pkg/analysis_server/lib/src/services/completion/dart/arglist_contributor.dart - sdk.git - Git at Google

 // Copyright (c) 2014, 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.

 library services.completion.contributor.dart.arglist;

 import 'dart:async';

 import 'package:analysis_server/src/ide_options.dart';
 import 'package:analysis_server/src/protocol_server.dart'
     hide Element, ElementKind;
 import 'package:analysis_server/src/provisional/completion/dart/completion_dart.dart';
 import 'package:analysis_server/src/services/completion/dart/utilities.dart';
 import 'package:analysis_server/src/services/correction/flutter_util.dart';
 import 'package:analysis_server/src/utilities/documentation.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/src/generated/utilities_dart.dart';

 /**
  * Determine the number of arguments.
  */
 int _argCount(DartCompletionRequest request) {
   AstNode node = request.target.containingNode;
   if (node is ArgumentList) {
     if (request.target.entity == node.rightParenthesis) {
       // Parser ignores trailing commas
       if (node.rightParenthesis.previous?.lexeme == ',') {
         return node.arguments.length + 1;
       }
     }
     return node.arguments.length;
   }
   return 0;
 }

 /**
  * If the containing [node] is an argument list
  * or named expression in an argument list
  * then return the simple identifier for the method, constructor, or annotation
  * to which the argument list is associated
  */
 SimpleIdentifier _getTargetId(AstNode node) {
   if (node is NamedExpression) {
     return _getTargetId(node.parent);
   }
   if (node is ArgumentList) {
     AstNode parent = node.parent;
     if (parent is MethodInvocation) {
       return parent.methodName;
     }
     if (parent is InstanceCreationExpression) {
       ConstructorName constructorName = parent.constructorName;
       if (constructorName != null) {
         if (constructorName.name != null) {
           return constructorName.name;
         }
         Identifier typeName = constructorName.type.name;
         if (typeName is SimpleIdentifier) {
           return typeName;
         }
         if (typeName is PrefixedIdentifier) {
           return typeName.identifier;
         }
       }
     }
     if (parent is Annotation) {
       return parent.constructorName ?? parent.name;
     }
   }
   return null;
 }

 /**
  * Determine if the completion target is at the end of the list of arguments.
  */
 bool _isAppendingToArgList(DartCompletionRequest request) {
   AstNode node = request.target.containingNode;
   if (node is ArgumentList) {
     var entity = request.target.entity;
     if (entity == node.rightParenthesis) {
       return true;
     }
     if (node.arguments.length > 0 && node.arguments.last == entity) {
       return entity is SimpleIdentifier;
     }
   }
   return false;
 }

 /**
  * Determine if the completion target is the label for a named argument.
  */
 bool _isEditingNamedArgLabel(DartCompletionRequest request) {
   AstNode node = request.target.containingNode;
   if (node is ArgumentList) {
     var entity = request.target.entity;
     if (entity is NamedExpression) {
       int offset = request.offset;
       if (entity.offset < offset && offset < entity.end) {
         return true;
       }
     }
   }
   return false;
 }

 /**
  * Return `true` if the [request] is inside of a [NamedExpression] name.
  */
 bool _isInNamedExpression(DartCompletionRequest request) {
   Object entity = request.target.entity;
   if (entity is NamedExpression) {
     Label name = entity.name;
     return name.offset < request.offset && request.offset < name.end;
   }
   return false;
 }

 /**
  * Determine if the completion target is in the middle or beginning of the list
  * of named parameters and is not preceded by a comma. This method assumes that
  * _isAppendingToArgList has been called and is false.
  */
 bool _isInsertingToArgListWithNoSynthetic(DartCompletionRequest request) {
   AstNode node = request.target.containingNode;
   if (node is ArgumentList) {
     var entity = request.target.entity;
     return entity is NamedExpression;
   }
   return false;
 }

