feat: add SwipeDismissConfig for modals

package/lib/src/modal/cupertino.dart

@@ -7,6 +7,7 @@ import 'package:flutter/rendering.dart';
 import '../foundation/sheet_controller.dart';
 import '../internal/double_utils.dart';
 import 'modal_sheet.dart';
+import 'swipe_dismiss_config.dart';
 
 const _minimizedViewportScale = 0.92;
 const _cupertinoBarrierColor = Color(0x18000000);
@@ -422,8 +423,7 @@ class CupertinoModalSheetPage<T> extends Page<T> {
     this.barrierColor = _cupertinoBarrierColor,
     this.transitionDuration = _cupertinoTransitionDuration,
     this.transitionCurve = _cupertinoTransitionCurve,
-    this.minFlingVelocityToDismiss = 1.0,
-    this.minDragDistanceToDismiss = 100.0,
+    this.swipeDismissConfig = const SwipeDismissConfig(),
     required this.child,
   });
 
@@ -447,9 +447,7 @@ class CupertinoModalSheetPage<T> extends Page<T> {
 
   final Curve transitionCurve;
 
-  final double minFlingVelocityToDismiss;
-
-  final double minDragDistanceToDismiss;
+  final SwipeDismissConfig swipeDismissConfig;
 
   @override
   Route<T> createRoute(BuildContext context) {
@@ -492,10 +490,7 @@ class _PageBasedCupertinoModalSheetRoute<T>
   Duration get transitionDuration => _page.transitionDuration;
 
   @override
-  double get minFlingVelocityToDismiss => _page.minFlingVelocityToDismiss;
-
-  @override
-  double get minDragDistanceToDismiss => _page.minDragDistanceToDismiss;
+  SwipeDismissConfig get swipeDismissConfig => _page.swipeDismissConfig;
 
   @override
   String get debugLabel => '${super.debugLabel}(${_page.name})';
@@ -516,8 +511,7 @@ class CupertinoModalSheetRoute<T> extends _BaseCupertinoModalSheetRoute<T> {
     this.barrierColor = _cupertinoBarrierColor,
     this.transitionDuration = _cupertinoTransitionDuration,
     this.transitionCurve = _cupertinoTransitionCurve,
-    this.minFlingVelocityToDismiss = 1.0,
-    this.minDragDistanceToDismiss = 100.0,
+    this.swipeDismissConfig = const SwipeDismissConfig(),
   });
 
   final WidgetBuilder builder;
@@ -544,10 +538,7 @@ class CupertinoModalSheetRoute<T> extends _BaseCupertinoModalSheetRoute<T> {
   final Curve transitionCurve;
 
   @override
-  final double minFlingVelocityToDismiss;
-
-  @override
-  final double minDragDistanceToDismiss;
+  final SwipeDismissConfig swipeDismissConfig;
 
   @override
   Widget buildContent(BuildContext context) {

package/lib/src/modal/modal.dart

@@ -6,3 +6,4 @@ export 'cupertino.dart'
         CupertinoStackedTransition;
 export 'modal_sheet.dart'
     show ModalSheetPage, ModalSheetRoute, ModalSheetRouteMixin;
+export 'swipe_dismiss_config.dart' show SwipeDismissConfig;

package/lib/src/modal/modal_sheet.dart

@@ -6,6 +6,7 @@ import 'package:flutter/material.dart';
 import '../foundation/sheet_drag.dart';
 import '../foundation/sheet_gesture_tamperer.dart';
 import '../internal/float_comp.dart';
+import 'swipe_dismiss_config.dart';
 
 const _minReleasedPageForwardAnimationTime = 300; // Milliseconds.
 const _releasedPageForwardAnimationCurve = Curves.fastLinearToSlowEaseIn;
@@ -24,8 +25,7 @@ class ModalSheetPage<T> extends Page<T> {
     this.barrierColor = Colors.black54,
     this.transitionDuration = const Duration(milliseconds: 300),
     this.transitionCurve = Curves.fastEaseInToSlowEaseOut,
-    this.minFlingVelocityToDismiss = 1.0,
-    this.minDragDistanceToDismiss = 100.0,
+    this.swipeDismissConfig = const SwipeDismissConfig(),
     required this.child,
   });
 
@@ -49,9 +49,7 @@ class ModalSheetPage<T> extends Page<T> {
 
   final Curve transitionCurve;
 
-  final double minFlingVelocityToDismiss;
-
-  final double minDragDistanceToDismiss;
+  final SwipeDismissConfig swipeDismissConfig;
 
   @override
   Route<T> createRoute(BuildContext context) {
@@ -93,10 +91,7 @@ class _PageBasedModalSheetRoute<T> extends PageRoute<T>
   Duration get transitionDuration => _page.transitionDuration;
 
   @override
-  double get minFlingVelocityToDismiss => _page.minFlingVelocityToDismiss;
-
-  @override
-  double get minDragDistanceToDismiss => _page.minDragDistanceToDismiss;
+  SwipeDismissConfig get swipeDismissConfig => _page.swipeDismissConfig;
 
