POTENTIALLY BREAKING CHANGE: Added UAssetDefinition_FlowAsset impleme…

…nting a new way of defining editor-only asset properties like asset category.

This is a direct replacement for FAssetTypeActions_FlowAsset. If you had any custom asset class extending `UFlowAsset`, you probably need to convert your custom FAssetTypeActions to UAssetDefinition. This is quite a straightforward process.

Source/FlowEditor/FlowEditor.Build.cs

@@ -24,6 +24,7 @@ public FlowEditor(ReadOnlyTargetRules target) : base(target)
 		PrivateDependencyModuleNames.AddRange(new[]
 		{
 			"ApplicationCore",
+			"AssetDefinition",
 			"AssetSearch",
 			"AssetTools",
 			"BlueprintGraph",

Source/FlowEditor/Private/Asset/AssetDefinition_FlowAsset.cpp

@@ -0,0 +1,77 @@
+// Copyright https://github.com/MothCocoon/FlowGraph/graphs/contributors
+
+#include "Asset/AssetDefinition_FlowAsset.h"
+#include "Asset/SFlowDiff.h"
+#include "FlowEditorModule.h"
+#include "Graph/FlowGraphSettings.h"
+
+#include "FlowAsset.h"
+
+#include UE_INLINE_GENERATED_CPP_BY_NAME(AssetDefinition_FlowAsset)
+
+#define LOCTEXT_NAMESPACE "AssetDefinition_FlowAsset"
+
+FText UAssetDefinition_FlowAsset::GetAssetDisplayName() const
+{
+	return LOCTEXT("AssetTypeActions_FlowAsset", "Flow Asset");
+}
+
+FLinearColor UAssetDefinition_FlowAsset::GetAssetColor() const
+{
+	return FColor(255, 196, 128);
+}
+
+TSoftClassPtr<UObject> UAssetDefinition_FlowAsset::GetAssetClass() const
+{
+	return UFlowAsset::StaticClass();
+}
+
+TConstArrayView<FAssetCategoryPath> UAssetDefinition_FlowAsset::GetAssetCategories() const
+{
+	if (UFlowGraphSettings::Get()->bExposeFlowAssetCreation)
+	{
+		static const auto Categories = {FFLowAssetCategoryPaths::Flow};
+		return Categories;
+	}
+
+	return {};
+}
+
+FAssetSupportResponse UAssetDefinition_FlowAsset::CanLocalize(const FAssetData& InAsset) const
+{
+	return FAssetSupportResponse::Supported();
+}
+
+EAssetCommandResult UAssetDefinition_FlowAsset::OpenAssets(const FAssetOpenArgs& OpenArgs) const
+{
+	for (UFlowAsset* FlowAsset : OpenArgs.LoadObjects<UFlowAsset>())
+	{
+		const FFlowEditorModule* FlowModule = &FModuleManager::LoadModuleChecked<FFlowEditorModule>("FlowEditor");
+		FlowModule->CreateFlowAssetEditor(OpenArgs.GetToolkitMode(), OpenArgs.ToolkitHost, FlowAsset);
+	}
+
+	return EAssetCommandResult::Handled;
+}
+
+EAssetCommandResult UAssetDefinition_FlowAsset::PerformAssetDiff(const FAssetDiffArgs& DiffArgs) const
+{
+	if (DiffArgs.OldAsset == nullptr && DiffArgs.NewAsset == nullptr)
+	{
+		return EAssetCommandResult::Unhandled;
+	}
+
+	const UFlowAsset* OldFlow = CastChecked<UFlowAsset>(DiffArgs.OldAsset);
+	const UFlowAsset* NewFlow = CastChecked<UFlowAsset>(DiffArgs.NewAsset);
+
+	// sometimes we're comparing different revisions of one single asset (other 
+	// times we're comparing two completely separate assets altogether)
+	const bool bIsSingleAsset = (OldFlow->GetName() == NewFlow->GetName());
+
+	static const FText BasicWindowTitle = LOCTEXT("FlowAssetDiff", "FlowAsset Diff");
+	const FText WindowTitle = !bIsSingleAsset ? BasicWindowTitle : FText::Format(LOCTEXT("FlowAsset Diff", "{0} - FlowAsset Diff"), FText::FromString(NewFlow->GetName()));
+
+	SFlowDiff::CreateDiffWindow(WindowTitle, OldFlow, NewFlow, DiffArgs.OldRevision, DiffArgs.NewRevision);
+	return EAssetCommandResult::Handled;
+}
+
+#undef LOCTEXT_NAMESPACE

