Navigation extension point.

pkg/analysis_server/lib/src/computer/computer_navigation.dart

-// 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 computer.navigation;
-
-import 'dart:collection';
-
-import 'package:analysis_server/src/protocol_server.dart' as protocol;
-import 'package:analyzer/src/generated/ast.dart';
-import 'package:analyzer/src/generated/element.dart';
-import 'package:analyzer/src/generated/scanner.dart';
-import 'package:analyzer/src/generated/source.dart';
-
-/**
- * A computer for navigation regions in a Dart [CompilationUnit].
- */
-class DartUnitNavigationComputer {
-  final List<String> files = <String>[];
-  final Map<String, int> fileMap = new HashMap<String, int>();
-  final List<protocol.NavigationTarget> targets = <protocol.NavigationTarget>[];
-  final Map<Element, int> targetMap = new HashMap<Element, int>();
-  final List<protocol.NavigationRegion> regions = <protocol.NavigationRegion>[];
-
-  /**
-   * Computes [regions], [targets] and [files].
-   */
-  void compute(AstNode node) {
-    node.accept(new _DartUnitNavigationComputerVisitor(this));
-  }
-
-  int _addFile(String file) {
-    int index = fileMap[file];
-    if (index == null) {
-      index = files.length;
-      files.add(file);
-      fileMap[file] = index;
-    }
-    return index;
-  }
-
-  void _addRegion(int offset, int length, Element element) {
-    if (element is FieldFormalParameterElement) {
-      element = (element as FieldFormalParameterElement).field;
-    }
-    if (element == null || element == DynamicElementImpl.instance) {
-      return;
-    }
-    if (element.location == null) {
-      return;
-    }
-    int targetIndex = _addTarget(element);
-    regions
-        .add(new protocol.NavigationRegion(offset, length, <int>[targetIndex]));
-  }
-
-  void _addRegion_nodeStart_nodeEnd(AstNode a, AstNode b, Element element) {
-    int offset = a.offset;
-    int length = b.end - offset;
-    _addRegion(offset, length, element);
-  }
-
-  void _addRegion_tokenStart_nodeEnd(Token a, AstNode b, Element element) {
-    int offset = a.offset;
-    int length = b.end - offset;
-    _addRegion(offset, length, element);
-  }
-
-  void _addRegionForNode(AstNode node, Element element) {
-    int offset = node.offset;
-    int length = node.length;
-    _addRegion(offset, length, element);
-  }
-
-  void _addRegionForToken(Token token, Element element) {
-    int offset = token.offset;
-    int length = token.length;
-    _addRegion(offset, length, element);
-  }
-
-  int _addTarget(Element element) {
-    int index = targetMap[element];
-    if (index == null) {
-      index = targets.length;
-      protocol.NavigationTarget target =
-          protocol.newNavigationTarget_fromElement(element, _addFile);
-      targets.add(target);
-      targetMap[element] = index;
-    }
-    return index;
-  }
-}
-
-class _DartUnitNavigationComputerVisitor extends RecursiveAstVisitor {
-  final DartUnitNavigationComputer computer;
-
-  _DartUnitNavigationComputerVisitor(this.computer);
-
-  @override
-  visitAssignmentExpression(AssignmentExpression node) {
-    _safelyVisit(node.leftHandSide);
-    computer._addRegionForToken(node.operator, node.bestElement);
-    _safelyVisit(node.rightHandSide);
-  }
-
-  @override
-  visitBinaryExpression(BinaryExpression node) {
-    _safelyVisit(node.leftOperand);
-    computer._addRegionForToken(node.operator, node.bestElement);
-    _safelyVisit(node.rightOperand);
-  }
-
-  @override
-  visitCompilationUnit(CompilationUnit unit) {
-    // prepare top-level nodes sorted by their offsets
-    List<AstNode> nodes = <AstNode>[];
-    nodes.addAll(unit.directives);
-    nodes.addAll(unit.declarations);
-    nodes.sort((a, b) {
-      return a.offset - b.offset;
-    });
-    // visit sorted nodes
-    for (AstNode node in nodes) {
-      node.accept(this);
-    }
-  }
-
-  @override
-  visitConstructorDeclaration(ConstructorDeclaration node) {
-    // associate constructor with "T" or "T.name"
-    {
-      AstNode firstNode = node.returnType;
-      AstNode lastNode = node.name;
-      if (lastNode == null) {
-        lastNode = firstNode;
