chore: tweak back to top button

web/src/components/PagedMemoList/PagedMemoList.tsx

 import { Button } from "@usememos/mui";
-import { ArrowDownIcon, LoaderIcon } from "lucide-react";
-import { useEffect, useRef, useState, useMemo } from "react";
-import { useLocation } from "react-router-dom";
+import { ArrowDownIcon, ArrowUpIcon, LoaderIcon, SlashIcon } from "lucide-react";
+import { useEffect, useMemo, useRef, useState } from "react";
 import PullToRefresh from "react-simple-pull-to-refresh";
-import ScrollToTop from "@/components/ScrollToTop";
 import { DEFAULT_LIST_MEMOS_PAGE_SIZE } from "@/helpers/consts";
 import useResponsiveWidth from "@/hooks/useResponsiveWidth";
 import { Routes } from "@/router";
@@ -30,32 +28,15 @@ const PagedMemoList = (props: Props) => {
   const memoStore = useMemoStore();
   const memoList = useMemoList();
   const containerRef = useRef<HTMLDivElement>(null);
-  const [containerRightOffset, setContainerRightOffset] = useState(0);
   const [state, setState] = useState<State>({
     isRequesting: true, // Initial request
     nextPageToken: "",
   });
-  const sortedMemoList = props.listSort ? props.listSort(memoList.value) : memoList.value;
-  const location = useLocation();
-
-  const shouldShowScrollToTop = useMemo(
+  const shouldShowBackToTop = useMemo(
     () => [Routes.ROOT, Routes.EXPLORE, Routes.ARCHIVED].includes(location.pathname as Routes) || location.pathname.startsWith("/u/"),
     [location.pathname],
   );
-
-  useEffect(() => {
-    const updateOffset = () => {
-      if (containerRef.current) {
-        const rect = containerRef.current.getBoundingClientRect();
-        const offset = window.innerWidth - rect.right;
-        setContainerRightOffset(offset);
-      }
-    };
-
-    updateOffset();
-    window.addEventListener("resize", updateOffset);
-    return () => window.removeEventListener("resize", updateOffset);
-  }, []);
+  const sortedMemoList = props.listSort ? props.listSort(memoList.value) : memoList.value;
 
   const fetchMoreMemos = async (nextPageToken: string) => {
     setState((state) => ({ ...state, isRequesting: true }));
@@ -88,21 +69,29 @@ const PagedMemoList = (props: Props) => {
           <LoaderIcon className="animate-spin text-zinc-500" />
         </div>
       )}
-      {!state.isRequesting && state.nextPageToken && (
+      {!state.isRequesting && (
+        <>
+          {!state.nextPageToken && sortedMemoList.length === 0 ? (
+            <div className="w-full mt-12 mb-8 flex flex-col justify-center items-center italic">
+              <Empty />
+              <p className="mt-2 text-gray-600 dark:text-gray-400">{t("message.no-data")}</p>
+            </div>
+          ) : (
             <div className="w-full flex flex-row justify-center items-center my-4">
+              {state.nextPageToken && (
+                <>
                   <Button variant="plain" onClick={() => fetchMoreMemos(state.nextPageToken)}>
                     {t("memo.load-more")}
-            <ArrowDownIcon className="ml-2 w-4 h-auto" />
+                    <ArrowDownIcon className="ml-1 w-4 h-auto" />
                   </Button>
-        </div>
+                  {shouldShowBackToTop && <SlashIcon className="mx-1 w-4 h-auto opacity-40" />}
+                </>
               )}
-      {!state.isRequesting && !state.nextPageToken && sortedMemoList.length === 0 && (
-        <div className="w-full mt-12 mb-8 flex flex-col justify-center items-center italic">
-          <Empty />
-          <p className="mt-2 text-gray-600 dark:text-gray-400">{t("message.no-data")}</p>
+              {shouldShowBackToTop && <BackToTop />}
             </div>
           )}
-      <ScrollToTop enabled={shouldShowScrollToTop} className="fixed bottom-6" style={{ right: `calc(1rem + ${containerRightOffset}px)` }} />
+        </>
+      )}
     </div>
   );
 
@@ -130,4 +119,46 @@ const PagedMemoList = (props: Props) => {
   );
 };
 
+const BackToTop = () => {
+  const t = useTranslate();
+  const [isVisible, setIsVisible] = useState(false);
+  const [shouldRender, setShouldRender] = useState(false);
+
+  useEffect(() => {
+    const handleScroll = () => {
+      const shouldBeVisible = window.scrollY > 400;
+      if (shouldBeVisible !== isVisible) {
+        if (shouldBeVisible) {
+          setShouldRender(true);
+          setIsVisible(true);
+        } else {
+          setShouldRender(false);
+          setIsVisible(false);
+        }
+      }
+    };
+
+    window.addEventListener("scroll", handleScroll);
+    return () => window.removeEventListener("scroll", handleScroll);
+  }, [isVisible]);
+
+  const scrollToTop = () => {
+    window.scrollTo({
+      top: 0,
+      behavior: "smooth",
+    });
+  };
+
+  if (!shouldRender) {
+    return null;
+  }
+
+  return (
+    <Button variant="plain" onClick={scrollToTop}>
+      {t("router.back-to-top")}
+      <ArrowUpIcon className="ml-1 w-4 h-auto" />
+    </Button>
+  );
+};
+
 export default PagedMemoList;

web/src/components/ScrollToTop.tsx

-import clsx from "clsx";
-import { ArrowUpIcon } from "lucide-react";
-import { useEffect, useState } from "react";
-
-interface ScrollToTopProps {
-  className?: string;
-  style?: React.CSSProperties;
-  enabled?: boolean;
-}
-
-const ScrollToTop = ({ className, style, enabled = true }: ScrollToTopProps) => {
-  const [isVisible, setIsVisible] = useState(false);
-  const [shouldRender, setShouldRender] = useState(false);
-
-  useEffect(() => {
-    const handleScroll = () => {
-      const shouldBeVisible = window.scrollY > 400;
-      if (shouldBeVisible !== isVisible) {
-        if (shouldBeVisible) {
-          setShouldRender(true);
-          setTimeout(() => setIsVisible(true), 50);
-        } else {
-          setIsVisible(false);
-          setTimeout(() => setShouldRender(false), 200);
-        }
-      }
-    };
-
-    if (enabled) {
-      window.addEventListener("scroll", handleScroll);
-      return () => window.removeEventListener("scroll", handleScroll);
-    }
-  }, [enabled, isVisible]);
-
-  const scrollToTop = () => {
-    window.scrollTo({
-      top: 0,
-      behavior: "smooth",
-    });
-  };
-
-  if (!enabled || !shouldRender) {
-    return null;
-  }
-
-  return (
-    <button
-      onClick={scrollToTop}
-      className={clsx(
-        "p-3 bg-primary dark:bg-primary-dark hover:bg-primary-darker dark:hover:bg-primary-darker rounded-full shadow-lg",
-        "transition-all duration-200",
-        "opacity-0 scale-95",
-        isVisible && "opacity-100 scale-100",
-        className,
-      )}
-      style={style}
-      aria-label="Scroll to top"
-    >
-      <ArrowUpIcon className="w-5 h-5 text-white" />
-    </button>
-  );
-};
-
-export default ScrollToTop;