SPIGOT-5311: Add API to get/set item associated with throwable projectiles

By: Lars Dormans <lars.dormans@live.nl>

paper-api/src/main/java/org/bukkit/entity/Egg.java

@@ -3,4 +3,4 @@ package org.bukkit.entity;
 /**
  * Represents a thrown egg.
  */
-public interface Egg extends Projectile {}
+public interface Egg extends ThrowableProjectile {}

paper-api/src/main/java/org/bukkit/entity/EnderPearl.java

@@ -3,6 +3,6 @@ package org.bukkit.entity;
 /**
  * Represents a thrown Ender Pearl entity
  */
-public interface EnderPearl extends Projectile {
+public interface EnderPearl extends ThrowableProjectile {
 
 }

paper-api/src/main/java/org/bukkit/entity/LargeFireball.java

@@ -3,5 +3,5 @@ package org.bukkit.entity;
 /**
  * Represents a large {@link Fireball}
  */
-public interface LargeFireball extends Fireball {
+public interface LargeFireball extends SizedFireball {
 }

paper-api/src/main/java/org/bukkit/entity/SizedFireball.java

@@ -0,0 +1,25 @@
+package org.bukkit.entity;
+
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Represents a sized fireball.
+ */
+public interface SizedFireball extends Fireball {
+
+    /**
+     * Gets the display {@link ItemStack}.
+     *
+     * @return display ItemStack
+     */
+    @NotNull
+    ItemStack getDisplayItem();
+
+    /**
+     * Sets the display {@link ItemStack} for the fireball.
+     *
+     * @param item the ItemStack to display
+     */
+    void setDisplayItem(@NotNull ItemStack item);
+}

paper-api/src/main/java/org/bukkit/entity/SmallFireball.java

@@ -3,6 +3,6 @@ package org.bukkit.entity;
 /**
  * Represents a small {@link Fireball}
  */
-public interface SmallFireball extends Fireball {
+public interface SmallFireball extends SizedFireball {
 
 }

paper-api/src/main/java/org/bukkit/entity/Snowball.java

@@ -3,4 +3,4 @@ package org.bukkit.entity;
 /**
  * Represents a snowball.
  */
-public interface Snowball extends Projectile {}
+public interface Snowball extends ThrowableProjectile {}

paper-api/src/main/java/org/bukkit/entity/ThrowableProjectile.java

@@ -0,0 +1,22 @@
+package org.bukkit.entity;
+
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+
+public interface ThrowableProjectile extends Projectile {
+
+    /**
+     * Gets the ItemStack the thrown projectile will display.
+     *
+     * @return The thrown item display ItemStack
+     */
+    @NotNull
+    ItemStack getItem();
+
+    /**
+     * Sets the display ItemStack for the thrown projectile.
+     *
+     * @param item ItemStack set to be displayed
+     */
+    void setItem(@NotNull ItemStack item);
+}

paper-api/src/main/java/org/bukkit/entity/ThrownExpBottle.java

@@ -3,6 +3,6 @@ package org.bukkit.entity;
 /**
  * Represents a thrown Experience bottle.
  */
-public interface ThrownExpBottle extends Projectile {
+public interface ThrownExpBottle extends ThrowableProjectile {
 
 }