fix(pdf): live ink follows pen + stop zoom jump

Two critical PDF-editor bugs.

1. Live ink only appeared after lifting the pen. The page overlay
   painter captured the live stroke as a build-time snapshot, so
   per-move repaints redrew stale (null) data until commit. Route
   the live stroke through a ValueNotifier the painter reads at
   paint time (repaint: merge(overlayRepaint, liveStrokeVN)).

2. Pinch-zoom jumped on Windows touch. pdfrx's internal forked
   InteractiveViewer scales with an unguarded scaleStart*details.scale
   that pops on a touch-count blip or one-frame spike. Take over the
   pinch: scaleEnabled:false (pdfrx keeps 1-finger scroll + wheel),
   a glitch-guarded ScaleGestureRecognizer drives focal zoom via the
   pdfrx controller, reusing absolutePinchScale + the re-baseline /
   per-frame-clamp / focal-jump guards already proven on the note
   canvas.

Zoom + pen feel are device-validated. analyze clean, tests green.

lib/editor/canvas/pen_editor_screen.dart

@@ -20,7 +20,9 @@
 // wiring verbatim. Highlights are in-memory only for now — see
 // TODO(persist-highlights).
 
-import 'package:flutter/gestures.dart' show PointerDeviceKind;
+import 'package:flutter/foundation.dart'
+    show ValueListenable, visibleForTesting;
+import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:pdfrx/pdfrx.dart';
 import 'package:uuid/uuid.dart';
@@ -50,6 +52,7 @@ import 'input_diagnostics.dart';
 import 'pen_canvas.dart' show CanvasTool;
 import 'pen_palette_widgets.dart';
 import 'pen_stroke.dart';
+import 'pinch_scale_solver.dart';
 
 /// Stable deterministic document-id for a file path (djb2 hash → hex).
 ///
@@ -132,6 +135,42 @@ class _PenEditorScreenState extends State<PenEditorScreen> {
   final ValueNotifier<int> _overlayRepaint = ValueNotifier<int>(0);
   void _bumpOverlay() => _overlayRepaint.value++;
 
+  // ── Glitch-guarded pinch zoom (we own scale; pdfrx owns scroll) ─────────────
+  // pdfrx's scaleEnabled is off, so we drive 2-finger zoom through the public
+  // controller (zoomOnLocalPosition) with the SAME guards as the note canvas's
+  // PenInteractiveViewer: per-frame scale-ratio clamp, pointer-count re-baseline
+  // to the last APPLIED scale, and a focal-jump guard. Tracking is absolute from
+  // a gesture-start snapshot via absolutePinchScale() — never a live read-back.
+
+  static const double _kPinchMinScale = 0.5;
+  static const double _kPinchMaxScale = 8.0;
+
+  /// A real pinch changes scale modestly per frame; a frame demanding far more
+  /// is a Windows multi-touch glitch and is dropped (so the zoom can't pop).
+  static const double _kScaleGlitchHi = 1.4;
+  static const double _kScaleGlitchLo = 1 / _kScaleGlitchHi;
+
+  /// A single-frame focal-midpoint jump beyond this is a touch misread → drop.
+  static const double _kFocalGlitchPx = 250.0;
+
+  /// Matrix scale captured at the current baseline (gesture start or the last
+  /// pointer-count re-baseline). Null when no pinch is active.
+  double? _pinchScaleStart;
+
+  /// Pointer count of the previous accepted pinch frame; a change re-baselines.
+  int _pinchPointerCount = 0;
+
+  /// The recognizer's cumulative `details.scale` on the previous accepted frame.
+  double _pinchLastRawScale = 1.0;
+
+  /// The absolute scale we last APPLIED. Re-baseline anchors to THIS (not a live
+  /// matrix read) so the displayed scale stays continuous across a finger blip.
+  double _pinchLastAppliedScale = 1.0;
+
+  /// The recognizer's cumulative `details.scale` at the current baseline; the
+  /// absolute target normalizes against it (see [absolutePinchScale]).
+  double _pinchRawScaleAtBaseline = 1.0;
+
   // ── Live stroke state (viewer-level pen capture) ────────────────────────────
 
   /// The page index the in-progress stroke belongs to (the page of its first
@@ -142,8 +181,16 @@ class _PenEditorScreenState extends State<PenEditorScreen> {
   /// In-progress stroke points (normalized to [_liveStrokePage]).
   final List<PenPoint> _livePoints = [];
 