   @override
   String get debugLabel => '${super.debugLabel}(${_page.name})';
@@ -117,8 +112,7 @@ class ModalSheetRoute<T> extends PageRoute<T> with ModalSheetRouteMixin<T> {
     this.swipeDismissible = false,
     this.transitionDuration = const Duration(milliseconds: 300),
     this.transitionCurve = Curves.fastEaseInToSlowEaseOut,
-    this.minFlingVelocityToDismiss = 1.0,
-    this.minDragDistanceToDismiss = 100.0,
+    this.swipeDismissConfig = const SwipeDismissConfig(),
   });
 
   final WidgetBuilder builder;
@@ -145,10 +139,7 @@ class ModalSheetRoute<T> extends PageRoute<T> with ModalSheetRouteMixin<T> {
   final Curve transitionCurve;
 
   @override
-  final double minFlingVelocityToDismiss;
-
-  @override
-  final double minDragDistanceToDismiss;
+  final SwipeDismissConfig swipeDismissConfig;
 
   @override
   Widget buildContent(BuildContext context) {
@@ -159,8 +150,7 @@ class ModalSheetRoute<T> extends PageRoute<T> with ModalSheetRouteMixin<T> {
 mixin ModalSheetRouteMixin<T> on ModalRoute<T> {
   bool get swipeDismissible;
   Curve get transitionCurve;
-  double get minFlingVelocityToDismiss;
-  double get minDragDistanceToDismiss;
+  SwipeDismissConfig get swipeDismissConfig;
 
   @override
   bool get opaque => false;
@@ -169,8 +159,7 @@ mixin ModalSheetRouteMixin<T> on ModalRoute<T> {
   late final _swipeDismissibleController = _SwipeDismissibleController(
     route: this,
     transitionController: controller!,
-    minFlingVelocityToDismiss: minFlingVelocityToDismiss,
-    minDragDistanceToDismiss: minDragDistanceToDismiss,
+    swipeDismissConfig: swipeDismissConfig,
   );
 
   Widget buildContent(BuildContext context);
@@ -248,14 +237,12 @@ class _SwipeDismissibleController with SheetGestureTamperer {
   _SwipeDismissibleController({
     required this.route,
     required this.transitionController,
-    required this.minFlingVelocityToDismiss,
-    required this.minDragDistanceToDismiss,
+    required this.swipeDismissConfig,
   });
 
   final ModalRoute<dynamic> route;
   final AnimationController transitionController;
-  final double minFlingVelocityToDismiss;
-  final double minDragDistanceToDismiss;
+  final SwipeDismissConfig swipeDismissConfig;
 
   BuildContext get _context => route.subtreeContext!;
 
@@ -370,12 +357,12 @@ class _SwipeDismissibleController with SheetGestureTamperer {
       invokePop = false;
     } else if (effectiveVelocity < 0) {
       // Flings down.
-      invokePop = effectiveVelocity.abs() > minFlingVelocityToDismiss;
+      invokePop = effectiveVelocity.abs() > swipeDismissConfig.minFlingVelocity;
     } else if (FloatComp.velocity(MediaQuery.devicePixelRatioOf(_context))
         .isApprox(effectiveVelocity, 0)) {
       assert(draggedDistance >= 0);
       // Dragged down enough to dismiss.
-      invokePop = draggedDistance > minDragDistanceToDismiss;
+      invokePop = draggedDistance > swipeDismissConfig.minDragDistance;
     } else {
       // Flings up.
       invokePop = false;

package/lib/src/modal/swipe_dismiss_config.dart

@@ -0,0 +1,33 @@
+/// Configuration class for handling swipe-to-dismiss gestures.
+///
+/// The [SwipeDismissConfig] class provides parameters to control the behavior
+/// of swipe-to-dismiss interactions for modals. It defines the minimum velocity
+/// required for the swipe gesture ([minFlingVelocity]) and the minimum distance
+/// the user needs to drag ([minDragDistance]) for a swipe to result in a dismissal.
+class SwipeDismissConfig {
+  const SwipeDismissConfig({
+    this.minFlingVelocity = 1.0,
+    this.minDragDistance = 300.0,
+  });
+
+  /// The minimum velocity that a fling gesture must reach to trigger a dismissal.
+  final double minFlingVelocity;
+
+  /// The minimum distance that must be dragged before the modal is dismissed.
+  final double minDragDistance;
+
+  @override
+  bool operator ==(covariant SwipeDismissConfig other) {
+    if (identical(this, other)) return true;
+
+    return 
+      other.minFlingVelocity == minFlingVelocity &&
+      other.minDragDistance == minDragDistance;
+  }
+
+  @override
+  int get hashCode => minFlingVelocity.hashCode ^ minDragDistance.hashCode;
+
+  @override
+  String toString() => 'SwipeDismissConfig(minFlingVelocity: $minFlingVelocity, minDragDistance: $minDragDistance)';
+}