use shared data context between artboard and state machine

this PR changes multiple files addressing three things:
the first two are pretty basic changes: rename the method `dataContextFromInstance` to `setDataContextFromInstance` and remove the side effect of setting the parent of the data context in `internalDataContext`.
The other change is commented in the code: instead of creating a new data context for nested state machines, it is shared between the nested artboard and its state machines. This was already so in the cpp runtime, but the flutter bridge wasn't doing the same.

Diffs=
eed8230f8 use shared data context between artboard and state machine (#8299)

Co-authored-by: hernan <hernan@rive.app>

.rive_head

@@ -1 +1 @@
-56d95d2006868350ebb0c080447d07647d1a5855
+eed8230f84e2894d0436dd1d94566c59f4dfcb6f

include/rive/animation/nested_state_machine.hpp

@@ -36,7 +36,7 @@ class NestedStateMachine : public NestedStateMachineBase
     size_t inputCount() { return m_nestedInputs.size(); }
     NestedInput* input(size_t index);
     NestedInput* input(std::string name);
-    void dataContextFromInstance(ViewModelInstance* viewModelInstance);
+    void setDataContextFromInstance(ViewModelInstance* viewModelInstance);
     void dataContext(DataContext* dataContext);
 };
 } // namespace rive

include/rive/animation/state_machine_instance.hpp

@@ -84,7 +84,7 @@ class StateMachineInstance : public Scene, public NestedEventNotifier, public Ne
     SMIBool* getBool(const std::string& name) const override;
     SMINumber* getNumber(const std::string& name) const override;
     SMITrigger* getTrigger(const std::string& name) const override;
-    void dataContextFromInstance(ViewModelInstance* viewModelInstance) override;
+    void setDataContextFromInstance(ViewModelInstance* viewModelInstance) override;
     void dataContext(DataContext* dataContext);
 
     size_t currentAnimationCount() const;

include/rive/artboard.hpp

@@ -181,14 +181,14 @@ class Artboard : public ArtboardBase, public CoreContext
     bool isTranslucent() const;
     bool isTranslucent(const LinearAnimation*) const;
     bool isTranslucent(const LinearAnimationInstance*) const;
-    void dataContext(DataContext* dataContext, DataContext* parent);
-    void internalDataContext(DataContext* dataContext, DataContext* parent, bool isRoot);
+    void dataContext(DataContext* dataContext);
+    void internalDataContext(DataContext* dataContext, bool isRoot);
     void clearDataContext();
-    void dataContextFromInstance(ViewModelInstance* viewModelInstance, DataContext* parent);
-    void dataContextFromInstance(ViewModelInstance* viewModelInstance,
-                                 DataContext* parent,
-                                 bool isRoot);
-    void dataContextFromInstance(ViewModelInstance* viewModelInstance);
+    void setDataContextFromInstance(ViewModelInstance* viewModelInstance, DataContext* parent);
+    void setDataContextFromInstance(ViewModelInstance* viewModelInstance,
+                                    DataContext* parent,
+                                    bool isRoot);
+    void setDataContextFromInstance(ViewModelInstance* viewModelInstance);
     void addDataBind(DataBind* dataBind);
     void populateDataBinds(std::vector<DataBind*>* dataBinds);
     void sortDataBinds(std::vector<DataBind*> dataBinds);

include/rive/nested_artboard.hpp

@@ -64,8 +64,8 @@ class NestedArtboard : public NestedArtboardBase
     void decodeDataBindPathIds(Span<const uint8_t> value) override;
     void copyDataBindPathIds(const NestedArtboardBase& object) override;
     std::vector<uint32_t> dataBindPathIds() { return m_DataBindPathIdsBuffer; };
-    void dataContextFromInstance(ViewModelInstance* viewModelInstance, DataContext* parent);
-    void internalDataContext(DataContext* dataContext, DataContext* parent);
+    void setDataContextFromInstance(ViewModelInstance* viewModelInstance, DataContext* parent);
+    void internalDataContext(DataContext* dataContext);
     void clearDataContext();
 };
 } // namespace rive

include/rive/scene.hpp

@@ -48,7 +48,7 @@ class Scene : public KeyedCallbackReporter, public CallbackContext
 
     void draw(Renderer*);
 
