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.

 import 'dart:async';

 import 'package:analysis_server/src/computer/computer_hover.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/utilities/flutter.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/dart/element/type.dart';
 import 'package:analyzer/src/util/comment.dart';
 import 'package:meta/meta.dart';

 /// A contributor that produces suggestions for named expression labels that
 /// correspond to named parameters when completing in argument lists.
 class ArgListContributor extends DartCompletionContributor {
   /// The request that is currently being handled.
   DartCompletionRequest request;

   /// The argument list that is the containing node of the target, or `null` if
   /// the containing node of the target is not an argument list (such as when
   /// it's a named expression).
   ArgumentList argumentList;

   /// The list of suggestions that is currently being built.
   List<CompletionSuggestion> suggestions;

   @override
   Future<List<CompletionSuggestion>> computeSuggestions(
       DartCompletionRequest request) async {
     var executable = request.target.executableElement;
     if (executable == null) {
       return const <CompletionSuggestion>[];
     }
     var node = request.target.containingNode;
     if (node is ArgumentList) {
       argumentList = node;
     }

     this.request = request;
     suggestions = <CompletionSuggestion>[];
     _addSuggestions(executable.parameters);
     return suggestions;
   }

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

   void _addNamedParameterSuggestion(List<String> namedArgs,
       ParameterElement parameter, bool appendColon, bool appendComma) {
     var name = parameter.name;
     var type = parameter.type?.getDisplayString(withNullability: false);
     if (name != null && name.isNotEmpty && !namedArgs.contains(name)) {
       var completion = name;
       if (appendColon) {
         completion += ': ';
       }
       var selectionOffset = completion.length;

       // Optionally add Flutter child widget details.
       // todo (pq): revisit this special casing; likely it can be generalized away
       var element = parameter.enclosingElement;
       if (element is ConstructorElement) {
         var flutter = Flutter.of(request.result);
         if (flutter.isWidget(element.enclosingElement)) {
           var defaultValue = getDefaultStringParameterValue(parameter);
           // TODO(devoncarew): Should we remove the check here? We would then
           // suggest values for param types like closures.
           if (defaultValue != null && defaultValue.text == '[]') {
             var completionLength = completion.length;
             completion += defaultValue.text;
             if (defaultValue.cursorPosition != null) {
               selectionOffset = completionLength + defaultValue.cursorPosition;
             }
           }
         }
       }

       if (appendComma) {
         completion += ',';
       }

       int relevance;
       if (parameter.isRequiredNamed || parameter.hasRequired) {
         relevance = request.useNewRelevance
             ? Relevance.requiredNamedArgument
             : DART_RELEVANCE_NAMED_PARAMETER_REQUIRED;
       } else {
         relevance = request.useNewRelevance
             ? Relevance.namedArgument
             : DART_RELEVANCE_NAMED_PARAMETER;
       }

       var suggestion = CompletionSuggestion(
           CompletionSuggestionKind.NAMED_ARGUMENT,
           relevance,
           completion,
           selectionOffset,
           0,
           false,
           false,
           parameterName: name,
           parameterType: type);
       if (parameter is FieldFormalParameterElement) {
         _setDocumentation(suggestion, parameter);
         suggestion.element = convertElement(parameter);
       }

       suggestions.add(suggestion);
     }
   }

   void _addSuggestions(Iterable<ParameterElement> parameters) {
     if (parameters == null || parameters.isEmpty) {
       return;
     }
     var requiredParam =
         parameters.where((ParameterElement p) => p.isRequiredPositional);
     var 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() || _isAppendingToArgList()) {
       if (requiredCount == 0 || requiredCount < _argCount()) {
         var addTrailingComma = !_isFollowedByAComma() && _isInFlutterCreation();
         _addDefaultParamSuggestions(parameters, addTrailingComma);
       }
     } else if (_isInsertingToArgListWithNoSynthetic()) {
       _addDefaultParamSuggestions(parameters, true);
     } else if (_isInsertingToArgListWithSynthetic()) {
       _addDefaultParamSuggestions(parameters, !_isFollowedByAComma());
     } else {
       var argument = request.target.containingNode;
       if (argument is NamedExpression) {
         _buildClosureSuggestions(argument);
       }
     }
   }