-  /// Live stroke snapshot for the page overlay; null when idle.
+  /// CURRENT live stroke, published to the page overlay painters. The painter
-  PenStroke? _liveStroke;
+  /// reads this at PAINT time (not as a build-time snapshot), so a mid-stroke
+  /// update repaints immediately — the ink follows the pen instead of only
+  /// appearing on pointer-up. Null when idle.
+  ///
+  /// (The previous design passed a snapshot into the painter's constructor from
+  /// pageOverlaysBuilder, which only re-runs on setState; _bumpOverlay repainted
+  /// the painter but it still read the stale build-time snapshot → invisible ink
+  /// until commit. See `_LiveStrokeData` / `_PageOverlayPainter`.)
+  final ValueNotifier<_LiveStrokeData?> _liveStrokeVN = ValueNotifier(null);
 
   /// Latest pen-event debug readout — shown only when the diagnostic toggle is
   /// on, to inspect what Windows delivers.
@@ -310,6 +357,7 @@ class _PenEditorScreenState extends State<PenEditorScreen> {
       scheduler.dispose();
     }
     _overlayRepaint.dispose();
+    _liveStrokeVN.dispose();
     _penConfig?.dispose();
     PenInputService.instance.stop();
     DiagnosticLogger.instance.stop();
@@ -481,14 +529,16 @@ class _PenEditorScreenState extends State<PenEditorScreen> {
   void _updateLiveStroke() {
     final page = _liveStrokePage;
     if (page == null || _livePoints.isEmpty) return;
-    _liveStroke = PenStroke(
+    final stroke = PenStroke(
       points: List.of(_livePoints),
       color: _currentColor().toARGB32(),
       width: _currentStrokeWidth(),
       kind: _currentKind(),
       brush: _currentBrush(),
     );
-    _bumpOverlay();
+    // Publish the live stroke so the page overlay painter repaints it NOW
+    // (notifies its repaint Listenable) — the ink follows the pen.
+    _liveStrokeVN.value = _LiveStrokeData(page, stroke);
   }
 
   void _endStroke({required bool commit}) {
@@ -509,7 +559,7 @@ class _PenEditorScreenState extends State<PenEditorScreen> {
     }
     _liveStrokePage = null;
     _livePoints.clear();
-    _liveStroke = null;
+    _liveStrokeVN.value = null;
     _bumpOverlay();
   }
 
@@ -582,6 +632,68 @@ class _PenEditorScreenState extends State<PenEditorScreen> {
     });
   }
 
+  // ── Pinch zoom (glitch-guarded, drives pdfrx controller) ────────────────────
+
+  void _onPinchStart(ScaleStartDetails details) {
+    if (!_controller.isReady) return;
+    _pinchScaleStart = _controller.currentZoom;
+    _pinchPointerCount = details.pointerCount;
+    _pinchLastRawScale = 1.0;
+    _pinchLastAppliedScale = _pinchScaleStart!;
+    _pinchRawScaleAtBaseline = 1.0;
+  }
+
+  void _onPinchUpdate(ScaleUpdateDetails details) {
+    final scaleStart = _pinchScaleStart;
+    if (scaleStart == null || !_controller.isReady) return;
+
+    // Re-baseline on any pointer-count change (a finger lands/lifts, or a
+    // Windows touch 2↔1↔2 dropout). Anchor to the CLEAN tracked scale, not a
+    // matrix read-back, so the displayed scale is continuous; skip this frame.
+    if (details.pointerCount != _pinchPointerCount) {
+      _pinchPointerCount = details.pointerCount;
+      _pinchScaleStart = _pinchLastAppliedScale;
+      _pinchLastRawScale = details.scale;
+      _pinchRawScaleAtBaseline = details.scale;
+      return;
+    }
+
+    // Per-frame finger-motion ratio from the recognizer's OWN cumulative scale.
+    // A ratio outside the glitch band is a multi-touch spike → drop the frame;
+    // absolute tracking means the next good frame resumes from the true span.
+    final rawRatio =
+        _pinchLastRawScale > 0 ? details.scale / _pinchLastRawScale : 1.0;
+    final scaleDrop =
+        rawRatio > _kScaleGlitchHi || rawRatio < _kScaleGlitchLo;
+    final focalDrop = details.focalPointDelta.distance > _kFocalGlitchPx;
+    if (scaleDrop || focalDrop) return;
+
+    final targetScale = absolutePinchScale(
+      scaleStart: _pinchScaleStart!,
+      rawScaleAtBaseline: _pinchRawScaleAtBaseline,
+      rawScale: details.scale,
+      minScale: _kPinchMinScale,
+      maxScale: _kPinchMaxScale,
+    );
+
+    // Focal zoom: keep the document point under the live focal (finger midpoint)
+    // fixed, which also yields 2-finger pan for free as the focal moves.
+    // localFocalPoint is in the viewer's local coords (the overlay fills it).
+    _controller.zoomOnLocalPosition(
+      localPosition: details.localFocalPoint,
+      newZoom: targetScale,
+      duration: Duration.zero,
+    );
+
+    _pinchLastRawScale = details.scale;
+    _pinchLastAppliedScale = targetScale;
+  }
+
+  void _onPinchEnd(ScaleEndDetails details) {
+    _pinchScaleStart = null;
+    _pinchPointerCount = 0;
+  }
+
   // ── Text selection → highlight ─────────────────────────────────────────────
 
