Array.from(activeThemeIcon.classList).filter((className) => className.startsWith("bi-"));
+    activeThemeIcon.classList.remove(...classesToRemove);
+    activeThemeIcon.classList.add(activeThemeIconClass);
+    const themeSwitcherLabel = `${themeSwitcherText.textContent} (${btnToActive.dataset.bsThemeValue})`;
+    themeSwitcher.setAttribute("aria-label", themeSwitcherLabel);
+
+    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);
+      });
+    });
+  });
+})();