From 2ac6bccb9ebd8ca541047f0884da1c7e26d9392a Mon Sep 17 00:00:00 2001
From: Luigi Rosso <luigi.rosso@gmail.com>
Date: Fri, 26 Mar 2021 14:51:28 -0700
Subject: [PATCH] Updating with latest generated code.

---
 lib/src/core/core.dart                        |  2 +-
 lib/src/core/importers/artboard_importer.dart |  2 +-
 lib/src/generated/rive_core_context.dart      |  4 --
 lib/src/rive_core/animation/keyed_object.dart | 23 +++++++-
 .../rive_core/animation/keyed_property.dart   |  1 -
 lib/src/rive_core/animation/layer_state.dart  |  3 --
 .../rive_core/animation/linear_animation.dart |  9 +++-
 .../animation/state_machine_layer.dart        | 12 ++---
 .../rive_core/animation/state_transition.dart |  4 +-
 .../rive_core/bones/skeletal_component.dart   | 12 +----
 lib/src/rive_core/bones/skin.dart             | 13 +++--
 lib/src/rive_core/bones/tendon.dart           |  6 +--
 lib/src/rive_core/component.dart              |  4 +-
 lib/src/rive_core/runtime/runtime_header.dart |  3 ++
 .../shapes/paint/linear_gradient.dart         | 11 +++-
 .../rive_core/shapes/paint/shape_paint.dart   | 13 ++++-
 lib/src/rive_core/shapes/path_composer.dart   | 54 +++++--------------
 lib/src/rive_core/shapes/shape.dart           | 28 +++++-----
 .../rive_core/state_machine_controller.dart   | 12 +++--
 lib/src/rive_file.dart                        | 11 +++-
 lib/src/runtime_artboard.dart                 |  6 +--
 21 files changed, 128 insertions(+), 105 deletions(-)

diff --git a/lib/src/core/core.dart b/lib/src/core/core.dart
index fb8e784..8635b7c 100644
--- a/lib/src/core/core.dart
+++ b/lib/src/core/core.dart
@@ -53,7 +53,7 @@ abstract class CoreContext {
   void markDependencyOrderDirty();
   bool markDependenciesDirty(covariant Core rootObject);
   void removeObject<T extends Core>(T object);
-  T addObject<T extends Core>(T object);
+  T? addObject<T extends Core>(T? object);
   void markNeedsAdvance();
   void dirty(void Function() dirt);
 }
diff --git a/lib/src/core/importers/artboard_importer.dart b/lib/src/core/importers/artboard_importer.dart
index 2757717..79c847c 100644
--- a/lib/src/core/importers/artboard_importer.dart
+++ b/lib/src/core/importers/artboard_importer.dart
@@ -9,7 +9,7 @@ class ArtboardImporter extends ImportStackObject {
   ArtboardImporter(this.artboard);
   final List<LinearAnimation> animations = [];
 
-  void addComponent(Core<CoreContext> object) => artboard.addObject(object);
+  void addComponent(Core<CoreContext>? object) => artboard.addObject(object);
 
