feat(lightbox): 用户主页头像可预览，图箱支持缩放旋转反色

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/components/markdown/ImageLightbox.tsx

@@ -1,8 +1,26 @@
 "use client";
 
-import { useEffect, useCallback } from "react";
+import {
+  useEffect,
+  useCallback,
+  useRef,
+  useState,
+  type PointerEvent as ReactPointerEvent,
+  type ReactNode,
+} from "react";
 import { createPortal } from "react-dom";
-import { X, ChevronLeft, ChevronRight } from "lucide-react";
+import {
+  X,
+  ChevronLeft,
+  ChevronRight,
+  ZoomIn,
+  ZoomOut,
+  RotateCw,
+  RotateCcw,
+  FlipHorizontal,
+  Contrast,
+  Undo2,
+} from "lucide-react";
 
 export type LightboxItem = {
   src: string;
@@ -16,7 +34,78 @@ type ImageLightboxProps = {
   onIndexChange: (index: number) => void;
 };
 
-/** 全屏图箱：Esc 关闭，多图时左右切换 */
+type View = {
+  scale: number;
+  rotation: number;
+  invert: boolean;
+  flipX: boolean;
+  tx: number;
+  ty: number;
+};
+
+const IDENTITY: View = {
+  scale: 1,
+  rotation: 0,
+  invert: false,
+  flipX: false,
+  tx: 0,
+  ty: 0,
+};
+
+const MIN_SCALE = 0.25;
+const MAX_SCALE = 8;
+const ZOOM_STEP = 1.25;
+
+function clampScale(n: number) {
+  return Math.min(MAX_SCALE, Math.max(MIN_SCALE, n));
+}
+
+function norm360(deg: number) {
+  return ((deg % 360) + 360) % 360;
+}
+
+function isIdentity(v: View) {
+  return (
+    v.scale === 1 &&
+    norm360(v.rotation) === 0 &&
+    !v.invert &&
+    !v.flipX &&
+    v.tx === 0 &&
+    v.ty === 0
+  );
+}
+
+function ToolBtn({
+  label,
+  pressed,
+  disabled,
+  onClick,
+  children,
+  className = "",
+}: {
+  label: string;
+  pressed?: boolean;
+  disabled?: boolean;
+  onClick: () => void;
+  children: ReactNode;
+  className?: string;
+}) {
+  return (
+    <button
+      type="button"
+      className={`md-lightbox-tool${pressed ? " is-on" : ""}${className ? ` ${className}` : ""}`}
+      aria-label={label}
+      aria-pressed={pressed}
+      data-tip={label}
+      disabled={disabled}
+      onClick={onClick}
+    >
+      {children}
+    </button>
+  );
+}
+
+/** 全屏图箱：Esc 关闭，多图时左右切换；支持缩放 / 旋转 / 翻转 / 反色 */
 export default function ImageLightbox({
   items,
   index,
@@ -27,6 +116,20 @@ export default function ImageLightbox({
   const current = items[index];
   const hasNav = total > 1;
 
+  const [view, setView] = useState<View>(IDENTITY);
+  const [panning, setPanning] = useState(false);
+  const [snap, setSnap] = useState(false);
+  const viewRef = useRef(view);
+  viewRef.current = view;
+  const rootRef = useRef<HTMLDivElement>(null);
+  const stageRef = useRef<HTMLDivElement>(null);
+  const dragRef = useRef<{
+    x: number;
+    y: number;
+    tx: number;
+    ty: number;
+  } | null>(null);
+
   const goPrev = useCallback(() => {
     if (!hasNav) return;
     onIndexChange((index - 1 + total) % total);
@@ -37,25 +140,192 @@ export default function ImageLightbox({
     onIndexChange((index + 1) % total);
   }, [hasNav, index, total, onIndexChange]);
 