   /// Return the number of arguments in the argument list.
   int _argCount() {
     if (argumentList != null) {
       var paren = argumentList.rightParenthesis;
       if (request.target.entity == paren) {
         // Parser ignores trailing commas
         if (argumentList.findPrevious(paren)?.lexeme == ',') {
           return argumentList.arguments.length + 1;
         }
       }
       return argumentList.arguments.length;
     }
     return 0;
   }

   void _buildClosureSuggestions(NamedExpression argument) {
     // TODO(brianwilkerson) Consider moving this support so that it can be used
     //  whenever the context type is a FunctionType.
     var type = argument.staticParameterElement?.type;
     if (type is FunctionType) {
       var indent = getRequestLineIndent(request);
       var parametersString = buildClosureParameters(type);

       var blockBuffer = StringBuffer(parametersString);
       blockBuffer.writeln(' {');
       blockBuffer.write('$indent  ');
       var blockSelectionOffset = blockBuffer.length;
       blockBuffer.writeln();
       blockBuffer.write('$indent}');

       var expressionBuffer = StringBuffer(parametersString);
       expressionBuffer.write(' => ');
       var expressionSelectionOffset = expressionBuffer.length;

       if (argument.endToken.next?.type != TokenType.COMMA) {
         blockBuffer.write(',');
         expressionBuffer.write(',');
       }

       CompletionSuggestion createSuggestion({
         @required String completion,
         @required String displayText,
         @required int selectionOffset,
       }) {
         return CompletionSuggestion(
           CompletionSuggestionKind.INVOCATION,
           request.useNewRelevance ? Relevance.closure : DART_RELEVANCE_HIGH,
           completion,
           selectionOffset,
           0,
           false,
           false,
           displayText: displayText,
         );
       }

       suggestions.add(createSuggestion(
         completion: blockBuffer.toString(),
         displayText: '$parametersString {}',
         selectionOffset: blockSelectionOffset,
       ));
       suggestions.add(createSuggestion(
         completion: expressionBuffer.toString(),
         displayText: '$parametersString =>',
         selectionOffset: expressionSelectionOffset,
       ));
     }
   }

   /// Return `true` if the completion target is at the end of the list of
   /// arguments.
   bool _isAppendingToArgList() {
     if (argumentList != null) {
       var entity = request.target.entity;
       if (entity == argumentList.rightParenthesis) {
         return true;
       }
       if (argumentList.arguments.isNotEmpty &&
           argumentList.arguments.last == entity) {
         return entity is SimpleIdentifier;
       }
     }
     return false;
   }

   /// Return `true` if the completion target is the label for a named argument.
   bool _isEditingNamedArgLabel() {
     if (argumentList != null) {
       var entity = request.target.entity;
       if (entity is NamedExpression) {
         var offset = request.offset;
         if (entity.offset < offset && offset < entity.end) {
           return true;
         }
       }
     }
     return false;
   }

   bool _isFollowedByAComma() {
     // 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;
     var token =
         entity is AstNode ? entity.endToken : entity is Token ? entity : null;
     return (token != containingNode?.endToken) &&
         token?.next?.type == TokenType.COMMA &&
         !token.next.isSynthetic;
   }

   bool _isInFlutterCreation() {
     var flutter = Flutter.of(request.result);
     var containingNode = request.target?.containingNode;
     var newExpr = containingNode != null
         ? flutter.identifyNewExpression(containingNode.parent)
         : null;
     return newExpr != null && flutter.isWidgetCreation(newExpr);
   }

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

   /// Return `true` if the completion target is in the middle or beginning of
   /// the list of named arguments and is not preceded by a comma. This method
   /// assumes that [_isAppendingToArgList] has been called and returned `false`.
   bool _isInsertingToArgListWithNoSynthetic() {
     if (argumentList != null) {
       var entity = request.target.entity;
       return entity is NamedExpression;
     }
     return false;
   }

   /// Return `true` 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 both [_isAppendingToArgList] and
   /// [_isInsertingToArgListWithNoSynthetic] have been called and both returned
   /// `false`.
   bool _isInsertingToArgListWithSynthetic() {
     if (argumentList != null) {
       var entity = request.target.entity;
       if (entity is SimpleIdentifier) {
         var 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 (argumentList.arguments.length == argIndex + 1 ||
             argumentList.arguments.getRange(argIndex + 1, argIndex + 2).first
                 is NamedExpression) {
           return true;
         }
       }
     }
     return false;
   }

   /// Return a list containing the currently specified named arguments.
   List<String> _namedArgs() {
     var namedArgs = <String>[];
     if (argumentList != null) {
       for (var arg in argumentList.arguments) {
         if (arg is NamedExpression) {
           namedArgs.add(arg.name.label.name);
         }
       }
     }
     return namedArgs;
   }

   /// If the given [comment] is not `null`, fill the [suggestion] documentation
   /// fields.
   void _setDocumentation(CompletionSuggestion suggestion, Element element) {
     var doc = DartUnitHoverComputer.computeDocumentation(
         request.dartdocDirectiveInfo, element);
     if (doc != null) {
       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.

