Reuse generateTree code across versions (#2482)

worldedit-bukkit/src/main/java/com/fastasyncworldedit/bukkit/adapter/FaweAdapter.java

@@ -0,0 +1,72 @@
+package com.fastasyncworldedit.bukkit.adapter;
+
+import com.fastasyncworldedit.core.util.TaskManager;
+import com.sk89q.worldedit.EditSession;
+import com.sk89q.worldedit.bukkit.BukkitAdapter;
+import com.sk89q.worldedit.bukkit.BukkitWorld;
+import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldedit.util.TreeGenerator;
+import org.bukkit.Material;
+import org.bukkit.TreeType;
+import org.bukkit.World;
+import org.bukkit.block.BlockState;
+
+import java.util.List;
+
+/**
+ * A base class for version-specific implementations of the BukkitImplAdapter
+ *
+ * @param <TAG>          the version-specific NBT tag type
+ * @param <SERVER_LEVEL> the version-specific ServerLevel type
+ */
+public abstract class FaweAdapter<TAG, SERVER_LEVEL> extends CachedBukkitAdapter implements IDelegateBukkitImplAdapter<TAG> {
+
+    @Override
+    public boolean generateTree(
+            final TreeGenerator.TreeType treeType,
+            final EditSession editSession,
+            BlockVector3 blockVector3,
+            final World world
+    ) {
+        TreeType bukkitType = BukkitWorld.toBukkitTreeType(treeType);
+        if (bukkitType == TreeType.CHORUS_PLANT) {
+            // bukkit skips the feature gen which does this offset normally, so we have to add it back
+            blockVector3 = blockVector3.add(BlockVector3.UNIT_Y);
+        }
+        BlockVector3 target = blockVector3;
+        SERVER_LEVEL serverLevel = getServerLevel(world);
+        List<BlockState> placed = TaskManager.taskManager().sync(() -> {
+            preCaptureStates(serverLevel);
+            try {
+                if (!world.generateTree(BukkitAdapter.adapt(world, target), bukkitType)) {
+                    return null;
+                }
+                return getCapturedBlockStatesCopy(serverLevel);
+            } finally {
+                postCaptureBlockStates(serverLevel);
+            }
+        });
+
+        if (placed == null || placed.isEmpty()) {
+            return false;
+        }
+        for (BlockState blockState : placed) {
+            if (blockState == null || blockState.getType() == Material.AIR) {
+                continue;
+            }
+            editSession.setBlock(blockState.getX(), blockState.getY(), blockState.getZ(),
+                    BukkitAdapter.adapt(blockState.getBlockData())
+            );
+        }
+        return true;
+    }
+
+    protected abstract void preCaptureStates(SERVER_LEVEL serverLevel);
+
+    protected abstract List<BlockState> getCapturedBlockStatesCopy(SERVER_LEVEL serverLevel);
+
+    protected abstract void postCaptureBlockStates(SERVER_LEVEL serverLevel);
+
+    protected abstract SERVER_LEVEL getServerLevel(World world);
+
+}