feature: expose root viewmodel to scripting via context (#11539) 0eadaaea47

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

Author: bodymovin

.rive_head

@@ -1 +1 @@
-147fe75b6ba2592e3c8531b518433e87ab399b4c
+0eadaaea4797dfb4e6887ba05dd12774c3a7af97

include/rive/data_bind/data_context.hpp

@@ -34,6 +34,14 @@ class DataContext
     void viewModelInstance(rcp<ViewModelInstance> value);
     void advanced();
     rcp<ViewModelInstance> viewModelInstance() { return m_ViewModelInstance; };
+    rcp<ViewModelInstance> rootViewModelInstance()
+    {
+        if (m_Parent)
+        {
+            return m_Parent->rootViewModelInstance();
+        }
+        return m_ViewModelInstance;
+    };
 
     ViewModelInstanceValue* viewModelValue()
     {

include/rive/lua/rive_lua_libs.hpp

@@ -212,6 +212,7 @@ enum class LuaAtoms : int16_t
     // Scripted Context
     markNeedsUpdate,
     viewModel,
+    rootViewModel,
 
     // Animation
     duration,

src/lua/lua_scripted_context.cpp

@@ -42,6 +42,26 @@ static int context_namecall(lua_State* L)
                 }
                 return 0;
             }
+            case (int)LuaAtoms::rootViewModel:
+            {
+                auto scriptedObject = scriptedContext->scriptedObject();
+                auto dataContext = scriptedObject->dataContext();
+                if (dataContext)
+                {
+                    auto viewModelInstance =
+                        dataContext->rootViewModelInstance();
+                    if (viewModelInstance)
+                    {
+                        lua_newrive<ScriptedViewModel>(
+                            L,
+                            L,
+                            ref_rcp(viewModelInstance->viewModel()),
+                            viewModelInstance);
+                        return 1;
+                    }
+                }
+                return 0;
+            }
             default:
                 break;
         }

src/lua/rive_lua_libs.cpp

@@ -144,6 +144,7 @@ std::unordered_map<std::string, int16_t> atoms = {
     {"isClosed", (int16_t)LuaAtoms::isClosed},
     {"markNeedsUpdate", (int16_t)LuaAtoms::markNeedsUpdate},
     {"viewModel", (int16_t)LuaAtoms::viewModel},
+    {"rootViewModel", (int16_t)LuaAtoms::rootViewModel},
     {"duration", (int16_t)LuaAtoms::duration},
     {"setTime", (int16_t)LuaAtoms::setTime},
     {"setTimeFrames", (int16_t)LuaAtoms::setTimeFrames},

tests/unit_tests/assets/scripting_root_viewmodel.riv

@@ -205,3 +205,26 @@ TEST_CASE("script has access to the data bound view model", "[silver]")
 
     CHECK(silver.matches("viewmodel_from_context"));
 }
+
+TEST_CASE("script has access to the data root view model", "[silver]")
+{
+    rive::SerializingFactory silver;
+    auto file = ReadRiveFile("assets/scripting_root_viewmodel.riv", &silver);
+    auto artboard = file->artboardNamed("parent");
+
+    silver.frameSize(artboard->width(), artboard->height());
+    REQUIRE(artboard != nullptr);
+    auto stateMachine = artboard->stateMachineAt(0);
+
+    auto vmi = file->createDefaultViewModelInstance(artboard.get());
+    stateMachine->bindViewModelInstance(vmi);
+    stateMachine->advanceAndApply(0.1f);
+
+    auto renderer = silver.makeRenderer();
+    artboard->draw(renderer.get());
+    silver.addFrame();
+    stateMachine->advanceAndApply(0.1f);
+    artboard->draw(renderer.get());
+
+    CHECK(silver.matches("scripting_root_viewmodel"));
+}