pkg/analysis_server/lib/src/utilities/flutter.dart - sdk.git - Git at Google

 // Copyright (c) 2017, the Dart project authors. Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.

 import 'package:analysis_server/src/utilities/strings.dart';
 import 'package:analyzer/dart/analysis/results.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer_plugin/utilities/change_builder/change_builder_dart.dart';

 class Flutter {
   static const _nameAlign = 'Align';
   static const _nameCenter = 'Center';
   static const _nameContainer = 'Container';
   static const _namePadding = 'Padding';
   static const _nameState = 'State';
   static const _nameStatefulWidget = 'StatefulWidget';
   static const _nameStatelessWidget = 'StatelessWidget';
   static const _nameStreamBuilder = 'StreamBuilder';
   static const _nameWidget = 'Widget';

   static final mobile = Flutter._('flutter', 'package:flutter');
   static final web = Flutter._('flutter_web', 'package:flutter_web');

   static final _uriFlutterMobileWidgets =
       Uri.parse('package:flutter/widgets.dart');

   static final _uriFlutterWebWidgets =
       Uri.parse('package:flutter_web/widgets.dart');

   final String packageName;
   final String widgetsUri;

   final Uri _uriAlignment;
   final Uri _uriAsync;
   final Uri _uriBasic;
   final Uri _uriContainer;
   final Uri _uriEdgeInsets;
   final Uri _uriFramework;
   final Uri _uriWidgetsIcon;
   final Uri _uriWidgetsText;

   factory Flutter.of(ResolvedUnitResult resolvedUnit) {
     var uriConverter = resolvedUnit.session.uriConverter;
     var isMobile = uriConverter.uriToPath(_uriFlutterMobileWidgets) != null;
     var isWeb = uriConverter.uriToPath(_uriFlutterWebWidgets) != null;

     if (isMobile && isWeb) {
       var visitor = _IdentifyMobileOrWeb();
       resolvedUnit.unit.accept(visitor);
       isMobile = visitor.isMobile;
       isWeb = visitor.isWeb;
     }

     if (isMobile) {
       return mobile;
     }

     if (isWeb) {
       return web;
     }

     return mobile;
   }

   Flutter._(this.packageName, String uriPrefix)
       : widgetsUri = '$uriPrefix/widgets.dart',
         _uriAlignment = Uri.parse('$uriPrefix/src/painting/alignment.dart'),
         _uriAsync = Uri.parse('$uriPrefix/src/widgets/async.dart'),
         _uriBasic = Uri.parse('$uriPrefix/src/widgets/basic.dart'),
         _uriContainer = Uri.parse('$uriPrefix/src/widgets/container.dart'),
         _uriEdgeInsets = Uri.parse('$uriPrefix/src/painting/edge_insets.dart'),
         _uriFramework = Uri.parse('$uriPrefix/src/widgets/framework.dart'),
         _uriWidgetsIcon = Uri.parse('$uriPrefix/src/widgets/icon.dart'),
         _uriWidgetsText = Uri.parse('$uriPrefix/src/widgets/text.dart');

   /// Return the argument with the given [index], or `null` if none.
   Expression argumentByIndex(List<Expression> arguments, int index) {
     if (index < arguments.length) {
       return arguments[index];
     }
     return null;
   }

   /// Return the named expression with the given [name], or `null` if none.
   NamedExpression argumentByName(List<Expression> arguments, String name) {
     for (var argument in arguments) {
       if (argument is NamedExpression && argument.name.label.name == name) {
         return argument;
       }
     }
     return null;
   }

   void convertChildToChildren(
       InstanceCreationExpression childArg,
       NamedExpression namedExp,
       String eol,
       Function getNodeText,
       Function getLinePrefix,
       Function getIndent,
       Function getText,
       Function _addInsertEdit,
       Function _addRemoveEdit,
       Function _addReplaceEdit,
       Function rangeNode) {
     var childLoc = namedExp.offset + 'child'.length;
     _addInsertEdit(childLoc, 'ren');
     var listLoc = childArg.offset;
     String childArgSrc = getNodeText(childArg);
     if (!childArgSrc.contains(eol)) {
       _addInsertEdit(listLoc, '[');
       _addInsertEdit(listLoc + childArg.length, ']');
     } else {
       var newlineLoc = childArgSrc.lastIndexOf(eol);
       if (newlineLoc == childArgSrc.length) {
         newlineLoc -= 1;
       }
       String indentOld = getLinePrefix(childArg.offset + 1 + newlineLoc);
       var indentNew = '$indentOld${getIndent(1)}';
       // The separator includes 'child:' but that has no newlines.
       String separator =
           getText(namedExp.offset, childArg.offset - namedExp.offset);
       var prefix = separator.contains(eol) ? '' : '$eol$indentNew';
       if (prefix.isEmpty) {
         _addInsertEdit(namedExp.offset + 'child:'.length, ' [');
         _addRemoveEdit(SourceRange(childArg.offset - 2, 2));
       } else {
         _addInsertEdit(listLoc, '[');
       }
       var newChildArgSrc = childArgSrc.replaceAll(
           RegExp('^$indentOld', multiLine: true), '$indentNew');
       newChildArgSrc = '$prefix$newChildArgSrc,$eol$indentOld]';
       _addReplaceEdit(rangeNode(childArg), newChildArgSrc);
     }
   }

