SPIGOT-2706: Implement support for Lock NBT Tag

Containers may now implement the Lockable interface.

By: Senmori <thesenmori@gmail.com>

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

@@ -9,7 +9,7 @@ import org.bukkit.potion.PotionEffectType;
 /**
  * Represents a beacon.
  */
-public interface Beacon extends BlockState, InventoryHolder {
+public interface Beacon extends BlockState, InventoryHolder, Lockable {
 
     /**
      * Returns the list of players within the beacon's range of effect.

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

@@ -6,7 +6,7 @@ import org.bukkit.inventory.InventoryHolder;
 /**
  * Represents a brewing stand.
  */
-public interface BrewingStand extends BlockState, InventoryHolder {
+public interface BrewingStand extends BlockState, InventoryHolder, Lockable {
 
     /**
      * How much time is left in the brewing cycle

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

@@ -6,7 +6,7 @@ import org.bukkit.inventory.InventoryHolder;
 /**
  * Represents a chest.
  */
-public interface Chest extends BlockState, InventoryHolder {
+public interface Chest extends BlockState, InventoryHolder, Lockable {
 
     /**
      * Returns the chest's inventory. If this is a double chest, it returns

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

@@ -6,7 +6,7 @@ import org.bukkit.projectiles.BlockProjectileSource;
 /**
  * Represents a dispenser.
  */
-public interface Dispenser extends BlockState, InventoryHolder {
+public interface Dispenser extends BlockState, InventoryHolder, Lockable {
 
     /**
      * Gets the BlockProjectileSource object for this dispenser.

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

@@ -5,7 +5,7 @@ import org.bukkit.inventory.InventoryHolder;
 /**
  * Represents a dropper.
  */
-public interface Dropper extends BlockState, InventoryHolder {
+public interface Dropper extends BlockState, InventoryHolder, Lockable {
     /**
      * Tries to drop a randomly selected item from the Dropper's inventory,
      * following the normal behavior of a Dropper.

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

@@ -6,7 +6,7 @@ import org.bukkit.inventory.InventoryHolder;
 /**
  * Represents a furnace.
  */
-public interface Furnace extends BlockState, InventoryHolder {
+public interface Furnace extends BlockState, InventoryHolder, Lockable {
 
     /**
      * Get burn time.

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

@@ -5,6 +5,6 @@ import org.bukkit.inventory.InventoryHolder;
 /**
  * Represents a hopper.
  */
-public interface Hopper extends BlockState, InventoryHolder {
+public interface Hopper extends BlockState, InventoryHolder, Lockable {
 
 }

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

@@ -0,0 +1,31 @@
+package org.bukkit.block;
+
+/**
+ * Represents a block (usually a container) that may be locked. When a lock is
+ * active an item with a name corresponding to the key will be required to open
+ * this block.
+ */
+public interface Lockable {
+
+    /**
+     * Checks if the container has a valid (non empty) key.
+     *
+     * @return true if the key is valid.
+     */
+    boolean isLocked();
+
+    /**
+     * Gets the key needed to access the container.
+     *
+     * @return the key needed.
+     */
+    String getLock();
+
+    /**
+     * Sets the key required to access this container. Set to null (or empty
+     * string) to remove key.
+     *
+     * @param key the key required to access the container.
+     */
+    void setLock(String key);
+}