send status notification when analysis starts and ends

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 c29aa8a91f64a38f0b619a4abd10117242411ce8..686703e9b912f5ce7b1eb140bfea5bff059a859e 100644
--- a/pkg/analysis_server/lib/src/analysis_server.dart
+++ b/pkg/analysis_server/lib/src/analysis_server.dart
@@ -102,6 +102,12 @@ class AnalysisServer {
   bool running;
 
   /**
+   * A flag indicating the value of the 'analyzing' parameter sent in the last
+   * status message to the client.
+   */
+  bool statusAnalyzing = false;

[Paul Berry, 2014/06/25 19:38:16]

How about if we call this "wasAnalyzing"

[danrubel, 2014/06/26 11:53:22]

I want to convey that this field is associated with sending status messages to
the client. It is not immediately apparent that 'wasAnalyzing' is associated
with sending status.

+
+  /**
    * A list of the request handlers used to handle the requests sent to this
    * server.
    */
@@ -340,6 +346,7 @@ class AnalysisServer {
     }
     // prepare next operation
     ServerOperation operation = operationQueue.take();
+    sendStatusNotification(operation);
     // perform the operation
     try {
       operation.perform(this);
@@ -360,19 +367,18 @@ class AnalysisServer {
   }
 
   /**
-   * Send status notification to the client. The `contextId` indicates
-   * the current context being analyzed or `null` if analysis is complete.
+   * Send status notification to the client. The `operation` is the operation
+   * being performed or `null` if analysis is complete.
    */
-  void sendStatusNotification(String contextId) {
+  void sendStatusNotification(ServerOperation operation) {
+    // Only send status when it changes

[Paul Berry, 2014/06/25 19:38:16]

Then this code can look like:

  bool isAnalyzing = (operation != null);
  if (isAnalyzing == wasAnalyzing) {
    return;
  }
  wasAnalyzing = isAnalyzing;
  ...
  analysis['analyzing'] = isAnalyzing;

Not a huge deal, I just think the function would read a little more easily this
way.  Your call.

[danrubel, 2014/06/26 11:53:22]

You're right. I like it better that way. Done.

+    if (statusAnalyzing == (operation != null)) {
+      return;
+    }
+    statusAnalyzing = (operation != null);
     Notification notification = new Notification(SERVER_STATUS);
     Map<String, Object> analysis = new Map();
-    if (contextId != null) {
-      analysis['analyzing'] = true;
-      // TODO(danrubel): replace contextId with real analysisTarget
-      analysis['analysisTarget'] = contextId;
-    } else {
-      analysis['analyzing'] = false;
-    }
+    analysis['analyzing'] = statusAnalyzing;
     notification.params['analysis'] = analysis;
     channel.sendNotification(notification);
   }