Fix: SheetController attached to NavigationSheet always emits minPixe…

…ls = 0.0 (#164)

Fixes #163.

**New APIs**
- `ExtentScopeBuilder`

**Internal changes**
- Removed `SheetExtentConfig`, `SheetExtentFactory`, and their
subclasses.
- Accordingly, `SheetExtentScope` widgets now also take responsibility
for creating the `SheetExtent`s they host.
- Moved the responsibility for managing the scope keys of the local
`SheetExtentScope`s from `NavigationSheetExtent` to each
`NavigationSheetRoute`.

**Misc**
- Added a regression test for #163.
- Bumped the version to 0.7.2.

package/CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## 0.7.2 Jun 9, 2024
+
+- Fix: Attaching SheetController to NavigationSheet causes "Null check operator used on a null value" (#151)
+- Fix: SheetController attached to NavigationSheet always emits minPixels = 0.0 (#163)
+
 ## 0.7.1 Jun 1, 2024
 
 - Fix: Unwanted bouncing effect when opening keyboard on NavigationSheet (#153)

package/lib/src/draggable/draggable_sheet.dart

@@ -1,3 +1,4 @@
+import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 
 import '../foundation/keyboard_dismissible.dart';
@@ -8,7 +9,7 @@ import '../foundation/sheet_physics.dart';
 import '../foundation/sheet_theme.dart';
 import '../foundation/sheet_viewport.dart';
 import '../scrollable/scrollable_sheet.dart';
-import 'draggable_sheet_extent.dart';
+import 'draggable_sheet_extent_scope.dart';
 import 'sheet_draggable.dart';
 
 /// A sheet that can be dragged.
@@ -73,17 +74,14 @@ class DraggableSheet extends StatelessWidget {
         this.keyboardDismissBehavior ?? theme?.keyboardDismissBehavior;
     final gestureTamper = TamperSheetGesture.maybeOf(context);
 
-    Widget result = SheetExtentScope(
+    Widget result = DraggableSheetExtentScope(
       controller: controller,
-      factory: const DraggableSheetExtentFactory(),
-      config: DraggableSheetExtentConfig(
-        initialExtent: initialExtent,
-        minExtent: minExtent,
-        maxExtent: maxExtent,
-        physics: physics,
-        gestureTamperer: gestureTamper,
-        debugLabel: 'DraggableSheet',
-      ),
+      initialExtent: initialExtent,
+      minExtent: minExtent,
+      maxExtent: maxExtent,
+      physics: physics,
+      gestureTamperer: gestureTamper,
+      debugLabel: kDebugMode ? 'DraggableSheet' : null,
       child: SheetViewport(
         child: SheetContentViewport(
           child: SheetDraggable(

package/lib/src/draggable/draggable_sheet_extent.dart

@@ -5,56 +5,27 @@ import 'package:meta/meta.dart';
 import '../foundation/sheet_extent.dart';
 
 @internal
-class DraggableSheetExtentFactory extends SheetExtentFactory<
-    DraggableSheetExtentConfig, DraggableSheetExtent> {
-  const DraggableSheetExtentFactory();
-
-  @override
-  DraggableSheetExtent createSheetExtent({
-    required SheetContext context,
-    required DraggableSheetExtentConfig config,
-  }) {
-    return DraggableSheetExtent(context: context, config: config);
-  }
-}
-
-@internal
-class DraggableSheetExtentConfig extends SheetExtentConfig {
-  const DraggableSheetExtentConfig({
-    required this.initialExtent,
+class DraggableSheetExtent extends SheetExtent {
+  DraggableSheetExtent({
+    required super.context,
     required super.minExtent,
     required super.maxExtent,
+    required this.initialExtent,
     required super.physics,
-    required super.gestureTamperer,
+    super.gestureTamperer,
     super.debugLabel,
   });
 
+  /// {@template DraggableSheetExtent.initialExtent}
+  /// The initial extent of the sheet.
+  /// {@endtemplate}
   final Extent initialExtent;
 
