InvMenuTest.php

<?php
namespace imt;

use muqsit\invmenu\{InvMenu, InvMenuHandler};

use pocketmine\block\Block;
use pocketmine\event\block\BlockPlaceEvent;
use pocketmine\event\Listener;
use pocketmine\item\Item;
use pocketmine\Player;
use pocketmine\plugin\PluginBase;
use pocketmine\scheduler\Task;
use pocketmine\Server;
use pocketmine\utils\TextFormat as TF;

class Main extends PluginBase implements Listener {

    /** @var InvMenu */
    private $menu;

    public function onEnable() : void
    {
        if (!InvMenuHandler::isRegistered()) {
            InvMenuHandler::register($this);
        }

        $this->menu = InvMenu::create(InvMenu::TYPE_HOPPER)
            ->readonly()
            ->setListener([$this, 'handleClicking'])
            ->sessionize();

        $this->getServer()->getPluginManager()->registerEvents($this, $this);
    }

    public function handleClicking(Player $player, Item $itemClicked) : bool
    {
        $player->sendMessage(TF::RED.'Hi '.$itemClicked->getName());
        return true;
    }

    public function onBlockPlace(BlockPlaceEvent $event) : void
    {
        if ($event->getBlock()->getId() === Block::GLASS) {
            $player = $event->getPlayer();
            $this->menu->send($player);
            $player->getServer()->getScheduler()->scheduleRepeatingTask(new class($this->menu->getInventory($player)) extends Task {

                /** @var \pocketmine\inventory\BaseInventory */
                public $inventory;

                public function __construct($inventory)
                {
                    $this->inventory = $inventory;
                }

                public function onRun(int $tick) : void
                {
                    if (empty($this->inventory->getViewers())) {
                        Server::getInstance()->getScheduler()->cancelTask($this->getTaskId());
                        return;
                    }

                    $this->inventory->setContents([Item::get(mt_rand(256, 511)), Item::get(mt_rand(256, 511)), Item::get(mt_rand(256, 511)), Item::get(mt_rand(256, 511)), Item::get(mt_rand(256, 511))]);
                }
            }, 20);
        }
    }
}