	import 'dart:async';

	import 'package:analysis_server/src/computer/computer_hover.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/utilities/flutter.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/dart/element/type.dart';
	import 'package:analyzer/src/util/comment.dart';
	import 'package:meta/meta.dart';

	/// A contributor that produces suggestions for named expression labels that
	/// correspond to named parameters when completing in argument lists.
	class ArgListContributor extends DartCompletionContributor {
	/// The request that is currently being handled.
	DartCompletionRequest request;

	/// The argument list that is the containing node of the target, or `null` if
	/// the containing node of the target is not an argument list (such as when
	/// it's a named expression).
	ArgumentList argumentList;

	/// The list of suggestions that is currently being built.
	List<CompletionSuggestion> suggestions;

	@override
	Future<List<CompletionSuggestion>> computeSuggestions(
	DartCompletionRequest request) async {
	var executable = request.target.executableElement;
	if (executable == null) {
	return const <CompletionSuggestion>[];
	}
	var node = request.target.containingNode;
	if (node is ArgumentList) {
	argumentList = node;
	}

	this.request = request;
	suggestions = <CompletionSuggestion>[];
	_addSuggestions(executable.parameters);
	return suggestions;
	}

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

	void _addNamedParameterSuggestion(List<String> namedArgs,
	ParameterElement parameter, bool appendColon, bool appendComma) {
	var name = parameter.name;
	var type = parameter.type?.getDisplayString(withNullability: false);
	if (name != null && name.isNotEmpty && !namedArgs.contains(name)) {
	var completion = name;
	if (appendColon) {
	completion += ': ';
	}
	var selectionOffset = completion.length;

	// Optionally add Flutter child widget details.
	// todo (pq): revisit this special casing; likely it can be generalized away
	var element = parameter.enclosingElement;
	if (element is ConstructorElement) {
	var flutter = Flutter.of(request.result);
	if (flutter.isWidget(element.enclosingElement)) {
	var defaultValue = getDefaultStringParameterValue(parameter);
	// TODO(devoncarew): Should we remove the check here? We would then
	// suggest values for param types like closures.
	if (defaultValue != null && defaultValue.text == '[]') {
	var completionLength = completion.length;
	completion += defaultValue.text;
	if (defaultValue.cursorPosition != null) {
	selectionOffset = completionLength + defaultValue.cursorPosition;
	}
	}
	}
	}

	if (appendComma) {
	completion += ',';
	}

	int relevance;
	if (parameter.isRequiredNamed \|\| parameter.hasRequired) {
	relevance = request.useNewRelevance
	? Relevance.requiredNamedArgument
	: DART_RELEVANCE_NAMED_PARAMETER_REQUIRED;
	} else {
	relevance = request.useNewRelevance
	? Relevance.namedArgument
	: DART_RELEVANCE_NAMED_PARAMETER;
	}

	var suggestion = CompletionSuggestion(
	CompletionSuggestionKind.NAMED_ARGUMENT,
	relevance,
	completion,
	selectionOffset,
	0,
	false,
	false,
	parameterName: name,
	parameterType: type);
	if (parameter is FieldFormalParameterElement) {
	_setDocumentation(suggestion, parameter);
	suggestion.element = convertElement(parameter);
	}

	suggestions.add(suggestion);
	}
	}

	void _addSuggestions(Iterable<ParameterElement> parameters) {
	if (parameters == null \|\| parameters.isEmpty) {
	return;
	}
	var requiredParam =
	parameters.where((ParameterElement p) => p.isRequiredPositional);
	var 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() \|\| _isAppendingToArgList()) {
	if (requiredCount == 0 \|\| requiredCount < _argCount()) {
	var addTrailingComma = !_isFollowedByAComma() && _isInFlutterCreation();
	_addDefaultParamSuggestions(parameters, addTrailingComma);
	}
	} else if (_isInsertingToArgListWithNoSynthetic()) {
	_addDefaultParamSuggestions(parameters, true);
	} else if (_isInsertingToArgListWithSynthetic()) {
	_addDefaultParamSuggestions(parameters, !_isFollowedByAComma());
	} else {
	var argument = request.target.containingNode;
	if (argument is NamedExpression) {
	_buildClosureSuggestions(argument);
	}
	}
	}