   void addAnimation(Animation animation) {
     if (animation is LinearAnimation) {
diff --git a/lib/src/generated/rive_core_context.dart b/lib/src/generated/rive_core_context.dart
index a31c6fd..097df3d 100644
--- a/lib/src/generated/rive_core_context.dart
+++ b/lib/src/generated/rive_core_context.dart
@@ -58,7 +58,6 @@ import 'package:rive/src/generated/shapes/paint/stroke_base.dart';
 import 'package:rive/src/generated/shapes/paint/trim_path_base.dart';
 import 'package:rive/src/generated/shapes/parametric_path_base.dart';
 import 'package:rive/src/generated/shapes/path_base.dart';
-import 'package:rive/src/generated/shapes/path_composer_base.dart';
 import 'package:rive/src/generated/shapes/path_vertex_base.dart';
 import 'package:rive/src/generated/shapes/points_path_base.dart';
 import 'package:rive/src/generated/shapes/polygon_base.dart';
@@ -112,7 +111,6 @@ import 'package:rive/src/rive_core/shapes/paint/radial_gradient.dart';
 import 'package:rive/src/rive_core/shapes/paint/solid_color.dart';
 import 'package:rive/src/rive_core/shapes/paint/stroke.dart';
 import 'package:rive/src/rive_core/shapes/paint/trim_path.dart';
-import 'package:rive/src/rive_core/shapes/path_composer.dart';
 import 'package:rive/src/rive_core/shapes/points_path.dart';
 import 'package:rive/src/rive_core/shapes/polygon.dart';
 import 'package:rive/src/rive_core/shapes/rectangle.dart';
@@ -211,8 +209,6 @@ class RiveCoreContext {
         return Polygon();
       case StarBase.typeKey:
         return Star();
-      case PathComposerBase.typeKey:
-        return PathComposer();
       case CubicDetachedVertexBase.typeKey:
         return CubicDetachedVertex();
       case DrawRulesBase.typeKey:
diff --git a/lib/src/rive_core/animation/keyed_object.dart b/lib/src/rive_core/animation/keyed_object.dart
index c182738..d752b70 100644
--- a/lib/src/rive_core/animation/keyed_object.dart
+++ b/lib/src/rive_core/animation/keyed_object.dart
@@ -1,6 +1,7 @@
 import 'dart:collection';
 import 'package:rive/src/core/core.dart';
 import 'package:rive/src/rive_core/animation/keyed_property.dart';
+import 'package:rive/src/rive_core/component.dart';
 import 'package:rive/src/generated/animation/keyed_object_base.dart';
 import 'linear_animation.dart';
 export 'package:rive/src/generated/animation/keyed_object_base.dart';
@@ -10,14 +11,34 @@ class KeyedObject extends KeyedObjectBase<RuntimeArtboard> {
       HashMap<int, KeyedProperty>();
   Iterable<KeyedProperty> get keyedProperties => _keyedProperties.values;
   @override
+  void onAddedDirty() {}
+  @override
   void onAdded() {}
   @override
-  void onAddedDirty() {}
+  bool validate() {
+    if (!super.validate()) {
+      return false;
+    }
+    var component = context.resolve<Component>(objectId);
+    if (component == null) {
+      return false;
+    }
+    return true;
+  }
+
   @override
   void onRemoved() {
     super.onRemoved();
   }
 
+  bool isValidKeyedProperty(KeyedProperty property) {
+    var value = _keyedProperties[property.propertyKey];
+    if (value != null && value != property) {
+      return false;
+    }
+    return true;
+  }
+
   bool internalAddKeyedProperty(KeyedProperty property) {
     var value = _keyedProperties[property.propertyKey];
     if (value != null && value != property) {
diff --git a/lib/src/rive_core/animation/keyed_property.dart b/lib/src/rive_core/animation/keyed_property.dart
index 3d88c31..5a9cec8 100644
--- a/lib/src/rive_core/animation/keyed_property.dart
+++ b/lib/src/rive_core/animation/keyed_property.dart
@@ -84,7 +84,6 @@ class KeyedProperty extends KeyedPropertyBase<RuntimeArtboard>
   }
 
   void _sortAndValidateKeyFrames() {
-    assert(hasValidated);
     sort();
     for (int i = 0; i < _keyframes.length - 1; i++) {
       var a = _keyframes[i];
diff --git a/lib/src/rive_core/animation/layer_state.dart b/lib/src/rive_core/animation/layer_state.dart
index 7f81f87..324c175 100644
--- a/lib/src/rive_core/animation/layer_state.dart
+++ b/lib/src/rive_core/animation/layer_state.dart
@@ -4,12 +4,9 @@ import 'package:rive/src/rive_core/animation/state_transition.dart';
 import 'package:rive/src/generated/animation/layer_state_base.dart';
 export 'package:rive/src/generated/animation/layer_state_base.dart';
 
