制作插件

关于插件

A plugin is a great way to extend the editor with useful tools. It can be made entirely with GDScript and standard scenes, without even reloading the editor. Unlike modules, you don’t need to create C++ code nor recompile the engine. While this makes plugins less powerful, there are still many things you can do with them. Note that a plugin is similar to any scene you can already make, except it is created using a script to add editor functionality.

这个教程会教您写两个简单的插件来帮助您理解插件如何运作和如何写插件。首先是一个可以往任何场景添加的自定义节点,其次呢,是个可以往编辑器里添加的自定义面板。

创建一个插件

Before starting, create a new empty project wherever you want. This will serve as a base to develop and test the plugins.

The first thing you need for the editor to identify a new plugin is to create two files: a plugin.cfg for configuration and a tool script with the functionality. Plugins have a standard path like addons/plugin_name inside the project folder. Godot provides a dialog for generating those files and placing them where they need to be.

In the main toolbar, click the Project dropdown. Then click Project Settings.... Go to the Plugins tab and then click on the Create button in the top-right.

You will see the dialog appear, like so:

../../../_images/making_plugins-create_plugin_dialog.png

The placeholder text in each field describes how it affects the plugin’s creation of the files and the config file’s values.

To continue with the example, use the following values:

Plugin Name: My Custom Node
Subfolder: my_custom_node
Description: A custom node made to extend the Godot Engine.
Author: Your Name Here
Version: 1.0.0
Language: GDScript
Script Name: custom_node.gd
Activate now: No

You should end up with a directory structure like this:

../../../_images/making_plugins-my_custom_mode_folder.png

plugin.cfg is a simple INI file with metadata about your plugin. The name and description help people undersatnd what it does. Your name helps you get properly credited for your work. The version number helps others know if they have an outdated version; if you are unsure on how to come up with the version number, check out Semantic Versioning. The main script file will instruct Godot what your plugin does in the editor once it is active.

脚本文件

Upon creation of the plugin, the dialog will automatically open the EditorPlugin script for you. The script has two requirements that you cannot change: it must be a tool script, or else it will not load properly in the editor, and it must inherit from class_EditorPlugin.

警告

In addition to the EditorPlugin script, any other GDScript that your plugin uses must also be a tool. Any GDScript without tool imported into the editor will act like an empty file!

It’s important to deal with initialization and clean-up of resources. A good practice is to use the virtual function _enter_tree() to initialize your plugin and _exit_tree() to clean it up. Thankfully, the dialog generates these callbacks for you. Your script should look something like this:

tool
extends EditorPlugin

func _enter_tree():
    # Initialization of the plugin goes here
    pass

func _exit_tree():
    # Clean-up of the plugin goes here
    pass
#if TOOLS
using Godot;
using System;

[Tool]
public class CustomNode : EditorPlugin
{
    public override void _EnterTree()
    {
        // Initialization of the plugin goes here
    }

    public override void _ExitTree()
    {
        // Clean-up of the plugin goes here
    }
}
#endif

这是创建新插件时使用的好模板。

自定义节点

有时您希望在许多节点中存在某种行为,例如可以重复使用的自定义场景或控件。 实例化在很多情况下都很有用,但有时它会很麻烦,特别是如果您在许多项目中使用它。 一个很好的解决方案是创建一个插件,添加一个具有自定义行为的节点。

警告

Nodes added via an EditorPlugin are “CustomType” nodes. While they work with any scripting language, they have fewer features than the Script Class system. If you are writing GDScript or NativeScript, we recommend using them instead.

To create a new node type, you can use the function add_custom_type() from the class_EditorPlugin class. This function can add new types to the editor (nodes or resources). However, before you can create the type, you need a script that will act as the logic for the type. While that script doesn’t have to use the tool keyword, it can be added so the script runs in the editor.

For this tutorial, we’ll create a simple button that prints a message when clicked. For that, we’ll need a simple script that extends from class_Button. It could also extend class_BaseButton if you prefer:

tool
extends Button

func _enter_tree():
    connect("pressed", self, "clicked")

func clicked():
    print("You clicked me!")
using Godot;
using System;

[Tool]
public class MyButton : Button
{
    public override void _EnterTree()
    {
        Connect("pressed", this, "clicked");
    }

    public void clicked()
    {
        GD.Print("You clicked me!");
    }
}

That’s it for our basic button. You can save this as my_button.gd inside the plugin folder. You’ll also need a 16×16 icon to show in the scene tree. If you don’t have one, you can grab the default one from the engine and save it in your addons/my_custom_node folder as icon.png, or use the default Godot logo (preload(“res://icon.png”)). You can also use SVG icons if desired.