   void _onTextSelectionChange(PdfTextSelection selection) {
@@ -804,6 +916,15 @@ class _PenEditorScreenState extends State<PenEditorScreen> {
       widget.pdfPath,
       controller: _controller,
       params: PdfViewerParams(
+        // pdfrx keeps 1-finger scroll + wheel (panEnabled) but we TAKE OVER the
+        // 2-finger pinch (scaleEnabled:false): pdfrx's forked InteractiveViewer
+        // applies `desiredScale = _scaleStart * details.scale` with no per-frame
+        // glitch guard, so a Windows-touch scale spike or pointer-count blip pops
+        // the zoom and snaps back. We drive zoom ourselves via the glitch-guarded
+        // _TwoFingerPinch recognizer in viewerOverlayBuilder → controller.
+        // zoomOnLocalPosition (focal zoom). See _onPinchUpdate.
+        panEnabled: true,
+        scaleEnabled: false,
         // Native vector text selection. Pen falls through to this only in
         // select-text mode (PenCaptureRegion.captureEnabled == false).
         textSelectionParams: PdfTextSelectionParams(
@@ -840,11 +961,11 @@ class _PenEditorScreenState extends State<PenEditorScreen> {
               child: IgnorePointer(
                 child: CustomPaint(
                   painter: _PageOverlayPainter(
-                    repaint: _overlayRepaint,
+                    overlayRepaint: _overlayRepaint,
+                    liveStrokeVN: _liveStrokeVN,
+                    pageIndex: pageIndex,
                     strokes: _strokesByPage[pageIndex] ?? const [],
                     highlights: _highlightsByPage[pageIndex] ?? const [],
-                    liveStroke:
-                        _liveStrokePage == pageIndex ? _liveStroke : null,
                     pageSize: pageRectInViewer.size,
                     thinning: _penConfig?.value.pressureSensitivity ??
                         kDefaultPenThinning,
@@ -883,11 +1004,32 @@ class _PenEditorScreenState extends State<PenEditorScreen> {
               ),
           ];
         },
-        // (2) Viewer-level pen capture. Stylus is captured ONLY when a pen tool
+        // (2) Viewer-level pen capture + our glitch-guarded pinch. Stylus is
-        // is active; touch/mouse (and pen in select-text mode) fall through to
+        // captured ONLY when a pen tool is active; touch/mouse (and pen in
-        // pdfrx for scroll/zoom/text-selection.
+        // select-text mode) fall through to pdfrx for scroll/text-selection.
+        // The pinch recognizer is touch-only and concedes the arena below 2
+        // pointers, so 1-finger scroll still reaches pdfrx and the pen (captured
+        // outside the arena by PenCaptureRegion) is never stolen.
         viewerOverlayBuilder: (context, size, handleLinkTap) {
           return [
+            Positioned.fill(
+              child: RawGestureDetector(
+                // translucent (NOT opaque): the touch must ALSO hit-test pdfrx
+                // underneath so its pan recognizer can win the 1-finger case.
+                behavior: HitTestBehavior.translucent,
+                gestures: {
+                  _TwoFingerPinch:
+                      GestureRecognizerFactoryWithHandlers<_TwoFingerPinch>(
+                    () => _TwoFingerPinch(debugOwner: this),
+                    (r) => r
+                      ..onStart = _onPinchStart
+                      ..onUpdate = _onPinchUpdate
+                      ..onEnd = _onPinchEnd,
+                  ),
+                },
+                child: const SizedBox.expand(),
+              ),
+            ),
             Positioned.fill(
               child: PenCaptureRegion(
                 captureEnabled: _penCaptureEnabled,
@@ -1151,23 +1293,88 @@ class _PenEditorScreenState extends State<PenEditorScreen> {
   }
 }
 
