Open signature in a landscape overlay and fix mobile touch

The inline signature pad on the confirm page was unusable on phones:
the canvas had a fixed 480px internal width but shrank via max-width
on small screens, so pointer coordinates landed in only the top-left
fraction of the drawing buffer. Edge-of-screen strokes also collided
with iOS Safari back-swipe.

Tapping the new signature trigger now opens a full-screen overlay
that rotates to landscape (via 100dvh/100dvw + CSS rotate on portrait
phones, plus an opportunistic screen.orientation.lock) so customers
get the widest possible signing area, away from the system edge.

Also swap the hand-rolled drawing logic for signature_pad, with a
ResizeObserver-driven resize that preserves strokes via
toData/fromData and scales the canvas to devicePixelRatio.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/SignatureOverlay.css

@@ -0,0 +1,75 @@
+.signature-overlay {
+  position: fixed;
+  inset: 0;
+  z-index: 2000;
+  background: #f8fafc;
+  overscroll-behavior: contain;
+  touch-action: none;
+}
+
+.signature-overlay-stage {
+  position: absolute;
+  inset: 0;
+  display: flex;
+  flex-direction: column;
+  padding: 12px 16px;
+  gap: 10px;
+  box-sizing: border-box;
+}
+
+/* Phones in portrait: rotate the whole stage to use landscape space */
+@media (orientation: portrait) and (max-width: 820px) {
+  .signature-overlay-stage {
+    inset: auto;
+    top: 50%;
+    left: 50%;
+    width: 100dvh;
+    height: 100dvw;
+    transform: translate(-50%, -50%) rotate(90deg);
+    transform-origin: center center;
+  }
+}
+
+.signature-overlay-bar {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  flex-shrink: 0;
+}
+
+.signature-overlay-title {
+  font-size: 15px;
+  font-weight: 500;
+  color: #1f2937;
+}
+
+.signature-overlay-pad {
+  flex: 1 1 auto;
+  min-height: 0;
+  border: 1px dashed #94a3b8;
+  border-radius: 12px;
+  background: #ffffff;
+  overflow: hidden;
+  /* keep room from screen edges so iOS back-swipe doesn't intercept */
+  margin: 0 4px;
+}
+
+.signature-pad-wrap {
+  width: 100%;
+  height: 100%;
+  display: block;
+  touch-action: none;
+}
+
+.signature-pad-canvas {
+  display: block;
+  width: 100%;
+  height: 100%;
+  background: #ffffff;
+  touch-action: none;
+  cursor: crosshair;
+}
+
+.signature-overlay-actions {
+  flex-shrink: 0;
+}

src/components/SignatureOverlay.tsx

@@ -0,0 +1,74 @@
+import { useEffect, useRef, useState } from 'react';
+import { Button } from 'antd';
+import SignaturePad, { type SignaturePadHandle } from './SignaturePad';
+import './SignatureOverlay.css';
+
+interface SignatureOverlayProps {
+  open: boolean;
+  onCancel: () => void;
+  onConfirm: (dataUrl: string) => void;
+}
+
+function SignatureOverlay({ open, onCancel, onConfirm }: SignatureOverlayProps) {
+  const padRef = useRef<SignaturePadHandle>(null);
+  const [data, setData] = useState('');
+
+  useEffect(() => {
+    if (!open) return;
+
+    const orientation = (screen as Screen & {
+      orientation?: { lock?: (o: string) => Promise<void> };
+    }).orientation;
+    if (orientation?.lock) {
+      orientation.lock('landscape').catch(() => {
+        // ignore; iOS Safari etc. don't permit lock outside fullscreen
+      });
+    }
+
+    const prevOverflow = document.body.style.overflow;
+    document.body.style.overflow = 'hidden';
+    return () => {
+      document.body.style.overflow = prevOverflow;
+    };
+  }, [open]);
+
+  if (!open) return null;
+
+  const handleClear = () => {
+    padRef.current?.clear();
+    setData('');
+  };
+
+  const handleConfirm = () => {
+    if (padRef.current?.isEmpty()) return;
+    const url = padRef.current?.getDataURL() || data;
+    if (!url) return;
+    onConfirm(url);
+  };
+
+  return (
+    <div className="signature-overlay" role="dialog" aria-modal="true">
+      <div className="signature-overlay-stage">
+        <div className="signature-overlay-bar">
+          <Button type="text" onClick={onCancel}>
+            取消
+          </Button>
+          <span className="signature-overlay-title">请在框内签名</span>
+          <Button type="text" onClick={handleClear}>
+            清除
+          </Button>
+        </div>
+        <div className="signature-overlay-pad">
+          <SignaturePad ref={padRef} onChange={setData} />
+        </div>
+        <div className="signature-overlay-actions">
+          <Button size="large" type="primary" block onClick={handleConfirm}>
+            保存签名
+          </Button>
+        </div>
+      </div>
+    </div>
+  );
+}
+
+export default SignatureOverlay;