-class _UnknownLayerState extends LayerState {}
-
 abstract class LayerState extends LayerStateBase {
   final Set<StateTransition> _transitions = {};
   Iterable<StateTransition> get transitions => _transitions;
-  static final LayerState unknown = _UnknownLayerState();
   @override
   void onAdded() {}
   @override
diff --git a/lib/src/rive_core/animation/linear_animation.dart b/lib/src/rive_core/animation/linear_animation.dart
index d912250..9c6c239 100644
--- a/lib/src/rive_core/animation/linear_animation.dart
+++ b/lib/src/rive_core/animation/linear_animation.dart
@@ -10,11 +10,18 @@ class LinearAnimation extends LinearAnimationBase {
   final _keyedObjects = HashMap<int, KeyedObject>();
   Iterable<KeyedObject> get keyedObjects => _keyedObjects.values;
   bool internalAddKeyedObject(KeyedObject object) {
+    if (internalCheckAddKeyedObject(object)) {
+      _keyedObjects[object.objectId] = object;
+      return true;
+    }
+    return false;
+  }
+
+  bool internalCheckAddKeyedObject(KeyedObject object) {
     var value = _keyedObjects[object.objectId];
     if (value != null && value != object) {
       return false;
     }
-    _keyedObjects[object.objectId] = object;
     return true;
   }
 
diff --git a/lib/src/rive_core/animation/state_machine_layer.dart b/lib/src/rive_core/animation/state_machine_layer.dart
index 7c7f3a0..f9caa2c 100644
--- a/lib/src/rive_core/animation/state_machine_layer.dart
+++ b/lib/src/rive_core/animation/state_machine_layer.dart
@@ -10,12 +10,12 @@ import 'package:rive/src/generated/animation/state_machine_layer_base.dart';
 export 'package:rive/src/generated/animation/state_machine_layer_base.dart';
 
 class StateMachineLayer extends StateMachineLayerBase {
-  LayerState _entryState = LayerState.unknown;
-  LayerState _anyState = LayerState.unknown;
-  LayerState _exitState = LayerState.unknown;
-  LayerState get entryState => _entryState;
-  LayerState get anyState => _anyState;
-  LayerState get exitState => _exitState;
+  LayerState? _entryState;
+  LayerState? _anyState;
+  LayerState? _exitState;
+  LayerState? get entryState => _entryState;
+  LayerState? get anyState => _anyState;
+  LayerState? get exitState => _exitState;
   @override
   ListBase<StateMachineComponent> machineComponentList(StateMachine machine) =>
       machine.layers;
diff --git a/lib/src/rive_core/animation/state_transition.dart b/lib/src/rive_core/animation/state_transition.dart
index 32c5e12..10a5ba0 100644
--- a/lib/src/rive_core/animation/state_transition.dart
+++ b/lib/src/rive_core/animation/state_transition.dart
@@ -7,11 +7,11 @@ export 'package:rive/src/generated/animation/state_transition_base.dart';
 
 class StateTransition extends StateTransitionBase {
   final StateTransitionConditions conditions = StateTransitionConditions();
-  LayerState stateTo = LayerState.unknown;
+  LayerState? stateTo;
   static final StateTransition unknown = StateTransition();
   @override
   bool validate() {
-    return super.validate() && stateTo != LayerState.unknown;
+    return super.validate() && stateTo != null;
   }
 
   @override
diff --git a/lib/src/rive_core/bones/skeletal_component.dart b/lib/src/rive_core/bones/skeletal_component.dart
index 531e709..159005e 100644
--- a/lib/src/rive_core/bones/skeletal_component.dart
+++ b/lib/src/rive_core/bones/skeletal_component.dart
@@ -1,14 +1,4 @@
 import 'package:rive/src/generated/bones/skeletal_component_base.dart';
 export 'package:rive/src/generated/bones/skeletal_component_base.dart';
 
