Making main screen plugins

What this tutorial covers

Making plugins page, making a basic plugin that extends the editor is fairly easy. Main screen plugins allow you to create new UIs in the central part of the editor, which appear next to the “2D”, “3D”, “Script”, and “AssetLib” buttons. Such editor plugins are referred as “Main screen plugins”. This tutorial leads you through the creation of a basic main screen plugin. For the sake of simplicity, our main screen plugin will contain a single button that prints text to the console.

Initializing the plugin

main_screen, but you can use any name you’d like. _enter_tree() and _exit_tree() methods, but for a main screen plugin we need to add a few extra methods. Add five extra methods such that the script looks like this:

  1. toolextends EditorPluginfunc _enter_tree():    passfunc _exit_tree():    passfunc has_main_screen():    return truefunc make_visible(visible):    passfunc get_plugin_name():    return "Main Screen Plugin"func get_plugin_icon():    return get_editor_interface().get_base_control().get_icon("Node", "EditorIcons")

has_main_screen() function, which is overloaded so it returns true. This function is automatically called by the editor on plugin activation, to tell it that this plugin adds a new center view to the editor. For now, we’ll leave this script as-is and we’ll come back to it later.

Main screen scene

Control (for this example plugin, we’ll make the root node a CenterContainer). Select this root node, and in the viewport, click the Layout menu and select Full Rect. You also need to enable the Expand vertical size flag in the inspector. The panel now uses all the space available in the main viewport. Button node, and set the text to “Print Hello” or similar. Add a script to the button like this:

  1. toolextends Buttonfunc _on_PrintHello_pressed():    print("Hello from the main screen plugin!")

Using signals article. main_panel.tscn.

Update the plugin script

main_screen_plugin.gd script so the plugin instances our main panel scene and places it where it needs to be. Here is the full plugin script:

  1. toolextends EditorPluginconst MainPanel = preload("res://addons/main_screen/main_panel.tscn")var main_panel_instancefunc _enter_tree():    main_panel_instance = MainPanel.instance()    # Add the main panel to the editor's main viewport.    get_editor_interface().get_editor_viewport().add_child(main_panel_instance)    # Hide the main panel. Very much required.    make_visible(false)func _exit_tree():    if main_panel_instance:        main_panel_instance.queue_free()func has_main_screen():    return truefunc make_visible(visible):    if main_panel_instance:        main_panel_instance.visible = visiblefunc get_plugin_name():    return "Main Screen Plugin"func get_plugin_icon():    # Must return some kind of Texture for the icon.    return get_editor_interface().get_base_control().get_icon("Node", "EditorIcons")

MainPanel is a constant that holds a reference to the scene, and we instance it into main_panel_instance. _enter_tree() function is called before _ready(). This is where we instance the main panel scene, and add them as children of specific parts of the editor. We use get_editor_interface().get_editor_viewport() to obtain the viewport and add our main panel instance as a child to it. We call the make_visible(false) function to hide the main panel so it doesn’t compete for space when first activating the plugin. _exit_tree() function is called when the plugin is deactivated. If the main screen still exists, we call queue_free() to free the instance and remove it from memory. make_visible() function is overridden to hide or show the main panel as needed. This function is automatically called by the editor when the user clicks on the main viewport buttons at the top of the editor. get_plugin_name() and get_plugin_icon() functions control the displayed name and icon for the plugin’s main viewport button. handles() function, which allows you to handle a node type, automatically focusing the main screen when the type is selected. This is similar to how clicking on a 3D node will automatically switch to the 3D viewport.

Try the plugin

Activate the plugin in the Project Settings. You’ll observe a new button next to 2D, 3D, Script above the main viewport. Clicking it will take you to your new main screen plugin, and the button in the middle will print text. https://github.com/godotengine/godot-demo-projects/tree/master/plugins https://github.com/godotengine/godot-demo-projects/tree/master/misc/2.5d