Custom sections, menu entries and tabs

Resources

• Use ToolMenus.Edit command in editor to see the menu entry points
• See this cool post on how to add custom entries to toolbar and menu entries in menu.
• See _Resources (Slate) for more details about reusing engine slate icons & styles.
• See this for dynamic tool menu entries and to get context.
• See this cool post (use translator) about general extensions (check at the end (FWorkflowCentricApplication section) for a cool example of using a FSummoner).
• See this for more info on how to create custom editor classes and how they work. And the differences between FAssetEditorToolkit and FWorkflowCentricApplication.
• See this for more information on editor layouts for application modes.
• See this for information about application modes
• See this for examples on how to add specific tabs/toolbars/menu to your custom asset
• See Summoners (Tabs)

Engine menu creation

• Level Editor Toolbar: FLevelEditorToolBar::RegisterLevelEditorToolBar(

Add something to a toolbar

Default way

TODO:

UToolMenu* ToolbarMenu = UToolMenus::Get()->ExtendMenu("Kismet.SubobjectEditorContextMenu");  
FToolMenuSection& ToolbarSection = ToolbarMenu->AddSection("PrefabSystemSection.BlueprintEditor.Component", INVTEXT("Pefabab System"));  
  
ToolbarSection.AddDynamicEntry(...);

With extender

TSharedPtr<FExtender> TabExtender = MakeShareable(new FExtender);  
TabExtender->AddToolBarExtension(  
    "Asset",  
    EExtensionHook::After,  
    nullptr,  
    FToolBarExtensionDelegate::CreateLambda([](FToolBarBuilder& ToolBarBuilder)  
    {
	    ToolBarBuilder.BeginSection("QuixelBridge");
	    {
	        ToolBarBuilder.AddToolBarButton(
		        FName("Quixel Bridge"),
		        INVTEXT("Bridge"),  
		        INVTEXT("Megascans Link with Bridge"),
		        SlateIcon(),  
		        EUserInterfaceActionType::Button,  
		        FName("QuixelBridge")
			);
		}
		ToolBarBuilder.EndSection();  
    })
);
BlueprintEditor->AddToolbarExtender(TabExtender);

Result:

Contexts

You can get the context of a ToolbarSection if using MyToolMenuSection.AddDynamicEntry.

Example:

UToolMenu* ToolbarMenu = UToolMenus::Get()->ExtendMenu("Kismet.SubobjectEditorContextMenu");
FToolMenuSection& ToolbarSection = ToolbarMenu->AddSection("PrefabSystemSection.BlueprintEditor.Component", INVTEXT("PefababSystem"));
  
ToolbarSection.AddDynamicEntry(FName("PrefabReferenceComponentSubMenu"), FNewToolMenuSectionDelegate::CreateLambda([this](FToolMenuSection& InSection)  
{
	// For accuracy, this would be null because we are in a subobject context
	UBlueprintEditorToolMenuContext* BlueprintEditorContext = InSection.FindContext<UBlueprintEditorToolMenuContext>();
	// ...

For example here we are only showing this menu entry if the right clicked component is a UPSPrefabReferenceComponent:

ToolbarSection.AddDynamicEntry(FName("PrefabReferenceComponentSubMenu"), FNewToolMenuSectionDelegate::CreateLambda([this](FToolMenuSection& InSection)  
{  
    USubobjectEditorMenuContext* SubobjectEditorMenuContext = InSection.FindContext<USubobjectEditorMenuContext>();  
	if (SubobjectEditorMenuContext)
	{
		bool bCanShow = false;
		TArray<UObject*> SelectedObjects = SubobjectEditorMenuContext->GetSelectedObjects();
		for (auto& SelectedObject : SelectedObjects)
		{
			auto* Casted = Cast<UPSPrefabReferenceComponent>(SelectedObject);
			if (Casted)
			{
				bCanShow = true;
				break;
			}
		}
	InSection.AddMenuEntry(...)
	// ...

• UBlueprintEditorToolMenuContext // Appears when the section is in the “main” part of the BP Editor UI
• UContentBrowserAssetContextMenuContext // for an entry on the right click menu of an CB asset
• UAssetEditorToolkitMenuContext
• USubobjectEditorMenuContext // For a subobject entry (ex: component)
• ULevelEditorMenuContext // for a menu on the main level toolbar (only in LevelEditor.LevelEditorToolbar ?)

Tabs

See https://github.com/aquanox/SubsystemBrowserPlugin/blob/main/Source/SubsystemBrowser/SubsystemBrowserModule.cpp#L49-L76.

Other

Combo Button

Text not showing in button

I found out that when adding a ComboButton in the level editor toolbar, the text inside the button wasn’t displayed (this didn’t happen in other toolbars).

The fix is to override the style on the button (which is an FToolMenuEntry) like so: Button.StyleNameOverride = "CalloutToolbar";. The only mention on what this style does in the source code was the following: // This style displays button text.