new onPriorityChanged event stream

pkg/analysis_server/lib/src/analysis_server.dart

Index: pkg/analysis_server/lib/src/analysis_server.dart
diff --git a/pkg/analysis_server/lib/src/analysis_server.dart b/pkg/analysis_server/lib/src/analysis_server.dart
index 145c000d09a215624e9d7fcf452aafccd4a04233..fe370927919c770f5e6524f6f47b223e9ad275b7 100644
--- a/pkg/analysis_server/lib/src/analysis_server.dart
+++ b/pkg/analysis_server/lib/src/analysis_server.dart
@@ -163,6 +163,11 @@ class AnalysisServer {
   StreamController<ChangeNotice> _onFileAnalyzedController;
 
   /**
+   * The controller used to notify others when priority sources change.
+   */
+  StreamController<PriorityChangeEvent> _onPriorityChangeController;
+
+  /**
    * True if any exceptions thrown by analysis should be propagated up the call
    * stack.
    */
@@ -195,6 +200,8 @@ class AnalysisServer {
     _onAnalysisStartedController = new StreamController.broadcast();
     _onAnalysisCompleteController = new StreamController.broadcast();
     _onFileAnalyzedController = new StreamController.broadcast();
+    _onPriorityChangeController =
+        new StreamController<PriorityChangeEvent>.broadcast();
     running = true;
     Notification notification = new ServerConnectedParams().toNotification();
     channel.sendNotification(notification);
@@ -219,6 +226,12 @@ class AnalysisServer {
   Stream get onFileAnalyzed => _onFileAnalyzedController.stream;
 
   /**
+   * The stream that is notified when priority sources change.
+   */
+  Stream<PriorityChangeEvent> get onPriorityChange =>
+      _onPriorityChangeController.stream;
+
+  /**
    * Adds the given [ServerOperation] to the queue, but does not schedule
    * operations execution.
    */
@@ -346,23 +359,6 @@ class AnalysisServer {
     return context.getErrors(source);
   }
 
-  /**
-   * Returns resolved [AstNode]s at the given [offset] of the given [file].
-   *
-   * May be empty, but not `null`.
-   */
-  List<AstNode> getNodesAtOffset(String file, int offset) {
-    List<CompilationUnit> units = getResolvedCompilationUnits(file);
-    List<AstNode> nodes = <AstNode>[];
-    for (CompilationUnit unit in units) {
-      AstNode node = new NodeLocator.con1(offset).searchWithin(unit);
-      if (node != null) {
-        nodes.add(node);
-      }
-    }
-    return nodes;
-  }
-
 // TODO(brianwilkerson) Add the following method after 'prioritySources' has
 // been added to InternalAnalysisContext.
 //  /**
@@ -381,29 +377,20 @@ class AnalysisServer {
 //  }
 
   /**
-   * Returns resolved [CompilationUnit]s of the Dart file with the given [path].
+   * Returns resolved [AstNode]s at the given [offset] of the given [file].
    *
    * May be empty, but not `null`.
    */
-  List<CompilationUnit> getResolvedCompilationUnits(String path) {
-    List<CompilationUnit> units = <CompilationUnit>[];
-    // prepare AnalysisContext
-    AnalysisContext context = getAnalysisContext(path);
-    if (context == null) {
-      return units;
-    }
-    // add a unit for each unit/library combination
-    Source unitSource = getSource(path);
-    List<Source> librarySources = context.getLibrariesContaining(unitSource);
-    for (Source librarySource in librarySources) {
-      CompilationUnit unit =
-          context.resolveCompilationUnit2(unitSource, librarySource);
-      if (unit != null) {
-        units.add(unit);
+  List<AstNode> getNodesAtOffset(String file, int offset) {
+    List<CompilationUnit> units = getResolvedCompilationUnits(file);
+    List<AstNode> nodes = <AstNode>[];
+    for (CompilationUnit unit in units) {
+      AstNode node = new NodeLocator.con1(offset).searchWithin(unit);
+      if (node != null) {
+        nodes.add(node);
       }
     }
-    // done
-    return units;
+    return nodes;
   }
 