src/components/SignaturePad.tsx

@@ -1,4 +1,5 @@
 import { forwardRef, useEffect, useImperativeHandle, useRef } from 'react';
+import SignaturePadLib, { type PointGroup } from 'signature_pad';
 
 export interface SignaturePadHandle {
   clear: () => void;
@@ -7,123 +8,86 @@ export interface SignaturePadHandle {
 }
 
 interface SignaturePadProps {
-  width?: number;
-  height?: number;
   onChange?: (dataUrl: string) => void;
+  className?: string;
 }
 
 const SignaturePad = forwardRef<SignaturePadHandle, SignaturePadProps>(function SignaturePad(
-  { width = 480, height = 180, onChange },
+  { onChange, className },
   ref,
 ) {
+  const wrapRef = useRef<HTMLDivElement>(null);
   const canvasRef = useRef<HTMLCanvasElement>(null);
-  const drawingRef = useRef(false);
-  const emptyRef = useRef(true);
-  const lastPointRef = useRef<{ x: number; y: number } | null>(null);
-
-  const getContext = () => canvasRef.current?.getContext('2d') ?? null;
-
-  const resetCanvas = () => {
-    const canvas = canvasRef.current;
-    const ctx = getContext();
-    if (!canvas || !ctx) return;
-    ctx.fillStyle = '#ffffff';
-    ctx.fillRect(0, 0, canvas.width, canvas.height);
-    ctx.lineWidth = 2.5;
-    ctx.lineCap = 'round';
-    ctx.lineJoin = 'round';
-    ctx.strokeStyle = '#111827';
-    emptyRef.current = true;
-  };
+  const padRef = useRef<SignaturePadLib | null>(null);
+  const onChangeRef = useRef(onChange);
+  onChangeRef.current = onChange;
 
   useEffect(() => {
     const canvas = canvasRef.current;
-    if (!canvas) return;
-    // 高 DPI 适配
-    const ratio = window.devicePixelRatio || 1;
-    canvas.width = width * ratio;
-    canvas.height = height * ratio;
-    canvas.style.width = `${width}px`;
-    canvas.style.height = `${height}px`;
-    const ctx = canvas.getContext('2d');
-    if (ctx) ctx.scale(ratio, ratio);
-    resetCanvas();
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [width, height]);
+    const wrap = wrapRef.current;
+    if (!canvas || !wrap) return;
 
-  const pointFromEvent = (
-    e: React.PointerEvent<HTMLCanvasElement>,
-  ): { x: number; y: number } | null => {
-    const canvas = canvasRef.current;
-    if (!canvas) return null;
-    const rect = canvas.getBoundingClientRect();
-    return {
-      x: e.clientX - rect.left,
-      y: e.clientY - rect.top,
+    const pad = new SignaturePadLib(canvas, {
+      penColor: '#111827',
+      backgroundColor: '#ffffff',
+      minWidth: 0.8,
+      maxWidth: 2.6,
+    });
+    padRef.current = pad;
+
+    const resize = () => {
+      const rect = wrap.getBoundingClientRect();
+      const cssW = Math.max(1, Math.floor(rect.width));
+      const cssH = Math.max(1, Math.floor(rect.height));
+      const ratio = Math.max(1, window.devicePixelRatio || 1);
+
+      const data: PointGroup[] = pad.toData();
+      canvas.width = cssW * ratio;
+      canvas.height = cssH * ratio;
+      canvas.style.width = `${cssW}px`;
+      canvas.style.height = `${cssH}px`;
+      const ctx = canvas.getContext('2d');
+      ctx?.scale(ratio, ratio);
+      pad.clear();
+      if (data.length) pad.fromData(data);
     };
-  };
 
