Adding writable and written books. (#1397)

* Adding writable and written books.
* Added a PlayerEditBookEvent.
* Changed BookEditPacket field names.

src/pocketmine/event/player/PlayerEditBookEvent.php

@@ -0,0 +1,101 @@
+<?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\event\player;
+
+use pocketmine\event\Cancellable;
+use pocketmine\item\WritableBook;
+use pocketmine\Player;
+
+class PlayerEditBookEvent extends PlayerEvent implements Cancellable{
+	public static $handlerList = null;
+
+	const ACTION_REPLACE_PAGE = 0;
+	const ACTION_ADD_PAGE = 1;
+	const ACTION_DELETE_PAGE = 2;
+	const ACTION_SWAP_PAGES = 3;
+	const ACTION_SIGN_BOOK = 4;
+
+	/** @var WritableBook */
+	private $oldBook;
+	/** @var int */
+	private $action;
+	/** @var WritableBook */
+	private $newBook;
+	/** @var int[] */
+	private $modifiedPages;
+
+	public function __construct(Player $player, WritableBook $oldBook, WritableBook $newBook, int $action, array $modifiedPages){
+		$this->player = $player;
+		$this->oldBook = $oldBook;
+		$this->newBook = $newBook;
+		$this->action = $action;
+		$this->modifiedPages = $modifiedPages;
+	}
+
+	/**
+	 * Returns the action of the event.
+	 *
+	 * @return int
+	 */
+	public function getAction() : int{
+		return $this->action;
+	}
+
+	/**
+	 * Returns the book before it was modified.
+	 *
+	 * @return WritableBook
+	 */
+	public function getOldBook() : WritableBook{
+		return $this->oldBook;
+	}
+
+	/**
+	 * Returns the book after it was modified.
+	 * The new book may be a written book, if the book was signed.
+	 *
+	 * @return WritableBook
+	 */
+	public function getNewBook() : WritableBook{
+		return $this->newBook;
+	}
+
+	/**
+	 * Sets the new book as the given instance.
+	 *
+	 * @param WritableBook $book
+	 */
+	public function setNewBook(WritableBook $book) : void{
+		$this->newBook = $book;
+	}
+
+	/**
+	 * Returns an array containing the page IDs of modified pages.
+	 *
+	 * @return int[]
+	 */
+	public function getModifiedPages() : array{
+		return $this->modifiedPages;
+	}
+}