packages/flutter/test/widgets/two_dimensional_utils.dart - mirrors/flutter - Git at Google

 // Copyright 2014 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 import 'dart:math' as math;

 import 'package:flutter/foundation.dart' show clampDouble;
 import 'package:flutter/gestures.dart' show DragStartBehavior;
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart' show ViewportOffset;


 // BUILDER DELEGATE ---

 final TwoDimensionalChildBuilderDelegate builderDelegate = TwoDimensionalChildBuilderDelegate(
   maxXIndex: 5,
   maxYIndex: 5,
   builder: (BuildContext context, ChildVicinity vicinity) {
     return Container(
       color: vicinity.xIndex.isEven && vicinity.yIndex.isEven
         ? Colors.amber[100]
         : (vicinity.xIndex.isOdd && vicinity.yIndex.isOdd
         ? Colors.blueAccent[100]
         : null),
       height: 200,
       width: 200,
       child: Center(child: Text('R${vicinity.xIndex}:C${vicinity.yIndex}')),
     );
   }
 );

 // Creates a simple 2D table of 200x200 squares with a builder delegate.
 Widget simpleBuilderTest({
   Axis mainAxis = Axis.vertical,
   bool? primary,
   ScrollableDetails? verticalDetails,
   ScrollableDetails? horizontalDetails,
   TwoDimensionalChildBuilderDelegate? delegate,
   double? cacheExtent,
   DiagonalDragBehavior? diagonalDrag,
   Clip? clipBehavior,
   String? restorationID,
   bool useCacheExtent = false,
   bool applyDimensions = true,
   bool forgetToLayoutChild = false,
   bool setLayoutOffset = true,
 }) {
   return MaterialApp(
     theme: ThemeData(useMaterial3: false),
     restorationScopeId: restorationID,
     home: Scaffold(
       body: SimpleBuilderTableView(
         mainAxis: mainAxis,
         verticalDetails: verticalDetails ?? const ScrollableDetails.vertical(),
         horizontalDetails: horizontalDetails ?? const ScrollableDetails.horizontal(),
         cacheExtent: cacheExtent,
         useCacheExtent: useCacheExtent,
         diagonalDragBehavior: diagonalDrag ?? DiagonalDragBehavior.none,
         clipBehavior: clipBehavior ?? Clip.hardEdge,
         delegate: delegate ?? builderDelegate,
         applyDimensions: applyDimensions,
         forgetToLayoutChild: forgetToLayoutChild,
         setLayoutOffset: setLayoutOffset,
       ),
     ),
   );
 }

 class SimpleBuilderTableView extends TwoDimensionalScrollView {
   const SimpleBuilderTableView({
     super.key,
     super.primary,
     super.mainAxis = Axis.vertical,
     super.verticalDetails = const ScrollableDetails.vertical(),
     super.horizontalDetails = const ScrollableDetails.horizontal(),
     required TwoDimensionalChildBuilderDelegate delegate,
     super.cacheExtent,
     super.diagonalDragBehavior = DiagonalDragBehavior.none,
     super.dragStartBehavior = DragStartBehavior.start,
     super.keyboardDismissBehavior = ScrollViewKeyboardDismissBehavior.manual,
     super.clipBehavior = Clip.hardEdge,
     this.useCacheExtent = false,
     this.applyDimensions = true,
     this.forgetToLayoutChild = false,
     this.setLayoutOffset = true,
   }) : super(delegate: delegate);

   // Piped through for testing in RenderTwoDimensionalViewport
   final bool useCacheExtent;
   final bool applyDimensions;
   final bool forgetToLayoutChild;
   final bool setLayoutOffset;

   @override
   Widget buildViewport(BuildContext context, ViewportOffset verticalOffset, ViewportOffset horizontalOffset) {
     return SimpleBuilderTableViewport(
       horizontalOffset: horizontalOffset,
       horizontalAxisDirection: horizontalDetails.direction,
       verticalOffset: verticalOffset,
       verticalAxisDirection: verticalDetails.direction,
       mainAxis: mainAxis,
       delegate: delegate as TwoDimensionalChildBuilderDelegate,
       cacheExtent: cacheExtent,
       clipBehavior: clipBehavior,
       useCacheExtent: useCacheExtent,
       applyDimensions: applyDimensions,
       forgetToLayoutChild: forgetToLayoutChild,
       setLayoutOffset: setLayoutOffset,
     );
   }
 }

 class SimpleBuilderTableViewport extends TwoDimensionalViewport {
   const SimpleBuilderTableViewport({
     super.key,
     required super.verticalOffset,
     required super.verticalAxisDirection,
     required super.horizontalOffset,
     required super.horizontalAxisDirection,
     required TwoDimensionalChildBuilderDelegate delegate,
     required super.mainAxis,
     super.cacheExtent,
     super.clipBehavior = Clip.hardEdge,
     this.useCacheExtent = false,
     this.applyDimensions = true,
     this.forgetToLayoutChild = false,
     this.setLayoutOffset = true,
   }) : super(delegate: delegate);

