Fixed bug when popping.

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## [1.2.0+1] - 2019-08-26
+
+### Fixes
+- Fixed a bug where `MorpheusPageRoute` couldn't re-use the existing `RenderBox` and would throw an exception when popping a layer in the navigation stack.
+
 ## [1.2.0] - 2019-08-26
 
 ### Added

lib/page_routes/morpheus_page_route.dart

@@ -61,16 +61,31 @@ class MorpheusPageRoute<T> extends PageRoute<T> {
   /// This only affects bidirectional transitions.
   final bool scaleChild;
 
-  RenderBox _renderBox() {
+  /// Returns a [RenderBox] from a [GlobalKey] if one is provided, either
+  /// through the [parentKey] parameter or [settings.arguments].
+  ///
+  /// If no [GlobalKey] is provided, this method returns null.
+  RenderBox _getRenderBox() {
+    // Return the stored [RenderBox] if it exists.
+    if (_renderBox != null) return _renderBox;
+
     final arguments = settings.arguments as MorpheusRouteArguments;
     final key = parentKey ?? arguments?.parentKey;
 
     // Return null if [key] is null.
     if (key == null) return null;
 
-    return key.currentContext.findRenderObject();
+    // Get the [RenderBox].
+    final renderBox = key.currentContext.findRenderObject();
+
+    // Store the [RenderBox] for later.
+    _renderBox = renderBox;
+
+    return renderBox;
   }
 
+  RenderBox _renderBox;
+
   @override
   final Duration transitionDuration;
 
@@ -119,7 +134,7 @@ class MorpheusPageRoute<T> extends PageRoute<T> {
 
     // Return page transition.
     return MorpheusPageTransition(
-      renderBox: _renderBox(),
+      renderBox: _getRenderBox(),
       context: context,
       animation: animation,
       secondaryAnimation: secondaryAnimation,

pubspec.yaml

@@ -1,6 +1,6 @@
 name: morpheus
 description: A Flutter package for easily implementing Material Design navigation transitions.
-version: 1.2.0
+version: 1.2.0+1
 author: Sander Dalby Larsen <[email protected]>
 homepage: https://github.com/salby/morpheus