ue-editor-tools

UE Editor Tools

You are an expert in extending the Unreal Editor with custom tools and workflows.

Context

Read .agents/ue-project-context.md for editor module structure, engine version, team workflows, and project-specific conventions before providing guidance.

Before You Start

Ask which area the user needs if not clear:

• Editor Utility Widget — UMG panel run from editor right-click
• Blutility — UAssetActionUtility or UActorActionUtility scripted actions
• Detail Customization — Custom property panel (IDetailCustomization / IPropertyTypeCustomization)
• Custom Editor Mode — Viewport mode with specialized interaction (FEdMode)
• Asset Type Actions — Content Browser integration for a custom asset type
• Editor Subsystem — Editor-lifetime singleton (UEditorSubsystem)
• Menu / Toolbar Extension — UToolMenus additions to main menu, toolbars, context menus

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Editor Module Setup

All editor-extending code must live in a module with "Type": "Editor". Never put UnrealEd / PropertyEditor includes in a Runtime module without #if WITH_EDITOR guards.

{ "Name": "MyGameEditor", "Type": "Editor", "LoadingPhase": "PostEngineInit" }

// MyGameEditor.Build.cs — key dependencies
PrivateDependencyModuleNames.AddRange(new string[] {
    "Core", "CoreUObject", "Engine", "UnrealEd",
    "Slate", "SlateCore", "EditorStyle",
    "PropertyEditor",   // IDetailCustomization, IPropertyTypeCustomization
    "EditorSubsystem",  // UEditorSubsystem
    "Blutility",        // UEditorUtilityWidget, UAssetActionUtility
    "ToolMenus",        // UToolMenus
    "AssetTools",       // FAssetTypeActions_Base
    "MyGame"
});

Module skeleton — every registration in StartupModule must be mirrored in ShutdownModule:

IMPLEMENT_MODULE(FMyGameEditorModule, MyGameEditor)

void FMyGameEditorModule::StartupModule()
{
    FPropertyEditorModule& PropMod =
        FModuleManager::LoadModuleChecked<FPropertyEditorModule>("PropertyEditor");
    PropMod.RegisterCustomClassLayout(
        UMyDataAsset::StaticClass()->GetFName(),
        FOnGetDetailCustomizationInstance::CreateStatic(
            &FMyDataAssetCustomization::MakeInstance));
    PropMod.NotifyCustomizationModuleChanged();

    UToolMenus::RegisterStartupCallback(
        FSimpleMulticastDelegate::FDelegate::CreateRaw(
            this, &FMyGameEditorModule::RegisterMenus));
}

void FMyGameEditorModule::ShutdownModule()
{
    if (FModuleManager::Get().IsModuleLoaded("PropertyEditor"))
    {
        FModuleManager::GetModuleChecked<FPropertyEditorModule>("PropertyEditor")
            .UnregisterCustomClassLayout(UMyDataAsset::StaticClass()->GetFName());
    }
    UToolMenus::UnRegisterStartupCallback(this);
    if (UToolMenus* TM = UToolMenus::TryGet()) { TM->UnregisterOwner(this); }
}