   // Piped through for testing in RenderTwoDimensionalViewport
   final bool useCacheExtent;
   final bool applyDimensions;
   final bool forgetToLayoutChild;
   final bool setLayoutOffset;

   @override
   RenderTwoDimensionalViewport createRenderObject(BuildContext context) {
     return RenderSimpleBuilderTableViewport(
       horizontalOffset: horizontalOffset,
       horizontalAxisDirection: horizontalAxisDirection,
       verticalOffset: verticalOffset,
       verticalAxisDirection: verticalAxisDirection,
       mainAxis: mainAxis,
       delegate: delegate as TwoDimensionalChildBuilderDelegate,
       childManager: context as TwoDimensionalChildManager,
       cacheExtent: cacheExtent,
       clipBehavior: clipBehavior,
       useCacheExtent: useCacheExtent,
       applyDimensions: applyDimensions,
       forgetToLayoutChild: forgetToLayoutChild,
       setLayoutOffset: setLayoutOffset,
     );
   }

   @override
   void updateRenderObject(BuildContext context, RenderSimpleBuilderTableViewport renderObject) {
     renderObject
       ..horizontalOffset = horizontalOffset
       ..horizontalAxisDirection = horizontalAxisDirection
       ..verticalOffset = verticalOffset
       ..verticalAxisDirection = verticalAxisDirection
       ..mainAxis = mainAxis
       ..delegate = delegate
       ..cacheExtent = cacheExtent
       ..clipBehavior = clipBehavior;
   }
 }

 class RenderSimpleBuilderTableViewport extends RenderTwoDimensionalViewport {
   RenderSimpleBuilderTableViewport({
     required super.horizontalOffset,
     required super.horizontalAxisDirection,
     required super.verticalOffset,
     required super.verticalAxisDirection,
     required TwoDimensionalChildBuilderDelegate delegate,
     required super.mainAxis,
     required super.childManager,
     super.cacheExtent,
     super.clipBehavior = Clip.hardEdge,
     this.applyDimensions = true,
     this.setLayoutOffset = true,
     this.useCacheExtent = false,
     this.forgetToLayoutChild = false,
   }) : super(delegate: delegate);

   // These are to test conditions to validate subclass implementations after
   // layoutChildSequence
   final bool applyDimensions;
   final bool setLayoutOffset;
   final bool useCacheExtent;
   final bool forgetToLayoutChild;

   RenderBox? testGetChildFor(ChildVicinity vicinity) => getChildFor(vicinity);

   @override
   TestExtendedParentData parentDataOf(RenderBox child) {
     return child.parentData! as TestExtendedParentData;
   }

   @override
   void setupParentData(RenderBox child) {
     if (child.parentData is! TestExtendedParentData) {
       child.parentData = TestExtendedParentData();
     }
   }

   @override
   void layoutChildSequence() {
     // Really simple table implementation for testing.
     // Every child is 200x200 square
     final double horizontalPixels = horizontalOffset.pixels;
     final double verticalPixels = verticalOffset.pixels;
     final double viewportWidth = viewportDimension.width + (useCacheExtent ? cacheExtent : 0.0);
     final double viewportHeight = viewportDimension.height + (useCacheExtent ? cacheExtent : 0.0);
     final TwoDimensionalChildBuilderDelegate builderDelegate = delegate as TwoDimensionalChildBuilderDelegate;

     final int maxRowIndex;
     final int maxColumnIndex;
     maxRowIndex = builderDelegate.maxYIndex ?? 5;
     maxColumnIndex = builderDelegate.maxXIndex ?? 5;

     final int leadingColumn = math.max((horizontalPixels / 200).floor(), 0);
     final int leadingRow = math.max((verticalPixels / 200).floor(), 0);
     final int trailingColumn = math.min(
       ((horizontalPixels + viewportWidth) / 200).ceil(),
       maxColumnIndex,
     );
     final int trailingRow = math.min(
       ((verticalPixels + viewportHeight) / 200).ceil(),
       maxRowIndex,
     );

     double xLayoutOffset = (leadingColumn * 200) - horizontalOffset.pixels;
     for (int column = leadingColumn; column <= trailingColumn; column++) {
       double yLayoutOffset = (leadingRow * 200) - verticalOffset.pixels;
       for (int row = leadingRow; row <= trailingRow; row++) {
         final ChildVicinity vicinity = ChildVicinity(xIndex: column, yIndex: row);
         final RenderBox child = buildOrObtainChildFor(vicinity)!;
         if (!forgetToLayoutChild) {
           child.layout(constraints.tighten(width: 200.0, height: 200.0));
         }

