Remove circular dependency between Tree and its children

src/world/generator/object/Tree.php

@@ -26,7 +26,6 @@ namespace pocketmine\world\generator\object;
 use pocketmine\block\Block;
 use pocketmine\block\Leaves;
 use pocketmine\block\Sapling;
-use pocketmine\block\utils\TreeType;
 use pocketmine\block\VanillaBlocks;
 use pocketmine\utils\Random;
 use pocketmine\world\BlockTransaction;
@@ -49,32 +48,6 @@ abstract class Tree{
 		$this->treeHeight = $treeHeight;
 	}
 
-	/**
-	 * @param TreeType|null $type default oak
-	 */
-	public static function get(Random $random, ?TreeType $type = null) : ?self{
-		$type = $type ?? TreeType::OAK();
-		if($type->equals(TreeType::SPRUCE())){
-			return new SpruceTree();
-		}elseif($type->equals(TreeType::BIRCH())){
-			if($random->nextBoundedInt(39) === 0){
-				return new BirchTree(true);
-			}else{
-				return new BirchTree();
-			}
-		}elseif($type->equals(TreeType::JUNGLE())){
-			return new JungleTree();
-		}elseif($type->equals(TreeType::OAK())){ //default
-			return new OakTree();
-			/*if($random->nextRange(0, 9) === 0){
-				$tree = new BigTree();
-			}else{*/
-
-			//}
-		}
-		return null;
-	}
-
 	public function canPlaceObject(ChunkManager $world, int $x, int $y, int $z, Random $random) : bool{
 		$radiusToCheck = 0;
 		for($yy = 0; $yy < $this->treeHeight + 3; ++$yy){

src/world/generator/object/TreeFactory.php

@@ -0,0 +1,56 @@
+<?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\world\generator\object;
+
+use pocketmine\block\utils\TreeType;
+use pocketmine\utils\Random;
+
+final class TreeFactory{
+
+	/**
+	 * @param TreeType|null $type default oak
+	 */
+	public static function get(Random $random, ?TreeType $type = null) : ?Tree{
+		$type = $type ?? TreeType::OAK();
+		if($type->equals(TreeType::SPRUCE())){
+			return new SpruceTree();
+		}elseif($type->equals(TreeType::BIRCH())){
+			if($random->nextBoundedInt(39) === 0){
+				return new BirchTree(true);
+			}else{
+				return new BirchTree();
+			}
+		}elseif($type->equals(TreeType::JUNGLE())){
+			return new JungleTree();
+		}elseif($type->equals(TreeType::OAK())){ //default
+			return new OakTree();
+			/*if($random->nextRange(0, 9) === 0){
+				$tree = new BigTree();
+			}else{*/
+
+			//}
+		}
+		return null;
+	}
+}

src/world/generator/populator/Tree.php

@@ -27,7 +27,7 @@ use pocketmine\block\BlockLegacyIds;
 use pocketmine\block\utils\TreeType;
 use pocketmine\utils\Random;
 use pocketmine\world\ChunkManager;
-use pocketmine\world\generator\object\Tree as ObjectTree;
+use pocketmine\world\generator\object\TreeFactory;
 
 class Tree extends Populator{
 	/** @var int */
@@ -62,7 +62,7 @@ class Tree extends Populator{
 			if($y === -1){
 				continue;
 			}
-			$tree = ObjectTree::get($random, $this->type);
+			$tree = TreeFactory::get($random, $this->type);
 			$transaction = $tree?->getBlockTransaction($world, $x, $y, $z, $random);
 			$transaction?->apply();
 		}