-class _UnknownSkeletalComponent extends SkeletalComponent {
-  @override
-  double x = 0;
-  @override
-  double y = 0;
-}
-
-// ignore: avoid_classes_with_only_static_members
-abstract class SkeletalComponent extends SkeletalComponentBase {
-  static final SkeletalComponent unknown = _UnknownSkeletalComponent();
-}
+abstract class SkeletalComponent extends SkeletalComponentBase {}
diff --git a/lib/src/rive_core/bones/skin.dart b/lib/src/rive_core/bones/skin.dart
index a16bab5..1f8fba6 100644
--- a/lib/src/rive_core/bones/skin.dart
+++ b/lib/src/rive_core/bones/skin.dart
@@ -32,7 +32,10 @@ class Skin extends SkinBase {
     var temp = Mat2D();
     var bidx = 6;
     for (final tendon in _tendons) {
-      var boneWorld = tendon.bone.worldTransform;
+      if (tendon.bone == null) {
+        continue;
+      }
+      var boneWorld = tendon.bone!.worldTransform;
       var wt = Mat2D.multiply(temp, boneWorld, tendon.inverseBind);
       _boneTransforms[bidx++] = wt[0];
       _boneTransforms[bidx++] = wt[1];
@@ -77,7 +80,7 @@ class Skin extends SkinBase {
   void buildDependencies() {
     super.buildDependencies();
     for (final tendon in _tendons) {
-      tendon.bone.addDependent(this);
+      tendon.bone?.addDependent(this);
     }
   }
 
@@ -88,7 +91,9 @@ class Skin extends SkinBase {
       case TendonBase.typeKey:
         _tendons.add(child as Tendon);
         markRebuildDependencies();
-        parent!.markRebuildDependencies();
+        if (parent is Skinnable) {
+          parent!.markRebuildDependencies();
+        }
         break;
     }
   }
@@ -104,7 +109,7 @@ class Skin extends SkinBase {
         } else {
           markRebuildDependencies();
         }
-        parent!.markRebuildDependencies();
+        parent?.markRebuildDependencies();
         break;
     }
   }
diff --git a/lib/src/rive_core/bones/tendon.dart b/lib/src/rive_core/bones/tendon.dart
index b332714..05466a1 100644
--- a/lib/src/rive_core/bones/tendon.dart
+++ b/lib/src/rive_core/bones/tendon.dart
@@ -6,8 +6,8 @@ export 'package:rive/src/generated/bones/tendon_base.dart';
 class Tendon extends TendonBase {
   final Mat2D _bind = Mat2D();
   Mat2D? _inverseBind;
-  SkeletalComponent _bone = SkeletalComponent.unknown;
-  SkeletalComponent get bone => _bone;
+  SkeletalComponent? _bone;
+  SkeletalComponent? get bone => _bone;
   Mat2D get inverseBind {
     if (_inverseBind == null) {
       _inverseBind = Mat2D();
@@ -21,7 +21,7 @@ class Tendon extends TendonBase {
   @override
   void onAddedDirty() {
     super.onAddedDirty();
-    _bone = context.resolveWithDefault(boneId, SkeletalComponent.unknown);
+    _bone = context.resolve(boneId);
     _bind[0] = xx;
     _bind[1] = xy;
     _bind[2] = yx;
diff --git a/lib/src/rive_core/component.dart b/lib/src/rive_core/component.dart
index e9b6170..abe65ef 100644
--- a/lib/src/rive_core/component.dart
+++ b/lib/src/rive_core/component.dart
@@ -135,7 +135,9 @@ abstract class Component extends ComponentBase<RuntimeArtboard>
   void onAdded() {}
   @override
   void onAddedDirty() {
-    parent = context.resolve(parentId);
+    if (parentId != Core.missingId) {
+      parent = context.resolve(parentId);
+    }
   }
 
   @override
diff --git a/lib/src/rive_core/runtime/runtime_header.dart b/lib/src/rive_core/runtime/runtime_header.dart
index 0eefc8b..b5c6565 100644
--- a/lib/src/rive_core/runtime/runtime_header.dart
+++ b/lib/src/rive_core/runtime/runtime_header.dart
@@ -36,6 +36,9 @@ class RuntimeHeader {
       throw RiveUnsupportedVersionException(riveVersion.major,
           riveVersion.minor, readMajorVersion, readMinorVersion);
     }
+    if (readMajorVersion == 6) {
+      reader.readVarUint();
+    }
     int fileId = reader.readVarUint();
     var propertyFields = HashMap<int, int>();
     var propertyKeys = <int>[];
diff --git a/lib/src/rive_core/shapes/paint/linear_gradient.dart b/lib/src/rive_core/shapes/paint/linear_gradient.dart
index c9d73a2..28535de 100644
--- a/lib/src/rive_core/shapes/paint/linear_gradient.dart
+++ b/lib/src/rive_core/shapes/paint/linear_gradient.dart
@@ -105,6 +105,12 @@ class LinearGradient extends LinearGradientBase with ShapePaintMutator {
     addDirt(ComponentDirt.transform);
   }
 
