Navigation extension point.

pkg/analysis_server/lib/src/domains/analysis/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 domains.analysis.navigation;
+
+import 'dart:collection';
+
+import 'package:analysis_server/analysis/navigation/navigation_core.dart';
+import 'package:analysis_server/src/analysis_server.dart';
+import 'package:analysis_server/src/collections.dart';
+import 'package:analysis_server/src/protocol_server.dart' as protocol;
+import 'package:analyzer/src/generated/engine.dart'
+    show AnalysisContext, AnalysisEngine;
+import 'package:analyzer/src/generated/java_engine.dart' show CaughtException;
+import 'package:analyzer/src/generated/source.dart' show Source;
+
+/**
+ * Compute all known navigation information for the given part of [source].
+ */
+NavigationHolder computeNavigation(AnalysisServer server,
+    AnalysisContext context, Source source, int offset, int length) {
+  NavigationHolderImpl holder = new NavigationHolderImpl();
+  List<NavigationContributor> contributors =
+      server.serverPlugin.navigationContributors;
+  for (NavigationContributor contributor in contributors) {
+    try {
+      contributor.computeNavigation(holder, context, source, offset, length);
+    } catch (exception, stackTrace) {
+      AnalysisEngine.instance.logger.logError(
+          'Exception from navigation contributor: ${contributor.runtimeType}',
+          new CaughtException(exception, stackTrace));
+    }
+  }
+  return holder;
+}
+
+/**
+ * A concrete implementation of  [NavigationHolder].
+ */
+class NavigationHolderImpl implements NavigationHolder {
+  final List<String> files = <String>[];
+  final Map<String, int> fileMap = new HashMap<String, int>();
+  final List<protocol.NavigationTarget> targets = <protocol.NavigationTarget>[];
+  final Map<Pair<protocol.ElementKind, protocol.Location>, int> targetMap =
+      new HashMap<Pair<protocol.ElementKind, protocol.Location>, int>();
+  final List<protocol.NavigationRegion> regions = <protocol.NavigationRegion>[];
+
+  @override
+  void addRegion(int offset, int length, protocol.ElementKind targetKind,
+      protocol.Location targetLocation) {
+    int targetIndex = _addTarget(targetKind, targetLocation);
+    protocol.NavigationRegion region =
+        new protocol.NavigationRegion(offset, length, <int>[targetIndex]);
+    regions.add(region);
+  }
+
+  int _addFile(String file) {
+    int index = fileMap[file];
+    if (index == null) {
+      index = files.length;
+      files.add(file);
+      fileMap[file] = index;
+    }
+    return index;
+  }
+
+  int _addTarget(protocol.ElementKind kind, protocol.Location location) {
+    var pair =
+        new Pair<protocol.ElementKind, protocol.Location>(kind, location);
+    int index = targetMap[pair];
+    if (index == null) {
+      String file = location.file;
+      int fileIndex = _addFile(file);
+      index = targets.length;
+      protocol.NavigationTarget target = new protocol.NavigationTarget(
+          kind,
+          fileIndex,
+          location.offset,
+          location.length,
+          location.startLine,
+          location.startColumn);
+      targets.add(target);
+      targetMap[pair] = index;
+    }
+    return index;
+  }
+}