   void convertChildToChildren2(
       DartFileEditBuilder builder,
       Expression childArg,
       NamedExpression namedExp,
       String eol,
       Function getNodeText,
       Function getLinePrefix,
       Function getIndent,
       Function getText,
       Function rangeNode) {
     var childLoc = namedExp.offset + 'child'.length;
     builder.addSimpleInsertion(childLoc, 'ren');
     var listLoc = childArg.offset;
     String childArgSrc = getNodeText(childArg);
     if (!childArgSrc.contains(eol)) {
       builder.addSimpleInsertion(listLoc, '[');
       builder.addSimpleInsertion(listLoc + childArg.length, ']');
     } else {
       var newlineLoc = childArgSrc.lastIndexOf(eol);
       if (newlineLoc == childArgSrc.length) {
         newlineLoc -= 1;
       }
       String indentOld = getLinePrefix(childArg.offset + 1 + newlineLoc);
       var indentNew = '$indentOld${getIndent(1)}';
       // The separator includes 'child:' but that has no newlines.
       String separator =
           getText(namedExp.offset, childArg.offset - namedExp.offset);
       var prefix = separator.contains(eol) ? '' : '$eol$indentNew';
       if (prefix.isEmpty) {
         builder.addSimpleInsertion(namedExp.offset + 'child:'.length, ' [');
         builder.addDeletion(SourceRange(childArg.offset - 2, 2));
       } else {
         builder.addSimpleInsertion(listLoc, '[');
       }
       var newChildArgSrc = childArgSrc.replaceAll(
           RegExp('^$indentOld', multiLine: true), '$indentNew');
       newChildArgSrc = '$prefix$newChildArgSrc,$eol$indentOld]';
       builder.addSimpleReplacement(rangeNode(childArg), newChildArgSrc);
     }
   }

   /// Return the named expression representing the `child` argument of the given
   /// [newExpr], or `null` if none.
   NamedExpression findChildArgument(InstanceCreationExpression newExpr) =>
       newExpr.argumentList.arguments
           .firstWhere(isChildArgument, orElse: () => null);

   /// Return the named expression representing the `children` argument of the
   /// given [newExpr], or `null` if none.
   NamedExpression findChildrenArgument(InstanceCreationExpression newExpr) =>
       newExpr.argumentList.arguments
           .firstWhere(isChildrenArgument, orElse: () => null);

   /// Return the Flutter instance creation expression that is the value of the
   /// 'child' argument of the given [newExpr], or null if none.
   InstanceCreationExpression findChildWidget(
       InstanceCreationExpression newExpr) {
     var child = findChildArgument(newExpr);
     return getChildWidget(child);
   }

   /// Return the named expression with the given [name], or `null` if none.
   NamedExpression findNamedArgument(
     InstanceCreationExpression creation,
     String name,
   ) {
     var arguments = creation.argumentList.arguments;
     return argumentByName(arguments, name);
   }

   /// If the given [node] is a simple identifier, find the named expression
   /// whose name is the given [name] that is an argument to a Flutter instance
   /// creation expression. Return null if any condition cannot be satisfied.
   NamedExpression findNamedExpression(AstNode node, String name) {
     if (node is! SimpleIdentifier) {
       return null;
     }
     SimpleIdentifier namedArg = node;
     NamedExpression namedExp;
     if (namedArg.parent is Label && namedArg.parent.parent is NamedExpression) {
       namedExp = namedArg.parent.parent;
       if (namedArg.name != name || namedExp.expression == null) {
         return null;
       }
     } else {
       return null;
     }
     if (namedExp.parent?.parent is! InstanceCreationExpression) {
       return null;
     }
     InstanceCreationExpression newExpr = namedExp.parent.parent;
     if (newExpr == null || !isWidgetCreation(newExpr)) {
       return null;
     }
     return namedExp;
   }

   /// Return the expression that is a Flutter Widget that is the value of the
   /// given [child], or null if none.
   Expression getChildWidget(NamedExpression child) {
     var expression = child?.expression;
     if (isWidgetExpression(expression)) {
       return expression;
     }
     return null;
   }

   /// Return the presentation for the given Flutter `Widget` creation [node].
   String getWidgetPresentationText(InstanceCreationExpression node) {
     var element = node.constructorName.staticElement?.enclosingElement;
     if (!isWidget(element)) {
       return null;
     }
     List<Expression> arguments = node.argumentList.arguments;
     if (_isExactWidget(element, 'Icon', _uriWidgetsIcon)) {
       if (arguments.isNotEmpty) {
         var text = arguments[0].toString();
         var arg = shorten(text, 32);
         return 'Icon($arg)';
       } else {
         return 'Icon';
       }
     }
     if (_isExactWidget(element, 'Text', _uriWidgetsText)) {
       if (arguments.isNotEmpty) {
         var text = arguments[0].toString();
         var arg = shorten(text, 32);
         return 'Text($arg)';
       } else {
         return 'Text';
       }
     }
     return element.name;
   }

