tool to save asset icon to png file

SaveIconTextureOfAsset.cs

/*
 * SaveIconTextureOfAsset
 * tool to save asset icon to png file
 * 
 * 
 * https://gist.github.com/anatawa12/06751ee6e6b64cc30cee89b8dd2c3ea4
 *
 * Click `Tools/anatawa12 gists/SaveIconTextureOfAsset` to open this window.
 *
 * MIT License
 * 
 * Copyright (c) 2023 anatawa12
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#if UNITY_EDITOR && (!ANATAWA12_GISTS_VPM_PACKAGE || GIST_06751ee6e6b64cc30cee89b8dd2c3ea4)

using System;
using System.Collections.Generic;
using UnityEditor;
using UnityEngine;
using UnityEngine.Rendering;
using Object = UnityEngine.Object;

namespace anatawa12.gists
{
    internal class SaveIconTextureOfAsset : EditorWindow
    {
        private const string GIST_NAME = "SaveIconTextureOfAsset";

        [MenuItem("Tools/anatawa12 gists/" + GIST_NAME)]
        static void Create() => GetWindow<SaveIconTextureOfAsset>(GIST_NAME);

        Object target;
        bool inProgress;

        private void OnGUI()
        {
            target = EditorGUILayout.ObjectField("Target", target, typeof(Object), false);

            EditorGUI.BeginDisabledGroup(inProgress || target == null);
            if (GUILayout.Button("Save"))
            {
                if (target == null)
                {
                    EditorUtility.DisplayDialog("Error", "target is null", "OK");
                    return;
                }

                var path = AssetDatabase.GetAssetPath(target);
                if (string.IsNullOrEmpty(path))
                {
                    EditorUtility.DisplayDialog("Error", "target is not asset", "OK");
                    return;
                }

                var icon = AssetDatabase.GetCachedIcon(path) as Texture2D;
                if (icon == null)
                {
                    EditorUtility.DisplayDialog("Error", "failed to get icon", "OK");
                    return;
                }

                inProgress = true;
                AsyncGPUReadback.Request(icon, 0, TextureFormat.RGBA32, (result) =>
                {
                    inProgress = false;
                    if (result.hasError)
                    {
                        EditorUtility.DisplayDialog("Error", "failed to read icon", "OK");
                        return;
                    }

                    var saveTexture = new Texture2D(result.width, result.height, TextureFormat.RGBA32, 1, false);
                    saveTexture.LoadRawTextureData(result.GetData<byte>());
                    saveTexture.Apply();

                    var bytes = saveTexture.EncodeToPNG();

                    var savePath = EditorUtility.SaveFilePanel("Save Icon Texture", "", target.name + ".png", "png");
                    if (string.IsNullOrEmpty(savePath))
                        return;

                    System.IO.File.WriteAllBytes(savePath, bytes);
                });
            }
            EditorGUI.EndDisabledGroup();
        }
    }
}

#endif