Add source annotations for breakpoints.

runtime/observatory/lib/src/elements/script_inset.dart

Index: runtime/observatory/lib/src/elements/script_inset.dart
diff --git a/runtime/observatory/lib/src/elements/script_inset.dart b/runtime/observatory/lib/src/elements/script_inset.dart
index a7223c8c93d5c6a9b545fcb994d461f6e88af6f2..8a9546740a599840b78565617ff376ce22b50198 100644
--- a/runtime/observatory/lib/src/elements/script_inset.dart
+++ b/runtime/observatory/lib/src/elements/script_inset.dart
@@ -57,11 +57,15 @@ abstract class Annotation implements Comparable<Annotation> {
   int line;
   int columnStart;
   int columnStop;
+  int get priority;
 
   void applyStyleTo(element);
 
   int compareTo(Annotation other) {
     if (line == other.line) {
+      if (columnStart == other.columnStart) {
+        return priority.compareTo(other.priority);
+      }
       return columnStart.compareTo(other.columnStart);
     }
     return line.compareTo(other.line);
@@ -100,6 +104,8 @@ abstract class Annotation implements Comparable<Annotation> {
 }
 
 class CurrentExecutionAnnotation extends Annotation {
+  int priority = 0;  // highest priority.
+
   void applyStyleTo(element) {
     if (element == null) {
       return;  // TODO(rmacnak): Handling overlapping annotations.
@@ -109,9 +115,40 @@ class CurrentExecutionAnnotation extends Annotation {
   }
 }
 
+class BreakpointAnnotation extends Annotation {
+  Breakpoint bpt;
+  int priority = 1;
+
+  BreakpointAnnotation(this.bpt) {
+    var script = bpt.location.script;
+    var pos = bpt.location.tokenPos;
+    line = script.tokenToLine(pos);
+    columnStart = script.tokenToCol(pos) - 1;  // tokenToCol is 1-origin.
+    var length = script.guessTokenLength(line, columnStart);
+    if (length == null) {
+      length = 1;
+    }
+    columnStop = columnStart + length;
+  }
+
+  void applyStyleTo(element) {
+    if (element == null) {
+      return;  // TODO(rmacnak): Handling overlapping annotations.
+    }
+    var script = bpt.location.script;
+    var pos = bpt.location.tokenPos;
+    int line = script.tokenToLine(pos);
+    int column = script.tokenToCol(pos);
+    element.classes.add("breakAnnotation");
+    element.title = "Breakpoint ${bpt.number} at ${line}:${column}";
+  }
+}
+
 class LibraryAnnotation extends Annotation {
   Library target;
   String url;
+  int priority = 2;
+
   LibraryAnnotation(this.target, this.url);
 
   void applyStyleTo(element) {
@@ -126,6 +163,8 @@ class LibraryAnnotation extends Annotation {
 class PartAnnotation extends Annotation {
   Script part;
   String url;
+  int priority = 2;
+
   PartAnnotation(this.part, this.url);
 
   void applyStyleTo(element) {
@@ -139,6 +178,7 @@ class PartAnnotation extends Annotation {
 
 class LocalVariableAnnotation extends Annotation {
   final value;
+  int priority = 2;
 
   LocalVariableAnnotation(LocalVarLocation location, this.value) {
     line = location.line;
@@ -157,6 +197,7 @@ class LocalVariableAnnotation extends Annotation {
 
 class CallSiteAnnotation extends Annotation {
   CallSite callSite;
+  int priority = 2;
 
   CallSiteAnnotation(this.callSite) {
     line = callSite.line;
@@ -203,6 +244,8 @@ class CallSiteAnnotation extends Annotation {
 
 abstract class DeclarationAnnotation extends Annotation {
   String url;
+  int priority = 2;
+
   DeclarationAnnotation(decl, this.url) {
     assert(decl.loaded);
     SourceLocation location = decl.location;
@@ -326,7 +369,8 @@ class ScriptInsetElement extends ObservatoryElement {
   var annotations = [];
   var annotationsCursor;
 
-  StreamSubscription scriptChangeSubscription;
+  StreamSubscription _scriptChangeSubscription;
+  Future<StreamSubscription> _debugSubscriptionFuture;
 
   bool hasLoadedLibraryDeclarations = false;
 
@@ -341,15 +385,45 @@ class ScriptInsetElement extends ObservatoryElement {
     }
   }
 
+  void attached() {
+    super.attached();
+    _debugSubscriptionFuture =
+        app.vm.listenEventStream(VM.kDebugStream, _onDebugEvent);
+  }
+
   void detached() {
-    if (scriptChangeSubscription != null) {
+    cancelFutureSubscription(_debugSubscriptionFuture);
+    _debugSubscriptionFuture = null;
+    if (_scriptChangeSubscription != null) {
       // Don't leak. If only Dart and Javascript exposed weak references...
-      scriptChangeSubscription.cancel();
-      scriptChangeSubscription = null;
+      _scriptChangeSubscription.cancel();
+      _scriptChangeSubscription = null;
     }
     super.detached();
   }
 
+  void _onDebugEvent(event) {
+    if (script == null) {
+      return;
+    }
+    switch (event.kind) {
+      case ServiceEvent.kBreakpointAdded:
+      case ServiceEvent.kBreakpointResolved:
+      case ServiceEvent.kBreakpointRemoved:
+        var loc = event.breakpoint.location;
+        if (loc.script == script) {
+          int line = script.tokenToLine(loc.tokenPos);
+          if ((line >= _startLine) && (line <= _endLine)) {
+            _updateTask.queue();
+          }
+        }
+        break;
+      default:
+        // Ignore.
+        break;
+    }
+  }
+
   void currentPosChanged(oldValue) {
     _updateTask.queue();
     _scrollToCurrentPos();
@@ -407,8 +481,8 @@ class ScriptInsetElement extends ObservatoryElement {
       return;
     }
 
-    if (scriptChangeSubscription == null) {
-      scriptChangeSubscription = script.changes.listen((_) => update());
+    if (_scriptChangeSubscription == null) {
+      _scriptChangeSubscription = script.changes.listen((_) => update());
     }
 
     computeAnnotations();
@@ -450,6 +524,7 @@ class ScriptInsetElement extends ObservatoryElement {
     annotations.clear();
 
     addCurrentExecutionAnnotation();
+    addBreakpointAnnotations();
 
     if (!inDebuggerContext && script.library != null) {
       if (hasLoadedLibraryDeclarations) {
@@ -487,6 +562,19 @@ class ScriptInsetElement extends ObservatoryElement {
     }
   }
 
+  void addBreakpointAnnotations() {
+    for (var line = _startLine; line <= _endLine; line++) {
+      var bpts = script.getLine(line).breakpoints;
+      if (bpts != null) {
+        for (var bpt in bpts) {
+          if (bpt.location != null) {
+            annotations.add(new BreakpointAnnotation(bpt));
+          }
+        }
+      }
+    }
+  }
+
   Future loadDeclarationsOfLibrary(Library lib) {
     return lib.load().then((lib) {
       var loads = [];