         if (setLayoutOffset) {
           parentDataOf(child).layoutOffset = Offset(xLayoutOffset, yLayoutOffset);
         }
         yLayoutOffset += 200;
       }
       xLayoutOffset += 200;
     }
     if (applyDimensions) {
       final double verticalExtent = 200 * (maxRowIndex + 1);
       verticalOffset.applyContentDimensions(
         0.0,
         clampDouble(verticalExtent - viewportDimension.height, 0.0, double.infinity),
       );
       final double horizontalExtent = 200 * (maxColumnIndex + 1);
       horizontalOffset.applyContentDimensions(
         0.0,
         clampDouble(horizontalExtent - viewportDimension.width, 0.0, double.infinity),
       );
     }
   }
 }

 // LIST DELEGATE ---
 final List<List<Widget>> children = List<List<Widget>>.generate(
   100,
   (int xIndex) {
     return List<Widget>.generate(
       100,
       (int yIndex) {
         return Container(
           color: xIndex.isEven && yIndex.isEven
             ? Colors.amber[100]
             : (xIndex.isOdd && yIndex.isOdd
               ? Colors.blueAccent[100]
               : null),
           height: 200,
           width: 200,
           child: Center(child: Text('R$xIndex:C$yIndex')),
         );
       },
     );
   },
 );

 // Builds a simple 2D table of 200x200 squares with a list delegate.
 Widget simpleListTest({
   Axis mainAxis = Axis.vertical,
   bool? primary,
   ScrollableDetails? verticalDetails,
   ScrollableDetails? horizontalDetails,
   TwoDimensionalChildListDelegate? delegate,
   double? cacheExtent,
   DiagonalDragBehavior? diagonalDrag,
   Clip? clipBehavior,
 }) {
   return MaterialApp(
     theme: ThemeData(useMaterial3: true),
     home: Scaffold(
       body: SimpleListTableView(
         mainAxis: mainAxis,
         verticalDetails: verticalDetails ?? const ScrollableDetails.vertical(),
         horizontalDetails: horizontalDetails ?? const ScrollableDetails.horizontal(),
         cacheExtent: cacheExtent,
         diagonalDragBehavior: diagonalDrag ?? DiagonalDragBehavior.none,
         clipBehavior: clipBehavior ?? Clip.hardEdge,
         delegate: delegate ?? TwoDimensionalChildListDelegate(children: children),
       ),
     ),
   );
 }

 class SimpleListTableView extends TwoDimensionalScrollView {
   const SimpleListTableView({
     super.key,
     super.primary,
     super.mainAxis = Axis.vertical,
     super.verticalDetails = const ScrollableDetails.vertical(),
     super.horizontalDetails = const ScrollableDetails.horizontal(),
     required TwoDimensionalChildListDelegate delegate,
     super.cacheExtent,
     super.diagonalDragBehavior = DiagonalDragBehavior.none,
     super.dragStartBehavior = DragStartBehavior.start,
     super.keyboardDismissBehavior = ScrollViewKeyboardDismissBehavior.manual,
     super.clipBehavior = Clip.hardEdge,
   }) : super(delegate: delegate);

   @override
   Widget buildViewport(BuildContext context, ViewportOffset verticalOffset, ViewportOffset horizontalOffset) {
     return SimpleListTableViewport(
       horizontalOffset: horizontalOffset,
       horizontalAxisDirection: horizontalDetails.direction,
       verticalOffset: verticalOffset,
       verticalAxisDirection: verticalDetails.direction,
       mainAxis: mainAxis,
       delegate: delegate as TwoDimensionalChildListDelegate,
       cacheExtent: cacheExtent,
       clipBehavior: clipBehavior,
     );
   }
 }

 class SimpleListTableViewport extends TwoDimensionalViewport {
   const SimpleListTableViewport({
     super.key,
     required super.verticalOffset,
     required super.verticalAxisDirection,
     required super.horizontalOffset,
     required super.horizontalAxisDirection,
     required TwoDimensionalChildListDelegate delegate,
     required super.mainAxis,
     super.cacheExtent,
     super.clipBehavior = Clip.hardEdge,
   }) : super(delegate: delegate);

   @override
   RenderTwoDimensionalViewport createRenderObject(BuildContext context) {
     return RenderSimpleListTableViewport(
       horizontalOffset: horizontalOffset,
       horizontalAxisDirection: horizontalAxisDirection,
       verticalOffset: verticalOffset,
       verticalAxisDirection: verticalAxisDirection,
       mainAxis: mainAxis,
       delegate: delegate as TwoDimensionalChildListDelegate,
       childManager: context as TwoDimensionalChildManager,
       cacheExtent: cacheExtent,
       clipBehavior: clipBehavior,
     );
   }