   /// Return the instance creation expression that surrounds the given
   /// [node], if any, else null. The [node] may be the instance creation
   /// expression itself or the identifier that names the constructor.
   InstanceCreationExpression identifyNewExpression(AstNode node) {
     InstanceCreationExpression newExpr;
     if (node is SimpleIdentifier) {
       if (node.parent is ConstructorName &&
           node.parent.parent is InstanceCreationExpression) {
         newExpr = node.parent.parent;
       } else if (node.parent?.parent is ConstructorName &&
           node.parent.parent?.parent is InstanceCreationExpression) {
         newExpr = node.parent.parent.parent;
       }
     } else if (node is InstanceCreationExpression) {
       newExpr = node;
     }
     return newExpr;
   }

   /// Attempt to find and return the closest expression that encloses the [node]
   /// and is an independent Flutter `Widget`.  Return `null` if nothing found.
   Expression identifyWidgetExpression(AstNode node) {
     for (; node != null; node = node.parent) {
       if (isWidgetExpression(node)) {
         var parent = node.parent;

         if (node is AssignmentExpression) {
           return null;
         }
         if (parent is AssignmentExpression) {
           if (parent.rightHandSide == node) {
             return node;
           }
           return null;
         }

         if (parent is ArgumentList ||
             parent is ConditionalExpression && parent.thenExpression == node ||
             parent is ConditionalExpression && parent.elseExpression == node ||
             parent is ExpressionFunctionBody && parent.expression == node ||
             parent is ForElement && parent.body == node ||
             parent is IfElement && parent.thenElement == node ||
             parent is IfElement && parent.elseElement == node ||
             parent is ListLiteral ||
             parent is NamedExpression && parent.expression == node ||
             parent is Statement) {
           return node;
         }
       }
       if (node is ArgumentList || node is Statement || node is FunctionBody) {
         return null;
       }
     }
     return null;
   }

   /// Return `true` is the given [argument] is the `child` argument.
   bool isChildArgument(Expression argument) =>
       argument is NamedExpression && argument.name.label.name == 'child';

   /// Return `true` is the given [argument] is the `child` argument.
   bool isChildrenArgument(Expression argument) =>
       argument is NamedExpression && argument.name.label.name == 'children';

   /// Return `true` if the given [type] is the dart.ui class `Color`, or its
   /// subtype.
   bool isColor(DartType type) {
     if (type is! InterfaceType) {
       return false;
     }

     bool isColorElement(ClassElement element) {
       if (element == null) {
         return false;
       }

       bool isExactColor(ClassElement element) =>
           element?.name == 'Color' && element.library.name == 'dart.ui';
       if (isExactColor(element)) {
         return true;
       }
       for (var type in element.allSupertypes) {
         if (isExactColor(type.element)) {
           return true;
         }
       }
       return false;
     }

     return isColorElement(type.element);
   }

   /// Return `true` if the [element] is the Flutter class `Alignment`.
   bool isExactAlignment(ClassElement element) {
     return _isExactWidget(element, 'Alignment', _uriAlignment);
   }

   /// Return `true` if the [element] is the Flutter class
   /// `AlignmentDirectional`.
   bool isExactAlignmentDirectional(ClassElement element) {
     return _isExactWidget(element, 'AlignmentDirectional', _uriAlignment);
   }

   /// Return `true` if the [element] is the Flutter class `AlignmentGeometry`.
   bool isExactAlignmentGeometry(ClassElement element) {
     return _isExactWidget(element, 'AlignmentGeometry', _uriAlignment);
   }

   /// Return `true` if the [type] is the Flutter type `EdgeInsetsGeometry`.
   bool isExactEdgeInsetsGeometryType(DartType type) {
     return type is InterfaceType &&
         _isExactWidget(type.element, 'EdgeInsetsGeometry', _uriEdgeInsets);
   }

   /// Return `true` if the [node] is creation of `Align`.
   bool isExactlyAlignCreation(InstanceCreationExpression node) {
     var type = node?.staticType;
     return isExactWidgetTypeAlign(type);
   }

   /// Return `true` if the [node] is creation of `Container`.
   bool isExactlyContainerCreation(InstanceCreationExpression node) {
     var type = node?.staticType;
     return isExactWidgetTypeContainer(type);
   }

   /// Return `true` if the [node] is creation of `Padding`.
   bool isExactlyPaddingCreation(InstanceCreationExpression node) {
     var type = node?.staticType;
     return isExactWidgetTypePadding(type);
   }

   /// Return `true` if the given [type] is the Flutter class `StatefulWidget`.
   bool isExactlyStatefulWidgetType(DartType type) {
     return type is InterfaceType &&
         _isExactWidget(type.element, _nameStatefulWidget, _uriFramework);
   }

   /// Return `true` if the given [type] is the Flutter class `StatelessWidget`.
   bool isExactlyStatelessWidgetType(DartType type) {
     return type is InterfaceType &&
         _isExactWidget(type.element, _nameStatelessWidget, _uriFramework);
   }

   /// Return `true` if the given [element] is the Flutter class `State`.
   bool isExactState(ClassElement element) {
     return _isExactWidget(element, _nameState, _uriFramework);
   }

   /// Return `true` if the given [type] is the Flutter class `Align`.
   bool isExactWidgetTypeAlign(DartType type) {
     return type is InterfaceType &&
         _isExactWidget(type.element, _nameAlign, _uriBasic);
   }