-    virtual void dataContextFromInstance(ViewModelInstance* viewModelInstance);
+    virtual void setDataContextFromInstance(ViewModelInstance* viewModelInstance);
 
     virtual HitResult pointerDown(Vec2D);
     virtual HitResult pointerMove(Vec2D);

src/animation/nested_state_machine.cpp

@@ -109,11 +109,11 @@ NestedInput* NestedStateMachine::input(std::string name)
 
 void NestedStateMachine::addNestedInput(NestedInput* input) { m_nestedInputs.push_back(input); }
 
-void NestedStateMachine::dataContextFromInstance(ViewModelInstance* viewModelInstance)
+void NestedStateMachine::setDataContextFromInstance(ViewModelInstance* viewModelInstance)
 {
     if (m_StateMachineInstance != nullptr)
     {
-        m_StateMachineInstance->dataContextFromInstance(viewModelInstance);
+        m_StateMachineInstance->setDataContextFromInstance(viewModelInstance);
     }
 }
 

src/animation/state_machine_instance.cpp

@@ -1137,7 +1137,7 @@ SMITrigger* StateMachineInstance::getTrigger(const std::string& name) const
     return getNamedInput<StateMachineTrigger, SMITrigger>(name);
 }
 
-void StateMachineInstance::dataContextFromInstance(ViewModelInstance* viewModelInstance)
+void StateMachineInstance::setDataContextFromInstance(ViewModelInstance* viewModelInstance)
 {
     dataContext(new DataContext(viewModelInstance));
 }

src/artboard.cpp

@@ -1173,10 +1173,9 @@ StatusCode Artboard::import(ImportStack& importStack)
     return result;
 }
 
-void Artboard::internalDataContext(DataContext* value, DataContext* parent, bool isRoot)
+void Artboard::internalDataContext(DataContext* value, bool isRoot)
 {
     m_DataContext = value;
-    m_DataContext->parent(parent);
     for (auto nestedArtboard : m_NestedArtboards)
     {
         if (nestedArtboard->artboardInstance() == nullptr)
@@ -1186,11 +1185,11 @@ void Artboard::internalDataContext(DataContext* value, DataContext* parent, bool
         auto value = m_DataContext->getViewModelInstance(nestedArtboard->dataBindPathIds());
         if (value != nullptr && value->is<ViewModelInstance>())
         {
-            nestedArtboard->dataContextFromInstance(value, m_DataContext);
+            nestedArtboard->setDataContextFromInstance(value, m_DataContext);
         }
         else
         {
-            nestedArtboard->internalDataContext(m_DataContext, m_DataContext->parent());
+            nestedArtboard->internalDataContext(m_DataContext);
         }
     }
     for (auto dataBind : m_DataBinds)
@@ -1271,24 +1270,21 @@ void Artboard::collectDataBinds()
 
 void Artboard::addDataBind(DataBind* dataBind) { m_DataBinds.push_back(dataBind); }
 
-void Artboard::dataContext(DataContext* value, DataContext* parent)
-{
-    internalDataContext(value, parent, true);
-}
+void Artboard::dataContext(DataContext* value) { internalDataContext(value, true); }
 
-void Artboard::dataContextFromInstance(ViewModelInstance* viewModelInstance)
+void Artboard::setDataContextFromInstance(ViewModelInstance* viewModelInstance)
 {
-    dataContextFromInstance(viewModelInstance, nullptr, true);
+    setDataContextFromInstance(viewModelInstance, nullptr, true);
 }
 
-void Artboard::dataContextFromInstance(ViewModelInstance* viewModelInstance, DataContext* parent)
+void Artboard::setDataContextFromInstance(ViewModelInstance* viewModelInstance, DataContext* parent)
 {
-    dataContextFromInstance(viewModelInstance, parent, true);
+    setDataContextFromInstance(viewModelInstance, parent, true);
 }
 
-void Artboard::dataContextFromInstance(ViewModelInstance* viewModelInstance,
-                                       DataContext* parent,
-                                       bool isRoot)
+void Artboard::setDataContextFromInstance(ViewModelInstance* viewModelInstance,
+                                          DataContext* parent,
+                                          bool isRoot)
 {
     if (viewModelInstance == nullptr)
     {
@@ -1298,7 +1294,9 @@ void Artboard::dataContextFromInstance(ViewModelInstance* viewModelInstance,
     {
         viewModelInstance->setAsRoot();
     }
-    internalDataContext(new DataContext(viewModelInstance), parent, isRoot);
+    auto dataContext = new DataContext(viewModelInstance);
+    dataContext->parent(parent);
+    internalDataContext(dataContext, isRoot);
 }
 
 ////////// ArtboardInstance

src/data_bind/context/context_value_list.cpp

@@ -22,7 +22,7 @@ std::unique_ptr<ArtboardInstance> DataBindContextValueList::createArtboard(
         auto dataContext = mainArtboard->dataContext();
         auto artboardCopy = artboard->instance();
         artboardCopy->advanceInternal(0.0f, false);
-        artboardCopy->dataContextFromInstance(listItem->viewModelInstance(), dataContext, false);
+        artboardCopy->setDataContextFromInstance(listItem->viewModelInstance(), dataContext, false);
         return artboardCopy;
     }
     return nullptr;

src/nested_artboard.cpp

@@ -276,9 +276,9 @@ void NestedArtboard::copyDataBindPathIds(const NestedArtboardBase& object)
     m_DataBindPathIdsBuffer = object.as<NestedArtboard>()->m_DataBindPathIdsBuffer;
 }
 
-void NestedArtboard::internalDataContext(DataContext* value, DataContext* parent)
+void NestedArtboard::internalDataContext(DataContext* value)
 {
-    artboardInstance()->internalDataContext(value, parent, false);
+    artboardInstance()->internalDataContext(value, false);
     for (auto animation : m_NestedAnimations)
     {
         if (animation->is<NestedStateMachine>())
@@ -290,10 +290,10 @@ void NestedArtboard::internalDataContext(DataContext* value, DataContext* parent
 
 void NestedArtboard::clearDataContext() { artboardInstance()->clearDataContext(); }
 
-void NestedArtboard::dataContextFromInstance(ViewModelInstance* viewModelInstance,
-                                             DataContext* parent)
+void NestedArtboard::setDataContextFromInstance(ViewModelInstance* viewModelInstance,
+                                                DataContext* parent)
 {
-    artboardInstance()->dataContextFromInstance(viewModelInstance, parent, false);
+    artboardInstance()->setDataContextFromInstance(viewModelInstance, parent, false);
     for (auto animation : m_NestedAnimations)
     {
         if (animation->is<NestedStateMachine>())

src/scene.cpp

@@ -25,7 +25,7 @@ SMIInput* Scene::input(size_t index) const { return nullptr; }
 SMIBool* Scene::getBool(const std::string&) const { return nullptr; }
 SMINumber* Scene::getNumber(const std::string&) const { return nullptr; }
 SMITrigger* Scene::getTrigger(const std::string&) const { return nullptr; }
-void Scene::dataContextFromInstance(ViewModelInstance* viewModelInstance) {}
+void Scene::setDataContextFromInstance(ViewModelInstance* viewModelInstance) {}
 
 void Scene::reportKeyedCallback(uint32_t objectId, uint32_t propertyKey, float elapsedSeconds)
 {

viewer/src/viewer_content/scene_content.cpp

@@ -88,7 +88,7 @@ class SceneContent : public ViewerContent
         m_ArtboardInstance = m_File->artboardAt(m_ArtboardIndex);
         // m_ViewModelInstance = m_File->viewModelInstanceNamed("vm-3");
         m_ViewModelInstance = m_File->createViewModelInstance(m_ArtboardInstance.get());
-        m_ArtboardInstance->dataContextFromInstance(m_ViewModelInstance);
+        m_ArtboardInstance->setDataContextFromInstance(m_ViewModelInstance);
 
         m_ArtboardInstance->advance(0.0f);
         loadNames(m_ArtboardInstance.get());