   @override
   void updateRenderObject(BuildContext context, RenderSimpleListTableViewport renderObject) {
     renderObject
       ..horizontalOffset = horizontalOffset
       ..horizontalAxisDirection = horizontalAxisDirection
       ..verticalOffset = verticalOffset
       ..verticalAxisDirection = verticalAxisDirection
       ..mainAxis = mainAxis
       ..delegate = delegate
       ..cacheExtent = cacheExtent
       ..clipBehavior = clipBehavior;
   }
 }

 class RenderSimpleListTableViewport extends RenderTwoDimensionalViewport {
   RenderSimpleListTableViewport({
     required super.horizontalOffset,
     required super.horizontalAxisDirection,
     required super.verticalOffset,
     required super.verticalAxisDirection,
     required TwoDimensionalChildListDelegate delegate,
     required super.mainAxis,
     required super.childManager,
     super.cacheExtent,
     super.clipBehavior = Clip.hardEdge,
   }) : super(delegate: delegate);

   @override
   void layoutChildSequence() {
     // Really simple table implementation for testing.
     // Every child is 200x200 square
     final double horizontalPixels = horizontalOffset.pixels;
     final double verticalPixels = verticalOffset.pixels;
     final TwoDimensionalChildListDelegate listDelegate = delegate as TwoDimensionalChildListDelegate;
     final int rowCount;
     final int columnCount;
     rowCount = listDelegate.children.length;
     columnCount = listDelegate.children[0].length;

     final int leadingColumn = math.max((horizontalPixels / 200).floor(), 0);
     final int leadingRow = math.max((verticalPixels / 200).floor(), 0);
     final int trailingColumn = math.min(
       ((horizontalPixels + viewportDimension.width) / 200).ceil(),
       columnCount - 1,
     );
     final int trailingRow = math.min(
       ((verticalPixels + viewportDimension.height) / 200).ceil(),
       rowCount - 1,
     );

     double xLayoutOffset = (leadingColumn * 200) - horizontalOffset.pixels;
     for (int column = leadingColumn; column <= trailingColumn; column++) {
       double yLayoutOffset = (leadingRow * 200) - verticalOffset.pixels;
       for (int row = leadingRow; row <= trailingRow; row++) {
         final ChildVicinity vicinity = ChildVicinity(xIndex: column, yIndex: row);
         final RenderBox child = buildOrObtainChildFor(vicinity)!;
         child.layout(constraints.tighten(width: 200.0, height: 200.0));

         parentDataOf(child).layoutOffset = Offset(xLayoutOffset, yLayoutOffset);
         yLayoutOffset += 200;
       }
       xLayoutOffset += 200;
     }

     verticalOffset.applyContentDimensions(
       0.0,
       math.max(200 * rowCount - viewportDimension.height, 0.0),
     );
     horizontalOffset.applyContentDimensions(
       0,
       math.max(200 * columnCount - viewportDimension.width, 0.0),
     );
   }
 }

 class KeepAliveCheckBox extends StatefulWidget {
   const KeepAliveCheckBox({ super.key });

   @override
   KeepAliveCheckBoxState createState() => KeepAliveCheckBoxState();
 }

 class KeepAliveCheckBoxState extends State<KeepAliveCheckBox> with AutomaticKeepAliveClientMixin {
   bool checkValue = false;

   @override
   bool get wantKeepAlive => _wantKeepAlive;
   bool _wantKeepAlive = false;
   set wantKeepAlive(bool value) {
     if (_wantKeepAlive != value) {
       _wantKeepAlive = value;
       updateKeepAlive();
     }
   }

   @override
   Widget build(BuildContext context) {
     super.build(context);
     return Checkbox(
       value: checkValue,
       onChanged: (bool? value) {
         if (checkValue != value) {
           setState(() {
             checkValue = value!;
             wantKeepAlive = value;
           });
         }
       },
     );
   }
 }

 // TwoDimensionalViewportParentData already mixes in KeepAliveParentDataMixin,
 // and so should be compatible with both the KeepAlive and
 // TestParentDataWidget ParentDataWidgets.
 // This ParentData is set up above as part of the
 // RenderSimpleBuilderTableViewport for testing.
 class TestExtendedParentData extends TwoDimensionalViewportParentData {
   int? testValue;
 }

 class TestParentDataWidget extends ParentDataWidget<TestExtendedParentData> {
   const TestParentDataWidget({
     super.key,
     required super.child,
     this.testValue,
   });

   final int? testValue;

   @override
   void applyParentData(RenderObject renderObject) {
     assert(renderObject.parentData is TestExtendedParentData);
     final TestExtendedParentData parentData = renderObject.parentData! as TestExtendedParentData;
     parentData.testValue = testValue;
   }