   /// Return `true` if the given [type] is the Flutter class `Center`.
   bool isExactWidgetTypeCenter(DartType type) {
     return type is InterfaceType &&
         _isExactWidget(type.element, _nameCenter, _uriBasic);
   }

   /// Return `true` if the given [type] is the Flutter class `Container`.
   bool isExactWidgetTypeContainer(DartType type) {
     return type is InterfaceType &&
         _isExactWidget(type.element, _nameContainer, _uriContainer);
   }

   /// Return `true` if the given [type] is the Flutter class `Padding`.
   bool isExactWidgetTypePadding(DartType type) {
     return type is InterfaceType &&
         _isExactWidget(type.element, _namePadding, _uriBasic);
   }

   /// Return `true` if the given [type] is the Flutter class `StreamBuilder`.
   bool isExactWidgetTypeStreamBuilder(DartType type) {
     return type is InterfaceType &&
         _isExactWidget(type.element, _nameStreamBuilder, _uriAsync);
   }

   /// Return `true` if the given [type] is the Flutter class `Widget`, or its
   /// subtype.
   bool isListOfWidgetsType(DartType type) {
     return type is InterfaceType &&
         type.isDartCoreList &&
         isWidgetType(type.typeArguments[0]);
   }

   /// Return `true` if the given [type] is the dart.ui class `Color`, or its
   /// subtype.
   bool isMatrix4(DartType type) {
     if (type is! InterfaceType) {
       return false;
     }

     bool isMatrix4Element(ClassElement element) {
       if (element == null) {
         return false;
       }

       bool isExactMatrix4(ClassElement element) =>
           element?.name == 'Matrix4' &&
           element.library.name == 'vector_math_64';
       if (isExactMatrix4(element)) {
         return true;
       }
       for (var type in element.allSupertypes) {
         if (isExactMatrix4(type.element)) {
           return true;
         }
       }
       return false;
     }

     return isMatrix4Element(type.element);
   }

   /// Return `true` if the given [element] has the Flutter class `State` as
   /// a superclass.
   bool isState(ClassElement element) {
     return _hasSupertype(element, _uriFramework, _nameState);
   }

   /// Return `true` if the given [element] is a [ClassElement] that extends
   /// the Flutter class `StatefulWidget`.
   bool isStatefulWidgetDeclaration(Element element) {
     if (element is ClassElement) {
       return isExactlyStatefulWidgetType(element.supertype);
     }
     return false;
   }

   /// Return `true` if the given [element] is the Flutter class `Widget`, or its
   /// subtype.
   bool isWidget(ClassElement element) {
     if (element == null) {
       return false;
     }
     if (_isExactWidget(element, _nameWidget, _uriFramework)) {
       return true;
     }
     for (var type in element.allSupertypes) {
       if (_isExactWidget(type.element, _nameWidget, _uriFramework)) {
         return true;
       }
     }
     return false;
   }

   /// Return `true` if the given [expr] is a constructor invocation for a
   /// class that has the Flutter class `Widget` as a superclass.
   bool isWidgetCreation(InstanceCreationExpression expr) {
     var element = expr?.constructorName?.staticElement?.enclosingElement;
     return isWidget(element);
   }

   /// Return `true` if the given [node] is the Flutter class `Widget`, or its
   /// subtype.
   bool isWidgetExpression(AstNode node) {
     if (node == null) {
       return false;
     }
     if (node.parent is TypeName || node.parent?.parent is TypeName) {
       return false;
     }
     if (node.parent is ConstructorName) {
       return false;
     }
     if (node is NamedExpression) {
       return false;
     }
     if (node is Expression) {
       return isWidgetType(node.staticType);
     }
     return false;
   }

   /// Return `true` if the given [type] is the Flutter class `Widget`, or its
   /// subtype.
   bool isWidgetType(DartType type) {
     return type is InterfaceType && isWidget(type.element);
   }

   /// Return `true` if the given [element] has a supertype with the
   /// [requiredName] defined in the file with the [requiredUri].
   bool _hasSupertype(
       ClassElement element, Uri requiredUri, String requiredName) {
     if (element == null) {
       return false;
     }
     for (var type in element.allSupertypes) {
       if (type.element.name == requiredName) {
         var uri = type.element.source.uri;
         if (uri == requiredUri) {
           return true;
         }
       }
     }
     return false;
   }

   /// Return `true` if the given [element] is the exact [type] defined in the
   /// file with the given [uri].
   bool _isExactWidget(ClassElement element, String type, Uri uri) {
     return element != null && element.name == type && element.source.uri == uri;
   }
 }

 class _IdentifyMobileOrWeb extends GeneralizingAstVisitor<void> {
   bool isMobile = false;
   bool isWeb = false;

   @override
   void visitExpression(Expression node) {
     if (isMobile || isWeb) {
       return;
     }

     if (Flutter.mobile.isWidgetExpression(node)) {
       isMobile = true;
       return;
     }

     if (Flutter.web.isWidgetExpression(node)) {
       isWeb = true;
       return;
     }

     super.visitExpression(node);
   }
 }
	// Copyright (c) 2017, the Dart project authors. Please see the AUTHORS file
	// for details. All rights reserved. Use of this source code is governed by a
	// BSD-style license that can be found in the LICENSE file.

