Implement item brushes and item NBT for bukkit.

This allows usage of `/br <apply|paint> <shape> item` and the `offhand`
syntax for item parser to use NBT.

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitAdapter.java

@@ -439,6 +439,9 @@ public class BukkitAdapter {
      */
     public static BaseItemStack adapt(ItemStack itemStack) {
         checkNotNull(itemStack);
+        if (WorldEditPlugin.getInstance().getBukkitImplAdapter() != null) {
+            return WorldEditPlugin.getInstance().getBukkitImplAdapter().adapt(itemStack);
+        }
         return new BaseItemStack(ItemTypes.get(itemStack.getType().getKey().toString()), itemStack.getAmount());
     }
 
@@ -450,6 +453,9 @@ public class BukkitAdapter {
      */
     public static ItemStack adapt(BaseItemStack item) {
         checkNotNull(item);
+        if (WorldEditPlugin.getInstance().getBukkitImplAdapter() != null) {
+            return WorldEditPlugin.getInstance().getBukkitImplAdapter().adapt(item);
+        }
         return new ItemStack(adapt(item.getType()), item.getAmount());
     }
 }

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitWorld.java

@@ -22,6 +22,7 @@ package com.sk89q.worldedit.bukkit;
 import com.sk89q.worldedit.EditSession;
 import com.sk89q.worldedit.WorldEdit;
 import com.sk89q.worldedit.WorldEditException;
+import com.sk89q.worldedit.blocks.BaseItem;
 import com.sk89q.worldedit.blocks.BaseItemStack;
 import com.sk89q.worldedit.bukkit.adapter.BukkitImplAdapter;
 import com.sk89q.worldedit.entity.BaseEntity;
@@ -30,6 +31,7 @@ import com.sk89q.worldedit.math.BlockVector2;
 import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.math.Vector3;
 import com.sk89q.worldedit.regions.Region;
+import com.sk89q.worldedit.util.Direction;
 import com.sk89q.worldedit.util.TreeGenerator;
 import com.sk89q.worldedit.world.AbstractWorld;
 import com.sk89q.worldedit.world.biome.BiomeType;
@@ -461,6 +463,16 @@ public class BukkitWorld extends AbstractWorld {
         return false;
     }
 
+    @Override
+    public boolean useItem(BlockVector3 position, BaseItem item, Direction face) {
+        BukkitImplAdapter adapter = WorldEditPlugin.getInstance().getBukkitImplAdapter();
+        if (adapter != null) {
+            return adapter.simulateItemUse(getWorld(), position, item, face);
+        }
+
+        return false;
+    }
+
     @Override
     public BiomeType getBiome(BlockVector2 position) {
         return BukkitAdapter.adapt(getWorld().getBiome(position.getBlockX(), position.getBlockZ()));

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/adapter/BukkitImplAdapter.java

@@ -20,17 +20,22 @@
 package com.sk89q.worldedit.bukkit.adapter;
 
 import com.sk89q.jnbt.CompoundTag;
+import com.sk89q.worldedit.blocks.BaseItem;
+import com.sk89q.worldedit.blocks.BaseItemStack;
 import com.sk89q.worldedit.entity.BaseEntity;
 import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.registry.state.Property;
+import com.sk89q.worldedit.util.Direction;
 import com.sk89q.worldedit.world.DataFixer;
 import com.sk89q.worldedit.world.block.BaseBlock;
 import com.sk89q.worldedit.world.block.BlockState;
 import com.sk89q.worldedit.world.block.BlockStateHolder;
 import com.sk89q.worldedit.world.block.BlockType;
 import org.bukkit.Location;
+import org.bukkit.World;
 import org.bukkit.entity.Entity;
 import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemStack;
 
 import java.util.Map;
 
@@ -126,4 +131,33 @@ public interface BukkitImplAdapter {
      * @param player The player
      */
     void sendFakeOP(Player player);
+
+    /**
+     * Simulates a player using an item.
+     *
+     * @param world the world
+     * @param position the location
+     * @param item the item to be used
+     * @param face the direction in which to "face" when using the item
+     * @return whether the usage was successful
+     */
+    default boolean simulateItemUse(World world, BlockVector3 position, BaseItem item, Direction face) {
+        return false;
+    }
+
+    /**
+     * Create a Bukkit ItemStack with NBT, if available.
+     *
+     * @param item the WorldEdit BaseItemStack to adapt
+     * @return the Bukkit ItemStack
+     */
+    ItemStack adapt(BaseItemStack item);
+
+    /**
+     * Create a WorldEdit ItemStack with NBT, if available.
+     *
+     * @param itemStack the Bukkit ItemStack to adapt
+     * @return the WorldEdit BaseItemStack
+     */
+    BaseItemStack adapt(ItemStack itemStack);
 }