	/// Return the number of arguments in the argument list.
	int _argCount() {
	if (argumentList != null) {
	var paren = argumentList.rightParenthesis;
	if (request.target.entity == paren) {
	// Parser ignores trailing commas
	if (argumentList.findPrevious(paren)?.lexeme == ',') {
	return argumentList.arguments.length + 1;
	}
	}
	return argumentList.arguments.length;
	}
	return 0;
	}

	void _buildClosureSuggestions(NamedExpression argument) {
	// TODO(brianwilkerson) Consider moving this support so that it can be used
	// whenever the context type is a FunctionType.
	var type = argument.staticParameterElement?.type;
	if (type is FunctionType) {
	var indent = getRequestLineIndent(request);
	var parametersString = buildClosureParameters(type);

	var blockBuffer = StringBuffer(parametersString);
	blockBuffer.writeln(' {');
	blockBuffer.write('$indent ');
	var blockSelectionOffset = blockBuffer.length;
	blockBuffer.writeln();
	blockBuffer.write('$indent}');

	var expressionBuffer = StringBuffer(parametersString);
	expressionBuffer.write(' => ');
	var expressionSelectionOffset = expressionBuffer.length;

	if (argument.endToken.next?.type != TokenType.COMMA) {
	blockBuffer.write(',');
	expressionBuffer.write(',');
	}

	CompletionSuggestion createSuggestion({
	@required String completion,
	@required String displayText,
	@required int selectionOffset,
	}) {
	return CompletionSuggestion(
	CompletionSuggestionKind.INVOCATION,
	request.useNewRelevance ? Relevance.closure : DART_RELEVANCE_HIGH,
	completion,
	selectionOffset,
	0,
	false,
	false,
	displayText: displayText,
	);
	}

	suggestions.add(createSuggestion(
	completion: blockBuffer.toString(),
	displayText: '$parametersString {}',
	selectionOffset: blockSelectionOffset,
	));
	suggestions.add(createSuggestion(
	completion: expressionBuffer.toString(),
	displayText: '$parametersString =>',
	selectionOffset: expressionSelectionOffset,
	));
	}
	}

	/// Return `true` if the completion target is at the end of the list of
	/// arguments.
	bool _isAppendingToArgList() {
	if (argumentList != null) {
	var entity = request.target.entity;
	if (entity == argumentList.rightParenthesis) {
	return true;
	}
	if (argumentList.arguments.isNotEmpty &&
	argumentList.arguments.last == entity) {
	return entity is SimpleIdentifier;
	}
	}
	return false;
	}

	/// Return `true` if the completion target is the label for a named argument.
	bool _isEditingNamedArgLabel() {
	if (argumentList != null) {
	var entity = request.target.entity;
	if (entity is NamedExpression) {
	var offset = request.offset;
	if (entity.offset < offset && offset < entity.end) {
	return true;
	}
	}
	}
	return false;
	}

	bool _isFollowedByAComma() {
	// 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;
	var token =
	entity is AstNode ? entity.endToken : entity is Token ? entity : null;
	return (token != containingNode?.endToken) &&
	token?.next?.type == TokenType.COMMA &&
	!token.next.isSynthetic;
	}

	bool _isInFlutterCreation() {
	var flutter = Flutter.of(request.result);
	var containingNode = request.target?.containingNode;
	var newExpr = containingNode != null
	? flutter.identifyNewExpression(containingNode.parent)
	: null;
	return newExpr != null && flutter.isWidgetCreation(newExpr);
	}

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

	/// Return `true` if the completion target is in the middle or beginning of
	/// the list of named arguments and is not preceded by a comma. This method
	/// assumes that [_isAppendingToArgList] has been called and returned `false`.
	bool _isInsertingToArgListWithNoSynthetic() {
	if (argumentList != null) {
	var entity = request.target.entity;
	return entity is NamedExpression;
	}
	return false;
	}

	/// Return `true` 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 both [_isAppendingToArgList] and
	/// [_isInsertingToArgListWithNoSynthetic] have been called and both returned
	/// `false`.
	bool _isInsertingToArgListWithSynthetic() {
	if (argumentList != null) {
	var entity = request.target.entity;
	if (entity is SimpleIdentifier) {
	var 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 (argumentList.arguments.length == argIndex + 1 \|\|
	argumentList.arguments.getRange(argIndex + 1, argIndex + 2).first
	is NamedExpression) {
	return true;
	}
	}
	}
	return false;
	}

	/// Return a list containing the currently specified named arguments.
	List<String> _namedArgs() {
	var namedArgs = <String>[];
	if (argumentList != null) {
	for (var arg in argumentList.arguments) {
	if (arg is NamedExpression) {
	namedArgs.add(arg.name.label.name);
	}
	}
	}
	return namedArgs;
	}

	/// If the given [comment] is not `null`, fill the [suggestion] documentation
	/// fields.
	void _setDocumentation(CompletionSuggestion suggestion, Element element) {
	var doc = DartUnitHoverComputer.computeDocumentation(
	request.dartdocDirectiveInfo, element);
	if (doc != null) {
	suggestion.docComplete = doc;
	suggestion.docSummary = getDartDocSummary(doc);
	}
	}
	}