	import 'package:analysis_server/src/utilities/strings.dart';
	import 'package:analyzer/dart/analysis/results.dart';
	import 'package:analyzer/dart/ast/ast.dart';
	import 'package:analyzer/dart/ast/visitor.dart';
	import 'package:analyzer/dart/element/element.dart';
	import 'package:analyzer/dart/element/type.dart';
	import 'package:analyzer/src/generated/source.dart';
	import 'package:analyzer_plugin/utilities/change_builder/change_builder_dart.dart';

	class Flutter {
	static const _nameAlign = 'Align';
	static const _nameCenter = 'Center';
	static const _nameContainer = 'Container';
	static const _namePadding = 'Padding';
	static const _nameState = 'State';
	static const _nameStatefulWidget = 'StatefulWidget';
	static const _nameStatelessWidget = 'StatelessWidget';
	static const _nameStreamBuilder = 'StreamBuilder';
	static const _nameWidget = 'Widget';

	static final mobile = Flutter._('flutter', 'package:flutter');
	static final web = Flutter._('flutter_web', 'package:flutter_web');

	static final _uriFlutterMobileWidgets =
	Uri.parse('package:flutter/widgets.dart');

	static final _uriFlutterWebWidgets =
	Uri.parse('package:flutter_web/widgets.dart');

	final String packageName;
	final String widgetsUri;

	final Uri _uriAlignment;
	final Uri _uriAsync;
	final Uri _uriBasic;
	final Uri _uriContainer;
	final Uri _uriEdgeInsets;
	final Uri _uriFramework;
	final Uri _uriWidgetsIcon;
	final Uri _uriWidgetsText;

	factory Flutter.of(ResolvedUnitResult resolvedUnit) {
	var uriConverter = resolvedUnit.session.uriConverter;
	var isMobile = uriConverter.uriToPath(_uriFlutterMobileWidgets) != null;
	var isWeb = uriConverter.uriToPath(_uriFlutterWebWidgets) != null;

	if (isMobile && isWeb) {
	var visitor = _IdentifyMobileOrWeb();
	resolvedUnit.unit.accept(visitor);
	isMobile = visitor.isMobile;
	isWeb = visitor.isWeb;
	}

	if (isMobile) {
	return mobile;
	}

	if (isWeb) {
	return web;
	}

	return mobile;
	}

	Flutter._(this.packageName, String uriPrefix)
	: widgetsUri = '$uriPrefix/widgets.dart',
	_uriAlignment = Uri.parse('$uriPrefix/src/painting/alignment.dart'),
	_uriAsync = Uri.parse('$uriPrefix/src/widgets/async.dart'),
	_uriBasic = Uri.parse('$uriPrefix/src/widgets/basic.dart'),
	_uriContainer = Uri.parse('$uriPrefix/src/widgets/container.dart'),
	_uriEdgeInsets = Uri.parse('$uriPrefix/src/painting/edge_insets.dart'),
	_uriFramework = Uri.parse('$uriPrefix/src/widgets/framework.dart'),
	_uriWidgetsIcon = Uri.parse('$uriPrefix/src/widgets/icon.dart'),
	_uriWidgetsText = Uri.parse('$uriPrefix/src/widgets/text.dart');

	/// Return the argument with the given [index], or `null` if none.
	Expression argumentByIndex(List<Expression> arguments, int index) {
	if (index < arguments.length) {
	return arguments[index];
	}
	return null;
	}

	/// Return the named expression with the given [name], or `null` if none.
	NamedExpression argumentByName(List<Expression> arguments, String name) {
	for (var argument in arguments) {
	if (argument is NamedExpression && argument.name.label.name == name) {
	return argument;
	}
	}
	return null;
	}

	void convertChildToChildren(
	InstanceCreationExpression childArg,
	NamedExpression namedExp,
	String eol,
	Function getNodeText,
	Function getLinePrefix,
	Function getIndent,
	Function getText,
	Function _addInsertEdit,
	Function _addRemoveEdit,
	Function _addReplaceEdit,
	Function rangeNode) {
	var childLoc = namedExp.offset + 'child'.length;
	_addInsertEdit(childLoc, 'ren');
	var listLoc = childArg.offset;
	String childArgSrc = getNodeText(childArg);
	if (!childArgSrc.contains(eol)) {
	_addInsertEdit(listLoc, '[');
	_addInsertEdit(listLoc + childArg.length, ']');
	} else {
	var newlineLoc = childArgSrc.lastIndexOf(eol);
	if (newlineLoc == childArgSrc.length) {
	newlineLoc -= 1;
	}
	String indentOld = getLinePrefix(childArg.offset + 1 + newlineLoc);
	var indentNew = '$indentOld${getIndent(1)}';
	// The separator includes 'child:' but that has no newlines.
	String separator =
	getText(namedExp.offset, childArg.offset - namedExp.offset);
	var prefix = separator.contains(eol) ? '' : '$eol$indentNew';
	if (prefix.isEmpty) {
	_addInsertEdit(namedExp.offset + 'child:'.length, ' [');
	_addRemoveEdit(SourceRange(childArg.offset - 2, 2));
	} else {
	_addInsertEdit(listLoc, '[');
	}
	var newChildArgSrc = childArgSrc.replaceAll(
	RegExp('^$indentOld', multiLine: true), '$indentNew');
	newChildArgSrc = '$prefix$newChildArgSrc,$eol$indentOld]';
	_addReplaceEdit(rangeNode(childArg), newChildArgSrc);
	}
	}

