Add AnalysisContext.onResultInvalidated(descriptor).

pkg/analyzer/lib/src/generated/engine.dart

Index: pkg/analyzer/lib/src/generated/engine.dart
diff --git a/pkg/analyzer/lib/src/generated/engine.dart b/pkg/analyzer/lib/src/generated/engine.dart
index 57d35d91212d749e4133189ddc1390cfaf43d1d1..8729c2847fb2031082366b5aef587f7957711fca 100644
--- a/pkg/analyzer/lib/src/generated/engine.dart
+++ b/pkg/analyzer/lib/src/generated/engine.dart
@@ -514,9 +514,16 @@ abstract class AnalysisContext {
   bool isServerLibrary(Source librarySource);
 
   /**
+   * Return the stream that is notified when a result with the given
+   * [descriptor] is changed, e.g. computed or invalidated.
+   */
+  Stream<ResultChangedEvent> onResultChanged(ResultDescriptor descriptor);
+
+  /**
    * Return the stream that is notified when a new value for the given
    * [descriptor] is computed.
    */
+  @deprecated
   Stream<ComputedResult> onResultComputed(ResultDescriptor descriptor);
 
   /**
@@ -545,7 +552,7 @@ abstract class AnalysisContext {
    * analysis results. This method can be long running.
    *
    * The implementation that uses the task model notifies subscribers of
-   * [onResultComputed] about computed results.
+   * [onResultChanged] about computed results.
    *
    * The following results are computed for Dart sources.
    *
@@ -1841,6 +1848,7 @@ class ChangeSet_ContentChange {
 /**
  * [ComputedResult] describes a value computed for a [ResultDescriptor].
  */
+@deprecated
 class ComputedResult<V> {
   /**
    * The context in which the value was computed.
@@ -1865,7 +1873,7 @@ class ComputedResult<V> {
   ComputedResult(this.context, this.descriptor, this.target, this.value);
 
   @override
-  String toString() => '$descriptor of $target in $context';
+  String toString() => 'Computed $descriptor of $target in $context';
 }
 
 /**
@@ -2408,6 +2416,54 @@ class ResolutionEraser extends GeneralizingAstVisitor<Object> {
 }
 
 /**
+ * [ResultChangedEvent] describes a change to an analysis result.
+ */
+class ResultChangedEvent<V> {
+  /**
+   * The context in which the result was changed.
+   */
+  final AnalysisContext context;
+
+  /**
+   * The target for which the result was changed.
+   */
+  final AnalysisTarget target;
+
+  /**
+   * The descriptor of the result which was changed.
+   */
+  final ResultDescriptor<V> descriptor;
+
+  /**
+   * If the result [wasComputed], the new value of the result. If the result
+   * [wasInvalidated], the value of before it was invalidated, may be the
+   * default value if the result was flushed.
+   */
+  final V value;
+
+  /**
+   * Is `true` if the result was computed, or `false` is is was invalidated.
+   */
+  final bool _wasComputed;
+
+  ResultChangedEvent(this.context, this.target, this.descriptor, this.value,
+      this._wasComputed);
+
+  /**
+   * Returns `true` if the result was computed.
+   */
+  bool get wasComputed => _wasComputed;
+
+  /**
+   * Returns `true` if the result was invalidated.
+   */
+  bool get wasInvalidated => !_wasComputed;
+
+  @override
+  String toString() => '$descriptor of $target';

[Brian Wilkerson, 2016/03/08 20:47:02]

" in $context"?

[scheglov, 2016/03/08 20:53:46]

Done.

+}
+
+/**
  * [SourcesChangedEvent] indicates which sources have been added, removed,
  * or whose contents have changed.
  */