+/// A [ScaleGestureRecognizer] that competes ONLY for 2-finger touch gestures.
+///
+/// pdfrx's internal pan recognizer runs underneath (scaleEnabled is off, so it
+/// still scrolls on 1 finger). A vanilla ScaleGestureRecognizer is eager: with a
+/// single uncontested pointer it would win the arena and STEAL 1-finger scroll.
+/// Restricting [supportedDevices] to touch keeps the stylus out (the pen is
+/// captured outside the arena by [PenCaptureRegion]); rejecting the pointer while
+/// fewer than 2 are down hands the 1-finger gesture back to pdfrx immediately,
+/// and accepting on the 2nd finger lets us drive the pinch. Guarding inside
+/// onUpdate would be too late — by then the arena is already won.
+class _TwoFingerPinch extends ScaleGestureRecognizer {
+  _TwoFingerPinch({super.debugOwner})
+      : super(supportedDevices: const {PointerDeviceKind.touch});
+
+  final Set<int> _pointers = <int>{};
+
+  @override
+  void addAllowedPointer(PointerDownEvent event) {
+    _pointers.add(event.pointer);
+    super.addAllowedPointer(event);
+    if (_pointers.length < 2) {
+      // Concede the 1-finger case now so pdfrx's pan wins without waiting.
+      resolvePointer(event.pointer, GestureDisposition.rejected);
+    } else {
+      // Second finger down: claim the gesture before pdfrx treats it as a pan.
+      resolve(GestureDisposition.accepted);
+    }
+  }
+
+  @override
+  void handleEvent(PointerEvent event) {
+    if (event is PointerUpEvent || event is PointerCancelEvent) {
+      _pointers.remove(event.pointer);
+    }
+    super.handleEvent(event);
+  }
+
+  @override
+  void rejectGesture(int pointer) {
+    _pointers.remove(pointer);
+    super.rejectGesture(pointer);
+  }
+}
+
+/// The currently in-progress stroke and the page it belongs to. Published via a
+/// [ValueNotifier] so [_PageOverlayPainter] can read the live stroke at PAINT
+/// time (driven by the notifier) instead of capturing a stale build-time
+/// snapshot — that snapshot bug made ink appear only on pointer-up.
+class _LiveStrokeData {
+  const _LiveStrokeData(this.page, this.stroke);
+
+  final int page;
+  final PenStroke stroke;
+}
+
 /// Paints one page's overlay: text highlights (under), committed ink, then the
 /// live in-progress stroke (over). Strokes are in normalized page coords; the
 /// painter scales them to the on-screen page rect ([pageSize]) so they stay
 /// glued to the page under pdfrx's native zoom/scroll.
+///
+/// The live stroke is read from [liveStrokeVN] at paint time (not passed as a
+/// constructor snapshot) so that mid-stroke updates — which notify the merged
+/// repaint Listenable — redraw the in-progress ink immediately. Committed
+/// strokes + highlights still arrive via the constructor (they change only on
+/// setState, which rebuilds this painter).
 class _PageOverlayPainter extends CustomPainter {
   _PageOverlayPainter({
-    required Listenable repaint,
+    required Listenable overlayRepaint,
+    required this.liveStrokeVN,
+    required this.pageIndex,
     required this.strokes,
     required this.highlights,
-    required this.liveStroke,
     required this.pageSize,
     required this.thinning,
-  }) : super(repaint: repaint);
+  }) : super(repaint: Listenable.merge([overlayRepaint, liveStrokeVN]));
 