Source/FlowEditor/Private/FlowEditorModule.cpp

@@ -3,7 +3,6 @@
 #include "FlowEditorModule.h"
 #include "FlowEditorStyle.h"
 
-#include "Asset/AssetTypeActions_FlowAsset.h"
 #include "Asset/FlowAssetEditor.h"
 #include "Asset/FlowAssetIndexer.h"
 #include "Graph/FlowGraphConnectionDrawingPolicy.h"
@@ -56,6 +55,7 @@ static FName AssetSearchModuleName = TEXT("AssetSearch");
 #define LOCTEXT_NAMESPACE "FlowEditorModule"
 
 EAssetTypeCategories::Type FFlowEditorModule::FlowAssetCategory = static_cast<EAssetTypeCategories::Type>(0);
+FAssetCategoryPath FFLowAssetCategoryPaths::Flow(LOCTEXT("Flow", "Flow"));
 
 void FFlowEditorModule::StartupModule()
 {
@@ -166,10 +166,6 @@ void FFlowEditorModule::RegisterAssets()
 		}
 	}
 
-	const TSharedRef<IAssetTypeActions> FlowAssetActions = MakeShareable(new FAssetTypeActions_FlowAsset());
-	RegisteredAssetActions.Add(FlowAssetActions);
-	AssetTools.RegisterAssetTypeActions(FlowAssetActions);
-
 	const TSharedRef<IAssetTypeActions> FlowNodeActions = MakeShareable(new FAssetTypeActions_FlowNodeBlueprint());
 	RegisteredAssetActions.Add(FlowNodeActions);
 	AssetTools.RegisterAssetTypeActions(FlowNodeActions);

Source/FlowEditor/Public/Asset/AssetDefinition_FlowAsset.h

@@ -0,0 +1,25 @@
+// Copyright https://github.com/MothCocoon/FlowGraph/graphs/contributors
+
+#pragma once
+
+#include "AssetDefinition.h"
+#include "AssetDefinition_FlowAsset.generated.h"
+
+/**
+ * 
+ */
+UCLASS()
+class FLOWEDITOR_API UAssetDefinition_FlowAsset : public UAssetDefinition
+{
+	GENERATED_BODY()
+
+public:
+	virtual FText GetAssetDisplayName() const override;
+	virtual FLinearColor GetAssetColor() const override;
+	virtual TSoftClassPtr<UObject> GetAssetClass() const override;
+	virtual TConstArrayView<FAssetCategoryPath> GetAssetCategories() const override;
+	virtual FAssetSupportResponse CanLocalize(const FAssetData& InAsset) const override;
+
+	virtual EAssetCommandResult OpenAssets(const FAssetOpenArgs& OpenArgs) const override;
+	virtual EAssetCommandResult PerformAssetDiff(const FAssetDiffArgs& DiffArgs) const override;
+};

Source/FlowEditor/Public/FlowEditorModule.h

@@ -15,6 +15,11 @@ struct FGraphPanelPinConnectionFactory;
 class FFlowAssetEditor;
 class UFlowAsset;
 
+struct FLOWEDITOR_API FFLowAssetCategoryPaths : EAssetCategoryPaths
+{
+	static FAssetCategoryPath Flow;
+};
+
 class FLOWEDITOR_API FFlowEditorModule : public IModuleInterface
 {
 public: