The constructor for ToolbarOverlay accepts a list of IDs corresponding to UnityEditor.Toolbars.EditorToolbarElement::id.
Toolbars are composed of collections of UnityEditor.Toolbars.EditorToolbarElement. In this way it is very simple to reuse elements to create customized toolbars.
Toolbar overlays require specific styling, so in most cases it is preferable to inherit one of the predefined EditorToolbar types when creating Visual Elements. If custom UI is required, it is valid to inherit any UnityEngine.UIElements.VisualElement type and provide styling yourself.
using UnityEditor;
using UnityEditor.Overlays;
using UnityEditor.Toolbars;
using UnityEngine;
// [EditorToolbarElement(Identifier, EditorWindowType)] is used to register toolbar elements for use in ToolbarOverlay
// implementations.
[EditorToolbarElement(id, typeof(SceneView))]
class CreateCubes : 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; }
// As this is ultimately just 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. Here we will just set up the basics:
// a tooltip, icon, and action.
public CreateCubes()
{
// 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 Cubes";
icon = AssetDatabase.LoadAssetAtPath<Texture2D>("Assets/CreateCubesIcon.png");
tooltip = "Instantiate some cubes in the scene.";
clicked += OnClick;
}
// This method will be invoked when the `CreateCubes` button is clicked.
void OnClick()
{
var parent = new GameObject("Cubes").transform;
// When writing editor tools don't forget to be a good citizen and implement Undo!
Undo.RegisterCreatedObjectUndo(parent.gameObject, "Create Cubes in Sphere");
for (int i = 0; i < 50; i++)
{
var cube = GameObject.CreatePrimitive(PrimitiveType.Cube).transform;
Undo.RegisterCreatedObjectUndo(cube.gameObject, "Create Cubes in Sphere");
cube.position = Random.insideUnitSphere * 25;
cube.rotation = Quaternion.LookRotation(Random.onUnitSphere);
Undo.SetTransformParent(cube, parent, "Create Cubes in Sphere");
cube.SetParent(parent);
}
Selection.activeTransform = parent;
if (containerWindow is SceneView view)
view.FrameSelected();
}
}
// Same as above, except this time we'll create a toggle + dropdown toolbar item.
[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 };
DropdownToggleExample()
{
text = "Color Bar";
tooltip = "Display a color swatch 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();
}
}
// All Overlays must be tagged with the OverlayAttribute
[Overlay(typeof(SceneView), "Placement Tools")]
// IconAttribute provides a way to define an icon for when an Overlay is in collapsed form. If not provided, the first
// two letters of the Overlay name will be used.
[Icon("Assets/PlacementToolsIcon.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 2 EditorToolbarElementAttribute IDs. This will
// create a toolbar overlay with buttons for the CreateCubes and DropdownToggleExample examples.
// 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(
CreateCubes.id,
DropdownToggleExample.id)
{}
}