Version: 2022.2
Create and manage overlay configurations
Position GameObjects

Create your own overlay

You can create custom panel overlays and toolbar overlays for the Scene view window.

Tip: For information about creating UIElements, refer to the UI Elements Developer Guide.

Understand EditorToolbarElement

A toolbar element can contain text, an icon, or a combination of both.

Use EditorToolbarElement(Identifier, EditorWindowType) to register toolbar elements to use in ToolbarOverlay implementations.

You can inherit from any VisualElement type and create styling yourself, but toolbar elements require specific styling. It is preferable to inherit from one of these predefined EditorToolbar types:

  • EditorToolbarButton: Based on UnityEditor.UIElements.ToolbarButton
  • EditorToolbarToggle: Based on UnityEditor.UIElements.ToolbarToggle
  • EditorToolbarDropdown: Based on EditorToolbarButton
  • EditorToolbarDropdownToggle: Based on UnityEngine.UIElements.BaseField

Tip: If a toolbar is docked horizontally or vertically, its text might not be visible or clipped. You can specify an icon for each toolbar to avoid text clipping.

Create a panel overlay

All overlays must inherit from the Overlay base class and implement the CreatePanelContent method. This creates a basic panel that you can use and that you can add toolbar elements to.

To create a panel overlay:

  1. Create a new C# script in the Editor folder and name it.

  2. Open the script you created.

  3. Remove the default content from the script.

  4. Implement the Overlay class from the UnityEditor.Overlays namespace.

  5. Override the CreatePanelContent function and add your content to the visual element.

  6. Add the OverlayAttribute attribute to the class.

  7. In the OverlayAttribute, specify which type of window you want this overlay to be in:

    • If you want the overlay to be available in all Editor windows, specify EditorWindow as the type.
    • If you want the overlay to only be available in the Scene view, specify SceneView as the type.
  8. In the OverlayAttribute, add a name, ID, and display name to the overlay.

  9. To add an icon that displays when your overlay is collapsed, add the Icon attribute to the Overlay class and specify an icon. If the overlay has no icon, then by default the system uses the first two letters of the overlay name or the first two initial letters of the first two words.

示例

using UnityEditor;
using UnityEditor.Overlays;
using UnityEngine.UIElements;
[Overlay(typeof(SceneView), "Panel Overlay Example", true)]
public class MyToolButtonOverlay : Overlay
{
    public override VisualElement CreatePanelContent()
    {
        var root = new VisualElement() { name = "My Toolbar Root" };
        root.Add(new Label() { text = "Hello" });
        return root;

    }
}

Create a toolbar overlay

Toolbar overlays are containers that hold toolbar items and are composed of collections of EditorToolbarElement.

Toolbar overlays have built-in horizontal, vertical, and panel layouts. ToolbarOverlay implements a parameterless constructor that passes the EditorToolbarElementAttribute ID. Unlike panel overlays, the contents are defined as standalone pieces that are collected to form a strip of elements.

When you create toolbar overlays:

  • Use EditorToolbarElement(Identifier, EditorWindowType) to register toolbar elements to use in the ToolbarOverlay implementation.
  • Tag all overlays with OverlayAttribute.
  • Make sure that toolbar overlays inherit ToolbarOverlay and implement a parameterless constructor.
  • Make sure that the contents of a toolbar are populated with string IDs, which are passed to the base constructor.
  • Make sure that IDs are defined by EditorToolbarElementAttribute.
  • Use the Icon attribute to add icon an icon to your overlay. The icon is visible when an overlay is collapsed. If the overlay does not have an icon, the first two letters of the overlay name (or the first two initial letters of the first two words) are shown when the overlay is collapsed.

When you implement elements specific to ToolbarOverlay in an overlay:

  • Use the IAccessContainerWindow interface for toolbars only. The element is not aware of its context. In the DropdownToggleExample, if you toggle the element it won’t do anything.
  • Use UIElement styling for visuals. The toolbar element won’t have its styling in an overlay.

To create a toolbar overlay:

  1. Create a new C# script in the Editor folder and name it.
  2. Open the script you created.
  3. Remove the default content from the script.
  4. Add toolbar elements to the script.
  5. Add toolbar elements to the overlay constructor.
  6. Add the panel overlay and implement the toolbar elements.

示例

This example is of an overlay named Element Toolbars Example that demonstrates these toolbar elements:

  • EditorToolbarButton
  • EditorToolbarToggle
  • EditorToolbarDropdown
  • EditorToolbarDropdownToggle

Each toolbar element is created as a standalone class and then added to the overlay panel.

This overlay:

  • Can be arranged as a panel, horizontally, and vertically.
  • Has buttons that include text and tooltips.
  • Has toolbar icons defined by the Icon attribute. This icon displays when the overlay is collapsed.
    using System.Collections;
    using System.Collections.Generic;
    using System.Text;
    using UnityEngine;
    using UnityEditor.EditorTools;
    using UnityEditor.Toolbars;
    using UnityEditor.Overlays;
    using UnityEngine.UIElements;
    using UnityEditor;

    // Use [EditorToolbarElement(Identifier, EditorWindowType)] to register toolbar elements for use in ToolbarOverlay implementation.

    [EditorToolbarElement(id, typeof(SceneView))]
    class DropdownExample : EditorToolbarDropdown
    {
        public const string id = "ExampleToolbar/Dropdown";

        static string dropChoice = null;

        public DropdownExample()
        {
            text = "Axis";
            clicked += ShowDropdown;
        }

        void ShowDropdown()
        {
            var menu = new GenericMenu();
            menu.AddItem(new GUIContent("X"), dropChoice == "X", () => { text = "X"; dropChoice = "X"; });
            menu.AddItem(new GUIContent("Y"), dropChoice == "Y", () => { text = "Y"; dropChoice = "Y"; });
            menu.AddItem(new GUIContent("Z"), dropChoice == "Z", () => { text = "Z"; dropChoice = "Z"; });
            menu.ShowAsContext();
        }
    }
    [EditorToolbarElement(id, typeof(SceneView))]
    class ToggleExample : EditorToolbarToggle
    {
        public const string id = "ExampleToolbar/Toggle";
        public ToggleExample()
        {
            text = "Toggle OFF";
            this.RegisterValueChangedCallback(Test);
        }

        void Test(ChangeEvent<bool> evt)
        {
            if (evt.newValue)
            {
                Debug.Log("ON");
                text = "Toggle ON";
            }
            else
            {
                Debug.Log("OFF");
                text = "Toggle OFF";
            }
        }
    }

    [EditorToolbarElement(id, typeof(SceneView))]
    class DropdownToggleExample : EditorToolbarDropdownToggle, IAccessContainerWindow
    {
        public const string id = "ExampleToolbar/DropdownToggle";

        // This property is specified by IAccessContainerWindow and is used to access the Overlay's EditorWindow.

        public EditorWindow containerWindow { get; set; }
        static int colorIndex = 0;
        static readonly Color[] colors = new Color[] { Color.red, Color.green, Color.cyan };
        public DropdownToggleExample()
        {
            text = "Color Bar";
            tooltip = "Display a color rectangle in the top left of the Scene view. Toggle on or off, and open the dropdown" +
                      "to change the color.";

        // When the dropdown is opened, ShowColorMenu is invoked and we can create a popup menu.

            dropdownClicked += ShowColorMenu;

        // Subscribe to the Scene view OnGUI callback so that we can draw our color swatch.

            SceneView.duringSceneGui += DrawColorSwatch;
        }

        void DrawColorSwatch(SceneView view)
        {

         // Test that this callback is for the Scene View that we're interested in, and also check if the toggle is on
        // or off (value).

            if (view != containerWindow || !value)
            {
                return;
            }

            Handles.BeginGUI();
            GUI.color = colors[colorIndex];
            GUI.DrawTexture(new Rect(8, 8, 120, 24), Texture2D.whiteTexture);
            GUI.color = Color.white;
            Handles.EndGUI();
        }

        // When the dropdown button is clicked, this method will create a popup menu at the mouse cursor position.

        void ShowColorMenu()
        {
            var menu = new GenericMenu();
            menu.AddItem(new GUIContent("Red"), colorIndex == 0, () => colorIndex = 0);
            menu.AddItem(new GUIContent("Green"), colorIndex == 1, () => colorIndex = 1);
            menu.AddItem(new GUIContent("Blue"), colorIndex == 2, () => colorIndex = 2);
            menu.ShowAsContext();
        }
    }

    [EditorToolbarElement(id, typeof(SceneView))]
    class CreateCube : EditorToolbarButton//, IAccessContainerWindow
    {
        // This ID is used to populate toolbar elements.

        public const string id = "ExampleToolbar/Button";

        // IAccessContainerWindow provides a way for toolbar elements to access the `EditorWindow` in which they exist.
        // Here we use `containerWindow` to focus the camera on our newly instantiated objects after creation.
        //public EditorWindow containerWindow { get; set; }

        // Because this is a VisualElement, it is appropriate to place initialization logic in the constructor.
        // In this method you can also register to any additional events as required. In this example there is a tooltip, an icon, and an action.

        public CreateCube()
        {

    // A toolbar element can be either text, icon, or a combination of the two. Keep in mind that if a toolbar is
        // docked horizontally the text will be clipped, so usually it's a good idea to specify an icon.

            text = "Create Cube";
            icon = AssetDatabase.LoadAssetAtPath<Texture2D>("Assets/CreateCubeIcon.png");
            tooltip = "Instantiate a cube in the scene.";
            clicked += OnClick;
        }

        // This method will be invoked when the `Create Cube` button is clicked.

        void OnClick()
        {
            var newObj = GameObject.CreatePrimitive(PrimitiveType.Cube).transform;

        // When writing editor tools don't forget to be a good citizen and implement Undo!

            Undo.RegisterCreatedObjectUndo(newObj.gameObject, "Create Cube");

        //if (containerWindow is SceneView view)
        //    view.FrameSelected();

        }

    }

    // All Overlays must be tagged with the OverlayAttribute

    [Overlay(typeof(SceneView), "ElementToolbars Example")]

        // IconAttribute provides a way to define an icon for when an Overlay is in collapsed form. If not provided, the name initials are used.

    [Icon("Assets/unity.png")]

    // Toolbar Overlays must inherit `ToolbarOverlay` and implement a parameter-less constructor. The contents of a toolbar are populated with string IDs, which are passed to the base constructor. IDs are defined by EditorToolbarElementAttribute.

    public class EditorToolbarExample : ToolbarOverlay
    {

     // ToolbarOverlay implements a parameterless constructor, passing the EditorToolbarElementAttribute ID.
    // This is the only code required to implement a toolbar Overlay. Unlike panel Overlays, the contents are defined
    // as standalone pieces that will be collected to form a strip of elements.

        EditorToolbarExample() : base(
            CreateCube.id,
            ToggleExample.id,
            DropdownExample.id,
            DropdownToggleExample.id
            )
        { }
    }


Toolbar elements implementations

The controls for toolbar elements are the same as their equivalent in UIToolkit, but they inherit some toolbar functionalities and specific styling.

This section has examples of the following toolbar elements:

EditorToolbarButton

EditorToolbarButton is a standalone class that contains the logic of the element. This example creates a button that generates a cube when you click it:

[EditorToolbarElement(id, typeof(SceneView))]
class CreateCube : EditorToolbarButton
{
// This ID is used to populate toolbar elements.

public const string id = "ExampleToolbar/Button";   

// Because this is a VisualElement, it is appropriate to place initialization logic in the constructor.

// In this method you can also register to any additional events as required. In this example there is a tooltip, an icon, and an action.

    public CreateCube()
       {

// A toolbar element can be either text, icon, or a combination of the two. Keep in mind that if a toolbar is docked horizontally the text will be clipped, so it's a good idea to specify an icon.

            text = "Create Cube";
            icon = AssetDatabase.LoadAssetAtPath<Texture2D>("Assets/CreateCubeIcon.png");
            tooltip = "Instantiate a cube in the scene.";
            clicked += OnClick;
}

void OnClick()
{
    var newObj = GameObject.CreatePrimitive(PrimitiveType.Cube).transform;

    // When writing editor tools, don't forget to be a good citizen and implement Undo.

    Undo.RegisterCreatedObjectUndo(newObj.gameObject, "Create Cube");

// Note: Using ObjectFactory class instead of GameObject(like in this example) will register the undo entry automatically removing the need to register manually.

}
}

Add the element’s ID to the Overlay constructor:

[Overlay(typeof(SceneView), "ElementToolbar Example")]
[Icon("Assets/unity.png")]
public class EditorToolbarExample : ToolbarOverlay
{
    EditorToolbarExample() : base(CreateCube.id) { }

}

EditorToolbarToggle

Create a standalone class that contains all the logic of the element. This example creates a toggle that prints its state in the console and updates its text in the element:

[EditorToolbarElement(id, typeof(SceneView))]
class ToggleExample : EditorToolbarToggle
{
    public const string id = "ExampleToolbar/Toggle";
    public ToggleExample()
    {
        text = "Toggle OFF";

    // Register the class to a callback for when the toggle’s state changes

        this.RegisterValueChangedCallback(OnStateChange);
    }

    void OnStateChange(ChangeEvent<bool> evt)
    {
        if (evt.newValue)
        {