   @override
   Type get debugTypicalAncestorWidgetClass => SimpleBuilderTableViewport;
 }
	// Copyright 2014 The Flutter Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	import 'dart:math' as math;

	import 'package:flutter/foundation.dart' show clampDouble;
	import 'package:flutter/gestures.dart' show DragStartBehavior;
	import 'package:flutter/material.dart';
	import 'package:flutter/rendering.dart' show ViewportOffset;


	// BUILDER DELEGATE ---

	final TwoDimensionalChildBuilderDelegate builderDelegate = TwoDimensionalChildBuilderDelegate(
	maxXIndex: 5,
	maxYIndex: 5,
	builder: (BuildContext context, ChildVicinity vicinity) {
	return Container(
	color: vicinity.xIndex.isEven && vicinity.yIndex.isEven
	? Colors.amber[100]
	: (vicinity.xIndex.isOdd && vicinity.yIndex.isOdd
	? Colors.blueAccent[100]
	: null),
	height: 200,
	width: 200,
	child: Center(child: Text('R${vicinity.xIndex}:C${vicinity.yIndex}')),
	);
	}
	);

	// Creates a simple 2D table of 200x200 squares with a builder delegate.
	Widget simpleBuilderTest({
	Axis mainAxis = Axis.vertical,
	bool? primary,
	ScrollableDetails? verticalDetails,
	ScrollableDetails? horizontalDetails,
	TwoDimensionalChildBuilderDelegate? delegate,
	double? cacheExtent,
	DiagonalDragBehavior? diagonalDrag,
	Clip? clipBehavior,
	String? restorationID,
	bool useCacheExtent = false,
	bool applyDimensions = true,
	bool forgetToLayoutChild = false,
	bool setLayoutOffset = true,
	}) {
	return MaterialApp(
	theme: ThemeData(useMaterial3: false),
	restorationScopeId: restorationID,
	home: Scaffold(
	body: SimpleBuilderTableView(
	mainAxis: mainAxis,
	verticalDetails: verticalDetails ?? const ScrollableDetails.vertical(),
	horizontalDetails: horizontalDetails ?? const ScrollableDetails.horizontal(),
	cacheExtent: cacheExtent,
	useCacheExtent: useCacheExtent,
	diagonalDragBehavior: diagonalDrag ?? DiagonalDragBehavior.none,
	clipBehavior: clipBehavior ?? Clip.hardEdge,
	delegate: delegate ?? builderDelegate,
	applyDimensions: applyDimensions,
	forgetToLayoutChild: forgetToLayoutChild,
	setLayoutOffset: setLayoutOffset,
	),
	),
	);
	}

	class SimpleBuilderTableView extends TwoDimensionalScrollView {
	const SimpleBuilderTableView({
	super.key,
	super.primary,
	super.mainAxis = Axis.vertical,
	super.verticalDetails = const ScrollableDetails.vertical(),
	super.horizontalDetails = const ScrollableDetails.horizontal(),
	required TwoDimensionalChildBuilderDelegate delegate,
	super.cacheExtent,
	super.diagonalDragBehavior = DiagonalDragBehavior.none,
	super.dragStartBehavior = DragStartBehavior.start,
	super.keyboardDismissBehavior = ScrollViewKeyboardDismissBehavior.manual,
	super.clipBehavior = Clip.hardEdge,
	this.useCacheExtent = false,
	this.applyDimensions = true,
	this.forgetToLayoutChild = false,
	this.setLayoutOffset = true,
	}) : super(delegate: delegate);

	// Piped through for testing in RenderTwoDimensionalViewport
	final bool useCacheExtent;
	final bool applyDimensions;
	final bool forgetToLayoutChild;
	final bool setLayoutOffset;

	@override
	Widget buildViewport(BuildContext context, ViewportOffset verticalOffset, ViewportOffset horizontalOffset) {
	return SimpleBuilderTableViewport(
	horizontalOffset: horizontalOffset,
	horizontalAxisDirection: horizontalDetails.direction,
	verticalOffset: verticalOffset,
	verticalAxisDirection: verticalDetails.direction,
	mainAxis: mainAxis,
	delegate: delegate as TwoDimensionalChildBuilderDelegate,
	cacheExtent: cacheExtent,
	clipBehavior: clipBehavior,
	useCacheExtent: useCacheExtent,
	applyDimensions: applyDimensions,
	forgetToLayoutChild: forgetToLayoutChild,
	setLayoutOffset: setLayoutOffset,
	);
	}
	}

	class SimpleBuilderTableViewport extends TwoDimensionalViewport {
	const SimpleBuilderTableViewport({
	super.key,
	required super.verticalOffset,
	required super.verticalAxisDirection,
	required super.horizontalOffset,
	required super.horizontalAxisDirection,
	required TwoDimensionalChildBuilderDelegate delegate,
	required super.mainAxis,
	super.cacheExtent,
	super.clipBehavior = Clip.hardEdge,
	this.useCacheExtent = false,
	this.applyDimensions = true,
	this.forgetToLayoutChild = false,
	this.setLayoutOffset = true,
	}) : super(delegate: delegate);