+  @override
+  void onAdded() {
+    super.onAdded();
+    syncColor();
+  }
+
   @override
   void opacityChanged(double from, double to) {
     syncColor();
@@ -118,5 +124,8 @@ class LinearGradient extends LinearGradientBase with ShapePaintMutator {
   }
 
   @override
-  bool validate() => super.validate() && shapePaintContainer != null;
+  bool validate() {
+    print("${super.validate()} $shapePaintContainer");
+    return super.validate() && shapePaintContainer != null;
+  }
 }
diff --git a/lib/src/rive_core/shapes/paint/shape_paint.dart b/lib/src/rive_core/shapes/paint/shape_paint.dart
index 9524930..c5b0ea4 100644
--- a/lib/src/rive_core/shapes/paint/shape_paint.dart
+++ b/lib/src/rive_core/shapes/paint/shape_paint.dart
@@ -2,6 +2,7 @@ import 'dart:ui';
 import 'package:meta/meta.dart';
 import 'package:rive/src/rive_core/component.dart';
 import 'package:rive/src/rive_core/component_dirt.dart';
+import 'package:rive/src/rive_core/container_component.dart';
 import 'package:rive/src/rive_core/shapes/paint/shape_paint_mutator.dart';
 import 'package:rive/src/rive_core/shapes/shape_paint_container.dart';
 import 'package:rive/src/generated/shapes/paint/shape_paint_base.dart';
@@ -12,7 +13,7 @@ abstract class ShapePaint extends ShapePaintBase {
   Paint get paint => _paint;
   ShapePaintMutator? _paintMutator;
   ShapePaintContainer? get shapePaintContainer =>
-      parent as ShapePaintContainer?;
+      parent is ShapePaintContainer ? parent as ShapePaintContainer : null;
   ShapePaint() {
     _paint = makePaint();
   }
@@ -33,6 +34,16 @@ abstract class ShapePaint extends ShapePaintBase {
     super.childAdded(child);
     if (child is ShapePaintMutator) {
       _changeMutator(child as ShapePaintMutator);
+      if (shapePaintContainer != null) {
+        _initMutator();
+      }
+    }
+  }
+
+  @override
+  void parentChanged(ContainerComponent? from, ContainerComponent? to) {
+    super.parentChanged(from, to);
+    if (shapePaintContainer != null) {
       _initMutator();
     }
   }
diff --git a/lib/src/rive_core/shapes/path_composer.dart b/lib/src/rive_core/shapes/path_composer.dart
index c7ea7cb..59e31c5 100644
--- a/lib/src/rive_core/shapes/path_composer.dart
+++ b/lib/src/rive_core/shapes/path_composer.dart
@@ -1,39 +1,28 @@
 import 'dart:ui' as ui;
+import 'package:rive/src/rive_core/artboard.dart';
 import 'package:rive/src/rive_core/component.dart';
 import 'package:rive/src/rive_core/component_dirt.dart';
 import 'package:rive/src/rive_core/math/mat2d.dart';
 import 'package:rive/src/rive_core/shapes/shape.dart';
-import 'package:rive/src/generated/shapes/path_composer_base.dart';
 
