Overlay

描述

Overlay 是在编辑器窗口中可用的持久且可自定义的面板和工具栏。使用 Overlay 以方便且用户可控的方式公开操作和工具选项。

这是所有 Overlay 继承的基类。要创建 Overlay，请返回 UnityEngine.UIElements.VisualElement。

显示 Overlay 的最简单方法是使用 OverlayAttribute 并注册目标 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}");
    }
}

Overlay 可用于实现 ISupportsOverlays 的任何 EditorWindow。可以使用 OverlayCanvas.Add 和 OverlayCanvas.Remove 从 Overlay 菜单中添加和删除 Overlay。

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);
        }
    }
}

Overlay 可以通过 SceneView.AddOverlayToActiveView 和 SceneView.RemoveOverlayFromActiveView 在活动 SceneView 中显示。这对于需要显示 UI 的 EditorTool 很有用。

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);
    }
}

要创建可停靠在工具栏中的 Overlay，请参阅 ToolbarOverlay。

静态属性

属性

公共方法

事件