SPIGOT-7309: Add API for jukebox inventories

By: Parker Hawke <hawkeboyz2@hotmail.com>

paper-api/src/main/java/org/bukkit/block/Jukebox.java

@@ -1,14 +1,16 @@
 package org.bukkit.block;
 
 import org.bukkit.Material;
+import org.bukkit.inventory.BlockInventoryHolder;
 import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.JukeboxInventory;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 /**
  * Represents a captured state of a jukebox.
  */
-public interface Jukebox extends TileState {
+public interface Jukebox extends TileState, BlockInventoryHolder {
 
     /**
      * Gets the record inserted into the jukebox.
@@ -62,4 +64,19 @@ public interface Jukebox extends TileState {
      * @throws IllegalStateException if this block state is not placed
      */
     public boolean eject();
+
+    /**
+     * @return inventory
+     * @see Container#getInventory()
+     */
+    @NotNull
+    @Override
+    JukeboxInventory getInventory();
+
+    /**
+     * @return snapshot inventory
+     * @see Container#getSnapshotInventory()
+     */
+    @NotNull
+    JukeboxInventory getSnapshotInventory();
 }

paper-api/src/main/java/org/bukkit/event/inventory/InventoryType.java

@@ -138,6 +138,10 @@ public enum InventoryType {
      * Pseudo chiseled bookshelf inventory, with 6 slots of undefined type.
      */
     CHISELED_BOOKSHELF(6, "Chiseled Bookshelf", false),
+    /**
+     * Pseudo jukebox inventory with 1 slot of undefined type.
+     */
+    JUKEBOX(1, "Jukebox", false),
     /**
      * The new smithing inventory, with 3 CRAFTING slots and 1 RESULT slot.
      *

paper-api/src/main/java/org/bukkit/inventory/JukeboxInventory.java

@@ -0,0 +1,35 @@
+package org.bukkit.inventory;
+
+import org.bukkit.Tag;
+import org.bukkit.block.Jukebox;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * Interface to the inventory of a Jukebox.
+ */
+public interface JukeboxInventory extends Inventory {
+
+    /**
+     * Set the record in the jukebox.
+     * <p>
+     * This will immediately start playing the inserted item or stop playing if the
+     * item provided is null. If the provided item is not a record (according to
+     * {@link Tag#ITEMS_MUSIC_DISCS}), this method will do nothing and not set the
+     * item in the inventory.
+     *
+     * @param item the new record
+     */
+    void setRecord(@Nullable ItemStack item);
+
+    /**
+     * Get the record in the jukebox.
+     *
+     * @return the current record
+     */
+    @Nullable
+    ItemStack getRecord();
+
+    @Nullable
+    @Override
+    public Jukebox getHolder();
+}