-class PathComposer extends PathComposerBase {
-  static final PathComposer unknown = PathComposer();
-  Shape? _shape;
-  Shape? get shape => _shape;
+class PathComposer extends Component {
+  final Shape shape;
+  PathComposer(this.shape);
+  @override
+  Artboard? get artboard => shape.artboard;
   final ui.Path worldPath = ui.Path();
   final ui.Path localPath = ui.Path();
   ui.Path _fillPath = ui.Path();
   ui.Path get fillPath => _fillPath;
-  void _changeShape(Shape? value) {
-    if (value == _shape) {
-      return;
-    }
-    if (_shape != null && _shape!.pathComposer == this) {
-      _shape!.pathComposer = PathComposer.unknown;
-    }
-    value?.pathComposer = this;
-    _shape = value;
-  }
-
   void _recomputePath() {
-    assert(_shape != null);
-    var buildLocalPath = _shape!.wantLocalPath;
-    var buildWorldPath = _shape!.wantWorldPath || !buildLocalPath;
+    var buildLocalPath = shape.wantLocalPath;
+    var buildWorldPath = shape.wantWorldPath || !buildLocalPath;
     if (buildLocalPath) {
       localPath.reset();
-      var world = _shape!.worldTransform;
+      var world = shape.worldTransform;
       Mat2D inverseWorld = Mat2D();
       if (Mat2D.invert(inverseWorld, world)) {
-        for (final path in _shape!.paths) {
+        for (final path in shape.paths) {
           if (path.isHidden) {
             continue;
           }
@@ -46,7 +35,7 @@ class PathComposer extends PathComposerBase {
     }
     if (buildWorldPath) {
       worldPath.reset();
-      for (final path in _shape!.paths) {
+      for (final path in shape.paths) {
         if (path.isHidden) {
           continue;
         }
@@ -54,15 +43,14 @@ class PathComposer extends PathComposerBase {
             matrix4: path.pathTransform.mat4);
       }
     }
-    _fillPath = _shape!.fillInWorld ? worldPath : localPath;
+    _fillPath = shape.fillInWorld ? worldPath : localPath;
   }
 
   @override
   void buildDependencies() {
-    assert(_shape != null);
     super.buildDependencies();
-    _shape!.addDependent(this);
-    for (final path in _shape!.paths) {
+    shape.addDependent(this);
+    for (final path in shape.paths) {
       path.addDependent(this);
     }
   }
@@ -73,18 +61,4 @@ class PathComposer extends PathComposerBase {
       _recomputePath();
     }
   }
-
-  @override
-  bool resolveArtboard() {
-    _changeShape(null);
-    return super.resolveArtboard();
-  }
-
-  @override
-  void visitAncestor(Component ancestor) {
-    super.visitAncestor(ancestor);
-    if (_shape == null && ancestor is Shape) {
-      _changeShape(ancestor);
-    }
-  }
 }
diff --git a/lib/src/rive_core/shapes/shape.dart b/lib/src/rive_core/shapes/shape.dart
index e92a5af..f1c9231 100644
--- a/lib/src/rive_core/shapes/shape.dart
+++ b/lib/src/rive_core/shapes/shape.dart
@@ -18,24 +18,18 @@ class Shape extends ShapeBase with ShapePaintContainer {
   bool get wantLocalPath => _wantLocalPath;
   bool _fillInWorld = false;
   bool get fillInWorld => _fillInWorld;
-  PathComposer _pathComposer = PathComposer.unknown;
-  PathComposer get pathComposer => _pathComposer;
-  set pathComposer(PathComposer value) {
-    if (_pathComposer == value) {
-      return;
-    }
-    _pathComposer = value;
-    paintChanged();
+  late PathComposer pathComposer;
+  Shape() {
+    pathComposer = PathComposer(this);
   }
-
-  ui.Path get fillPath => _pathComposer.fillPath;
+  ui.Path get fillPath => pathComposer.fillPath;
   bool addPath(Path path) {
     paintChanged();
     return paths.add(path);
   }
 
   void _markComposerDirty() {
-    _pathComposer.addDirt(ComponentDirt.path, recurse: true);
+    pathComposer.addDirt(ComponentDirt.path, recurse: true);
     invalidateStrokeEffects();
   }
 
@@ -123,9 +117,8 @@ class Shape extends ShapeBase with ShapePaintContainer {
   void blendModeValueChanged(int from, int to) => _markBlendModeDirty();
   @override
   void draw(ui.Canvas canvas) {
-    assert(_pathComposer != PathComposer.unknown);
     bool clipped = clip(canvas);
-    var path = _pathComposer.fillPath;
+    var path = pathComposer.fillPath;
     if (!_fillInWorld) {
       canvas.save();
       canvas.transform(worldTransform.mat4);
@@ -139,8 +132,8 @@ class Shape extends ShapeBase with ShapePaintContainer {
     for (final stroke in strokes) {
       var transformAffectsStroke = stroke.transformAffectsStroke;
       var path = transformAffectsStroke
-          ? _pathComposer.localPath
-          : _pathComposer.worldPath;
+          ? pathComposer.localPath
+          : pathComposer.worldPath;
       if (transformAffectsStroke) {
         canvas.save();
         canvas.transform(worldTransform.mat4);
@@ -166,4 +159,9 @@ class Shape extends ShapeBase with ShapePaintContainer {
   void onStrokesChanged() => paintChanged();
   @override
   void onFillsChanged() => paintChanged();
+  @override
+  void buildDependencies() {
+    super.buildDependencies();
+    pathComposer.buildDependencies();
+  }
 }
diff --git a/lib/src/rive_core/state_machine_controller.dart b/lib/src/rive_core/state_machine_controller.dart
index b32d2bb..16d7c5c 100644
--- a/lib/src/rive_core/state_machine_controller.dart
+++ b/lib/src/rive_core/state_machine_controller.dart
@@ -10,7 +10,7 @@ import 'package:rive/src/rive_core/rive_animation_controller.dart';
 
 class LayerController {
   final StateMachineLayer layer;
-  LayerState _currentState = LayerState.unknown;
+  LayerState? _currentState;
   LinearAnimationInstance? _animationInstanceFrom;
   StateTransition? _transition;
   double _mix = 1.0;
@@ -18,7 +18,7 @@ class LayerController {
   LayerController(this.layer) {
     _changeState(layer.entryState);
   }
-  bool _changeState(LayerState state) {
+  bool _changeState(LayerState? state) {
     if (state == _currentState) {
       return false;
     }
@@ -27,7 +27,7 @@ class LayerController {
   }
 
   void dispose() {
-    _changeState(LayerState.unknown);
+    _changeState(null);
   }
 
   bool apply(CoreContext core, double elapsedSeconds,
@@ -71,7 +71,11 @@ class LayerController {
     return tryChangeState(_currentState, inputValues);
   }
 
-  bool tryChangeState(LayerState stateFrom, HashMap<int, dynamic> inputValues) {
+  bool tryChangeState(
+      LayerState? stateFrom, HashMap<int, dynamic> inputValues) {
+    if (stateFrom == null) {
+      return false;
+    }
     for (final transition in stateFrom.transitions) {
       bool valid = true;
       for (final condition in transition.conditions) {
diff --git a/lib/src/rive_file.dart b/lib/src/rive_file.dart
index 6eb2a89..3018e32 100644
--- a/lib/src/rive_file.dart
+++ b/lib/src/rive_file.dart
@@ -102,6 +102,13 @@ class RiveFile {
     while (!reader.isEOF) {
       final object = _readRuntimeObject(reader, propertyToField);
       if (object == null) {
+        // See if there's an artboard on the stack, need to track the null
+        // object as it'll still hold an id.
+        var artboardImporter =
+            importStack.latest<ArtboardImporter>(ArtboardBase.typeKey);
+        if (artboardImporter != null) {
+          artboardImporter.addComponent(null);
+        }
         continue;
       }
 
@@ -191,8 +198,8 @@ class RiveFile {
 
     for (final artboard in _artboards) {
       var runtimeArtboard = artboard as RuntimeArtboard;
-      for (final object in runtimeArtboard.objects) {
-        if (object != null && object.validate()) {
+      for (final object in runtimeArtboard.objects.whereNotNull()) {
+        if (object.validate()) {
           InternalCoreHelper.markValid(object);
         } else {
           throw RiveFormatErrorException(
diff --git a/lib/src/runtime_artboard.dart b/lib/src/runtime_artboard.dart
index 5acfda0..969d5ce 100644
--- a/lib/src/runtime_artboard.dart
+++ b/lib/src/runtime_artboard.dart
@@ -19,9 +19,9 @@ class RuntimeArtboard extends Artboard implements CoreContext {
   final Set<Component> _needDependenciesBuilt = {};
 
   @override
-  T addObject<T extends Core>(T object) {
-    object.context = this;
-    object.id = _objects.length;
+  T? addObject<T extends Core>(T? object) {
+    object?.context = this;
+    object?.id = _objects.length;
 
     _objects.add(object);
     return object;