feat: Added the OverflowMarquee, implemented auto-scrolling text.

frontend/components/OverflowMarquee.tsx

@@ -0,0 +1,117 @@
+import React, { useEffect, useLayoutEffect, useMemo, useRef, useState } from 'react';
+
+type OverflowMarqueeProps = {
+  children: React.ReactNode;
+  className?: string;
+  textClassName?: string;
+  title?: string;
+  speedPxPerSec?: number;
+  minDurationSec?: number;
+};
+
+type MarqueeMetrics = {
+  isOverflowing: boolean;
+  overflowPx: number;
+  durationSec: number;
+};
+
+const DEFAULT_SPEED_PX_PER_SEC = 24;
+const DEFAULT_MIN_DURATION_SEC = 4;
+
+const OverflowMarquee: React.FC<OverflowMarqueeProps> = ({
+  children,
+  className,
+  textClassName,
+  title,
+  speedPxPerSec = DEFAULT_SPEED_PX_PER_SEC,
+  minDurationSec = DEFAULT_MIN_DURATION_SEC,
+}) => {
+  const containerRef = useRef<HTMLSpanElement>(null);
+  const textRef = useRef<HTMLSpanElement>(null);
+  const [metrics, setMetrics] = useState<MarqueeMetrics>({
+    isOverflowing: false,
+    overflowPx: 0,
+    durationSec: minDurationSec,
+  });
+
+  const fallbackTitle = useMemo(() => {
+    if (title) return title;
+    return typeof children === 'string' ? children : undefined;
+  }, [children, title]);
+
+  const recompute = () => {
+    const container = containerRef.current;
+    const text = textRef.current;
+    if (!container || !text) return;
+
+    // Ensure we measure with current layout.
+    const available = container.clientWidth;
+    const content = text.scrollWidth;
+    const overflowPx = Math.ceil(content - available);
+
+    if (overflowPx > 1) {
+      const durationSec = Math.max(minDurationSec, overflowPx / Math.max(1, speedPxPerSec));
+      setMetrics({ isOverflowing: true, overflowPx, durationSec });
+    } else {
+      // Avoid re-render loops if already not overflowing.
+      setMetrics((prev) => (prev.isOverflowing ? { isOverflowing: false, overflowPx: 0, durationSec: minDurationSec } : prev));
+    }
+  };
+
+  useLayoutEffect(() => {
+    recompute();
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [children]);
+
+  useEffect(() => {
+    recompute();
+
+    const container = containerRef.current;
+    const text = textRef.current;
+    if (!container || !text) return;
+
+    const ro = new ResizeObserver(() => recompute());
+    ro.observe(container);
+    ro.observe(text);
+
+    const onResize = () => recompute();
+    window.addEventListener('resize', onResize);
+
+    return () => {
+      ro.disconnect();
+      window.removeEventListener('resize', onResize);
+    };
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
+  const textStyle: React.CSSProperties | undefined = metrics.isOverflowing
+    ? ({
+        ['--marquee-distance' as any]: `${metrics.overflowPx}px`,
+        ['--marquee-duration' as any]: `${metrics.durationSec}s`,
+      } satisfies React.CSSProperties)
+    : undefined;
+
+  return (
+    <span
+      ref={containerRef}
+      className={['overflow-marquee', className].filter(Boolean).join(' ')}
+      title={fallbackTitle}
+    >
+      <span
+        ref={textRef}
+        className={[
+          'overflow-marquee__text',
+          metrics.isOverflowing ? 'overflow-marquee__text--animate' : '',
+          textClassName,
+        ]
+          .filter(Boolean)
+          .join(' ')}
+        style={textStyle}
+      >
+        {children}
+      </span>
+    </span>
+  );
+};
+
+export default OverflowMarquee;