Use shouldIgnorePointer of scroll position

package/lib/src/scrollable/scrollable_sheet_activity.dart

@@ -12,6 +12,18 @@ import 'scrollable_sheet_extent.dart';
 import 'sheet_content_scroll_activity.dart';
 import 'sheet_content_scroll_position.dart';
 
+/// A [SheetActivity] that is associated with a [SheetContentScrollPosition].
+///
+/// This activity is responsible for both scrolling a scrollable content
+/// in the sheet and dragging the sheet itself.
+///
+/// [shouldIgnorePointer] and [SheetContentScrollPosition.shouldIgnorePointer]
+/// of the associated scroll position may be synchronized, but not always.
+/// For example, [BallisticScrollDrivenSheetActivity]'s [shouldIgnorePointer]
+/// is always `false` while the associated scroll position sets it to `true`
+/// in most cases to ensure that the pointer events, which potentially
+/// interrupt the ballistic scroll animation, are not stolen by clickable
+/// items in the scroll view.
 @internal
 abstract class ScrollableSheetActivity
     extends SheetActivity<ScrollableSheetExtent> {
@@ -196,7 +208,6 @@ class DragScrollDrivenSheetActivity extends ScrollableSheetActivity
       ..didDragEnd(details)
       ..goBallisticWithScrollPosition(
         velocity: -1 * details.velocityY,
-        shouldIgnorePointer: false,
         scrollPosition: scrollPosition,
       );
   }
@@ -215,14 +226,10 @@ class BallisticScrollDrivenSheetActivity extends ScrollableSheetActivity
     super.scrollPosition, {
     required this.simulation,
     required double initialPixels,
-    required this.shouldIgnorePointer,
   }) : _oldPixels = initialPixels;
 
   final Simulation simulation;
 
-  @override
-  final bool shouldIgnorePointer;
-
   double _oldPixels;
 
   @override
@@ -271,7 +278,6 @@ class BallisticScrollDrivenSheetActivity extends ScrollableSheetActivity
   void _end() {
     owner.goBallisticWithScrollPosition(
       velocity: 0,
-      shouldIgnorePointer: shouldIgnorePointer,
       scrollPosition: scrollPosition,
     );
   }

package/lib/src/scrollable/scrollable_sheet_extent.dart

@@ -161,7 +161,6 @@ class ScrollableSheetExtent extends SheetExtent
   @override
   void goBallisticWithScrollPosition({
     required double velocity,
-    required bool shouldIgnorePointer,
     required SheetContentScrollPosition scrollPosition,
   }) {
     assert(metrics.hasDimensions);
@@ -196,13 +195,12 @@ class ScrollableSheetExtent extends SheetExtent
           scrollPosition,
           simulation: scrollSimulation,
           initialPixels: scrollPixelsForScrollPhysics,
-          shouldIgnorePointer: shouldIgnorePointer,
         ),
       );
       scrollPosition.beginActivity(
         SheetContentBallisticScrollActivity(
           delegate: scrollPosition,
-          shouldIgnorePointer: shouldIgnorePointer,
+          shouldIgnorePointer: scrollPosition.shouldIgnorePointer,
           getVelocity: () => activity.velocity,
         ),
       );

package/lib/src/scrollable/sheet_content_scroll_position.dart

@@ -32,7 +32,6 @@ abstract class SheetContentScrollPositionOwner {
 
   void goBallisticWithScrollPosition({
     required double velocity,
-    required bool shouldIgnorePointer,
     required SheetContentScrollPosition scrollPosition,
   });
 }
@@ -69,6 +68,10 @@ class SheetContentScrollPosition extends ScrollPositionWithSingleContext {
   double _heldPreviousVelocity = 0.0;
   double get heldPreviousVelocity => _heldPreviousVelocity;
 
+  /// Whether the scroll view should prevent its contents from receiving
+  /// pointer events.
+  bool get shouldIgnorePointer => activity!.shouldIgnorePointer;
+
   /// Sets the user scroll direction.
   ///
   /// This exists only to expose `updateUserScrollDirection`
@@ -123,7 +126,6 @@ class SheetContentScrollPosition extends ScrollPositionWithSingleContext {
     if (owner != null && owner.hasPrimaryScrollPosition && !calledByOwner) {
       owner.goBallisticWithScrollPosition(
         velocity: velocity,
-        shouldIgnorePointer: activity?.shouldIgnorePointer ?? true,
         scrollPosition: this,
       );
       return;