	void convertChildToChildren2(
	DartFileEditBuilder builder,
	Expression childArg,
	NamedExpression namedExp,
	String eol,
	Function getNodeText,
	Function getLinePrefix,
	Function getIndent,
	Function getText,
	Function rangeNode) {
	var childLoc = namedExp.offset + 'child'.length;
	builder.addSimpleInsertion(childLoc, 'ren');
	var listLoc = childArg.offset;
	String childArgSrc = getNodeText(childArg);
	if (!childArgSrc.contains(eol)) {
	builder.addSimpleInsertion(listLoc, '[');
	builder.addSimpleInsertion(listLoc + childArg.length, ']');
	} else {
	var newlineLoc = childArgSrc.lastIndexOf(eol);
	if (newlineLoc == childArgSrc.length) {
	newlineLoc -= 1;
	}
	String indentOld = getLinePrefix(childArg.offset + 1 + newlineLoc);
	var indentNew = '$indentOld${getIndent(1)}';
	// The separator includes 'child:' but that has no newlines.
	String separator =
	getText(namedExp.offset, childArg.offset - namedExp.offset);
	var prefix = separator.contains(eol) ? '' : '$eol$indentNew';
	if (prefix.isEmpty) {
	builder.addSimpleInsertion(namedExp.offset + 'child:'.length, ' [');
	builder.addDeletion(SourceRange(childArg.offset - 2, 2));
	} else {
	builder.addSimpleInsertion(listLoc, '[');
	}
	var newChildArgSrc = childArgSrc.replaceAll(
	RegExp('^$indentOld', multiLine: true), '$indentNew');
	newChildArgSrc = '$prefix$newChildArgSrc,$eol$indentOld]';
	builder.addSimpleReplacement(rangeNode(childArg), newChildArgSrc);
	}
	}

	/// Return the named expression representing the `child` argument of the given
	/// [newExpr], or `null` if none.
	NamedExpression findChildArgument(InstanceCreationExpression newExpr) =>
	newExpr.argumentList.arguments
	.firstWhere(isChildArgument, orElse: () => null);

	/// Return the named expression representing the `children` argument of the
	/// given [newExpr], or `null` if none.
	NamedExpression findChildrenArgument(InstanceCreationExpression newExpr) =>
	newExpr.argumentList.arguments
	.firstWhere(isChildrenArgument, orElse: () => null);

	/// Return the Flutter instance creation expression that is the value of the
	/// 'child' argument of the given [newExpr], or null if none.
	InstanceCreationExpression findChildWidget(
	InstanceCreationExpression newExpr) {
	var child = findChildArgument(newExpr);
	return getChildWidget(child);
	}

	/// Return the named expression with the given [name], or `null` if none.
	NamedExpression findNamedArgument(
	InstanceCreationExpression creation,
	String name,
	) {
	var arguments = creation.argumentList.arguments;
	return argumentByName(arguments, name);
	}

	/// If the given [node] is a simple identifier, find the named expression
	/// whose name is the given [name] that is an argument to a Flutter instance
	/// creation expression. Return null if any condition cannot be satisfied.
	NamedExpression findNamedExpression(AstNode node, String name) {
	if (node is! SimpleIdentifier) {
	return null;
	}
	SimpleIdentifier namedArg = node;
	NamedExpression namedExp;
	if (namedArg.parent is Label && namedArg.parent.parent is NamedExpression) {
	namedExp = namedArg.parent.parent;
	if (namedArg.name != name \|\| namedExp.expression == null) {
	return null;
	}
	} else {
	return null;
	}
	if (namedExp.parent?.parent is! InstanceCreationExpression) {
	return null;
	}
	InstanceCreationExpression newExpr = namedExp.parent.parent;
	if (newExpr == null \|\| !isWidgetCreation(newExpr)) {
	return null;
	}
	return namedExp;
	}

	/// Return the expression that is a Flutter Widget that is the value of the
	/// given [child], or null if none.
	Expression getChildWidget(NamedExpression child) {
	var expression = child?.expression;
	if (isWidgetExpression(expression)) {
	return expression;
	}
	return null;
	}

	/// Return the presentation for the given Flutter `Widget` creation [node].
	String getWidgetPresentationText(InstanceCreationExpression node) {
	var element = node.constructorName.staticElement?.enclosingElement;
	if (!isWidget(element)) {
	return null;
	}
	List<Expression> arguments = node.argumentList.arguments;
	if (_isExactWidget(element, 'Icon', _uriWidgetsIcon)) {
	if (arguments.isNotEmpty) {
	var text = arguments[0].toString();
	var arg = shorten(text, 32);
	return 'Icon($arg)';
	} else {
	return 'Icon';
	}
	}
	if (_isExactWidget(element, 'Text', _uriWidgetsText)) {
	if (arguments.isNotEmpty) {
	var text = arguments[0].toString();
	var arg = shorten(text, 32);
	return 'Text($arg)';
	} else {
	return 'Text';
	}
	}
	return element.name;
	}

