break cycle between block and inventory packages

src/block/inventory/DoubleChestInventory.php

@@ -0,0 +1,99 @@
+<?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\block\inventory;
+
+use pocketmine\inventory\BaseInventory;
+use pocketmine\inventory\InventoryHolder;
+use pocketmine\item\Item;
+use pocketmine\player\Player;
+use pocketmine\world\Position;
+use function count;
+
+class DoubleChestInventory extends ChestInventory implements InventoryHolder{
+	/** @var ChestInventory */
+	private $left;
+	/** @var ChestInventory */
+	private $right;
+
+	public function __construct(ChestInventory $left, ChestInventory $right){
+		$this->left = $left;
+		$this->right = $right;
+		BaseInventory::__construct($this->left->getSize() + $this->right->getSize());
+	}
+
+	public function getInventory(){
+		return $this;
+	}
+
+	/**
+	 * @return Position
+	 */
+	public function getHolder(){
+		return $this->left->getHolder();
+	}
+
+	public function getItem(int $index) : Item{
+		return $index < $this->left->getSize() ? $this->left->getItem($index) : $this->right->getItem($index - $this->left->getSize());
+	}
+
+	public function setItem(int $index, Item $item) : void{
+		$old = $this->getItem($index);
+		$index < $this->left->getSize() ? $this->left->setItem($index, $item) : $this->right->setItem($index - $this->left->getSize(), $item);
+		$this->onSlotChange($index, $old);
+	}
+
+	public function getContents(bool $includeEmpty = false) : array{
+		$result = $this->left->getContents($includeEmpty);
+		$leftSize = $this->left->getSize();
+
+		foreach($this->right->getContents($includeEmpty) as $i => $item){
+			$result[$i + $leftSize] = $item;
+		}
+
+		return $result;
+	}
+
+	public function onOpen(Player $who) : void{
+		parent::onOpen($who);
+
+		if(count($this->getViewers()) === 1 and $this->right->getHolder()->isValid()){
+			$this->right->broadcastBlockEventPacket(true);
+		}
+	}
+
+	public function onClose(Player $who) : void{
+		if(count($this->getViewers()) === 1 and $this->right->getHolder()->isValid()){
+			$this->right->broadcastBlockEventPacket(false);
+		}
+		parent::onClose($who);
+	}
+
+	public function getLeftSide() : ChestInventory{
+		return $this->left;
+	}
+
+	public function getRightSide() : ChestInventory{
+		return $this->right;
+	}
+}