   /**
@@ -434,6 +421,32 @@ class AnalysisServer {
   }
 
   /**
+   * Returns resolved [CompilationUnit]s of the Dart file with the given [path].
+   *
+   * May be empty, but not `null`.
+   */
+  List<CompilationUnit> getResolvedCompilationUnits(String path) {
+    List<CompilationUnit> units = <CompilationUnit>[];
+    // prepare AnalysisContext
+    AnalysisContext context = getAnalysisContext(path);
+    if (context == null) {
+      return units;
+    }
+    // add a unit for each unit/library combination
+    Source unitSource = getSource(path);
+    List<Source> librarySources = context.getLibrariesContaining(unitSource);
+    for (Source librarySource in librarySources) {
+      CompilationUnit unit =
+          context.resolveCompilationUnit2(unitSource, librarySource);
+      if (unit != null) {
+        units.add(unit);
+      }
+    }
+    // done
+    return units;
+  }
+
+  /**
    * Return the [Source] of the Dart file with the given [path].
    */
   Source getSource(String path) {
@@ -741,7 +754,7 @@ class AnalysisServer {
   /**
    * Set the priority files to the given [files].
    */
-  void setPriorityFiles(Request request, List<String> files) {
+  void setPriorityFiles(String requestId, List<String> files) {
     Map<AnalysisContext, List<Source>> sourceMap =
         new HashMap<AnalysisContext, List<Source>>();
     List<String> unanalyzed = new List<String>();
@@ -762,7 +775,7 @@ class AnalysisServer {
       StringBuffer buffer = new StringBuffer();
       buffer.writeAll(unanalyzed, ', ');
       throw new RequestFailure(
-          new Response.unanalyzedPriorityFiles(request, buffer.toString()));
+          new Response.unanalyzedPriorityFiles(requestId, buffer.toString()));
     }
     folderMap.forEach((Folder folder, AnalysisContext context) {
       List<Source> sourceList = sourceMap[context];
@@ -771,6 +784,8 @@ class AnalysisServer {
       }
       context.analysisPriorityOrder = sourceList;
     });
+    Source firstSource = files.length > 0 ? getSource(files[0]) : null;
+    _onPriorityChangeController.add(new PriorityChangeEvent(firstSource));
   }
 
   /**
@@ -926,6 +941,16 @@ class ContextsChangedEvent {
       AnalysisContext.EMPTY_LIST, this.removed: AnalysisContext.EMPTY_LIST});
 }
 
+/**
+ * A [PriorityChangeEvent] indicates which sources are currently prioritized

[Brian Wilkerson, 2014/11/24 16:17:11]

I think it indicates that the list of priority changes has been changed.

[danrubel, 2014/11/24 17:54:06]

Cleaned up.

+ * and should be analyzed before other sources.
+ */
+class PriorityChangeEvent {
+  final Source firstSource;

[Brian Wilkerson, 2014/11/24 16:17:11]

Shouldn't this be a List<Source>? Or possibly a Map<AnalysisContext,
List<Source>>?

[danrubel, 2014/11/24 17:54:05]

I only need the first source if there is one and I was keeping the event
minimal. If we find listeners need more information, we can enhance the API.

[Brian Wilkerson, 2014/11/24 18:14:38]

Understood, and in general I agree with only doing what we need now (I
considered suggesting that we also include the old priority list but decided we
didn't need it yet and could cleanly add it later).

However, defining 'firstSource' means that we will always have to support it for
backward compatibility. In this case I think it would be better to support a
more general API and not have that constraint. (I suppose it won't be too
terrible to always need to have an accessor for the first element in the list,
but still...)

+
+  PriorityChangeEvent(this.firstSource);
+}
+
 class ServerContextManager extends ContextManager {
   final AnalysisServer analysisServer;