 /**
  * Determine if the completion target is in the middle or beginning of the list
  * of named parameters and is preceded by a comma. This method assumes that
  * _isAppendingToArgList and _isInsertingToArgListWithNoSynthetic have been
  * called and both return false.
  */
 bool _isInsertingToArgListWithSynthetic(DartCompletionRequest request) {
   AstNode node = request.target.containingNode;
   if (node is ArgumentList) {
     var entity = request.target.entity;
     if (entity is SimpleIdentifier) {
       int argIndex = request.target.argIndex;
       // if the next argument is a NamedExpression, then we are in the named
       // parameter list, guard first against end of list
       if (node.arguments.length == argIndex + 1 ||
           node.arguments.getRange(argIndex + 1, argIndex + 2).first
               is NamedExpression) {
         return true;
       }
     }
   }
   return false;
 }

 /**
  * Return a collection of currently specified named arguments
  */
 Iterable<String> _namedArgs(DartCompletionRequest request) {
   AstNode node = request.target.containingNode;
   List<String> namedArgs = new List<String>();
   if (node is ArgumentList) {
     for (Expression arg in node.arguments) {
       if (arg is NamedExpression) {
         namedArgs.add(arg.name.label.name);
       }
     }
   }
   return namedArgs;
 }

 /**
  * A contributor for calculating `completion.getSuggestions` request results
  * when the cursor position is inside the arguments to a method call.
  */
 class ArgListContributor extends DartCompletionContributor {
   DartCompletionRequest request;
   List<CompletionSuggestion> suggestions;

   @override
   Future<List<CompletionSuggestion>> computeSuggestions(
       DartCompletionRequest request) async {
     this.request = request;
     this.suggestions = <CompletionSuggestion>[];

     // Determine if the target is in an argument list
     // for a method or a constructor or an annotation
     // and resolve the identifier
     SimpleIdentifier targetId = _getTargetId(request.target.containingNode);
     if (targetId == null) {
       return EMPTY_LIST;
     }

     // Resolve the target expression to determine the arguments
     await request.resolveContainingExpression(targetId);
     // Gracefully degrade if the element could not be resolved
     // e.g. target changed, completion aborted
     targetId = _getTargetId(request.target.containingNode);
     if (targetId == null) {
       return EMPTY_LIST;
     }
     Element elem = targetId.bestElement;
     if (elem == null) {
       return EMPTY_LIST;
     }

     // Generate argument list suggestion based upon the type of element
     if (elem is ClassElement) {
       _addSuggestions(elem.unnamedConstructor?.parameters);
       return suggestions;
     }
     if (elem is ConstructorElement) {
       _addSuggestions(elem.parameters);
       return suggestions;
     }
     if (elem is FunctionElement) {
       _addSuggestions(elem.parameters);
       return suggestions;
     }
     if (elem is MethodElement) {
       _addSuggestions(elem.parameters);
       return suggestions;
     }
     return EMPTY_LIST;
   }

   void _addDefaultParamSuggestions(Iterable<ParameterElement> parameters,
       [bool appendComma = false]) {
     bool appendColon = !_isInNamedExpression(request);
     Iterable<String> namedArgs = _namedArgs(request);
     for (ParameterElement parameter in parameters) {
       if (parameter.parameterKind == ParameterKind.NAMED) {
         _addNamedParameterSuggestion(
             request, namedArgs, parameter, appendColon, appendComma);
       }
     }
   }

   void _addNamedParameterSuggestion(
       DartCompletionRequest request,
       List<String> namedArgs,
       ParameterElement parameter,
       bool appendColon,
       bool appendComma) {
     String name = parameter.name;
     String type = parameter.type?.displayName;
     if (name != null && name.length > 0 && !namedArgs.contains(name)) {
       String completion = name;
       if (appendColon) {
         completion += ': ';
       }
       int selectionOffset = completion.length;
       if (appendComma) {
         completion += ',';
       }
       CompletionSuggestion suggestion = new CompletionSuggestion(
           CompletionSuggestionKind.NAMED_ARGUMENT,
           DART_RELEVANCE_NAMED_PARAMETER,
           completion,
           selectionOffset,
           0,
           false,
           false,
           parameterName: name,
           parameterType: type);
       if (parameter is FieldFormalParameterElement) {
         _setDocumentation(suggestion, parameter.field?.documentationComment);
         suggestion.element = convertElement(parameter);
       }