	// Piped through for testing in RenderTwoDimensionalViewport
	final bool useCacheExtent;
	final bool applyDimensions;
	final bool forgetToLayoutChild;
	final bool setLayoutOffset;

	@override
	RenderTwoDimensionalViewport createRenderObject(BuildContext context) {
	return RenderSimpleBuilderTableViewport(
	horizontalOffset: horizontalOffset,
	horizontalAxisDirection: horizontalAxisDirection,
	verticalOffset: verticalOffset,
	verticalAxisDirection: verticalAxisDirection,
	mainAxis: mainAxis,
	delegate: delegate as TwoDimensionalChildBuilderDelegate,
	childManager: context as TwoDimensionalChildManager,
	cacheExtent: cacheExtent,
	clipBehavior: clipBehavior,
	useCacheExtent: useCacheExtent,
	applyDimensions: applyDimensions,
	forgetToLayoutChild: forgetToLayoutChild,
	setLayoutOffset: setLayoutOffset,
	);
	}

	@override
	void updateRenderObject(BuildContext context, RenderSimpleBuilderTableViewport renderObject) {
	renderObject
	..horizontalOffset = horizontalOffset
	..horizontalAxisDirection = horizontalAxisDirection
	..verticalOffset = verticalOffset
	..verticalAxisDirection = verticalAxisDirection
	..mainAxis = mainAxis
	..delegate = delegate
	..cacheExtent = cacheExtent
	..clipBehavior = clipBehavior;
	}
	}

	class RenderSimpleBuilderTableViewport extends RenderTwoDimensionalViewport {
	RenderSimpleBuilderTableViewport({
	required super.horizontalOffset,
	required super.horizontalAxisDirection,
	required super.verticalOffset,
	required super.verticalAxisDirection,
	required TwoDimensionalChildBuilderDelegate delegate,
	required super.mainAxis,
	required super.childManager,
	super.cacheExtent,
	super.clipBehavior = Clip.hardEdge,
	this.applyDimensions = true,
	this.setLayoutOffset = true,
	this.useCacheExtent = false,
	this.forgetToLayoutChild = false,
	}) : super(delegate: delegate);

	// These are to test conditions to validate subclass implementations after
	// layoutChildSequence
	final bool applyDimensions;
	final bool setLayoutOffset;
	final bool useCacheExtent;
	final bool forgetToLayoutChild;

	RenderBox? testGetChildFor(ChildVicinity vicinity) => getChildFor(vicinity);

	@override
	TestExtendedParentData parentDataOf(RenderBox child) {
	return child.parentData! as TestExtendedParentData;
	}

	@override
	void setupParentData(RenderBox child) {
	if (child.parentData is! TestExtendedParentData) {
	child.parentData = TestExtendedParentData();
	}
	}

	@override
	void layoutChildSequence() {
	// Really simple table implementation for testing.
	// Every child is 200x200 square
	final double horizontalPixels = horizontalOffset.pixels;
	final double verticalPixels = verticalOffset.pixels;
	final double viewportWidth = viewportDimension.width + (useCacheExtent ? cacheExtent : 0.0);
	final double viewportHeight = viewportDimension.height + (useCacheExtent ? cacheExtent : 0.0);
	final TwoDimensionalChildBuilderDelegate builderDelegate = delegate as TwoDimensionalChildBuilderDelegate;

	final int maxRowIndex;
	final int maxColumnIndex;
	maxRowIndex = builderDelegate.maxYIndex ?? 5;
	maxColumnIndex = builderDelegate.maxXIndex ?? 5;

	final int leadingColumn = math.max((horizontalPixels / 200).floor(), 0);
	final int leadingRow = math.max((verticalPixels / 200).floor(), 0);
	final int trailingColumn = math.min(
	((horizontalPixels + viewportWidth) / 200).ceil(),
	maxColumnIndex,
	);
	final int trailingRow = math.min(
	((verticalPixels + viewportHeight) / 200).ceil(),
	maxRowIndex,
	);

	double xLayoutOffset = (leadingColumn * 200) - horizontalOffset.pixels;
	for (int column = leadingColumn; column <= trailingColumn; column++) {
	double yLayoutOffset = (leadingRow * 200) - verticalOffset.pixels;
	for (int row = leadingRow; row <= trailingRow; row++) {
	final ChildVicinity vicinity = ChildVicinity(xIndex: column, yIndex: row);
	final RenderBox child = buildOrObtainChildFor(vicinity)!;
	if (!forgetToLayoutChild) {
	child.layout(constraints.tighten(width: 200.0, height: 200.0));
	}