-  const handlePointerDown = (e: React.PointerEvent<HTMLCanvasElement>) => {
-    e.preventDefault();
-    const ctx = getContext();
-    const pt = pointFromEvent(e);
-    if (!ctx || !pt) return;
-    drawingRef.current = true;
-    lastPointRef.current = pt;
-    canvasRef.current?.setPointerCapture(e.pointerId);
-    // 画一个点（防止只点一下没移动看不到痕迹）
-    ctx.beginPath();
-    ctx.arc(pt.x, pt.y, 1.2, 0, Math.PI * 2);
-    ctx.fillStyle = '#111827';
-    ctx.fill();
-    emptyRef.current = false;
-  };
+    resize();
 
-  const handlePointerMove = (e: React.PointerEvent<HTMLCanvasElement>) => {
-    if (!drawingRef.current) return;
-    e.preventDefault();
-    const ctx = getContext();
-    const pt = pointFromEvent(e);
-    const last = lastPointRef.current;
-    if (!ctx || !pt || !last) return;
-    ctx.beginPath();
-    ctx.moveTo(last.x, last.y);
-    ctx.lineTo(pt.x, pt.y);
-    ctx.stroke();
-    lastPointRef.current = pt;
-    emptyRef.current = false;
-  };
+    const handleEnd = () => {
+      onChangeRef.current?.(pad.isEmpty() ? '' : pad.toDataURL('image/png'));
+    };
+    pad.addEventListener('endStroke', handleEnd);
 
-  const handlePointerUp = (e: React.PointerEvent<HTMLCanvasElement>) => {
-    if (!drawingRef.current) return;
-    drawingRef.current = false;
-    lastPointRef.current = null;
-    canvasRef.current?.releasePointerCapture(e.pointerId);
-    if (onChange && canvasRef.current) {
-      onChange(canvasRef.current.toDataURL('image/png'));
-    }
-  };
+    const ro = new ResizeObserver(resize);
+    ro.observe(wrap);
+    window.addEventListener('orientationchange', resize);
+
+    return () => {
+      pad.removeEventListener('endStroke', handleEnd);
+      pad.off();
+      ro.disconnect();
+      window.removeEventListener('orientationchange', resize);
+    };
+  }, []);
 
   useImperativeHandle(ref, () => ({
     clear: () => {
-      resetCanvas();
-      onChange?.('');
+      padRef.current?.clear();
+      onChangeRef.current?.('');
+    },
+    isEmpty: () => padRef.current?.isEmpty() ?? true,
+    getDataURL: () => {
+      const pad = padRef.current;
+      if (!pad || pad.isEmpty()) return '';
+      return pad.toDataURL('image/png');
     },
-    isEmpty: () => emptyRef.current,
-    getDataURL: () => (canvasRef.current ? canvasRef.current.toDataURL('image/png') : ''),
   }));
 
   return (
-    <canvas
-      ref={canvasRef}
-      className="signature-pad-canvas"
-      onPointerDown={handlePointerDown}
-      onPointerMove={handlePointerMove}
-      onPointerUp={handlePointerUp}
-      onPointerCancel={handlePointerUp}
-      onPointerLeave={handlePointerUp}
-      style={{ touchAction: 'none' }}
-    />
+    <div ref={wrapRef} className={`signature-pad-wrap ${className ?? ''}`}>
+      <canvas ref={canvasRef} className="signature-pad-canvas" style={{ touchAction: 'none' }} />
+    </div>
   );
 });
 

src/pages/AftersalesConfirm.tsx

@@ -1,4 +1,4 @@
-import { useEffect, useRef, useState } from 'react';
+import { useEffect, useState } from 'react';
 import { useParams } from 'react-router-dom';
 import { Card, Button, Spin, Result, message, Modal, Input } from 'antd';
 import {
@@ -6,11 +6,12 @@ import {
   CloseCircleOutlined,
   ClockCircleOutlined,
   ExclamationCircleOutlined,
+  EditOutlined,
 } from '@ant-design/icons';
 import { aftersalesApi } from '@/services/api';
 import type { AftersalesPublicView, AftersalesServiceType } from '@/types';
 import PublicLayout, { PublicLogo } from '@/components/PublicLayout';
-import SignaturePad, { type SignaturePadHandle } from '@/components/SignaturePad';
+import SignatureOverlay from '@/components/SignatureOverlay';
 import './styles/PublicQuery.css';
 import './styles/AftersalesConfirm.css';
 
