From 071201a5bba86afad3e2a5b41da3cf790b4784ec Mon Sep 17 00:00:00 2001
From: Viktor Lidholt <viktorl@google.com>
Date: Mon, 5 Oct 2015 11:24:59 -0700
Subject: [PATCH] Prevents sprite update methods to be called before the sprite
 box has been property intialized

---
 packages/flutter_sprites/lib/sprite_box.dart | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/packages/flutter_sprites/lib/sprite_box.dart b/packages/flutter_sprites/lib/sprite_box.dart
index 3abf3be04c..90f88c3b0e 100644
--- a/packages/flutter_sprites/lib/sprite_box.dart
+++ b/packages/flutter_sprites/lib/sprite_box.dart
@@ -86,6 +86,8 @@ class SpriteBox extends RenderBox {
     return _visibleArea;
   }
 
+  bool _initialized = false;
+
   // Setup
 
   /// Creates a new SpriteBox with a node as its content, by default uses letterboxing.
@@ -136,6 +138,7 @@ class SpriteBox extends RenderBox {
     size = constraints.biggest;
     _invalidateTransformMatrix();
     _callSpriteBoxPerformedLayout(_rootNode);
+    _initialized = true;
   }
 
   // Adding and removing nodes
@@ -361,11 +364,13 @@ class SpriteBox extends RenderBox {
 
     _frameRate = 1.0/delta;
 
-    _callConstraintsPreUpdate(delta);
-    _runActions(delta);
-    _callUpdate(_rootNode, delta);
-    _callStepPhysics(delta);
-    _callConstraintsConstrain(delta);
+    if (_initialized) {
+      _callConstraintsPreUpdate(delta);
+      _runActions(delta);
+      _callUpdate(_rootNode, delta);
+      _callStepPhysics(delta);
+      _callConstraintsConstrain(delta);
+    }
 
     // Schedule next update
     _scheduleTick();