Combine window.setTimeout/setInterval with Timer and Timer.repeating. Also

samples/calculator/calculator.dart

Index: samples/calculator/calculator.dart
diff --git a/samples/calculator/calculator.dart b/samples/calculator/calculator.dart
index 10a0477e9a567e954d619bf4ebb1bd7c750af2ed..cd6c2b4971373d8ff0b5d1808cb8784ae6af9f13 100644
--- a/samples/calculator/calculator.dart
+++ b/samples/calculator/calculator.dart
@@ -5,6 +5,7 @@
 import 'dart:html';
 import 'dart:math' as Math;
 import 'calcui.dart';
+import 'dart:async';
 
 Set numberKeyPresses;
 Set operatorKeyPresses;
@@ -324,8 +325,9 @@ void flickerKey(Element key, [String postfix = '-hover']) {
   }
   key.classes.add('${theClass}${postfix}');
   final String nextPostfix = (postfix == '-error') ? '-error' : '-press';
-  window.setTimeout(() => resetKey(key, '${theClass}${postfix}',
-    '${theClass}${nextPostfix}'), 80);
+  new Timer(const Duration(milliseconds: 80),
+      () => resetKey(key, '${theClass}${postfix}',
+      '${theClass}${nextPostfix}'));
 }
 
 void resetKey(Element key, String classToRemove, [String classToAdd = ""]) {
@@ -333,7 +335,8 @@ void resetKey(Element key, String classToRemove, [String classToAdd = ""]) {
     key.classes.remove(classToRemove);
     if (classToAdd.length > 0) {
       key.classes.add(classToAdd);
-      window.setTimeout(() => resetKey(key, classToAdd), 80);
+      new Timer(const Duration(milliseconds: 80),
+          () => resetKey(key, classToAdd));
     }
   }
 }