	if (setLayoutOffset) {
	parentDataOf(child).layoutOffset = Offset(xLayoutOffset, yLayoutOffset);
	}
	yLayoutOffset += 200;
	}
	xLayoutOffset += 200;
	}
	if (applyDimensions) {
	final double verticalExtent = 200 * (maxRowIndex + 1);
	verticalOffset.applyContentDimensions(
	0.0,
	clampDouble(verticalExtent - viewportDimension.height, 0.0, double.infinity),
	);
	final double horizontalExtent = 200 * (maxColumnIndex + 1);
	horizontalOffset.applyContentDimensions(
	0.0,
	clampDouble(horizontalExtent - viewportDimension.width, 0.0, double.infinity),
	);
	}
	}
	}

	// LIST DELEGATE ---
	final List<List<Widget>> children = List<List<Widget>>.generate(
	100,
	(int xIndex) {
	return List<Widget>.generate(
	100,
	(int yIndex) {
	return Container(
	color: xIndex.isEven && yIndex.isEven
	? Colors.amber[100]
	: (xIndex.isOdd && yIndex.isOdd
	? Colors.blueAccent[100]
	: null),
	height: 200,
	width: 200,
	child: Center(child: Text('R$xIndex:C$yIndex')),
	);
	},
	);
	},
	);

	// Builds a simple 2D table of 200x200 squares with a list delegate.
	Widget simpleListTest({
	Axis mainAxis = Axis.vertical,
	bool? primary,
	ScrollableDetails? verticalDetails,
	ScrollableDetails? horizontalDetails,
	TwoDimensionalChildListDelegate? delegate,
	double? cacheExtent,
	DiagonalDragBehavior? diagonalDrag,
	Clip? clipBehavior,
	}) {
	return MaterialApp(
	theme: ThemeData(useMaterial3: true),
	home: Scaffold(
	body: SimpleListTableView(
	mainAxis: mainAxis,
	verticalDetails: verticalDetails ?? const ScrollableDetails.vertical(),
	horizontalDetails: horizontalDetails ?? const ScrollableDetails.horizontal(),
	cacheExtent: cacheExtent,
	diagonalDragBehavior: diagonalDrag ?? DiagonalDragBehavior.none,
	clipBehavior: clipBehavior ?? Clip.hardEdge,
	delegate: delegate ?? TwoDimensionalChildListDelegate(children: children),
	),
	),
	);
	}

	class SimpleListTableView extends TwoDimensionalScrollView {
	const SimpleListTableView({
	super.key,
	super.primary,
	super.mainAxis = Axis.vertical,
	super.verticalDetails = const ScrollableDetails.vertical(),
	super.horizontalDetails = const ScrollableDetails.horizontal(),
	required TwoDimensionalChildListDelegate delegate,
	super.cacheExtent,
	super.diagonalDragBehavior = DiagonalDragBehavior.none,
	super.dragStartBehavior = DragStartBehavior.start,
	super.keyboardDismissBehavior = ScrollViewKeyboardDismissBehavior.manual,
	super.clipBehavior = Clip.hardEdge,
	}) : super(delegate: delegate);

	@override
	Widget buildViewport(BuildContext context, ViewportOffset verticalOffset, ViewportOffset horizontalOffset) {
	return SimpleListTableViewport(
	horizontalOffset: horizontalOffset,
	horizontalAxisDirection: horizontalDetails.direction,
	verticalOffset: verticalOffset,
	verticalAxisDirection: verticalDetails.direction,
	mainAxis: mainAxis,
	delegate: delegate as TwoDimensionalChildListDelegate,
	cacheExtent: cacheExtent,
	clipBehavior: clipBehavior,
	);
	}
	}

	class SimpleListTableViewport extends TwoDimensionalViewport {
	const SimpleListTableViewport({
	super.key,
	required super.verticalOffset,
	required super.verticalAxisDirection,
	required super.horizontalOffset,
	required super.horizontalAxisDirection,
	required TwoDimensionalChildListDelegate delegate,
	required super.mainAxis,
	super.cacheExtent,
	super.clipBehavior = Clip.hardEdge,
	}) : super(delegate: delegate);

	@override
	RenderTwoDimensionalViewport createRenderObject(BuildContext context) {
	return RenderSimpleListTableViewport(
	horizontalOffset: horizontalOffset,
	horizontalAxisDirection: horizontalAxisDirection,
	verticalOffset: verticalOffset,
	verticalAxisDirection: verticalAxisDirection,
	mainAxis: mainAxis,
	delegate: delegate as TwoDimensionalChildListDelegate,
	childManager: context as TwoDimensionalChildManager,
	cacheExtent: cacheExtent,
	clipBehavior: clipBehavior,
	);
	}

