From 9f278db3d911345a814953f94795f9e61c36cae9 Mon Sep 17 00:00:00 2001
From: Brent Vatne <brentvatne@gmail.com>
Date: Wed, 22 Aug 2018 17:08:36 -0700
Subject: [PATCH] Default to not animating the header background but keep
 around the translation background interpolator

---
 .../stack/src/views/Header/HeaderStyleInterpolator.js    | 9 ++++++++-
 packages/stack/src/views/StackView/StackViewLayout.js    | 2 ++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/packages/stack/src/views/Header/HeaderStyleInterpolator.js b/packages/stack/src/views/Header/HeaderStyleInterpolator.js
index 837f925c..0530fb92 100644
--- a/packages/stack/src/views/Header/HeaderStyleInterpolator.js
+++ b/packages/stack/src/views/Header/HeaderStyleInterpolator.js
@@ -324,8 +324,14 @@ function forCenterFromLeft(props) {
   };
 }
 
+// Default to no transition
+function forBackground() {
+  return null;
+}
+
+// Translate the background with the card
 const BACKGROUND_OFFSET = Dimensions.get('window').width;
-function forBackground(props) {
+function forBackgroundWithTranslation(props) {
   const { position, scene } = props;
   const interpolate = getSceneIndicesForInterpolationInputRange(props);
   if (!interpolate) return { opacity: 0 };
@@ -354,4 +360,5 @@ export default {
   forCenter,
   forRight,
   forBackground,
+  forBackgroundWithTranslation,
 };
diff --git a/packages/stack/src/views/StackView/StackViewLayout.js b/packages/stack/src/views/StackView/StackViewLayout.js
index e4190606..f9716e2b 100644
--- a/packages/stack/src/views/StackView/StackViewLayout.js
+++ b/packages/stack/src/views/StackView/StackViewLayout.js
@@ -151,6 +151,7 @@ class StackViewLayout extends React.Component {
       headerLeftInterpolator,
       headerTitleInterpolator,
       headerRightInterpolator,
+      headerBackgroundInterpolator,
     } = this._getTransitionConfig();
 
     const { transitionProps, ...passProps } = this.props;
@@ -168,6 +169,7 @@ class StackViewLayout extends React.Component {
           leftInterpolator: headerLeftInterpolator,
           titleInterpolator: headerTitleInterpolator,
           rightInterpolator: headerRightInterpolator,
+          backgroundInterpolator: headerBackgroundInterpolator,
         })}
       </NavigationProvider>
     );