-      }
-      if (firstNode != null && lastNode != null) {
-        computer._addRegion_nodeStart_nodeEnd(
-            firstNode, lastNode, node.element);
-      }
-    }
-    super.visitConstructorDeclaration(node);
-  }
-
-  @override
-  visitConstructorName(ConstructorName node) {
-    AstNode parent = node.parent;
-    if (parent is InstanceCreationExpression &&
-        parent.constructorName == node) {
-      _addConstructorName(parent, node);
-    } else if (parent is ConstructorDeclaration &&
-        parent.redirectedConstructor == node) {
-      _addConstructorName(node, node);
-    }
-  }
-
-  @override
-  visitExportDirective(ExportDirective node) {
-    ExportElement exportElement = node.element;
-    if (exportElement != null) {
-      Element libraryElement = exportElement.exportedLibrary;
-      _addUriDirectiveRegion(node, libraryElement);
-    }
-    super.visitExportDirective(node);
-  }
-
-  @override
-  visitImportDirective(ImportDirective node) {
-    ImportElement importElement = node.element;
-    if (importElement != null) {
-      Element libraryElement = importElement.importedLibrary;
-      _addUriDirectiveRegion(node, libraryElement);
-    }
-    super.visitImportDirective(node);
-  }
-
-  @override
-  visitIndexExpression(IndexExpression node) {
-    super.visitIndexExpression(node);
-    computer._addRegionForToken(node.rightBracket, node.bestElement);
-  }
-
-  @override
-  visitPartDirective(PartDirective node) {
-    _addUriDirectiveRegion(node, node.element);
-    super.visitPartDirective(node);
-  }
-
-  @override
-  visitPartOfDirective(PartOfDirective node) {
-    computer._addRegion_tokenStart_nodeEnd(
-        node.keyword, node.libraryName, node.element);
-    super.visitPartOfDirective(node);
-  }
-
-  @override
-  visitPostfixExpression(PostfixExpression node) {
-    super.visitPostfixExpression(node);
-    computer._addRegionForToken(node.operator, node.bestElement);
-  }
-
-  @override
-  visitPrefixExpression(PrefixExpression node) {
-    computer._addRegionForToken(node.operator, node.bestElement);
-    super.visitPrefixExpression(node);
-  }
-
-  @override
-  visitSimpleIdentifier(SimpleIdentifier node) {
-    if (node.parent is ConstructorDeclaration) {
-      return;
-    }
-    Element element = node.bestElement;
-    computer._addRegionForNode(node, element);
-  }
-
-  @override
-  visitSuperConstructorInvocation(SuperConstructorInvocation node) {
-    Element element = node.staticElement;
-    if (element != null && element.isSynthetic) {
-      element = element.enclosingElement;
-    }
-    // add region
-    SimpleIdentifier name = node.constructorName;
-    if (name != null) {
-      computer._addRegion_nodeStart_nodeEnd(node, name, element);
-    } else {
-      computer._addRegionForToken(node.superKeyword, element);
-    }
-    // process arguments
-    _safelyVisit(node.argumentList);
-  }
-
-  void _addConstructorName(AstNode parent, ConstructorName node) {
-    Element element = node.staticElement;
-    if (element == null) {
-      return;
-    }
-    // if a synthetic constructor, navigate to the class
-    if (element.isSynthetic) {
-      element = element.enclosingElement;
-    }
-    // add regions
-    TypeName typeName = node.type;
-    computer._addRegionForNode(typeName.name, element);
-    // <TypeA, TypeB>
-    TypeArgumentList typeArguments = typeName.typeArguments;
-    if (typeArguments != null) {
-      typeArguments.accept(this);
-    }
-    // optional "name"
-    if (node.name != null) {
-      computer._addRegionForNode(node.name, element);
-    }
-  }
-
-  /**
-   * If the source of the given [element] (referenced by the [node]) exists,
-   * then add the navigation region from the [node] to the [element].
-   */
-  void _addUriDirectiveRegion(UriBasedDirective node, Element element) {
-    if (element != null) {
-      Source source = element.source;
-      if (element.context.exists(source)) {
-        computer._addRegionForNode(node.uri, element);
-      }
-    }
-  }
-
-  void _safelyVisit(AstNode node) {
-    if (node != null) {
-      node.accept(this);
-    }
-  }
-}