Introduce Item use results - can be success, fail or none

closes #2693, closes #2705, closes #2734

src/pocketmine/item/ItemUseResult.php

@@ -0,0 +1,65 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+declare(strict_types=1);
+
+namespace pocketmine\item;
+
+final class ItemUseResult{
+	/** @var ItemUseResult */
+	private static $NONE;
+	/** @var ItemUseResult */
+	private static $FAILED;
+	/** @var ItemUseResult */
+	private static $SUCCEEDED;
+
+	/**
+	 * No action attempted to take place. Does nothing.
+	 *
+	 * @return ItemUseResult
+	 */
+	public static function none() : ItemUseResult{
+		return self::$NONE ?? (self::$NONE = new self());
+	}
+
+	/**
+	 * An action attempted to take place, but failed due to cancellation. This triggers rollback behaviour for a remote
+	 * player.
+	 *
+	 * @return ItemUseResult
+	 */
+	public static function fail() : ItemUseResult{
+		return self::$FAILED ?? (self::$FAILED = new self());
+	}
+
+	/**
+	 * An action took place successfully. Changes inventory contents if appropriate.
+	 *
+	 * @return ItemUseResult
+	 */
+	public static function success() : ItemUseResult{
+		return self::$SUCCEEDED ?? (self::$SUCCEEDED = new self());
+	}
+
+	private function __construct(){
+		//NOOP
+	}
+}