    // Put logic for when the state is ON here

                Debug.Log("Toggle State -> ON");
        text = "Toggle ON";
        }
        else
        {

    // Put logic for when the state is OFF here

                Debug.Log("Toggle State -> OFF");
        text = "Toggle OFF";
        }
    }
}

Add the element’s ID to the Overlay constructor:

[[Overlay(typeof(SceneView), "ElementToolbar Example")]
[Icon("Assets/unity.png")]
public class EditorToolbarExample : ToolbarOverlay
{
    EditorToolbarExample() : base(
ToggleExample.id
) { }

}

EditorToolbarDropdown

Create a standalone class that contains all the logic of the element. Here is a simple example of a dropdown that adjusts its text with the drop-down selection.

[EditorToolbarElement(id, typeof(SceneView))]
class DropdownExample : EditorToolbarDropdown
{
    public const string id = "ExampleToolbar/Dropdown";

    static string dropChoice = null;

    public DropdownExample()
    {
        text = "Axis";
        clicked += ShowDropdown;
    }

    void ShowDropdown()
    {

// A simple GenericMenu to populate the dropdown content

        var menu = new GenericMenu();
        menu.AddItem(new GUIContent("X"), dropChoice == "X", () => { text = "X"; dropChoice = "X"; });
        menu.AddItem(new GUIContent("Y"), dropChoice == "Y", () => { text = "Y"; dropChoice = "Y"; });
        menu.AddItem(new GUIContent("Z"), dropChoice == "Z", () => { text = "Z"; dropChoice = "Z"; });
        menu.ShowAsContext();
    }
}

Add the element’s ID to the Overlay constructor:

[Overlay(typeof(SceneView), "ElementToolbar Example")]
[Icon("Assets/unity.png")]
public class EditorToolbarExample : ToolbarOverlay
{
    EditorToolbarExample() : base(
DropdownExample.id
) { }

}

EditorToolbarDropdownToggle

Create a standalone class that contains all the logic of the element. A dropdown toggle is a dropdown that can toggled like the Gizmo menu in the Scene view. This example creates a rectangle in the corner of the Scene view whos color you can choose from a dropdown in the overlay.

[EditorToolbarElement(id, typeof(SceneView))]
class DropdownToggleExample : EditorToolbarDropdownToggle, IAccessContainerWindow
{
    public const string id = "ExampleToolbar/DropdownToggle";


    // This property is specified by IAccessContainerWindow and is used to access the Overlay's EditorWindow.

    public EditorWindow containerWindow { get; set; }
    static int colorIndex = 0;
    static readonly Color[] colors = new Color[] { Color.red, Color.green, Color.cyan };
    public DropdownToggleExample()
    {
        text = "Color Bar";
        tooltip = "Display a color rectangle in the top left of the Scene view. Toggle on or off, and open the dropdown" +
                "to change the color.";


   // When the dropdown is opened, ShowColorMenu is invoked and you can create a pop-up menu.

        dropdownClicked += ShowColorMenu;


    // Subscribe to the Scene view OnGUI callback to draw a color swatch.

        SceneView.duringSceneGui += DrawColorSwatch;
    }


    void DrawColorSwatch(SceneView view)
    {

        // Test that this callback is for the correct Scene view, and check if the toggle is on
     // or off (value).

        if (view != containerWindow || !value)
        {
            return;
        }


        Handles.BeginGUI();
            GUI.color = colors[colorIndex];
        GUI.DrawTexture(new Rect(8, 8, 120, 24), Texture2D.whiteTexture);
        GUI.color = Color.white;
        Handles.EndGUI();
    }


    // When the drop-down button is clicked, this method creates a pop-up menu at the mouse cursor position.

    void ShowColorMenu()
    {
        var menu = new GenericMenu();
        menu.AddItem(new GUIContent("Red"), colorIndex == 0, () => colorIndex = 0);
        menu.AddItem(new GUIContent("Green"), colorIndex == 1, () => colorIndex = 1);
        menu.AddItem(new GUIContent("Blue"), colorIndex == 2, () => colorIndex = 2);
        menu.ShowAsContext();
    }
}

Add the element’s ID to the Overlay constructor:

[Overlay(typeof(SceneView), "ElementToolbar Example")]
[Icon("Assets/unity.png")]
public class EditorToolbarExample : ToolbarOverlay
{
    EditorToolbarExample() : base(
DropdownToggleExample.id
) { }


}
Create and manage overlay configurations
Position GameObjects