../../../_images/making_plugins-custom_node_icon.png

Now, we need to add it as a custom type so it shows on the Create New Node dialog. For that, change the custom_node.gd script to the following:

tool
extends EditorPlugin

func _enter_tree():
    # Initialization of the plugin goes here
    # Add the new type with a name, a parent type, a script and an icon
    add_custom_type("MyButton", "Button", preload("my_button.gd"), preload("icon.png"))

func _exit_tree():
    # Clean-up of the plugin goes here
    # Always remember to remove it from the engine when deactivated
    remove_custom_type("MyButton")
#if TOOLS
using Godot;
using System;

[Tool]
public class CustomNode : EditorPlugin
{
    public override void _EnterTree()
    {
        // Initialization of the plugin goes here
        // Add the new type with a name, a parent type, a script and an icon
        var script = GD.Load<Script>("MyButton.cs");
        var texture = GD.Load<Texture>("icon.png");
        AddCustomType("MyButton", "Button", script, texture);
    }

    public override void _ExitTree()
    {
        // Clean-up of the plugin goes here
        // Always remember to remove it from the engine when deactivated
        RemoveCustomType("MyButton");
    }
}
#endif

完成后,插件应该已经在 项目设置 的插件列表中可用,因此请按照 Checking the results 中的说明激活它。

然后通过添加新节点来尝试:

../../../_images/making_plugins-custom_node_create.png

When you add the node, you can see that it already has the script you created attached to it. Set a text to the button, save and run the scene. When you click the button, you can see some text in the console:

../../../_images/making_plugins-custom_node_console.png

自定义窗口

有时,您需要扩展编辑器并添加始终可用的工具。 一种简单的方法是添加一个带插件的新扩展面板。 Docks只是基于Control的场景,因此它们的创建方式与通常的GUI场景类似。

Creating a custom dock is done just like a custom node. Create a new plugin.cfg file in the addons/my_custom_dock folder, then add the following content to it:

[plugin]

name="My Custom Dock"
description="A custom dock made so I can learn how to make plugins."
author="Your Name Here"
version="1.0"
script="custom_dock.gd"
[plugin]

name="My Custom Dock"
description="A custom dock made so I can learn how to make plugins."
author="Your Name Here"
version="1.0"
script="CustomDock.cs"

然后在同一文件夹中创建脚本 custom_dock.gd 。 使用 template we’ve seen before 填充它以获得良好的开端。

由于我们正在尝试添加新的自定义窗口,因此我们需要创建窗口的内容。 这只不过是一个标准的Godot场景:只需在编辑器中创建一个新场景然后编辑它。

对于编辑器停靠站,根节点 必须是 Control 或其子类之一。 在本教程中,您可以创建一个按钮。 根节点的名称也将是面板对话框中显示的名称,因此请务必为其指定一个简短的描述性名称。 另外,不要忘记在按钮上添加一些文字。

../../../_images/making_plugins-my_custom_dock_scene.png

Save this scene as my_dock.tscn. Now, we need to grab the scene we created then add it as a dock in the editor. For this, you can rely on the function add_control_to_dock() from the EditorPlugin class.

You need to select a dock position and define the control to add (which is the scene you just created). Don’t forget to remove the dock when the plugin is deactivated. The script could look like this:

tool
extends EditorPlugin

# A class member to hold the dock during the plugin life cycle
var dock

func _enter_tree():
    # Initialization of the plugin goes here
    # Load the dock scene and instance it
    dock = preload("res://addons/my_custom_dock/my_dock.tscn").instance()

    # Add the loaded scene to the docks
    add_control_to_dock(DOCK_SLOT_LEFT_UL, dock)
    # Note that LEFT_UL means the left of the editor, upper-left dock

func _exit_tree():
    # Clean-up of the plugin goes here
    # Remove the dock
    remove_control_from_docks(dock)
     # Erase the control from the memory
    dock.free()
#if TOOLS
using Godot;
using System;

[Tool]
public class CustomDock : EditorPlugin
{
    Control dock;

    public override void _EnterTree()
    {
        dock = (Control)GD.Load<PackedScene>("addons/my_custom_dock/my_dock.tscn").Instance();
        AddControlToDock(DockSlot.LeftUl, dock);
    }

    public override void _ExitTree()
    {
        // Clean-up of the plugin goes here
        // Remove the dock
        RemoveControlFromDocks(dock);
        // Erase the control from the memory
        dock.Free();
    }
}
#endif

Note that, while the dock will initially appear at its specified position, the user can freely change its position and save the resulting layout.

检查结果

现在是检查工作结果的时候了。 打开 项目设置 ,然后单击 插件 选项卡。 您的插件应该是列表中唯一的插件。 如果未显示,请单击右上角的 更新 按钮。

../../../_images/making_plugins-project_settings.png

您可以在 Status 列中看到该插件处于非激活状态; 点击状态选择 Active 。 在您关闭设置窗口之前,该扩展窗口应该可见。 您现在应该看到一个自定义窗口:

../../../_images/making_plugins-custom_dock.png

举一反三

现在您已经学会了如何制作基本插件,您可以通过多种方式扩展编辑器。 可以使用GDScript将许多功能添加到编辑器中; 它是一种创建专业编辑器的强大方法,无需深入研究C++模块。

您可以制作自己的插件来帮助自己或在 资源馆 中分享它们,以便人们可以从您的工作中受益。