       String defaultValue = _getDefaultValue(parameter, request.ideOptions);
       if (defaultValue != null) {
         StringBuffer sb = new StringBuffer();
         sb.write('${parameter.name}: ');
         int offset = sb.length;
         sb.write(defaultValue);
         if (appendComma) {
           sb.write(',');
         }
         suggestion.defaultArgumentListString = sb.toString();
         suggestion.defaultArgumentListTextRanges = [
           offset,
           defaultValue.length
         ];
       }

       suggestions.add(suggestion);
     }
   }

   void _addSuggestions(Iterable<ParameterElement> parameters) {
     if (parameters == null || parameters.length == 0) {
       return;
     }
     Iterable<ParameterElement> requiredParam = parameters.where(
         (ParameterElement p) => p.parameterKind == ParameterKind.REQUIRED);
     int requiredCount = requiredParam.length;
     // TODO (jwren) _isAppendingToArgList can be split into two cases (with and
     // without preceded), then _isAppendingToArgList,
     // _isInsertingToArgListWithNoSynthetic and
     // _isInsertingToArgListWithSynthetic could be formatted into a single
     // method which returns some enum with 5+ cases.
     if (_isEditingNamedArgLabel(request) || _isAppendingToArgList(request)) {
       if (requiredCount == 0 || requiredCount < _argCount(request)) {
         bool addTrailingComma =
             !_isFollowedByAComma(request) && _isInFlutterCreation(request);
         _addDefaultParamSuggestions(parameters, addTrailingComma);
       }
     } else if (_isInsertingToArgListWithNoSynthetic(request)) {
       _addDefaultParamSuggestions(parameters, true);
     } else if (_isInsertingToArgListWithSynthetic(request)) {
       _addDefaultParamSuggestions(parameters, !_isFollowedByAComma(request));
     }
   }

   String _getDefaultValue(ParameterElement param, IdeOptions options) {
     if (options?.generateFlutterWidgetChildrenBoilerPlate == true) {
       Element element = param.enclosingElement;
       if (element is ConstructorElement) {
         if (isFlutterWidget(element.enclosingElement) &&
             param.name == 'children') {
           return getDefaultStringParameterValue(param);
         }
       }
     }
     return null;
   }

   bool _isFollowedByAComma(DartCompletionRequest request) {
     // new A(^); NO
     // new A(one: 1, ^); NO
     // new A(^ , one: 1); YES
     // new A(^), ... NO

     var containingNode = request.target.containingNode;
     var entity = request.target.entity;
     Token token =
         entity is AstNode ? entity.endToken : entity is Token ? entity : null;
     return (token != containingNode?.endToken) &&
         token?.next?.type == TokenType.COMMA;
   }

   bool _isInFlutterCreation(DartCompletionRequest request) {
     AstNode containingNode = request?.target?.containingNode;
     InstanceCreationExpression newExpr = containingNode != null
         ? identifyNewExpression(containingNode.parent)
         : null;
     return newExpr != null && isFlutterInstanceCreationExpression(newExpr);
   }

   /**
    * If the given [comment] is not `null`, fill the [suggestion] documentation
    * fields.
    */
   static void _setDocumentation(
       CompletionSuggestion suggestion, String comment) {
     if (comment != null) {
       String doc = removeDartDocDelimiters(comment);
       suggestion.docComplete = doc;
       suggestion.docSummary = getDartDocSummary(doc);
     }
   }
 }
	// Copyright (c) 2014, 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.

