SceneViewContextMenu.cs

using System.Collections.Generic;
using System.Linq;
using UnityEditor;
using UnityEngine;
using UnityEngine.SceneManagement;

[InitializeOnLoad]
public static class SceneViewContextMenu
{
    private static Vector3[] corners = new Vector3[ 4 ];

    static SceneViewContextMenu()
    {
        SceneView.onSceneGUIDelegate += OnSceneGUI;
    }

    private static void OnSceneGUI( SceneView sceneView )
    {
        var e = Event.current;

        if ( e == null ) return;
        if ( e.type != EventType.MouseUp ) return;
        if ( e.button != 1 ) return;

        e.Use();

        ShowSpriteSelectionMenu( e.mousePosition );
    }

    private static void ShowSpriteSelectionMenu( Vector2 screenPos )
    {
        var groups = SceneViewRaycast( screenPos )
            .GroupBy( c => c.gameObject.scene.name )
            .ToArray()
        ;

        var isOneScene = GetAllScenes().Count( c => c.isLoaded ) <= 1;

        var menu = new GenericMenu();

        var nameTable = new Dictionary<string, int>();

        foreach ( var group in groups )
        {
            foreach ( var n in group )
            {
                var name = n.name;
                var sceneName = n.gameObject.scene.name;
                var nameWithSceneName = sceneName + "/" + name;
                var isSameName = nameTable.ContainsKey( nameWithSceneName );
                var text = isOneScene ? name : nameWithSceneName;
                if ( isSameName )
                {
                    var count = nameTable[ nameWithSceneName ]++;
                    text += " [" + count.ToString() + "]";
                }
                var content = new GUIContent( text );
                menu.AddItem( content, false, () => OnSelect( n ) );
                if ( !isSameName )
                {
                    nameTable.Add( nameWithSceneName, 1 );
                }
            }
        }
        menu.ShowAsContext();
    }

    private static void OnSelect( RectTransform rectTransform )
    {
        Selection.activeTransform = rectTransform;
        EditorGUIUtility.PingObject( rectTransform );
    }

    private static IEnumerable<RectTransform> SceneViewRaycast( Vector2 mousePos )
    {
        return GetAllScenes()
            .Where( c => c.isLoaded )
            .SelectMany( c => c.GetRootGameObjects() )
            .Where( c => c.activeInHierarchy )
            .SelectMany( c => c.GetComponentsInChildren<RectTransform>() )
            .Where( c =>
            {
                c.GetWorldCorners( corners );
                return NGUIEditorTools.SceneViewDistanceToRectangle( corners, mousePos ) == 0;
            } )
        ;
    }

    private static IEnumerable<Scene> GetAllScenes()
    {
        for ( int i = 0; i < SceneManager.sceneCount; i++ )
        {
            yield return SceneManager.GetSceneAt( i );
        }
    }
}