	/// Return the instance creation expression that surrounds the given
	/// [node], if any, else null. The [node] may be the instance creation
	/// expression itself or the identifier that names the constructor.
	InstanceCreationExpression identifyNewExpression(AstNode node) {
	InstanceCreationExpression newExpr;
	if (node is SimpleIdentifier) {
	if (node.parent is ConstructorName &&
	node.parent.parent is InstanceCreationExpression) {
	newExpr = node.parent.parent;
	} else if (node.parent?.parent is ConstructorName &&
	node.parent.parent?.parent is InstanceCreationExpression) {
	newExpr = node.parent.parent.parent;
	}
	} else if (node is InstanceCreationExpression) {
	newExpr = node;
	}
	return newExpr;
	}

	/// Attempt to find and return the closest expression that encloses the [node]
	/// and is an independent Flutter `Widget`. Return `null` if nothing found.
	Expression identifyWidgetExpression(AstNode node) {
	for (; node != null; node = node.parent) {
	if (isWidgetExpression(node)) {
	var parent = node.parent;

	if (node is AssignmentExpression) {
	return null;
	}
	if (parent is AssignmentExpression) {
	if (parent.rightHandSide == node) {
	return node;
	}
	return null;
	}

	if (parent is ArgumentList \|\|
	parent is ConditionalExpression && parent.thenExpression == node \|\|
	parent is ConditionalExpression && parent.elseExpression == node \|\|
	parent is ExpressionFunctionBody && parent.expression == node \|\|
	parent is ForElement && parent.body == node \|\|
	parent is IfElement && parent.thenElement == node \|\|
	parent is IfElement && parent.elseElement == node \|\|
	parent is ListLiteral \|\|
	parent is NamedExpression && parent.expression == node \|\|
	parent is Statement) {
	return node;
	}
	}
	if (node is ArgumentList \|\| node is Statement \|\| node is FunctionBody) {
	return null;
	}
	}
	return null;
	}

	/// Return `true` is the given [argument] is the `child` argument.
	bool isChildArgument(Expression argument) =>
	argument is NamedExpression && argument.name.label.name == 'child';

	/// Return `true` is the given [argument] is the `child` argument.
	bool isChildrenArgument(Expression argument) =>
	argument is NamedExpression && argument.name.label.name == 'children';

	/// Return `true` if the given [type] is the dart.ui class `Color`, or its
	/// subtype.
	bool isColor(DartType type) {
	if (type is! InterfaceType) {
	return false;
	}

	bool isColorElement(ClassElement element) {
	if (element == null) {
	return false;
	}

	bool isExactColor(ClassElement element) =>
	element?.name == 'Color' && element.library.name == 'dart.ui';
	if (isExactColor(element)) {
	return true;
	}
	for (var type in element.allSupertypes) {
	if (isExactColor(type.element)) {
	return true;
	}
	}
	return false;
	}

	return isColorElement(type.element);
	}

	/// Return `true` if the [element] is the Flutter class `Alignment`.
	bool isExactAlignment(ClassElement element) {
	return _isExactWidget(element, 'Alignment', _uriAlignment);
	}

	/// Return `true` if the [element] is the Flutter class
	/// `AlignmentDirectional`.
	bool isExactAlignmentDirectional(ClassElement element) {
	return _isExactWidget(element, 'AlignmentDirectional', _uriAlignment);
	}

	/// Return `true` if the [element] is the Flutter class `AlignmentGeometry`.
	bool isExactAlignmentGeometry(ClassElement element) {
	return _isExactWidget(element, 'AlignmentGeometry', _uriAlignment);
	}

	/// Return `true` if the [type] is the Flutter type `EdgeInsetsGeometry`.
	bool isExactEdgeInsetsGeometryType(DartType type) {
	return type is InterfaceType &&
	_isExactWidget(type.element, 'EdgeInsetsGeometry', _uriEdgeInsets);
	}

	/// Return `true` if the [node] is creation of `Align`.
	bool isExactlyAlignCreation(InstanceCreationExpression node) {
	var type = node?.staticType;
	return isExactWidgetTypeAlign(type);
	}

	/// Return `true` if the [node] is creation of `Container`.
	bool isExactlyContainerCreation(InstanceCreationExpression node) {
	var type = node?.staticType;
	return isExactWidgetTypeContainer(type);
	}

	/// Return `true` if the [node] is creation of `Padding`.
	bool isExactlyPaddingCreation(InstanceCreationExpression node) {
	var type = node?.staticType;
	return isExactWidgetTypePadding(type);
	}

	/// Return `true` if the given [type] is the Flutter class `StatefulWidget`.
	bool isExactlyStatefulWidgetType(DartType type) {
	return type is InterfaceType &&
	_isExactWidget(type.element, _nameStatefulWidget, _uriFramework);
	}

	/// Return `true` if the given [type] is the Flutter class `StatelessWidget`.
	bool isExactlyStatelessWidgetType(DartType type) {
	return type is InterfaceType &&
	_isExactWidget(type.element, _nameStatelessWidget, _uriFramework);
	}

	/// Return `true` if the given [element] is the Flutter class `State`.
	bool isExactState(ClassElement element) {
	return _isExactWidget(element, _nameState, _uriFramework);
	}