	library services.completion.contributor.dart.arglist;

	import 'dart:async';

	import 'package:analysis_server/src/ide_options.dart';
	import 'package:analysis_server/src/protocol_server.dart'
	hide Element, ElementKind;
	import 'package:analysis_server/src/provisional/completion/dart/completion_dart.dart';
	import 'package:analysis_server/src/services/completion/dart/utilities.dart';
	import 'package:analysis_server/src/services/correction/flutter_util.dart';
	import 'package:analysis_server/src/utilities/documentation.dart';
	import 'package:analyzer/dart/ast/ast.dart';
	import 'package:analyzer/dart/ast/token.dart';
	import 'package:analyzer/dart/element/element.dart';
	import 'package:analyzer/src/generated/utilities_dart.dart';

	/**
	* Determine the number of arguments.
	*/
	int _argCount(DartCompletionRequest request) {
	AstNode node = request.target.containingNode;
	if (node is ArgumentList) {
	if (request.target.entity == node.rightParenthesis) {
	// Parser ignores trailing commas
	if (node.rightParenthesis.previous?.lexeme == ',') {
	return node.arguments.length + 1;
	}
	}
	return node.arguments.length;
	}
	return 0;
	}

	/**
	* If the containing [node] is an argument list
	* or named expression in an argument list
	* then return the simple identifier for the method, constructor, or annotation
	* to which the argument list is associated
	*/
	SimpleIdentifier _getTargetId(AstNode node) {
	if (node is NamedExpression) {
	return _getTargetId(node.parent);
	}
	if (node is ArgumentList) {
	AstNode parent = node.parent;
	if (parent is MethodInvocation) {
	return parent.methodName;
	}
	if (parent is InstanceCreationExpression) {
	ConstructorName constructorName = parent.constructorName;
	if (constructorName != null) {
	if (constructorName.name != null) {
	return constructorName.name;
	}
	Identifier typeName = constructorName.type.name;
	if (typeName is SimpleIdentifier) {
	return typeName;
	}
	if (typeName is PrefixedIdentifier) {
	return typeName.identifier;
	}
	}
	}
	if (parent is Annotation) {
	return parent.constructorName ?? parent.name;
	}
	}
	return null;
	}

	/**
	* Determine if the completion target is at the end of the list of arguments.
	*/
	bool _isAppendingToArgList(DartCompletionRequest request) {
	AstNode node = request.target.containingNode;
	if (node is ArgumentList) {
	var entity = request.target.entity;
	if (entity == node.rightParenthesis) {
	return true;
	}
	if (node.arguments.length > 0 && node.arguments.last == entity) {
	return entity is SimpleIdentifier;
	}
	}
	return false;
	}

	/**
	* Determine if the completion target is the label for a named argument.
	*/
	bool _isEditingNamedArgLabel(DartCompletionRequest request) {
	AstNode node = request.target.containingNode;
	if (node is ArgumentList) {
	var entity = request.target.entity;
	if (entity is NamedExpression) {
	int offset = request.offset;
	if (entity.offset < offset && offset < entity.end) {
	return true;
	}
	}
	}
	return false;
	}

	/**
	* Return `true` if the [request] is inside of a [NamedExpression] name.
	*/
	bool _isInNamedExpression(DartCompletionRequest request) {
	Object entity = request.target.entity;
	if (entity is NamedExpression) {
	Label name = entity.name;
	return name.offset < request.offset && request.offset < name.end;
	}
	return false;
	}

	/**
	* Determine if the completion target is in the middle or beginning of the list
	* of named parameters and is not preceded by a comma. This method assumes that
	* _isAppendingToArgList has been called and is false.
	*/
	bool _isInsertingToArgListWithNoSynthetic(DartCompletionRequest request) {
	AstNode node = request.target.containingNode;
	if (node is ArgumentList) {
	var entity = request.target.entity;
	return entity is NamedExpression;
	}
	return false;
	}

