Add a mode to dartdoc to generate the navigation on the client.

utils/dartdoc/interact.dart

-// Copyright (c) 2011, 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.
-
-/** Provides client-side behavior for generated docs. */
-#library('interact');
-
-#import('dart:html');
-#import('../../frog/lang.dart');
-#import('markdown.dart', prefix: 'md');
-
-#source('classify.dart');
-
-main() {
-  window.on.contentLoaded.add((e) {
-    for (var elem in document.queryAll('.method, .field')) {
-      var showCode = elem.query('.show-code');
-
-      // Skip it if we don't have a code link. Will happen if source code is
-      // disabled.
-      if (showCode == null) continue;
-
-      var pre = elem.query('pre.source');
-      showCode.on.click.add((e) {
-        if (pre.classes.contains('expanded')) {
-          pre.classes.remove('expanded');
-        } else {
-          // Syntax highlight.
-          if (!pre.classes.contains('formatted')) {
-            pre.innerHTML = classifySource(new SourceFile('', pre.text));
-            pre.classes.add('formatted');
-          };
-          pre.classes.add('expanded');
-        }
-      });
-    }
-  });
-}