scroll

lib/widgets/swipe_question_tile.dart

@@ -1,6 +1,7 @@
 import 'dart:async';
 import 'dart:math' as math;
 
+import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 
@@ -76,6 +77,39 @@ class _SwipeQuestionTileState extends State<SwipeQuestionTile>
   double get _snappedVerticalOffset =>
       _snappedSliderValue / _sliderMax * _maxVerticalDrag;
 
+  void _applyVerticalInputDelta(double dy) {
+    setState(() {
+      _verticalOffset -= dy;
+      _verticalOffset = _verticalOffset.clamp(
+        -_maxVerticalDrag,
+        _maxVerticalDrag,
+      );
+      if (_atZero) {
+        _dragOffset = 0;
+      }
+      _maybeTriggerSnapFeedback(_snappedSliderValue);
+    });
+  }
+
+  /// One wheel notch / trackpad tick → one integer on the [-10, 10] scale.
+  void _stepSliderFromScroll(double scrollDy) {
+    if (scrollDy == 0) {
+      return;
+    }
+    final int next = (_snappedSliderValue + (scrollDy > 0 ? -1 : 1))
+        .clamp(_sliderMin, _sliderMax);
+    if (next == _snappedSliderValue) {
+      return;
+    }
+    setState(() {
+      _verticalOffset = next / _sliderMax * _maxVerticalDrag;
+      if (_atZero) {
+        _dragOffset = 0;
+      }
+      _maybeTriggerSnapFeedback(next);
+    });
+  }
+
   void _maybeTriggerSnapFeedback(int snapped) {
     if (snapped == _lastSnappedValue) {
       return;
@@ -216,26 +250,25 @@ class _SwipeQuestionTileState extends State<SwipeQuestionTile>
                               bottom: 8,
                               left: constraints.maxWidth * 0.22,
                               right: constraints.maxWidth * 0.22,
+                              child: Listener(
+                                onPointerSignal: (PointerSignalEvent event) {
+                                  if (widget.busy || _acting) {
+                                    return;
+                                  }
+                                  if (event is PointerScrollEvent) {
+                                    _stepSliderFromScroll(
+                                      event.scrollDelta.dy,
+                                    );
+                                  }
+                                },
                                 child: GestureDetector(
                                   behavior: HitTestBehavior.opaque,
                                   onVerticalDragUpdate: widget.busy || _acting
                                       ? null
-                                    : (DragUpdateDetails details) {
+                                      : (DragUpdateDetails details) =>
-                                        setState(() {
+                                            _applyVerticalInputDelta(
-                                          _verticalOffset -= details.delta.dy;
+                                          details.delta.dy,
-                                          _verticalOffset =
+                                        ),
-                                              _verticalOffset.clamp(
-                                            -_maxVerticalDrag,
-                                            _maxVerticalDrag,
-                                          );
-                                          if (_atZero) {
-                                            _dragOffset = 0;
-                                          }
-                                          _maybeTriggerSnapFeedback(
-                                            _snappedSliderValue,
-                                          );
-                                        });
-                                      },
                                   child: Center(
                                     child: Transform.translate(
                                       offset:
@@ -249,6 +282,7 @@ class _SwipeQuestionTileState extends State<SwipeQuestionTile>
                                   ),
                                 ),
                               ),
+                            ),
                           ],
                         ),
                       ),