Implemented Farmland turns to dirt when jumped on. (#4434)

src/block/Farmland.php

@@ -24,9 +24,13 @@ declare(strict_types=1);
 namespace pocketmine\block;
 
 use pocketmine\block\utils\BlockDataSerializer;
+use pocketmine\entity\Entity;
+use pocketmine\entity\Living;
+use pocketmine\event\entity\EntityTrampleFarmlandEvent;
 use pocketmine\item\Item;
 use pocketmine\math\AxisAlignedBB;
 use pocketmine\math\Facing;
+use function lcg_value;
 
 class Farmland extends Transparent{
 
@@ -86,6 +90,17 @@ class Farmland extends Transparent{
 		}
 	}
 
+	public function onEntityLand(Entity $entity) : ?float{
+		if($entity instanceof Living && lcg_value() < $entity->getFallDistance() - 0.5){
+			$ev = new EntityTrampleFarmlandEvent($entity, $this);
+			$ev->call();
+			if(!$ev->isCancelled()){
+				$this->getPosition()->getWorld()->setBlock($this->getPosition(), VanillaBlocks::DIRT());
+			}
+		}
+		return null;
+	}
+
 	protected function canHydrate() : bool{
 		//TODO: check rain
 		$start = $this->position->add(-4, 0, -4);

src/event/entity/EntityTrampleFarmlandEvent.php

@@ -0,0 +1,48 @@
+<?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\entity;
+
+use pocketmine\block\Block;
+use pocketmine\entity\Living;
+use pocketmine\event\Cancellable;
+use pocketmine\event\CancellableTrait;
+
+/**
+ * @phpstan-extends EntityEvent<Living>
+ */
+class EntityTrampleFarmlandEvent extends EntityEvent implements Cancellable{
+	use CancellableTrait;
+
+	/** @var Block */
+	private $block;
+
+	public function __construct(Living $entity, Block $block){
+		$this->entity = $entity;
+		$this->block = $block;
+	}
+
+	public function getBlock() : Block{
+		return $this->block;
+	}
+}