Add isolate tag-profile and better handling of errors

runtime/bin/vmservice/client/lib/src/elements/isolate_view.dart

 // Copyright (c) 2013, 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 isolate_view_element;
 
 import 'dart:async';
 import 'observatory_element.dart';
+import 'package:observatory/app.dart';
 import 'package:observatory/service.dart';
 import 'package:polymer/polymer.dart';
 
+class TagProfileChart {
+  var _table = new DataTable();
+  var _chart;
+
+  void update(TagProfile tagProfile) {
+    if (_table.columns == 0) {
+      // Initialize.
+      _table.addColumn('string', 'Time');
+      for (var tagName in tagProfile.names) {
+        if (tagName == 'Idle') {
+          // Skip Idle tag.
+          continue;
+        }
+        _table.addColumn('number', tagName);
+      }
+    }
+    _table.clearRows();
+    var idleIndex = tagProfile.names.indexOf('Idle');
+    assert(idleIndex != -1);
+    var t = tagProfile.updatedAtSeconds;
+    for (var i = 0; i < tagProfile.snapshots.length; i++) {
+      var snapshotTime = tagProfile.snapshots[i].seconds;
+      var row = [];
+      if (snapshotTime > 0.0) {
+        row.add('t ${(snapshotTime - t).toStringAsFixed(2)}');
+      } else {
+        row.add('');
+      }
+      var sum = tagProfile.snapshots[i].sum;
+      if (sum == 0) {
+        for (var j = 0; j < tagProfile.snapshots[i].counters.length; j++) {
+          if (j == idleIndex) {
+            // Skip idle.
+            continue;
+          }
+          row.add(0);
+        }
+     } else {
+       for (var j = 0; j < tagProfile.snapshots[i].counters.length; j++) {
+         if (j == idleIndex) {
+           // Skip idle.
+           continue;
+         }
+         var percentage = tagProfile.snapshots[i].counters[j] / sum * 100.0;
+         row.add(percentage.toInt());
+       }
+     }
+     _table.addRow(row);
+    }
+  }
+
+  void draw(var element) {
+    if (_chart == null) {
+      assert(element != null);
+      _chart = new Chart('SteppedAreaChart', element);
+      _chart.options['isStacked'] = true;
+      _chart.options['connectSteps'] = false;
+      _chart.options['vAxis'] = {
+        'minValue': 0.0,
+        'maxValue': 100.0,
+      };
+    }
+    _chart.draw(_table);
+  }
+}
+
 @CustomTag('isolate-view')
 class IsolateViewElement extends ObservatoryElement {
   @published Isolate isolate;
+  Timer _updateTimer;
+  TagProfileChart tagProfileChart = new TagProfileChart();
   IsolateViewElement.created() : super.created();
 
   Future<ServiceObject> eval(String text) {
     return isolate.get(
         isolate.rootLib.id + "/eval?expr=${Uri.encodeComponent(text)}");
   }
 
+  void enteredView() {
+    super.enteredView();
+    // Start a periodic timer to update the isolate summary once a second.
+    _updateTimer = new Timer.periodic(new Duration(seconds: 1), (_) {
+      isolate.updateTagProfile().then((tagProfile) {
+        tagProfileChart.update(tagProfile);
+        _drawTagProfileChart();
+      });
+    });
+  }
+
+  void leftView() {
+    super.leftView();
+    _updateTimer.cancel();
+  }
+
+  void _drawTagProfileChart() {
+    var element = shadowRoot.querySelector('#tagProfileChart');
+    if (element != null) {
+      tagProfileChart.draw(element);
+    }
+  }
+
   void refresh(var done) {
     isolate.reload().whenComplete(done);
   }
 
   void resume(var a, var b, var c) {
     isolate.get("resume").then((result) {
-        // TODO(turnidge): Instead of asserting here, handling errors
-        // properly.
-        assert(result.serviceType == 'Success');
-        isolate.reload();
-      });
+      // TODO(turnidge): Instead of asserting here, handling errors
+      // properly.
+      assert(result.serviceType == 'Success');
+      isolate.reload();
+    });
   }
 }