Unreal Engine Editor Plugin Template

This is a template of a plugin for UE4 that contains an Editor Utility Widget and can be opened via drop-down menu or a keyboard shortcut.
It works on UE4.27, UE5.0, UE5.1, UE5.2, UE5.3 and UE5.4.

Plugin structure

The plugin template is made of the following classes:

FMyPluginEditorModule Contains a logic that registers every needed component when started. It has a function for invoking the spawn of the editor's window and it constructs the plugin's logic object.
UMyPluginEditorBase The base of the object that contains the plugin's logic. This base handles only the widget creation and travels between levels. Any additional logic is handled by it's extension.
UMyPluginEditor The extension of the base object. Any logic that the plugin does should ends up here.
UMyPluginEditorWidget The base class of the widget which is stored inside the plugin's content directory and which is displayed in the editors window.
UMyPluginEditorSettings Settings. The object that reads and writes the values from the DefaultEditor.ini file.
FMyPluginEditorStyle Plugin style handle. Used to set the icon inside the Editor's UI.
FMyPluginEditorCommands Commands handle. Used to register a keyboard shortcut that opens the plugin's window.

Changing the plugin widget

Inside the plugin's content directory there is a MyPluginWidget_BP Editor Utility Widget which is opened when the plugin is invoked. The base class of this widget is UMyPluginEditorWidget. When the name of the widget is changed the following path in the UMyPluginEditorBase must bechanged:

#if ((ENGINE_MAJOR_VERSION == 5) && (ENGINE_MINOR_VERSION >= 1))
    FAssetData AssetData = AssetRegistryModule.Get().GetAssetByObjectPath(FSoftObjectPath("/MyPlugin/MyPluginWidget_BP.MyPluginWidget_BP"));
#else
    FAssetData AssetData = AssetRegistryModule.Get().GetAssetByObjectPath("/MyPlugin/MyPluginWidget_BP.MyPluginWidget_BP");
#endif

UI and Logic separation

This plugin template separates the UI and the Logic layers. All the UI part is inside the UMyPluginEditorWidget. All the logic part is inside the UMyPluginEditor object. Communication between these elements is handled by the following scheme:

UI -> Logic : by delegates

// MyPluginEditor.cpp
void UMyPluginEditor::InitializeTheWidget()
{
   EditorWidget->OnTestButtonPressedDelegate.BindUObject(this, &UMyPluginEditor::OnTestButtonPressed);
   EditorWidget->OnTestCheckboxDelegate.BindUObject(this, &UMyPluginEditor::OnTestCheckboxChanged);
}

// MyPluginEditorWidget.cpp
void UMyPluginEditorWidget::TestButtonPressed()
{
   OnTestButtonPressedDelegate.ExecuteIfBound();
}
void UMyPluginEditorWidget::TestCheckBoxCheckChanged(bool bIsChecked)
{
   OnTestCheckboxDelegate.ExecuteIfBound(bIsChecked);
}

Logic -> UI : by direct function call

// MyPluginEditor.cpp
void UMyPluginEditor::OnTestButtonPressed()
{
    EditorWidget->SetNumberOfTestButtonPressed(NumberOfTestButtonPressed);
}
void UMyPluginEditor::OnTestCheckboxChanged(bool bIsChecked)
{
    UMyPluginEditorSettings::SetIsCheckboxChecked(bIsChecked);
}

Changing plugin name and description

The name and the description of the plugin inside the Plugins Browser is controlled by the MyPlugin.uplugin file.
To change the name and the description and the location of the plugin's button in the drop-down menu the following code in the FMyPluginEditorModule::OnPostEngineInit() must be changed:

For Unreal Engine 5.4:

UToolMenu* Menu = UToolMenus::Get()->FindMenu("LevelEditor.MainMenu.Tools"); // The category under which the button will be placed
if (Menu)
{
    Menu->AddMenuEntry(NAME_None, FToolMenuEntry::InitMenuEntryWithCommandList(
        FMyPluginEditorCommands::Get().OpenMyPluginWindow,
        Commands,
        FText::FromString(TEXT("My Plugin")), // Name of the plugin
        FText::FromString(TEXT("Opens My Plugin Window")), // Description of the plugin
        FSlateIcon(FMyPluginEditorStyle::GetStyleSetName(), "MyPluginEditorStyle.MenuIcon")
    ));
}

For Unreal Engine 4.27-5.3:

MainMenuExtender->AddMenuExtension(
#if (ENGINE_MAJOR_VERSION == 5)
    FName(TEXT("Tools")), // The category under which the button will be placed
#else
    FName(TEXT("General")), // The category under which the button will be placed
#endif
    EExtensionHook::After,  // The order in which the button will be placed in the pointed category
    Commands,
    FMenuExtensionDelegate::CreateLambda([](FMenuBuilder& MenuBuilder)
    {
        MenuBuilder.AddMenuEntry(
            FMyPluginEditorCommands::Get().OpenMyPluginWindow,
            NAME_None,
            FText::FromString(TEXT("My Plugin")), // Name of the plugin
            FText::FromString(TEXT("Opens My Plugin Window")), // Description of the plugin
            FSlateIcon(FMyPluginEditorStyle::GetStyleSetName(), "MyPluginEditorStyle.MenuIcon")
        );
    })
);

Changing plugin name and description and default keyboard shortcut in the shortcut settings

In order to change name and description and the default value of the keyboard shortcut in the Editors Settings the following line in FMyPluginEditorCommands::RegisterCommands() must be changed.

UI_COMMAND(OpenMyPluginWindow, "My Plugin", "Opens My Plugin Window", EUserInterfaceActionType::Check, FInputChord(EModifierKey::Shift | EModifierKey::Alt, EKeys::M));

If you don't want to use keyboard shortcut simply leave the FInputChord() empty.

Support and contribution

This plugin template is free and opensource forever, but any contribution is welcomed and will warm my heart.

Final words

I wish to send special thanks to Monika, because she always supports me and believes in me (even if I don't), to Pawel, who gave me an opportunity to write and test new solutions on his project with the believe it won't break anything (too much).

This template is free to use by anybody, I hope it will help at least a little. Cheers! <3

zompi2/UE4EditorPluginTemplate