@@ -29,8 +30,7 @@ function AftersalesConfirmPage() {
   const [rejectReason, setRejectReason] = useState('');
   const [showRejectDialog, setShowRejectDialog] = useState(false);
   const [signatureData, setSignatureData] = useState('');
-
-  const signatureRef = useRef<SignaturePadHandle>(null);
+  const [showSignatureOverlay, setShowSignatureOverlay] = useState(false);
 
   const loadOrder = async () => {
     setLoading(true);
@@ -53,7 +53,7 @@ function AftersalesConfirmPage() {
   }, [serialNumber]);
 
   const handleAuthorize = async () => {
-    if (signatureRef.current?.isEmpty() || !signatureData) {
+    if (!signatureData) {
       message.error('请先签名');
       return;
     }
@@ -100,7 +100,6 @@ function AftersalesConfirmPage() {
   };
 
   const handleClearSignature = () => {
-    signatureRef.current?.clear();
     setSignatureData('');
   };
 
@@ -236,14 +235,33 @@ function AftersalesConfirmPage() {
           <>
             <div className="aftersales-signature-section">
               <div className="aftersales-signature-header">
-                <p className="aftersales-signature-tip">请在下方签名确认维修结果</p>
-                <Button size="small" type="link" onClick={handleClearSignature}>
-                  清除签名
-                </Button>
-              </div>
-              <div className="aftersales-signature-canvas-wrap">
-                <SignaturePad ref={signatureRef} onChange={setSignatureData} />
+                <p className="aftersales-signature-tip">请签名确认维修结果</p>
+                {signatureData && (
+                  <Button size="small" type="link" onClick={handleClearSignature}>
+                    清除签名
+                  </Button>
+                )}
               </div>
+              {signatureData ? (
+                <button
+                  type="button"
+                  className="aftersales-signature-preview"
+                  onClick={() => setShowSignatureOverlay(true)}
+                >
+                  <img src={signatureData} alt="客户签名" />
+                  <span className="aftersales-signature-preview-hint">点击可重新签名</span>
+                </button>
+              ) : (
+                <button
+                  type="button"
+                  className="aftersales-signature-trigger"
+                  onClick={() => setShowSignatureOverlay(true)}
+                >
+                  <EditOutlined />
+                  <span>点击此处签名</span>
+                  <small>将进入横屏签名页</small>
+                </button>
+              )}
             </div>
             <div className="aftersales-actions">
               <Button
@@ -269,6 +287,15 @@ function AftersalesConfirmPage() {
         )}
       </Card>
 
+      <SignatureOverlay
+        open={showSignatureOverlay}
+        onCancel={() => setShowSignatureOverlay(false)}
+        onConfirm={(url) => {
+          setSignatureData(url);
+          setShowSignatureOverlay(false);
+        }}
+      />
+
       <Modal
         title="请说明退回原因"
         open={showRejectDialog}

src/pages/styles/AftersalesConfirm.css

@@ -51,23 +51,64 @@
   font-weight: 500;
 }
 
-.aftersales-signature-canvas-wrap {
-  border: 1px dashed #94a3b8;
+.aftersales-signature-trigger {
+  width: 100%;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: 6px;
+  padding: 22px 16px;
+  border: 1.5px dashed #94a3b8;
+  border-radius: 12px;
+  background: #f8fafc;
+  color: #1f2937;
+  font-size: 16px;
+  font-weight: 500;
+  cursor: pointer;
+  -webkit-tap-highlight-color: transparent;
+  transition: background 0.15s, border-color 0.15s;
+}
+
+.aftersales-signature-trigger:active {
+  background: #eef2f7;
+  border-color: #1677ff;
+}
+
+.aftersales-signature-trigger .anticon {
+  font-size: 22px;
+  color: #1677ff;
+}
+
+.aftersales-signature-trigger small {
+  color: #6b7280;
+  font-size: 12px;
+  font-weight: 400;
+}
+
+.aftersales-signature-preview {
+  width: 100%;
+  padding: 8px;
+  border: 1px solid #e5e7eb;
   border-radius: 10px;
   background: #ffffff;
   display: flex;
-  justify-content: center;
-  padding: 8px;
-  touch-action: none;
+  flex-direction: column;
+  align-items: center;
+  gap: 6px;
+  cursor: pointer;
+  -webkit-tap-highlight-color: transparent;
 }
 
-.signature-pad-canvas {
-  display: block;
+.aftersales-signature-preview img {
   max-width: 100%;
-  touch-action: none;
-  background: #ffffff;
-  border-radius: 6px;
-  cursor: crosshair;
+  max-height: 160px;
+  display: block;
+}
+
+.aftersales-signature-preview-hint {
+  font-size: 12px;
+  color: #6b7280;
 }
 
 .aftersales-signature-archived {