+  /// Live stroke source, read at paint time. Only painted when its page matches
+  /// [pageIndex].
+  final ValueListenable<_LiveStrokeData?> liveStrokeVN;
+  final int pageIndex;
   final List<PenStroke> strokes;
   final List<Rect> highlights;
-  final PenStroke? liveStroke;
   final Size pageSize;
   final double thinning;
 
@@ -1205,16 +1412,16 @@ class _PageOverlayPainter extends CustomPainter {
       );
     }
 
-    // 3. Live stroke.
+    // 3. Live stroke — read from the notifier at paint time, only for this page.
-    final live = liveStroke;
+    final live = liveStrokeVN.value;
-    if (live != null && live.points.isNotEmpty) {
+    if (live != null && live.page == pageIndex && live.stroke.points.isNotEmpty) {
-      final path =
+      final path = buildStrokePath(live.stroke, size,
-          buildStrokePath(live, size, isComplete: false, thinning: thinning);
+          isComplete: false, thinning: thinning);
       if (!path.getBounds().isEmpty) {
         canvas.drawPath(
           path,
           Paint()
-            ..color = Color(live.color)
+            ..color = Color(live.stroke.color)
             ..style = PaintingStyle.fill
             ..isAntiAlias = true,
         );
@@ -1224,15 +1431,55 @@ class _PageOverlayPainter extends CustomPainter {
 
   @override
   bool shouldRepaint(_PageOverlayPainter old) =>
+      !identical(old.liveStrokeVN, liveStrokeVN) ||
+      old.pageIndex != pageIndex ||
       !identical(old.strokes, strokes) ||
       old.strokes.length != strokes.length ||
       !identical(old.highlights, highlights) ||
       old.highlights.length != highlights.length ||
-      !identical(old.liveStroke, liveStroke) ||
       old.pageSize != pageSize ||
       old.thinning != thinning;
 }
 
+/// Test-only handle on the live-stroke painter wiring (Bug 1 regression guard).
+///
+/// The live stroke must be read from a [ValueListenable] at PAINT time, so a
+/// mid-stroke update repaints WITHOUT a rebuild of `pageOverlaysBuilder`. This
+/// seam lets a widget test pump the real painter and assert that pushing a new
+/// value into the notifier triggers a repaint (which the old build-time-snapshot
+/// design did not).
+@visibleForTesting
+class LiveStrokeOverlayHarness {
+  LiveStrokeOverlayHarness({required this.pageIndex});
+
+  final int pageIndex;
+  final ValueNotifier<int> overlayRepaint = ValueNotifier<int>(0);
+  final ValueNotifier<_LiveStrokeData?> _liveStrokeVN = ValueNotifier(null);
+
+  /// Push a live stroke for [page] (or null to clear). Mirrors what
+  /// `_updateLiveStroke`/`_endStroke` do at runtime.
+  void setLiveStroke(int page, PenStroke? stroke) {
+    _liveStrokeVN.value = stroke == null ? null : _LiveStrokeData(page, stroke);
+  }
+
+  /// The real [CustomPainter] used by the editor, wired to this harness's
+  /// notifiers exactly as `pageOverlaysBuilder` wires it.
+  CustomPainter buildPainter() => _PageOverlayPainter(
+        overlayRepaint: overlayRepaint,
+        liveStrokeVN: _liveStrokeVN,
+        pageIndex: pageIndex,
+        strokes: const [],
+        highlights: const [],
+        pageSize: const Size(100, 100),
+        thinning: kDefaultPenThinning,
+      );
+
+  void dispose() {
+    overlayRepaint.dispose();
+    _liveStrokeVN.dispose();
+  }
+}
+
 /// A small sticky-note "tab" marker glued to a page at a scratch-link anchor.
 /// Tap opens the anchor's split view; long-press deletes the anchor.
 class _ScratchLinkMarker extends StatelessWidget {

