Unity Project View Asset Drag/Move Confirmation

DragAssetConfirmation.cs

// ----------------------------------------------
// -- Project View Asset Move Confirmation ------
// -- Place In Editor Folder --------------------
// ----------------------------------------------

using System;
using System.IO;
using UnityEditor;

internal sealed class DragAssetConfirmation : UnityEditor.AssetModificationProcessor
{
    private static bool moveAllItems;

    private static AssetMoveResult OnWillMoveAsset(string sourcePath, string destinationPath)
    {
        if (moveAllItems) return AssetMoveResult.DidNotMove;

        var sourceDir = Path.GetDirectoryName(sourcePath);
        var destinationDir = Path.GetDirectoryName(destinationPath);

        if (sourceDir == destinationDir) return AssetMoveResult.DidNotMove;

        var index = EditorUtility.DisplayDialogComplex
        (
            title: "Confirm Asset Move",
            message: $"{sourcePath} -> {destinationPath} Move These Items?",
            ok: "Ok",
            cancel: "Cancel",
            alt: "Move All Items"
        );

        switch (index)
        {
            case 0: return AssetMoveResult.DidNotMove;
            case 1: return AssetMoveResult.FailedMove;
            case 2:
            {
                moveAllItems = true;
                EditorApplication.delayCall += () => moveAllItems = false;
                return AssetMoveResult.DidNotMove;
            }
        }

        throw new InvalidOperationException();
    }
}