Extract Fallable into trait + interface

Traits are inferior to components in pretty much every aspect imaginable :(

src/pocketmine/block/Anvil.php

@@ -24,6 +24,8 @@ declare(strict_types=1);
 namespace pocketmine\block;
 
 use pocketmine\block\utils\BlockDataValidator;
+use pocketmine\block\utils\Fallable;
+use pocketmine\block\utils\FallableTrait;
 use pocketmine\inventory\AnvilInventory;
 use pocketmine\item\Item;
 use pocketmine\item\TieredTool;
@@ -33,7 +35,8 @@ use pocketmine\math\Facing;
 use pocketmine\math\Vector3;
 use pocketmine\Player;
 
-class Anvil extends Fallable{
+class Anvil extends Transparent implements Fallable{
+	use FallableTrait;
 
 	public const TYPE_NORMAL = 0;
 	public const TYPE_SLIGHTLY_DAMAGED = 4;
@@ -54,10 +57,6 @@ class Anvil extends Fallable{
 		return 0b11;
 	}
 
-	public function isTransparent() : bool{
-		return true;
-	}
-
 	public function getHardness() : float{
 		return 5;
 	}
@@ -92,4 +91,8 @@ class Anvil extends Fallable{
 		}
 		return parent::place($item, $blockReplace, $blockClicked, $face, $clickVector, $player);
 	}
+
+	public function tickFalling() : ?Block{
+		return null;
+	}
 }

src/pocketmine/block/ConcretePowder.php

@@ -23,9 +23,14 @@ declare(strict_types=1);
 
 namespace pocketmine\block;
 
+use pocketmine\block\utils\Fallable;
+use pocketmine\block\utils\FallableTrait;
 use pocketmine\math\Facing;
 
-class ConcretePowder extends Fallable{
+class ConcretePowder extends Solid implements Fallable{
+	use FallableTrait {
+		onNearbyBlockChange as protected startFalling;
+	}
 
 	public function getHardness() : float{
 		return 0.5;
@@ -39,7 +44,7 @@ class ConcretePowder extends Fallable{
 		if(($block = $this->checkAdjacentWater()) !== null){
 			$this->level->setBlock($this, $block);
 		}else{
-			parent::onNearbyBlockChange();
+			$this->startFalling();
 		}
 	}
 

src/pocketmine/block/Gravel.php

@@ -23,11 +23,14 @@ declare(strict_types=1);
 
 namespace pocketmine\block;
 
+use pocketmine\block\utils\Fallable;
+use pocketmine\block\utils\FallableTrait;
 use pocketmine\item\Item;
 use pocketmine\item\ItemFactory;
 use function mt_rand;
 
-class Gravel extends Fallable{
+class Gravel extends Solid implements Fallable{
+	use FallableTrait;
 
 	protected $id = self::GRAVEL;
 
@@ -56,4 +59,8 @@ class Gravel extends Fallable{
 
 		return parent::getDropsForCompatibleTool($item);
 	}
+
+	public function tickFalling() : ?Block{
+		return null;
+	}
 }

src/pocketmine/block/Sand.php

@@ -23,7 +23,11 @@ declare(strict_types=1);
 
 namespace pocketmine\block;
 
-class Sand extends Fallable{
+use pocketmine\block\utils\Fallable;
+use pocketmine\block\utils\FallableTrait;
+
+class Sand extends Solid implements Fallable{
+	use FallableTrait;
 
 	public function getHardness() : float{
 		return 0.5;
@@ -32,4 +36,8 @@ class Sand extends Fallable{
 	public function getToolType() : int{
 		return BlockToolType::TYPE_SHOVEL;
 	}
+
+	public function tickFalling() : ?Block{
+		return null;
+	}
 }

src/pocketmine/block/utils/Fallable.php

@@ -0,0 +1,38 @@
+<?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\utils;
+
+use pocketmine\block\Block;
+
+interface Fallable{
+
+	/**
+	 * Called every tick by FallingBlock to update the falling state of this block. Used by concrete to check when it
+	 * hits water.
+	 * Return null if you don't want to change the usual behaviour.
+	 *
+	 * @return Block|null
+	 */
+	public function tickFalling() : ?Block;
+}

src/pocketmine/block/utils/FallableTrait.php

@@ -21,33 +21,43 @@
 
 declare(strict_types=1);
 
-namespace pocketmine\block;
+namespace pocketmine\block\utils;
 
+use pocketmine\block\Block;
+use pocketmine\block\BlockFactory;
+use pocketmine\block\Fire;
+use pocketmine\block\Liquid;
 use pocketmine\entity\EntityFactory;
 use pocketmine\entity\object\FallingBlock;
+use pocketmine\level\Position;
 use pocketmine\math\Facing;
 
-abstract class Fallable extends Solid{
+/**
+ * This trait handles falling behaviour for blocks that need them.
+ * TODO: convert this into a dynamic component
+ * @see Fallable
+ */
+trait FallableTrait{
+
+	abstract protected function asPosition() : Position;
+
+	abstract protected function getId() : int;
+
+	abstract protected function getDamage() : int;
 
 	public function onNearbyBlockChange() : void{
-		$down = $this->getSide(Facing::DOWN);
-		if($down->getId() === self::AIR or $down instanceof Liquid or $down instanceof Fire){
-			$this->level->setBlock($this, BlockFactory::get(Block::AIR));
+		$pos = $this->asPosition();
+		$down = $pos->level->getBlock($pos->getSide(Facing::DOWN));
+		if($down->getId() === Block::AIR or $down instanceof Liquid or $down instanceof Fire){
+			$pos->level->setBlock($pos, BlockFactory::get(Block::AIR));
 
-			$nbt = EntityFactory::createBaseNBT($this->add(0.5, 0, 0.5));
+			$nbt = EntityFactory::createBaseNBT($pos->add(0.5, 0, 0.5));
 			$nbt->setInt("TileID", $this->getId());
 			$nbt->setByte("Data", $this->getDamage());
 
 			/** @var FallingBlock $fall */
-			$fall = EntityFactory::create(FallingBlock::class, $this->getLevel(), $nbt);
+			$fall = EntityFactory::create(FallingBlock::class, $pos->getLevel(), $nbt);
 			$fall->spawnToAll();
 		}
 	}
-
-	/**
-	 * @return null|Block
-	 */
-	public function tickFalling() : ?Block{
-		return null;
-	}
 }

src/pocketmine/entity/object/FallingBlock.php

@@ -25,7 +25,7 @@ namespace pocketmine\entity\object;
 
 use pocketmine\block\Block;
 use pocketmine\block\BlockFactory;
-use pocketmine\block\Fallable;
+use pocketmine\block\utils\Fallable;
 use pocketmine\entity\Entity;
 use pocketmine\event\entity\EntityBlockChangeEvent;
 use pocketmine\event\entity\EntityDamageEvent;