From 4cd223a7e5d5d26a30b3a9afd9021ef44ade39a0 Mon Sep 17 00:00:00 2001
From: Collin Jackson <jackson@google.com>
Date: Wed, 26 Aug 2015 10:45:05 -0700
Subject: [PATCH] Cancel timer when un-mounting date picker widget

---
 packages/flutter/lib/widgets/date_picker.dart | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/packages/flutter/lib/widgets/date_picker.dart b/packages/flutter/lib/widgets/date_picker.dart
index a24243e756..3197660d66 100644
--- a/packages/flutter/lib/widgets/date_picker.dart
+++ b/packages/flutter/lib/widgets/date_picker.dart
@@ -299,12 +299,16 @@ class MonthPicker extends ScrollableWidgetList {
   }
 
   DateTime _currentDate;
+  Timer _timer;
+
   void _updateCurrentDate() {
     _currentDate = new DateTime.now();
     DateTime tomorrow = new DateTime(_currentDate.year, _currentDate.month, _currentDate.day + 1);
     Duration timeUntilTomorrow = tomorrow.difference(_currentDate);
     timeUntilTomorrow += const Duration(seconds: 1);  // so we don't miss it by rounding
-    new Timer(timeUntilTomorrow, () {
+    if (_timer != null)
+      _timer.cancel();
+    _timer = new Timer(timeUntilTomorrow, () {
       setState(() {
         _updateCurrentDate();
       });
@@ -332,6 +336,13 @@ class MonthPicker extends ScrollableWidgetList {
     }
     return result;
   }
+
+  void didUnmount() {
+    super.didUnmount();
+    if (_timer != null) {
+      _timer.cancel();
+    }
+  }
 }
 
 // Scrollable list of years to allow picking a year