DelegateInventory.php

<?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\inventory;
 
use pocketmine\item\Item;
 
class DelegateInventory extends BaseInventory{
    private InventoryListener $inventoryListener;
    private bool $backingInventoryChanging = false;
 
    public function __construct(
        private Inventory $backingInventory
    ){
        parent::__construct();
        $weakThis = \WeakReference::create($this);
        $this->backingInventory->getListeners()->add($this->inventoryListener = new CallbackInventoryListener(
            static function(Inventory $unused, int $slot, Item $oldItem) use ($weakThis) : void{
                if(($strongThis = $weakThis->get()) !== null){
                    $strongThis->backingInventoryChanging = true;
                    try{
                        $strongThis->onSlotChange($slot, $oldItem);
                    }finally{
                        $strongThis->backingInventoryChanging = false;
                    }
                }
            },
            static function(Inventory $unused, array $oldContents) use ($weakThis) : void{
                if(($strongThis = $weakThis->get()) !== null){
                    $strongThis->backingInventoryChanging = true;
                    try{
                        $strongThis->onContentChange($oldContents);
                    }finally{
                        $strongThis->backingInventoryChanging = false;
                    }
                }
            }
        ));
    }
 
    public function __destruct(){
        $this->backingInventory->getListeners()->remove($this->inventoryListener);
    }
 
    public function getSize() : int{
        return $this->backingInventory->getSize();
    }
 
    public function getItem(int $index) : Item{
        return $this->backingInventory->getItem($index);
    }
 
    protected function internalSetItem(int $index, Item $item) : void{
        $this->backingInventory->setItem($index, $item);
    }
 
    public function getContents(bool $includeEmpty = false) : array{
        return $this->backingInventory->getContents($includeEmpty);
    }
 
    protected function internalSetContents(array $items) : void{
        $this->backingInventory->setContents($items);
    }
 
    public function isSlotEmpty(int $index) : bool{
        return $this->backingInventory->isSlotEmpty($index);
    }
 
    protected function onSlotChange(int $index, Item $before) : void{
        if($this->backingInventoryChanging){
            parent::onSlotChange($index, $before);
        }
    }
 
    protected function onContentChange(array $itemsBefore) : void{
        if($this->backingInventoryChanging){
            parent::onContentChange($itemsBefore);
        }
    }
}