Version: Unity 6 Preview (6000.0)
LanguageEnglish
  • C#

Overlay

class in UnityEditor.Overlays

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Description

Overlays are persistent and customizable panels and toolbars that are available within Editor Windows. Use Overlays to expose actions and tool options in a convenient and user-controllable way.

This is the base class that all overlays inherit from. To create an overlay, return a UnityEngine.UIElements.VisualElement.

The simplest way to display an overlay is to use OverlayAttribute and register a target EditorWindow.

using UnityEditor;
using UnityEditor.Overlays;
using UnityEngine.UIElements;

// Specifying `OverlayAttribute.editorWindowType` tells the OverlayCanvas to always show this Overlay in the menu. [Overlay(typeof(SceneView), "Selection Count")] class SelectionCount : Overlay { Label m_Label;

public override VisualElement CreatePanelContent() { Selection.selectionChanged += () => { if (m_Label != null) m_Label.text = $"Selection Count {Selection.count}"; };

return m_Label = new Label($"Selection Count {Selection.count}"); } }

Overlays can be used in any EditorWindow that implements ISupportsOverlays. You can use OverlayCanvas.Add and OverlayCanvas.Remove to add and remove overlays from the Overlays menu.

using System;
using UnityEditor;
using UnityEditor.Overlays;
using UnityEngine;
using UnityEngine.UIElements;

public class OverlayWindowExample : EditorWindow, ISupportsOverlays { bool m_ShowOverlay; InstanceOverlay m_Overlay;

// InstanceOverlay is not registered as a persistent overlay, and it must be instantiated through code. In contrast, // PersistentOverlay is registered with a target window type and will be available at any time. // All OverlayAttribute properties are optional. Here, we specify that when this overlay is added to a window for the // first time, so it is visible by default. If defaultDisplay is set to it's default value of false, the // Overlay will be available in the Overlay Menu when added to a window, but not visible. [Overlay(defaultDisplay = true)] class InstanceOverlay : Overlay { OverlayWindowExample m_Window; public InstanceOverlay(OverlayWindowExample win) => m_Window = win; public override VisualElement CreatePanelContent() => new Label() { text = $"Hello from {m_Window.name}!" }; }

// Persistent overlays are always available in the Overlay Menu. An Overlay is made persistent by assigning the // `editorWindowType` property in `OverlayAttribute`. [Overlay(typeof(OverlayWindowExample), "Persistent Overlay", defaultDisplay = true)] class PersistentOverlay : Overlay { public override VisualElement CreatePanelContent() => new Label() { text = "Hello, I'm always available!" }; }

[MenuItem("Window/Overlay Window")] static void Init() => GetWindow<OverlayWindowExample>();

void OnEnable() => m_Overlay = new InstanceOverlay(this);

void OnGUI() { EditorGUI.BeginChangeCheck(); m_ShowOverlay = EditorGUILayout.Toggle("Show Overlay", m_ShowOverlay); if (EditorGUI.EndChangeCheck()) { if (m_ShowOverlay) overlayCanvas.Add(m_Overlay); else overlayCanvas.Remove(m_Overlay); } } }

Overlays can be shown in the active SceneView through SceneView.AddOverlayToActiveView and SceneView.RemoveOverlayFromActiveView. This is useful for EditorTools that need to show UI.

using System.Linq;
using UnityEngine;
using UnityEditor;
using UnityEditor.EditorTools;
using UnityEditor.Overlays;
using UnityEngine.UIElements;

// A simple tool that moves the selected transforms using an Overlay interface. [EditorTool("Offset", typeof(Transform))] public class OffsetTool : EditorTool { // By default, overlays added to the canvas are not displayed. Setting the `defaultDisplay` property ensures that the // first time this Overlay is added to a canvas it will be visible. [Overlay(defaultDisplay = true)] class OffsetToolOverlay : Overlay { Transform[] selection;

public OffsetToolOverlay(Transform[] targets) => selection = targets;

public override VisualElement CreatePanelContent() { var root = new VisualElement(); root.Add(new Button(() => Move(Vector3.right)) { text = "Move Right" }); root.Add(new Button(() => Move(Vector3.up)) { text = "Move Up" }); root.Add(new Button(() => Move(Vector3.forward)) { text = "Move Forward" }); return root; }

void Move(Vector3 direction) { Undo.RecordObjects(selection, "Move Selection"); foreach (var transform in selection) transform.position += direction; } }

OffsetToolOverlay m_Overlay;

public override void OnActivated() { SceneView.AddOverlayToActiveView(m_Overlay = new OffsetToolOverlay(targets.Select(x => x as Transform).ToArray())); }

public override void OnWillBeDeactivated() { SceneView.RemoveOverlayFromActiveView(m_Overlay); } }

To create an Overlay that is dockable in a toolbar, see ToolbarOverlay.

Static Properties

ussClassNameUSS class name of elements of this type.

Properties

collapsedDefines whether the overlay is in collapsed form.
collapsedIconDefines a custom icon to use when that overlay is in collapsed form.
containerWindowEditorWindow the overlay is contained within.
defaultSizeSet defaultSize to define the size of an Overlay when it hasn't been resized by the user.
displayedShows or hides the overlay.
displayNameName of overlay used as title.
floatingReturns true if overlay is floating, returns false if overlay is docked in a corner or in a toolbar.
floatingPositionLocal position of closest overlay corner to closest dockposition when floating.
idOverlay unique ID.
isInToolbarReturns true if overlay is docked in a toolbar.
layoutThe preferred layout for the Overlay.
maxSizeMaximum size of the Overlay.
minSizeMinimum size of the Overlay.
rootVisualElementThe root VisualElement.
sizeSize of the Overlay.

Public Methods

CloseRemove the Overlay from its OverlayCanvas.
CreateContentCreates a new VisualElement containing the contents of this Overlay.
CreatePanelContentImplement this method to return your visual element content.
OnCreatedOnCreated is invoked when an Overlay is instantiated in an Overlay Canvas.
OnWillBeDestroyedCalled when an Overlay is about to be destroyed.
UndockIf this Overlay is currently in a toolbar, it will be removed and return to a floating state.

Events

collapsedChangedInvoked when Overlay.collapsed value is changed.
displayedChangedThis callback is invoked when the Overlay.displayed value has been changed.
floatingChangedCalled when the value of floating has changed.
floatingPositionChangedThis event is invoked when Overlay.floatingPosition is changed.
layoutChangedSubscribe to this event to be notified when the Overlay.Layout property is modified.