Navigation extension point.

pkg/analysis_server/lib/analysis/navigation/navigation_core.dart

Index: pkg/analysis_server/lib/analysis/navigation/navigation_core.dart
diff --git a/pkg/analysis_server/lib/analysis/navigation/navigation_core.dart b/pkg/analysis_server/lib/analysis/navigation/navigation_core.dart
new file mode 100644
index 0000000000000000000000000000000000000000..53ae022f79689a8cf5c10178ff2c5faff20ff005
--- /dev/null
+++ b/pkg/analysis_server/lib/analysis/navigation/navigation_core.dart
@@ -0,0 +1,55 @@
+// Copyright (c) 2015, 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 analysis_server.analysis.navigation.navigation_core;
+
+import 'package:analysis_server/src/protocol.dart'
+    show ElementKind, Location, NavigationRegion, NavigationTarget;
+import 'package:analyzer/src/generated/engine.dart' show AnalysisContext;
+import 'package:analyzer/src/generated/source.dart' show Source;
+
+/**
+ * An object used to produce navigation regions.
+ *
+ * Clients are expected to subtype this class when implementing plugins.
+ */
+abstract class NavigationContributor {
+  /**
+   * Contribute navigation regions for a part of the given [source] into the
+   * given [holder]. The part is specified by the [offset] and [length].
+   * The [context] can be used to get analysis results.
+   */
+  void computeNavigation(NavigationHolder holder, AnalysisContext context,
+      Source source, int offset, int length);
+}
+
+/**
+ * An object that [NavigationContributor]s use to record navigation regions
+ * into.
+ *
+ * Clients are not expected to subtype this class.
+ */
+abstract class NavigationHolder {

[Brian Wilkerson, 2015/09/01 14:55:42]

I don't think clients need the getters, so I'd like to remove them. Internally,
the method that computes navigations can return a NavigationHolderImpl.

[scheglov, 2015/09/01 20:06:14]

Done.

+  /**
+   * All the unique files referenced by [targets].
+   */
+  List<String> get files;
+
+  /**
+   * A list of navigation regions.
+   */
+  List<NavigationRegion> get regions;
+
+  /**
+   * All the unique targets referenced by [regions].
+   */
+  List<NavigationTarget> get targets;
+
+  /**
+   * Record a new navigation region with the given [offset] and [length] that
+   * should navigation to the given [targetLocation].
+   */
+  void addRegion(
+      int offset, int length, ElementKind targetKind, Location targetLocation);
+}