Broad rearrangement of handlers

Plugins/BlueprintMCP/Deprecated/UMCPHandler_AddMaterialExpression.h

@@ -0,0 +1,169 @@
+#pragma once
+
+#include "CoreMinimal.h"
+#include "MCPHandler.h"
+#include "MCPAssetFinder.h"
+#include "MCPUtils.h"
+#include "Materials/Material.h"
+#include "Materials/MaterialFunction.h"
+#include "Materials/MaterialExpression.h"
+#include "MaterialGraph/MaterialGraph.h"
+#include "MaterialGraph/MaterialGraphNode.h"
+#include "UObject/UObjectIterator.h"
+#include "UMCPHandler_AddMaterialExpression.generated.h"
+
+
+// ---------------------------------------------------------------------------
+// ---------------------------------------------------------------------------
+// ---------------------------------------------------------------------------
+
+UCLASS(meta=(Group="Unclassified"))
+class UMCPHandler_AddMaterialExpression : public UObject, public IMCPHandler
+{
+	GENERATED_BODY()
+
+public:
+	UPROPERTY(meta=(Optional, Description="Material name or package path (specify this or materialFunction, not both)"))
+	FString Material;
+
+	UPROPERTY(meta=(Optional, Description="Material function name or package path (specify this or material, not both)"))
+	FString MaterialFunction;
+
+	UPROPERTY(meta=(Description="Expression class name without 'MaterialExpression' prefix (e.g. 'Constant', 'ScalarParameter', 'Add', 'Multiply', 'Lerp')"))
+	FString ExpressionClass;
+
+	UPROPERTY(meta=(Optional, Description="X position in the material graph editor"))
+	int32 PosX = 0;
+
+	UPROPERTY(meta=(Optional, Description="Y position in the material graph editor"))
+	int32 PosY = 0;
+
+	virtual FString GetDescription() const override
+	{
+		return TEXT("Add a new expression node to a material or material function graph.");
+	}
+
+	virtual void Handle(const FJsonObject* Json, FStringBuilderBase& Result) override
+	{
+		if (Material.IsEmpty() && MaterialFunction.IsEmpty())
+		{
+			Result.Append(TEXT("ERROR: Specify 'material' or 'materialFunction'\n"));
+			return;
+		}
+		if (!Material.IsEmpty() && !MaterialFunction.IsEmpty())
+		{
+			Result.Append(TEXT("ERROR: Specify 'material' or 'materialFunction', not both\n"));
+			return;
+		}
+
+		// Resolve the expression class
+		UClass* ExprClass = ResolveExpressionClass(Result);
+		if (!ExprClass) return;
+
+		// Load material or material function
+		UMaterial* MaterialObj = nullptr;
+		UMaterialFunction* MatFunc = nullptr;
+		UObject* Owner = nullptr;
+
+		if (!MaterialFunction.IsEmpty())
+		{
+			MCPAssets<UMaterialFunction> Assets;
+			if (!Assets.Exact(MaterialFunction).Errors(Result).ENone().ETwo().Load()) return;
+			MatFunc = Assets.Object();
+			Owner = MatFunc;
+		}
+		else
+		{
+			MCPAssets<UMaterial> Assets;
+			if (!Assets.Exact(Material).Errors(Result).ENone().ETwo().Load()) return;
+			MaterialObj = Assets.Object();
+			Owner = MaterialObj;
+		}
+
+		// Ensure the MaterialGraph exists (commandlet mode doesn't auto-create it)
+		if (MaterialObj) MCPUtils::EnsureMaterialGraph(MaterialObj);
+
+		// Create the expression
+		UMaterialExpression* NewExpr = NewObject<UMaterialExpression>(Owner, ExprClass);
+		if (!NewExpr)
+		{
+			Result.Append(TEXT("ERROR: Failed to create material expression object\n"));
+			return;
+		}
+		NewExpr->MaterialExpressionEditorX = PosX;
+		NewExpr->MaterialExpressionEditorY = PosY;
+
+		if (MaterialObj)
+		{
+			MaterialObj->GetExpressionCollection().AddExpression(NewExpr);
+			if (MaterialObj->MaterialGraph)
+				MaterialObj->MaterialGraph->RebuildGraph();
+			MaterialObj->PreEditChange(nullptr);
+			MaterialObj->PostEditChange();
+			MaterialObj->MarkPackageDirty();
+		}
+		else
+		{
+			MatFunc->GetExpressionCollection().AddExpression(NewExpr);
+			MatFunc->PreEditChange(nullptr);
+			MatFunc->PostEditChange();
+			MatFunc->MarkPackageDirty();
+		}
+
+		// Save
+		bool bSaved = MaterialObj
+			? MCPUtils::SaveMaterialPackage(MaterialObj)
+			: MCPUtils::SaveGenericPackage(MatFunc);
+
+		// Output
+		Result.Appendf(TEXT("Added %s\n"), *MCPUtils::FormatName(NewExpr));
+
+		// Find the graph node GUID (only for materials with a material graph)
+		if (MaterialObj && MaterialObj->MaterialGraph)
+		{
+			for (UEdGraphNode* Node : MaterialObj->MaterialGraph->Nodes)
+			{
+				UMaterialGraphNode* MatNode = Cast<UMaterialGraphNode>(Node);
+				if (MatNode && MatNode->MaterialExpression == NewExpr)
+				{
+					Result.Appendf(TEXT("NodeId: %s\n"), *Node->NodeGuid.ToString());
+					break;
+				}
+			}
+		}
+
+		if (!bSaved)
+			Result.Append(TEXT("WARNING: Failed to save package\n"));
+	}
+
+private:
+	UClass* ResolveExpressionClass(FStringBuilderBase& Result)
+	{
+		// Convenience aliases
+		static TMap<FString, FString> Aliases = {
+			{TEXT("Lerp"), TEXT("LinearInterpolate")},
+		};
+
+		FString LookupName = ExpressionClass;
+		if (const FString* Alias = Aliases.Find(ExpressionClass))
+			LookupName = *Alias;
+
+		FString FullClassName = FString::Printf(TEXT("MaterialExpression%s"), *LookupName);
+		for (TObjectIterator<UClass> It; It; ++It)
+		{
+			if (It->GetName() == FullClassName && It->IsChildOf(UMaterialExpression::StaticClass()))
+			{
+				if (It->HasAnyClassFlags(CLASS_Abstract))
+				{
+					Result.Appendf(TEXT("ERROR: Expression class '%s' is abstract\n"), *ExpressionClass);
+					return nullptr;
+				}
+				return *It;
+			}
+		}
+
+		Result.Appendf(TEXT("ERROR: Unknown expression class '%s'. Use the UMaterialExpression subclass name without the 'MaterialExpression' prefix (e.g. 'Constant', 'ScalarParameter', 'Add', 'Multiply', 'Lerp')\n"),
+			*ExpressionClass);
+		return nullptr;
+	}
+};