	/**
	* Determine if the completion target is in the middle or beginning of the list
	* of named parameters and is preceded by a comma. This method assumes that
	* _isAppendingToArgList and _isInsertingToArgListWithNoSynthetic have been
	* called and both return false.
	*/
	bool _isInsertingToArgListWithSynthetic(DartCompletionRequest request) {
	AstNode node = request.target.containingNode;
	if (node is ArgumentList) {
	var entity = request.target.entity;
	if (entity is SimpleIdentifier) {
	int argIndex = request.target.argIndex;
	// if the next argument is a NamedExpression, then we are in the named
	// parameter list, guard first against end of list
	if (node.arguments.length == argIndex + 1 \|\|
	node.arguments.getRange(argIndex + 1, argIndex + 2).first
	is NamedExpression) {
	return true;
	}
	}
	}
	return false;
	}

	/**
	* Return a collection of currently specified named arguments
	*/
	Iterable<String> _namedArgs(DartCompletionRequest request) {
	AstNode node = request.target.containingNode;
	List<String> namedArgs = new List<String>();
	if (node is ArgumentList) {
	for (Expression arg in node.arguments) {
	if (arg is NamedExpression) {
	namedArgs.add(arg.name.label.name);
	}
	}
	}
	return namedArgs;
	}

	/**
	* A contributor for calculating `completion.getSuggestions` request results
	* when the cursor position is inside the arguments to a method call.
	*/
	class ArgListContributor extends DartCompletionContributor {
	DartCompletionRequest request;
	List<CompletionSuggestion> suggestions;

	@override
	Future<List<CompletionSuggestion>> computeSuggestions(
	DartCompletionRequest request) async {
	this.request = request;
	this.suggestions = <CompletionSuggestion>[];

	// Determine if the target is in an argument list
	// for a method or a constructor or an annotation
	// and resolve the identifier
	SimpleIdentifier targetId = _getTargetId(request.target.containingNode);
	if (targetId == null) {
	return EMPTY_LIST;
	}

	// Resolve the target expression to determine the arguments
	await request.resolveContainingExpression(targetId);
	// Gracefully degrade if the element could not be resolved
	// e.g. target changed, completion aborted
	targetId = _getTargetId(request.target.containingNode);
	if (targetId == null) {
	return EMPTY_LIST;
	}
	Element elem = targetId.bestElement;
	if (elem == null) {
	return EMPTY_LIST;
	}

	// Generate argument list suggestion based upon the type of element
	if (elem is ClassElement) {
	_addSuggestions(elem.unnamedConstructor?.parameters);
	return suggestions;
	}
	if (elem is ConstructorElement) {
	_addSuggestions(elem.parameters);
	return suggestions;
	}
	if (elem is FunctionElement) {
	_addSuggestions(elem.parameters);
	return suggestions;
	}
	if (elem is MethodElement) {
	_addSuggestions(elem.parameters);
	return suggestions;
	}
	return EMPTY_LIST;
	}

	void _addDefaultParamSuggestions(Iterable<ParameterElement> parameters,
	[bool appendComma = false]) {
	bool appendColon = !_isInNamedExpression(request);
	Iterable<String> namedArgs = _namedArgs(request);
	for (ParameterElement parameter in parameters) {
	if (parameter.parameterKind == ParameterKind.NAMED) {
	_addNamedParameterSuggestion(
	request, namedArgs, parameter, appendColon, appendComma);
	}
	}
	}

	void _addNamedParameterSuggestion(
	DartCompletionRequest request,
	List<String> namedArgs,
	ParameterElement parameter,
	bool appendColon,
	bool appendComma) {
	String name = parameter.name;
	String type = parameter.type?.displayName;
	if (name != null && name.length > 0 && !namedArgs.contains(name)) {
	String completion = name;
	if (appendColon) {
	completion += ': ';
	}
	int selectionOffset = completion.length;
	if (appendComma) {
	completion += ',';
	}
	CompletionSuggestion suggestion = new CompletionSuggestion(
	CompletionSuggestionKind.NAMED_ARGUMENT,
	DART_RELEVANCE_NAMED_PARAMETER,
	completion,
	selectionOffset,
	0,
	false,
	false,
	parameterName: name,
	parameterType: type);
	if (parameter is FieldFormalParameterElement) {
	_setDocumentation(suggestion, parameter.field?.documentationComment);
	suggestion.element = convertElement(parameter);
	}