+  const zoomBy = useCallback((factor: number, origin?: { x: number; y: number }) => {
+    setView((v) => {
+      const next = clampScale(v.scale * factor);
+      if (next === v.scale) return v;
+      if (!origin) {
+        const tx = next <= 1 ? 0 : v.tx;
+        const ty = next <= 1 ? 0 : v.ty;
+        return { ...v, scale: next, tx, ty };
+      }
+      const tx = origin.x - ((origin.x - v.tx) / v.scale) * next;
+      const ty = origin.y - ((origin.y - v.ty) / v.scale) * next;
+      return {
+        ...v,
+        scale: next,
+        tx: next <= 1 ? 0 : tx,
+        ty: next <= 1 ? 0 : ty,
+      };
+    });
+  }, []);
+
+  const resetView = useCallback(() => {
+    setSnap(true);
+    setView(IDENTITY);
+  }, []);
+
+  useEffect(() => {
+    if (!snap) return;
+    let inner = 0;
+    const outer = requestAnimationFrame(() => {
+      inner = requestAnimationFrame(() => setSnap(false));
+    });
+    return () => {
+      cancelAnimationFrame(outer);
+      cancelAnimationFrame(inner);
+    };
+  }, [snap]);
+
+  useEffect(() => {
+    setView(IDENTITY);
+    setPanning(false);
+    dragRef.current = null;
+  }, [index, current?.src]);
+
   useEffect(() => {
     const onKey = (e: KeyboardEvent) => {
-      if (e.key === "Escape") onClose();
-      else if (e.key === "ArrowLeft") goPrev();
-      else if (e.key === "ArrowRight") goNext();
+      if (e.key === "Escape") {
+        onClose();
+        return;
+      }
+      if (e.key === "ArrowLeft") {
+        goPrev();
+        return;
+      }
+      if (e.key === "ArrowRight") {
+        goNext();
+        return;
+      }
+      if (e.key === "+" || e.key === "=") {
+        e.preventDefault();
+        zoomBy(ZOOM_STEP);
+        return;
+      }
+      if (e.key === "-" || e.key === "_") {
+        e.preventDefault();
+        zoomBy(1 / ZOOM_STEP);
+        return;
+      }
+      if (e.key === "0") {
+        e.preventDefault();
+        resetView();
+        return;
+      }
+      if (e.key === "r" || e.key === "R") {
+        e.preventDefault();
+        setView((v) => ({
+          ...v,
+          rotation: v.rotation + (e.shiftKey ? -90 : 90),
+          tx: 0,
+          ty: 0,
+        }));
+        return;
+      }
+      if (e.key === "i" || e.key === "I") {
+        e.preventDefault();
+        setView((v) => ({ ...v, invert: !v.invert }));
+        return;
+      }
+      if (e.key === "h" || e.key === "H") {
+        e.preventDefault();
+        setView((v) => ({ ...v, flipX: !v.flipX }));
+      }
     };
     window.addEventListener("keydown", onKey);
-    const prev = document.body.style.overflow;
-    document.body.style.overflow = "hidden";
+    return () => window.removeEventListener("keydown", onKey);
+  }, [onClose, goPrev, goNext, zoomBy, resetView]);
+
+  // 锁背景滚动，但补上滚动条宽度，避免开关图箱时页面左右跳
+  useEffect(() => {
+    const html = document.documentElement;
+    const { body } = document;
+    const scrollbar = Math.max(0, window.innerWidth - html.clientWidth);
+    const prevOverflow = body.style.overflow;
+    const prevPaddingRight = body.style.paddingRight;
+    body.style.overflow = "hidden";
+    if (scrollbar > 0) {
+      const currentPad = parseFloat(getComputedStyle(body).paddingRight) || 0;
+      body.style.paddingRight = `${currentPad + scrollbar}px`;
+    }
     return () => {
-      window.removeEventListener("keydown", onKey);
-      document.body.style.overflow = prev;
+      body.style.overflow = prevOverflow;
+      body.style.paddingRight = prevPaddingRight;
     };
-  }, [onClose, goPrev, goNext]);
+  }, []);
+
+  useEffect(() => {
+    const el = rootRef.current;
+    if (!el) return;
+    const onWheel = (e: WheelEvent) => {
+      e.preventDefault();
+      e.stopPropagation();
+      const stage = stageRef.current;
+      const factor = e.deltaY < 0 ? ZOOM_STEP : 1 / ZOOM_STEP;
+      if (!stage) {
+        zoomBy(factor);
+        return;
+      }
+      const rect = stage.getBoundingClientRect();
+      zoomBy(factor, {
+        x: e.clientX - rect.left - rect.width / 2,
+        y: e.clientY - rect.top - rect.height / 2,
+      });
+    };
+    el.addEventListener("wheel", onWheel, { passive: false });
+    return () => el.removeEventListener("wheel", onWheel);
+  }, [zoomBy]);
+
+  const onPointerDown = (e: ReactPointerEvent<HTMLImageElement>) => {
+    if (e.button !== 0) return;
+    if (viewRef.current.scale <= 1.01) return;
+    e.currentTarget.setPointerCapture(e.pointerId);
+    dragRef.current = {
+      x: e.clientX,
+      y: e.clientY,
+      tx: viewRef.current.tx,
+      ty: viewRef.current.ty,
+    };
+    setPanning(true);
+  };
+
+  const onPointerMove = (e: ReactPointerEvent<HTMLImageElement>) => {
+    const drag = dragRef.current;
+    if (!drag) return;
+    setView((v) => ({
+      ...v,
+      tx: drag.tx + (e.clientX - drag.x),
+      ty: drag.ty + (e.clientY - drag.y),
+    }));
+  };
+
+  const endPan = (e: ReactPointerEvent<HTMLImageElement>) => {
+    if (!dragRef.current) return;
+    dragRef.current = null;
+    setPanning(false);
+    if (e.currentTarget.hasPointerCapture(e.pointerId)) {
+      e.currentTarget.releasePointerCapture(e.pointerId);
+    }
+  };
+
+  const onDoubleClick = () => {
+    setView((v) =>
+      v.scale > 1.01
+        ? { ...v, scale: 1, tx: 0, ty: 0 }
+        : { ...v, scale: 2, tx: 0, ty: 0 }
+    );
+  };
 
   if (!current || typeof document === "undefined") return null;
 