	/// Return `true` if the given [type] is the Flutter class `Align`.
	bool isExactWidgetTypeAlign(DartType type) {
	return type is InterfaceType &&
	_isExactWidget(type.element, _nameAlign, _uriBasic);
	}

	/// Return `true` if the given [type] is the Flutter class `Center`.
	bool isExactWidgetTypeCenter(DartType type) {
	return type is InterfaceType &&
	_isExactWidget(type.element, _nameCenter, _uriBasic);
	}

	/// Return `true` if the given [type] is the Flutter class `Container`.
	bool isExactWidgetTypeContainer(DartType type) {
	return type is InterfaceType &&
	_isExactWidget(type.element, _nameContainer, _uriContainer);
	}

	/// Return `true` if the given [type] is the Flutter class `Padding`.
	bool isExactWidgetTypePadding(DartType type) {
	return type is InterfaceType &&
	_isExactWidget(type.element, _namePadding, _uriBasic);
	}

	/// Return `true` if the given [type] is the Flutter class `StreamBuilder`.
	bool isExactWidgetTypeStreamBuilder(DartType type) {
	return type is InterfaceType &&
	_isExactWidget(type.element, _nameStreamBuilder, _uriAsync);
	}

	/// Return `true` if the given [type] is the Flutter class `Widget`, or its
	/// subtype.
	bool isListOfWidgetsType(DartType type) {
	return type is InterfaceType &&
	type.isDartCoreList &&
	isWidgetType(type.typeArguments[0]);
	}

	/// Return `true` if the given [type] is the dart.ui class `Color`, or its
	/// subtype.
	bool isMatrix4(DartType type) {
	if (type is! InterfaceType) {
	return false;
	}

	bool isMatrix4Element(ClassElement element) {
	if (element == null) {
	return false;
	}

	bool isExactMatrix4(ClassElement element) =>
	element?.name == 'Matrix4' &&
	element.library.name == 'vector_math_64';
	if (isExactMatrix4(element)) {
	return true;
	}
	for (var type in element.allSupertypes) {
	if (isExactMatrix4(type.element)) {
	return true;
	}
	}
	return false;
	}

	return isMatrix4Element(type.element);
	}

	/// Return `true` if the given [element] has the Flutter class `State` as
	/// a superclass.
	bool isState(ClassElement element) {
	return _hasSupertype(element, _uriFramework, _nameState);
	}

	/// Return `true` if the given [element] is a [ClassElement] that extends
	/// the Flutter class `StatefulWidget`.
	bool isStatefulWidgetDeclaration(Element element) {
	if (element is ClassElement) {
	return isExactlyStatefulWidgetType(element.supertype);
	}
	return false;
	}

	/// Return `true` if the given [element] is the Flutter class `Widget`, or its
	/// subtype.
	bool isWidget(ClassElement element) {
	if (element == null) {
	return false;
	}
	if (_isExactWidget(element, _nameWidget, _uriFramework)) {
	return true;
	}
	for (var type in element.allSupertypes) {
	if (_isExactWidget(type.element, _nameWidget, _uriFramework)) {
	return true;
	}
	}
	return false;
	}

	/// Return `true` if the given [expr] is a constructor invocation for a
	/// class that has the Flutter class `Widget` as a superclass.
	bool isWidgetCreation(InstanceCreationExpression expr) {
	var element = expr?.constructorName?.staticElement?.enclosingElement;
	return isWidget(element);
	}

	/// Return `true` if the given [node] is the Flutter class `Widget`, or its
	/// subtype.
	bool isWidgetExpression(AstNode node) {
	if (node == null) {
	return false;
	}
	if (node.parent is TypeName \|\| node.parent?.parent is TypeName) {
	return false;
	}
	if (node.parent is ConstructorName) {
	return false;
	}
	if (node is NamedExpression) {
	return false;
	}
	if (node is Expression) {
	return isWidgetType(node.staticType);
	}
	return false;
	}

	/// Return `true` if the given [type] is the Flutter class `Widget`, or its
	/// subtype.
	bool isWidgetType(DartType type) {
	return type is InterfaceType && isWidget(type.element);
	}

	/// Return `true` if the given [element] has a supertype with the
	/// [requiredName] defined in the file with the [requiredUri].
	bool _hasSupertype(
	ClassElement element, Uri requiredUri, String requiredName) {
	if (element == null) {
	return false;
	}
	for (var type in element.allSupertypes) {
	if (type.element.name == requiredName) {
	var uri = type.element.source.uri;
	if (uri == requiredUri) {
	return true;
	}
	}
	}
	return false;
	}

	/// Return `true` if the given [element] is the exact [type] defined in the
	/// file with the given [uri].
	bool _isExactWidget(ClassElement element, String type, Uri uri) {
	return element != null && element.name == type && element.source.uri == uri;
	}
	}

	class _IdentifyMobileOrWeb extends GeneralizingAstVisitor<void> {
	bool isMobile = false;
	bool isWeb = false;

	@override
	void visitExpression(Expression node) {
	if (isMobile \|\| isWeb) {
	return;
	}

	if (Flutter.mobile.isWidgetExpression(node)) {
	isMobile = true;
	return;
	}

	if (Flutter.web.isWidgetExpression(node)) {
	isWeb = true;
	return;
	}

	super.visitExpression(node);
	}
	}