From ff1bbd35c55c4e3bb4afdad5f7cd0371450b715b Mon Sep 17 00:00:00 2001
From: Collin Jackson <jackson@google.com>
Date: Thu, 18 Jun 2015 16:36:08 -0700
Subject: [PATCH] Widgets should be stateful in order to call setState

R=abarth@chromium.org, abarth

Review URL: https://codereview.chromium.org/1183143012.
---
 sdk/lib/widgets/button_base.dart | 2 +-
 sdk/lib/widgets/widget.dart      | 6 +++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/sdk/lib/widgets/button_base.dart b/sdk/lib/widgets/button_base.dart
index e0f88544b70..9fc93e9d768 100644
--- a/sdk/lib/widgets/button_base.dart
+++ b/sdk/lib/widgets/button_base.dart
@@ -6,7 +6,7 @@ import 'basic.dart';
 
 abstract class ButtonBase extends Component {
 
-  ButtonBase({ String key, this.highlight: false }) : super(key: key);
+  ButtonBase({ String key, this.highlight: false }) : super(key: key, stateful: true);
 
   bool highlight;
 
diff --git a/sdk/lib/widgets/widget.dart b/sdk/lib/widgets/widget.dart
index 9b4001eff92..4ad23dc9787 100644
--- a/sdk/lib/widgets/widget.dart
+++ b/sdk/lib/widgets/widget.dart
@@ -416,7 +416,7 @@ abstract class Component extends Widget {
 
   void setState(Function fn()) {
     assert(!_disqualifiedFromEverAppearingAgain);
-    _stateful = true;
+    assert(_stateful);
     fn();
     if (_isBuilding || _dirty || !_mounted)
       return;
@@ -813,6 +813,10 @@ class WidgetSkyBinding extends SkyBinding {
 }
 
 abstract class App extends Component {
+
+  // Apps are assumed to be stateful
+  App({ String key }) : super(key: key, stateful: true);
+
   void _handleEvent(sky.Event event) {
     if (event.type == 'back')
       onBack();