	String defaultValue = _getDefaultValue(parameter, request.ideOptions);
	if (defaultValue != null) {
	StringBuffer sb = new StringBuffer();
	sb.write('${parameter.name}: ');
	int offset = sb.length;
	sb.write(defaultValue);
	if (appendComma) {
	sb.write(',');
	}
	suggestion.defaultArgumentListString = sb.toString();
	suggestion.defaultArgumentListTextRanges = [
	offset,
	defaultValue.length
	];
	}

	suggestions.add(suggestion);
	}
	}

	void _addSuggestions(Iterable<ParameterElement> parameters) {
	if (parameters == null \|\| parameters.length == 0) {
	return;
	}
	Iterable<ParameterElement> requiredParam = parameters.where(
	(ParameterElement p) => p.parameterKind == ParameterKind.REQUIRED);
	int requiredCount = requiredParam.length;
	// TODO (jwren) _isAppendingToArgList can be split into two cases (with and
	// without preceded), then _isAppendingToArgList,
	// _isInsertingToArgListWithNoSynthetic and
	// _isInsertingToArgListWithSynthetic could be formatted into a single
	// method which returns some enum with 5+ cases.
	if (_isEditingNamedArgLabel(request) \|\| _isAppendingToArgList(request)) {
	if (requiredCount == 0 \|\| requiredCount < _argCount(request)) {
	bool addTrailingComma =
	!_isFollowedByAComma(request) && _isInFlutterCreation(request);
	_addDefaultParamSuggestions(parameters, addTrailingComma);
	}
	} else if (_isInsertingToArgListWithNoSynthetic(request)) {
	_addDefaultParamSuggestions(parameters, true);
	} else if (_isInsertingToArgListWithSynthetic(request)) {
	_addDefaultParamSuggestions(parameters, !_isFollowedByAComma(request));
	}
	}

	String _getDefaultValue(ParameterElement param, IdeOptions options) {
	if (options?.generateFlutterWidgetChildrenBoilerPlate == true) {
	Element element = param.enclosingElement;
	if (element is ConstructorElement) {
	if (isFlutterWidget(element.enclosingElement) &&
	param.name == 'children') {
	return getDefaultStringParameterValue(param);
	}
	}
	}
	return null;
	}

	bool _isFollowedByAComma(DartCompletionRequest request) {
	// new A(^); NO
	// new A(one: 1, ^); NO
	// new A(^ , one: 1); YES
	// new A(^), ... NO

	var containingNode = request.target.containingNode;
	var entity = request.target.entity;
	Token token =
	entity is AstNode ? entity.endToken : entity is Token ? entity : null;
	return (token != containingNode?.endToken) &&
	token?.next?.type == TokenType.COMMA;
	}

	bool _isInFlutterCreation(DartCompletionRequest request) {
	AstNode containingNode = request?.target?.containingNode;
	InstanceCreationExpression newExpr = containingNode != null
	? identifyNewExpression(containingNode.parent)
	: null;
	return newExpr != null && isFlutterInstanceCreationExpression(newExpr);
	}

	/**
	* If the given [comment] is not `null`, fill the [suggestion] documentation
	* fields.
	*/
	static void _setDocumentation(
	CompletionSuggestion suggestion, String comment) {
	if (comment != null) {
	String doc = removeDartDocDelimiters(comment);
	suggestion.docComplete = doc;
	suggestion.docSummary = getDartDocSummary(doc);
	}
	}
	}