+  const oddRot = Math.abs(view.rotation) % 180 !== 0;
+  const sx = view.scale * (view.flipX ? -1 : 1);
+  const zoomed = view.scale > 1.01;
+  const zoomPct = `${Math.round(view.scale * 100)}%`;
+
   return createPortal(
     <div
+      ref={rootRef}
       className="md-lightbox"
       role="dialog"
       aria-modal="true"
@@ -95,27 +365,116 @@ export default function ImageLightbox({
           >
             <ChevronRight size={28} />
           </button>
-          <div className="md-lightbox-counter" onClick={(e) => e.stopPropagation()}>
-            {index + 1} / {total}
-          </div>
         </>
       )}
 
-      <figure
-        className="md-lightbox-figure"
-        onClick={(e) => e.stopPropagation()}
+      <div
+        ref={stageRef}
+        className={`md-lightbox-stage${zoomed ? " is-zoomed" : ""}${panning ? " is-panning" : ""}`}
       >
-        {/* eslint-disable-next-line @next/next/no-img-element */}
-        <img
-          src={current.src}
-          alt={current.alt || ""}
-          className="md-lightbox-img"
-          draggable={false}
-        />
+        <figure className="md-lightbox-figure" onClick={(e) => e.stopPropagation()}>
+          {/* eslint-disable-next-line @next/next/no-img-element */}
+          <img
+            src={current.src}
+            alt={current.alt || ""}
+            className={`md-lightbox-img${oddRot ? " is-odd-rot" : ""}${snap ? " is-snap" : ""}`}
+            draggable={false}
+            style={{
+              transform: `translate(${view.tx}px, ${view.ty}px) rotate(${view.rotation}deg) scale(${sx}, ${view.scale})`,
+              filter: view.invert ? "invert(1)" : undefined,
+            }}
+            onPointerDown={onPointerDown}
+            onPointerMove={onPointerMove}
+            onPointerUp={endPan}
+            onPointerCancel={endPan}
+            onDoubleClick={onDoubleClick}
+          />
+        </figure>
+      </div>
+
+      <div className="md-lightbox-footer" onClick={(e) => e.stopPropagation()}>
         {current.alt ? (
-          <figcaption className="md-lightbox-caption">{current.alt}</figcaption>
+          <p className="md-lightbox-caption">{current.alt}</p>
         ) : null}
-      </figure>
+        <div className="md-lightbox-toolbar" role="toolbar" aria-label="图片工具">
+          <ToolBtn
+            label="缩小"
+            disabled={view.scale <= MIN_SCALE}
+            onClick={() => zoomBy(1 / ZOOM_STEP)}
+          >
+            <ZoomOut size={18} />
+          </ToolBtn>
+          <button
+            type="button"
+            className="md-lightbox-zoom-label"
+            aria-label="复位缩放"
+            data-tip="复位缩放"
+            onClick={() => setView((v) => ({ ...v, scale: 1, tx: 0, ty: 0 }))}
+          >
+            {zoomPct}
+          </button>
+          <ToolBtn
+            label="放大"
+            disabled={view.scale >= MAX_SCALE}
+            onClick={() => zoomBy(ZOOM_STEP)}
+          >
+            <ZoomIn size={18} />
+          </ToolBtn>
+          <span className="md-lightbox-sep" aria-hidden />
+          <ToolBtn
+            label="向左旋转"
+            onClick={() =>
+              setView((v) => ({
+                ...v,
+                rotation: v.rotation - 90,
+                tx: 0,
+                ty: 0,
+              }))
+            }
+          >
+            <RotateCcw size={18} />
+          </ToolBtn>
+          <ToolBtn
+            label="向右旋转"
+            onClick={() =>
+              setView((v) => ({
+                ...v,
+                rotation: v.rotation + 90,
+                tx: 0,
+                ty: 0,
+              }))
+            }
+          >
+            <RotateCw size={18} />
+          </ToolBtn>
+          <ToolBtn
+            label="水平翻转"
+            pressed={view.flipX}
+            onClick={() => setView((v) => ({ ...v, flipX: !v.flipX }))}
+          >
+            <FlipHorizontal size={18} />
+          </ToolBtn>
+          <ToolBtn
+            label="反色"
+            pressed={view.invert}
+            onClick={() => setView((v) => ({ ...v, invert: !v.invert }))}
+          >
+            <Contrast size={18} />
+          </ToolBtn>
+          <span className="md-lightbox-sep" aria-hidden />
+          <ToolBtn label="复位" disabled={isIdentity(view)} onClick={resetView}>
+            <Undo2 size={18} />
+          </ToolBtn>
+          {hasNav ? (
+            <>
+              <span className="md-lightbox-sep" aria-hidden />
+              <span className="md-lightbox-counter">
+                {index + 1} / {total}
+              </span>
+            </>
+          ) : null}
+        </div>
+      </div>
     </div>,
     document.body
   );