WIP: Add basic delete implementation for component prims

lib/usdUfe/ufe/UsdUndoDeleteCommand.cpp

@@ -30,6 +30,90 @@
 #include <usdUfe/ufe/UsdAttributes.h>
 #endif
 
+#include <ufe/pathString.h>
+
+namespace {
+
+// Validate that a prim can be deleted in a component stage.
+// Components only allow deleting prims whose path is contained within
+// either the material or geometry scope
+void validateComponentDelete(const PXR_NS::UsdPrim& prim)
+{
+    const PXR_NS::UsdStagePtr stage = prim.GetStage();
+    if (!stage) {
+        return;
+    }
+
+    // Get the prim path
+    const PXR_NS::SdfPath primPath = prim.GetPath();
+
+    // Get the default prim to construct full scope paths
+    auto defaultPrim = stage->GetDefaultPrim();
+    if (!defaultPrim) {
+        return;
+    }
+    const PXR_NS::SdfPath defaultPrimPath = defaultPrim.GetPath();
+
+    // Don't allow deleting the default prim itself
+    if (primPath == defaultPrimPath) {
+        const std::string error = PXR_NS::TfStringPrintf(
+            "Cannot delete prim \"%s\" in a component stage. "
+            "This is the default prim.",
+            primPath.GetText());
+        TF_WARN("%s", error.c_str());
+        throw std::runtime_error(error);
+    }
+
+    // Get material and mesh scope names from component
+    std::string materialScopeName = UsdUfe::getComponentMaterialScopeName(stage);
+    std::string meshScopeName     = UsdUfe::getComponentMeshScopeName(stage);
+
+    // Build full scope paths
+    std::vector<PXR_NS::SdfPath> scopePaths;
+    if (!materialScopeName.empty()) {
+        scopePaths.push_back(defaultPrimPath.AppendChild(PXR_NS::TfToken(materialScopeName)));
+    }
+    if (!meshScopeName.empty()) {
+        scopePaths.push_back(defaultPrimPath.AppendChild(PXR_NS::TfToken(meshScopeName)));
+    }
+
+    // Don't allow deleting the scope prims themselves
+    for (const PXR_NS::SdfPath& scopePath : scopePaths) {
+        if (primPath == scopePath) {
+            const std::string error = PXR_NS::TfStringPrintf(
+                "Cannot delete prim \"%s\" in a component stage. "
+                "This is a protected scope.",
+                primPath.GetText());
+            TF_WARN("%s", error.c_str());
+            throw std::runtime_error(error);
+        }
+    }
+
+    // Check if the prim path is contained within any of the scope paths
+    bool isInScope = false;
+    for (const PXR_NS::SdfPath& scopePath : scopePaths) {
+        if (primPath.HasPrefix(scopePath)) {
+            isInScope = true;
+            break;
+        }
+    }
+
+    // Allow if prim is within a component scope
+    if (isInScope) {
+        return;
+    }
+
+    // Disallow - prim is not in component scopes
+    const std::string error = PXR_NS::TfStringPrintf(
+        "Cannot delete prim \"%s\" in a component stage. "
+        "Only prims within component material or mesh scopes can be deleted. ",
+        primPath.GetText());
+    TF_WARN("%s", error.c_str());
+    throw std::runtime_error(error);
+}
+
+} // namespace
+
 namespace USDUFE_NS_DEF {
 
 USDUFE_VERIFY_CLASS_SETUP(Ufe::UndoableCommand, UsdUndoDeleteCommand);
@@ -75,7 +159,73 @@ void UsdUndoDeleteCommand::execute()
         throw std::runtime_error(error);
     }
 
-    if (!routingEditTarget.IsNull()) {
+    // Check if this is a component stage
+    const Ufe::Path proxyPath   = UsdUfe::stagePath(stage);
+    const bool      isComponent = UsdUfe::isComponentStage(proxyPath);
+
+    if (isComponent) {
+        // Validate that the prim can be deleted in a component stage
+        validateComponentDelete(_prim);
+
+        // Get all prim specs from all layers (including non-local layers like payloads)
+        const PXR_NS::SdfPrimSpecHandleVector primStack = _prim.GetPrimStack();
+
+        for (const PXR_NS::SdfPrimSpecHandle& primSpec : primStack) {
+            if (!primSpec)
+                continue;
+
+            const PXR_NS::SdfLayerHandle layer = primSpec->GetLayer();
+            if (!layer)
+                continue;
+
+            const PXR_NS::SdfPath primPath = primSpec->GetPath();
+
+            // DEBUG: Print primspec information
+            TF_WARN("DEBUG: Component delete - PrimSpec path: %s", primPath.GetText());
+            TF_WARN("DEBUG: Component delete - Layer: %s", layer->GetDisplayName().c_str());
+            TF_WARN("DEBUG: Component delete - Layer identifier: %s",
+                    layer->GetIdentifier().c_str());
+            TF_WARN("DEBUG: Component delete - PrimSpec specifier: %s",
+                    TfEnum::GetName(primSpec->GetSpecifier()).c_str());
+
+            UsdUfe::UsdUndoManager::instance().trackLayerStates(layer);
+
+            // Get the parent spec
+            PXR_NS::SdfPrimSpecHandle parent = primSpec->GetRealNameParent();
+            if (!parent) {
+                const std::string error = TfStringPrintf(
+                    "Failed to get parent for prim \"%s\" in layer \"%s\".",
+                    primPath.GetText(),
+                    layer->GetDisplayName().c_str());
+                TF_WARN("%s", error.c_str());
+                throw std::runtime_error(error);
+            }
+
+            // DEBUG: Print parent information
+            TF_WARN("DEBUG: Component delete - Parent path: %s", parent->GetPath().GetText());
+            TF_WARN("DEBUG: Component delete - Parent specifier: %s",
+                    TfEnum::GetName(parent->GetSpecifier()).c_str());
+            TF_WARN("DEBUG: Component delete - Parent has %zu children",
+                    parent->GetNameChildren().size());
+
+            // Remove the prim spec from its parent
+            if (!parent->RemoveNameChild(primSpec)) {
+                const std::string error = TfStringPrintf(
+                    "Failed to delete prim \"%s\" from layer \"%s\".",
+                    primPath.GetText(),
+                    layer->GetDisplayName().c_str());
+                TF_WARN("%s", error.c_str());
+                throw std::runtime_error(error);
+            }
+
+            // DEBUG: Confirm removal
+            TF_WARN("DEBUG: Component delete - Successfully removed prim from parent");
+
+            layer->RemovePrimIfInert(parent);
+        }
+    } else if (!routingEditTarget.IsNull()) {
+        // NOTE: Need to consider the case of edit routing as well probably
+        // maybe in the future???
         PXR_NS::UsdEditContext ctx(stage, routingEditTarget);
 
         // Note: we allow stronger opinion when editing inside a reference or payload.