test/pen_editor_live_stroke_test.dart

@@ -0,0 +1,126 @@
+// Regression guard for Bug 1 ("字迹写完才出现"): the PDF editor's per-page overlay
+// painter must read the in-progress stroke from a ValueListenable at PAINT time,
+// so a mid-stroke update repaints the live ink WITHOUT re-running
+// pageOverlaysBuilder (which only re-runs on setState). The old design captured
+// the live stroke as a build-time snapshot, so _bumpOverlay repainted the
+// painter but it still drew the stale (null) snapshot — the stroke only appeared
+// on pointer-up.
+//
+// These tests pump the REAL _PageOverlayPainter (via LiveStrokeOverlayHarness)
+// and assert (1) paint() reflects the CURRENT notifier value, and (2) updating
+// the notifier alone drives a CustomPaint repaint with no widget rebuild.
+
+import 'dart:ui' as ui;
+
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:badnote/editor/canvas/pen_editor_screen.dart';
+import 'package:badnote/editor/canvas/pen_stroke.dart';
+import 'package:badnote/editor/engine/brush.dart';
+
+PenStroke _stroke() => PenStroke(
+      points: const [
+        PenPoint(0.2, 0.2, 0.8),
+        PenPoint(0.5, 0.5, 0.8),
+        PenPoint(0.8, 0.8, 0.8),
+      ],
+      color: 0xFF000000,
+      width: 0.01,
+      kind: PenStrokeKind.pen,
+      brush: BrushKind.fountainPen,
+    );
+
+/// Records the number of drawPath calls a painter issues for the given size.
+int _drawPathCount(CustomPainter painter, Size size) {
+  final recorder = ui.PictureRecorder();
+  final canvas = _CountingCanvas(Canvas(recorder));
+  painter.paint(canvas, size);
+  recorder.endRecording().dispose();
+  return canvas.drawPathCount;
+}
+
+void main() {
+  const size = Size(100, 100);
+
+  test('paint() reads the CURRENT live stroke from the notifier at paint time',
+      () {
+    final harness = LiveStrokeOverlayHarness(pageIndex: 0);
+    addTearDown(harness.dispose);
+    final painter = harness.buildPainter();
+
+    // Idle: nothing to draw.
+    expect(_drawPathCount(painter, size), 0);
+
+    // Mid-stroke: pushing a live stroke into the notifier must make the SAME
+    // painter instance draw it on the next paint (no reconstruction).
+    harness.setLiveStroke(0, _stroke());
+    expect(_drawPathCount(painter, size), 1,
+        reason: 'painter must read the live stroke at paint time, not a '
+            'build-time snapshot');
+
+    // Cleared: back to nothing.
+    harness.setLiveStroke(0, null);
+    expect(_drawPathCount(painter, size), 0);
+  });
+
+  test('a live stroke on a DIFFERENT page is not painted here', () {
+    final harness = LiveStrokeOverlayHarness(pageIndex: 0);
+    addTearDown(harness.dispose);
+    final painter = harness.buildPainter();
+
+    harness.setLiveStroke(3, _stroke()); // belongs to page 3, not page 0
+    expect(_drawPathCount(painter, size), 0);
+  });
+
+  testWidgets('updating the live-stroke notifier repaints without a rebuild',
+      (tester) async {
+    final harness = LiveStrokeOverlayHarness(pageIndex: 0);
+    addTearDown(harness.dispose);
+
+    var builds = 0;
+    await tester.pumpWidget(
+      Directionality(
+        textDirection: TextDirection.ltr,
+        child: Builder(builder: (context) {
+          builds++;
+          return CustomPaint(
+            painter: harness.buildPainter(),
+            size: size,
+          );
+        }),
+      ),
+    );
+    expect(builds, 1);
+
+    // Pushing a live stroke must trigger a repaint of the CustomPaint via its
+    // merged repaint Listenable — WITHOUT rebuilding the widget tree (which is
+    // exactly the path _bumpOverlay/setState would NOT cover mid-stroke).
+    harness.setLiveStroke(0, _stroke());
+    await tester.pump();
+    expect(builds, 1, reason: 'no widget rebuild should be needed');
+
+    // And the painter now draws the live ink.
+    expect(_drawPathCount(harness.buildPainter(), size), 1);
+  });
+}
+
+/// A [Canvas] proxy that counts drawPath calls.
+class _CountingCanvas implements Canvas {
+  _CountingCanvas(this._inner);
+
+  final Canvas _inner;
+  int drawPathCount = 0;
+
+  @override
+  void drawPath(ui.Path path, ui.Paint paint) {
+    drawPathCount++;
+    _inner.drawPath(path, paint);
+  }
+
+  @override
+  void noSuchMethod(Invocation invocation) =>
+      _forward(invocation);
+
+  dynamic _forward(Invocation i) => null;
+}