feat: add navigation menu for mobile (#436)

close #40
If horizontal width of a navigation list exceeds a window size, it will
store them in a small menu.

Preview

![image](https://github.com/jsr-io/jsr/assets/114303361/1c58458e-452d-4903-a548-7114363360f2)

Author: ryuapp

frontend/components/Nav.tsx

@@ -1,5 +1,6 @@
 // Copyright 2024 the JSR authors. All rights reserved. MIT license.
 import { ComponentChildren } from "preact";
+import { NavMenu } from "../islands/NavMenu.tsx";
 
 export interface NavProps {
   children?: ComponentChildren;
@@ -11,9 +12,12 @@ export function Nav(props: NavProps) {
     <nav
       class={`${
         props.noTopMargin ? "" : "mt-3"
-      } md:border-b border-jsr-cyan-300/30 flex flex-wrap md:flex-nowrap flex-row max-w-full overflow-auto items-end`}
+      } md:border-b border-jsr-cyan-300/30 max-w-full flex justify-between overflow-hidden items-end`}
     >
-      {props.children}
+      <ul id="nav-items" class="flex flex-row">
+        {props.children}
+      </ul>
+      <NavMenu />
     </nav>
   );
 }

frontend/fresh.gen.ts

@@ -55,6 +55,7 @@ import * as $GithubUserLink from "./islands/GithubUserLink.tsx";
 import * as $GlobalSearch from "./islands/GlobalSearch.tsx";
 import * as $HeaderLogo from "./islands/HeaderLogo.tsx";
 import * as $HomepageHeroParticles from "./islands/HomepageHeroParticles.tsx";
+import * as $NavMenu from "./islands/NavMenu.tsx";
 import * as $PublishingTaskRequeue from "./islands/PublishingTaskRequeue.tsx";
 import * as $UserManageScopeInvite from "./islands/UserManageScopeInvite.tsx";
 import * as $UserMenu from "./islands/UserMenu.tsx";
@@ -127,6 +128,7 @@ const manifest = {
     "./islands/GlobalSearch.tsx": $GlobalSearch,
     "./islands/HeaderLogo.tsx": $HeaderLogo,
     "./islands/HomepageHeroParticles.tsx": $HomepageHeroParticles,
+    "./islands/NavMenu.tsx": $NavMenu,
     "./islands/PublishingTaskRequeue.tsx": $PublishingTaskRequeue,
     "./islands/UserManageScopeInvite.tsx": $UserManageScopeInvite,
     "./islands/UserMenu.tsx": $UserMenu,

frontend/islands/NavMenu.tsx

@@ -0,0 +1,81 @@
+// Copyright 2024 the JSR authors. All rights reserved. MIT license.
+import { useEffect, useLayoutEffect, useRef, useState } from "preact/hooks";
+import IconDots from "$tabler_icons/dots.tsx";
+
+const useWindowWidth = () => {
+  const [windowWidth, setWindowWidth] = useState(0);
+  const handleWidth = () => {
+    setWindowWidth(globalThis.innerWidth);
+  };
+  useLayoutEffect(() => {
+    handleWidth();
+    globalThis.addEventListener("resize", handleWidth);
+
+    return () => globalThis.removeEventListener("resize", handleWidth);
+  }, []);
+  return windowWidth;
+};
+
+export function NavMenu() {
+  const [open, setOpen] = useState(false);
+  const ref = useRef<HTMLButtonElement>(null);
+
+  useWindowWidth();
+  useEffect(() => {
+    function outsideClick(e: Event) {
+      if (ref.current && !ref.current.contains(e.target as Element)) {
+        setOpen(false);
+      }
+    }
+    document.addEventListener("click", outsideClick);
+    return () => document.removeEventListener("click", outsideClick);
+  }, []);
+
+  if (typeof document === "undefined") return null;
+
+  const navItems = document.getElementById("nav-items");
+  const nav = navItems?.parentElement;
+  let navWidth = 0;
+  if (nav) {
+    navWidth = nav.offsetWidth;
+  }
+
+  let sumWidth = 50;
+  let displayMenu = false;
+  const navMenuList = [];
+  if (navItems) {
+    for (let i = 0; i < navItems.children.length; i++) {
+      const child = navItems.children[i];
+      child.classList.remove("invisible");
+      sumWidth += child.clientWidth;
+
+      if (sumWidth > navWidth) {
+        displayMenu = true;
+        navMenuList.push(child.outerHTML);
+        child.classList.add("invisible");
+      }
+    }
+  }
+
+  return (
+    <button
+      id="nav-menu"
+      class={`group absolute right-4 md:right-10 rounded md:rounded-b-none border-1 md:border-b-0 border-jsr-cyan-100 hover:bg-jsr-cyan-50 hover:cursor-pointer ${
+        displayMenu ? "" : "hidden"
+      }`}
+      aria-expanded={open ? "true" : "false"}
+      onClick={() => setOpen((v) => !v)}
+      ref={ref}
+    >
+      <span class="flex p-1">
+        <IconDots />
+      </span>
+      {open && (
+        <div
+          class="absolute top-[120%] -right-4 z-[70] px-1 py-2 rounded border-1.5 border-current bg-white w-56 shadow overflow-hidden opacity-100 translate-y-0 transition [&>a]:rounded"
+          dangerouslySetInnerHTML={{ __html: navMenuList.join("") }}
+        />
+      )}
+    </button>
+  );
+}