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Source/Editor/GUI/Drag/DragScripts.cs

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+// Copyright (c) 2012-2020 Wojciech Figat. All rights reserved.
+
+using System;
+using System.Collections.Generic;
+using FlaxEngine;
+using FlaxEngine.GUI;
+
+namespace FlaxEditor.GUI.Drag
+{
+    /// <summary>
+    /// Scripts references drag handler.
+    /// </summary>
+    public sealed class DragScripts : DragScripts<DragEventArgs>
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="DragScripts"/> class.
+        /// </summary>
+        /// <param name="validateFunction">The validation function</param>
+        public DragScripts(Func<Script, bool> validateFunction)
+        : base(validateFunction)
+        {
+        }
+    }
+
+    /// <summary>
+    /// Helper class for handling <see cref="Script"/> instance drag and drop.
+    /// </summary>
+    /// <seealso cref="Script" />
+    public class DragScripts<U> : DragHelper<Script, U> where U : DragEventArgs
+    {
+        /// <summary>
+        /// The default prefix for drag data used for <see cref="Script"/>.
+        /// </summary>
+        public const string DragPrefix = "SCRIPT!?";
+
+        /// <summary>
+        /// Creates a new DragHelper
+        /// </summary>
+        /// <param name="validateFunction">The validation function</param>
+        public DragScripts(Func<Script, bool> validateFunction)
+        : base(validateFunction)
+        {
+        }
+
+
+        /// <inheritdoc/>
+        public override DragData ToDragData(Script item) => GetDragData(item);
+
+        /// <inheritdoc/>
+        public override DragData ToDragData(IEnumerable<Script> items) => GetDragData(items);
+
+        /// <summary>
+        /// Gets the drag data.
+        /// </summary>
+        /// <param name="item">The script.</param>
+        /// <returns>The data.</returns>
+        public static DragData GetDragData(Script item)
+        {
+            if (item == null)
+                throw new ArgumentNullException();
+
+            return new DragDataText(DragPrefix + item.ID.ToString("N"));
+        }
+
+        /// <summary>
+        /// Gets the drag data.
+        /// </summary>
+        /// <param name="items">The items.</param>
+        /// <returns>The data.</returns>
+        public static DragData GetDragData(IEnumerable<Script> items)
+        {
+            if (items == null)
+                throw new ArgumentNullException();
+
+            string text = DragPrefix;
+            foreach (var item in items)
+                text += item.ID.ToString("N") + '\n';
+
+            return new DragDataText(text);
+        }
+
+        /// <summary>
+        /// Tries to parse the drag data.
+        /// </summary>
+        /// <param name="data">The data.</param>
+        /// <returns>
+        /// Gathered objects or empty IEnumerable if cannot get any valid.
+        /// </returns>
+        public override IEnumerable<Script> FromDragData(DragData data)
+        {
+            if (data is DragDataText dataText)
+            {
+                if (dataText.Text.StartsWith(DragPrefix))
+                {
+                    // Remove prefix and parse spitted names
+                    var ids = dataText.Text.Remove(0, DragPrefix.Length).Split('\n');
+                    var results = new List<Script>(ids.Length);
+                    for (int i = 0; i < ids.Length; i++)
+                    {
+                        // Find element
+                        Guid id;
+                        if (Guid.TryParse(ids[i], out id))
+                        {
+                            var obj = FlaxEngine.Object.Find<Script>(ref id);
+
+                            // Check it
+                            if (obj != null)
+                                results.Add(obj);
+                        }
+                    }
+
+                    return results.ToArray();
+                }
+            }
+            return new Script[0];
+        }
+
+        /// <summary>
+        /// Tries to parse the drag data to validate if it has valid scripts darg.
+        /// </summary>
+        /// <param name="data">The data.</param>
+        /// <returns>True if drag data has valid scripts, otherwise false.</returns>
+        public static bool IsValidData(DragDataText data)
+        {
+            if (data.Text.StartsWith(DragPrefix))
+            {
+                // Remove prefix and parse spitted names
+                var ids = data.Text.Remove(0, DragPrefix.Length).Split('\n');
+                for (int i = 0; i < ids.Length; i++)
+                {
+                    // Find element
+                    Guid id;
+                    if (Guid.TryParse(ids[i], out id))
+                    {
+                        var obj = FlaxEngine.Object.Find<Script>(ref id);
+
+                        // Check it
+                        if (obj != null)
+                            return true;
+                    }
+                }
+            }
+
+            return false;
+        }
+    }
+}