-  @override
-  bool operator ==(Object other) {
-    if (identical(this, other)) return true;
-    return other is DraggableSheetExtentConfig &&
-        other.initialExtent == initialExtent &&
-        super == other;
-  }
-
-  @override
-  int get hashCode => Object.hash(initialExtent, super.hashCode);
-}
-
-@internal
-class DraggableSheetExtent extends SheetExtent<DraggableSheetExtentConfig> {
-  DraggableSheetExtent({
-    required super.context,
-    required super.config,
-  });
-
   @override
   void applyNewContentSize(Size contentSize) {
     super.applyNewContentSize(contentSize);
     if (metrics.maybePixels == null) {
-      setPixels(config.initialExtent.resolve(metrics.contentSize));
+      setPixels(initialExtent.resolve(metrics.contentSize));
     }
   }
 }

package/lib/src/draggable/draggable_sheet_extent_scope.dart

@@ -0,0 +1,55 @@
+import 'package:meta/meta.dart';
+
+import '../foundation/sheet_extent.dart';
+import '../foundation/sheet_extent_scope.dart';
+import 'draggable_sheet_extent.dart';
+
+@internal
+class DraggableSheetExtentScope extends SheetExtentScope {
+  const DraggableSheetExtentScope({
+    super.key,
+    super.controller,
+    super.isPrimary,
+    required this.initialExtent,
+    required super.minExtent,
+    required super.maxExtent,
+    required super.physics,
+    super.gestureTamperer,
+    this.debugLabel,
+    required super.child,
+  });
+
+  /// {@macro DraggableSheetExtent.initialExtent}
+  final Extent initialExtent;
+
+  /// {@macro SheetExtent.debugLabel}
+  final String? debugLabel;
+
+  @override
+  SheetExtentScopeState createState() {
+    return _DraggableSheetExtentScopeState();
+  }
+}
+
+class _DraggableSheetExtentScopeState extends SheetExtentScopeState<
+    DraggableSheetExtent, DraggableSheetExtentScope> {
+  @override
+  bool shouldRebuildExtent(DraggableSheetExtent oldExtent) {
+    return widget.initialExtent != oldExtent.initialExtent ||
+        widget.debugLabel != oldExtent.debugLabel ||
+        super.shouldRebuildExtent(oldExtent);
+  }
+
+  @override
+  DraggableSheetExtent buildExtent(SheetContext context) {
+    return DraggableSheetExtent(
+      context: context,
+      initialExtent: widget.initialExtent,
+      minExtent: widget.minExtent,
+      maxExtent: widget.maxExtent,
+      physics: widget.physics,
+      gestureTamperer: widget.gestureTamperer,
+      debugLabel: widget.debugLabel,
+    );
+  }
+}

package/lib/src/draggable/sheet_draggable.dart

@@ -3,6 +3,7 @@ import 'package:flutter/gestures.dart';
 import 'package:flutter/widgets.dart';
 
 import '../foundation/sheet_extent.dart';
+import '../foundation/sheet_extent_scope.dart';
 import '../scrollable/scrollable_sheet.dart';
 import 'draggable_sheet.dart';
 

package/lib/src/foundation/sheet_activity.dart

@@ -220,7 +220,7 @@ class DragSheetActivity extends SheetActivity
   @override
   void applyUserDragUpdate(Offset offset) {
     final physicsAppliedDelta =
-        owner.config.physics.applyPhysicsToOffset(offset.dy, owner.metrics);
+        owner.physics.applyPhysicsToOffset(offset.dy, owner.metrics);
     if (physicsAppliedDelta != 0) {
       owner.setPixels(owner.metrics.pixels + physicsAppliedDelta);
     }

package/lib/src/foundation/sheet_content_scaffold.dart

@@ -5,6 +5,7 @@ import 'package:flutter/rendering.dart';
 
 import '../draggable/sheet_draggable.dart';
 import 'sheet_extent.dart';
+import 'sheet_extent_scope.dart';
 import 'sheet_viewport.dart';
 
 class SheetContentScaffold extends StatelessWidget {