convert uri contributor to use new task model

pkg/analysis_server/lib/src/services/completion/uri_contributor.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 services.completion.contributor.dart.importuri;
-
-import 'dart:async';
-import 'dart:core' hide Resource;
-
-import 'package:analysis_server/src/services/completion/dart_completion_manager.dart';
-import 'package:analyzer/file_system/file_system.dart';
-import 'package:analyzer/src/generated/ast.dart';
-import 'package:analyzer/src/generated/sdk.dart';
-import 'package:analyzer/src/generated/source.dart';
-import 'package:path/path.dart' show posix;
-import 'package:path/src/context.dart';
-
-import '../../protocol_server.dart'
-    show CompletionSuggestion, CompletionSuggestionKind;
-
-/**
- * A contributor for calculating uri suggestions
- * for import and part directives.
- */
-class UriContributor extends DartCompletionContributor {
-  _UriSuggestionBuilder builder;
-
-  @override
-  bool computeFast(DartCompletionRequest request) {
-    builder = new _UriSuggestionBuilder(request);
-    return builder.computeFast(request.target.containingNode);
-  }
-
-  @override
-  Future<bool> computeFull(DartCompletionRequest request) {
-    return new Future.value(false);
-  }
-}
-
-class _UriSuggestionBuilder extends SimpleAstVisitor {
-  final DartCompletionRequest request;
-
-  _UriSuggestionBuilder(this.request);
-
-  bool computeFast(AstNode node) {
-    node.accept(this);
-    return true;
-  }
-
-  @override
-  visitExportDirective(ExportDirective node) {
-    visitNamespaceDirective(node);
-  }
-
-  @override
-  visitImportDirective(ImportDirective node) {
-    visitNamespaceDirective(node);
-  }
-
-  visitNamespaceDirective(NamespaceDirective node) {
-    StringLiteral uri = node.uri;
-    if (uri is SimpleStringLiteral) {
-      int offset = request.offset;
-      if (uri.offset < offset &&
-          (offset < uri.end || offset == uri.offset + 1)) {
-        // Handle degenerate case where import or export is only line in file
-        // and there is no semicolon
-        visitSimpleStringLiteral(uri);
-      }
-    }
-  }
-
-  @override
-  visitSimpleStringLiteral(SimpleStringLiteral node) {
-    AstNode parent = node.parent;
-    if (parent is NamespaceDirective && parent.uri == node) {
-      String partialUri = _extractPartialUri(node);
-      if (partialUri != null) {
-        _addDartSuggestions();
-        _addPackageSuggestions(partialUri);
-        _addFileSuggestions(partialUri);
-      }
-    } else if (parent is PartDirective && parent.uri == node) {
-      String partialUri = _extractPartialUri(node);
-      if (partialUri != null) {
-        _addFileSuggestions(partialUri);
-      }
-    }
-  }
-
-  void _addDartSuggestions() {
-    _addSuggestion('dart:');
-    SourceFactory factory = request.context.sourceFactory;
-    for (SdkLibrary lib in factory.dartSdk.sdkLibraries) {
-      if (!lib.isInternal && !lib.isImplementation) {
-        if (!lib.shortName.startsWith('dart:_')) {
-          _addSuggestion(lib.shortName,
-              relevance: lib.shortName == 'dart:core'
-                  ? DART_RELEVANCE_LOW
-                  : DART_RELEVANCE_DEFAULT);
-        }
-      }
-    }
-  }
-
-  void _addFileSuggestions(String partialUri) {
-    ResourceProvider resProvider = request.resourceProvider;
-    Context resContext = resProvider.pathContext;
-    Source source = request.source;
-
-    String parentUri;
-    if ((partialUri.endsWith('/'))) {
-      parentUri = partialUri;
-    } else {
-      parentUri = posix.dirname(partialUri);
-      if (parentUri != '.' && !parentUri.endsWith('/')) {
-        parentUri = '$parentUri/';
-      }
-    }
-    String uriPrefix = parentUri == '.' ? '' : parentUri;
-
-    String dirPath = resContext.normalize(parentUri);
-    if (resContext.isRelative(dirPath)) {
-      String sourceDirPath = resContext.dirname(source.fullName);
-      if (resContext.isAbsolute(sourceDirPath)) {
-        dirPath = resContext.join(sourceDirPath, dirPath);
-      } else {
-        return;
-      }
-    }
-
-    Resource dir = resProvider.getResource(dirPath);
-    if (dir is Folder) {
-      for (Resource child in dir.getChildren()) {
-        String completion;
-        if (child is Folder) {
-          completion = '$uriPrefix${child.shortName}/';
-        } else {
-          completion = '$uriPrefix${child.shortName}';
-        }
-        if (completion != source.shortName) {
-          _addSuggestion(completion);
-        }
-      }
-    }
-  }
-
-  void _addPackageFolderSuggestions(
-      String partial, String prefix, Folder folder) {
-    for (Resource child in folder.getChildren()) {
-      if (child is Folder) {
-        String childPrefix = '$prefix${child.shortName}/';
-        _addSuggestion(childPrefix);
-        if (partial.startsWith(childPrefix)) {
-          _addPackageFolderSuggestions(partial, childPrefix, child);
-        }
-      } else {
-        _addSuggestion('$prefix${child.shortName}');
-      }
-    }
-  }
-
-  void _addPackageSuggestions(String partial) {
-    SourceFactory factory = request.context.sourceFactory;
-    Map<String, List<Folder>> packageMap = factory.packageMap;
-    if (packageMap != null) {
-      _addSuggestion('package:');
-      packageMap.forEach((String pkgName, List<Folder> folders) {
-        String prefix = 'package:$pkgName/';
-        _addSuggestion(prefix);
-        for (Folder folder in folders) {
-          if (folder.exists) {
-            _addPackageFolderSuggestions(partial, prefix, folder);
-          }
-        }
-      });
-    }
-  }
-
-  void _addSuggestion(String completion,
-      {int relevance: DART_RELEVANCE_DEFAULT}) {
-    request.addSuggestion(new CompletionSuggestion(
-        CompletionSuggestionKind.IMPORT,
-        relevance,
-        completion,
-        completion.length,
-        0,
-        false,
-        false));
-  }
-
-  String _extractPartialUri(SimpleStringLiteral node) {
-    if (request.offset < node.contentsOffset) {
-      return null;
-    }
-    String partial = node.literal.lexeme.substring(
-        node.contentsOffset - node.offset, request.offset - node.offset);
-    request.replacementOffset = node.contentsOffset;
-    request.replacementLength = node.contentsEnd - node.contentsOffset;
-    return partial;
-  }
-}