	@override
	void updateRenderObject(BuildContext context, RenderSimpleListTableViewport renderObject) {
	renderObject
	..horizontalOffset = horizontalOffset
	..horizontalAxisDirection = horizontalAxisDirection
	..verticalOffset = verticalOffset
	..verticalAxisDirection = verticalAxisDirection
	..mainAxis = mainAxis
	..delegate = delegate
	..cacheExtent = cacheExtent
	..clipBehavior = clipBehavior;
	}
	}

	class RenderSimpleListTableViewport extends RenderTwoDimensionalViewport {
	RenderSimpleListTableViewport({
	required super.horizontalOffset,
	required super.horizontalAxisDirection,
	required super.verticalOffset,
	required super.verticalAxisDirection,
	required TwoDimensionalChildListDelegate delegate,
	required super.mainAxis,
	required super.childManager,
	super.cacheExtent,
	super.clipBehavior = Clip.hardEdge,
	}) : super(delegate: delegate);

	@override
	void layoutChildSequence() {
	// Really simple table implementation for testing.
	// Every child is 200x200 square
	final double horizontalPixels = horizontalOffset.pixels;
	final double verticalPixels = verticalOffset.pixels;
	final TwoDimensionalChildListDelegate listDelegate = delegate as TwoDimensionalChildListDelegate;
	final int rowCount;
	final int columnCount;
	rowCount = listDelegate.children.length;
	columnCount = listDelegate.children[0].length;

	final int leadingColumn = math.max((horizontalPixels / 200).floor(), 0);
	final int leadingRow = math.max((verticalPixels / 200).floor(), 0);
	final int trailingColumn = math.min(
	((horizontalPixels + viewportDimension.width) / 200).ceil(),
	columnCount - 1,
	);
	final int trailingRow = math.min(
	((verticalPixels + viewportDimension.height) / 200).ceil(),
	rowCount - 1,
	);

	double xLayoutOffset = (leadingColumn * 200) - horizontalOffset.pixels;
	for (int column = leadingColumn; column <= trailingColumn; column++) {
	double yLayoutOffset = (leadingRow * 200) - verticalOffset.pixels;
	for (int row = leadingRow; row <= trailingRow; row++) {
	final ChildVicinity vicinity = ChildVicinity(xIndex: column, yIndex: row);
	final RenderBox child = buildOrObtainChildFor(vicinity)!;
	child.layout(constraints.tighten(width: 200.0, height: 200.0));

	parentDataOf(child).layoutOffset = Offset(xLayoutOffset, yLayoutOffset);
	yLayoutOffset += 200;
	}
	xLayoutOffset += 200;
	}

	verticalOffset.applyContentDimensions(
	0.0,
	math.max(200 * rowCount - viewportDimension.height, 0.0),
	);
	horizontalOffset.applyContentDimensions(
	0,
	math.max(200 * columnCount - viewportDimension.width, 0.0),
	);
	}
	}

	class KeepAliveCheckBox extends StatefulWidget {
	const KeepAliveCheckBox({ super.key });

	@override
	KeepAliveCheckBoxState createState() => KeepAliveCheckBoxState();
	}

	class KeepAliveCheckBoxState extends State<KeepAliveCheckBox> with AutomaticKeepAliveClientMixin {
	bool checkValue = false;

	@override
	bool get wantKeepAlive => _wantKeepAlive;
	bool _wantKeepAlive = false;
	set wantKeepAlive(bool value) {
	if (_wantKeepAlive != value) {
	_wantKeepAlive = value;
	updateKeepAlive();
	}
	}

	@override
	Widget build(BuildContext context) {
	super.build(context);
	return Checkbox(
	value: checkValue,
	onChanged: (bool? value) {
	if (checkValue != value) {
	setState(() {
	checkValue = value!;
	wantKeepAlive = value;
	});
	}
	},
	);
	}
	}

	// TwoDimensionalViewportParentData already mixes in KeepAliveParentDataMixin,
	// and so should be compatible with both the KeepAlive and
	// TestParentDataWidget ParentDataWidgets.
	// This ParentData is set up above as part of the
	// RenderSimpleBuilderTableViewport for testing.
	class TestExtendedParentData extends TwoDimensionalViewportParentData {
	int? testValue;
	}

	class TestParentDataWidget extends ParentDataWidget<TestExtendedParentData> {
	const TestParentDataWidget({
	super.key,
	required super.child,
	this.testValue,
	});

	final int? testValue;

	@override
	void applyParentData(RenderObject renderObject) {
	assert(renderObject.parentData is TestExtendedParentData);
	final TestExtendedParentData parentData = renderObject.parentData! as TestExtendedParentData;
	parentData.testValue = testValue;
	}

	@override
	Type get debugTypicalAncestorWidgetClass => SimpleBuilderTableViewport;
	}