SPIGOT-1319: Add EntityBreedEvent

By: Ryan Michela <deltahat@gmail.com>

paper-api/src/main/java/org/bukkit/event/entity/EntityBreedEvent.java

@@ -0,0 +1,119 @@
+package org.bukkit.event.entity;
+
+import org.apache.commons.lang.Validate;
+import org.bukkit.entity.LivingEntity;
+import org.bukkit.event.Cancellable;
+import org.bukkit.event.HandlerList;
+import org.bukkit.inventory.ItemStack;
+
+/**
+ * Called when one Entity breeds with another Entity.
+ */
+public class EntityBreedEvent extends EntityEvent implements Cancellable {
+
+    private static final HandlerList handlers = new HandlerList();
+    //
+    private final LivingEntity mother;
+    private final LivingEntity father;
+    private final LivingEntity breeder;
+    private final ItemStack bredWith;
+    private int experience;
+    //
+    private boolean cancel;
+
+    public EntityBreedEvent(LivingEntity child, LivingEntity mother, LivingEntity father, LivingEntity breeder, ItemStack bredWith, int experience) {
+        super(child);
+
+        Validate.notNull(child, "Cannot have null child");
+        Validate.notNull(mother, "Cannot have null mother");
+        Validate.notNull(father, "Cannot have null father");
+
+        // Breeder can be null in the case of spontaneous conception
+        this.mother = mother;
+        this.father = father;
+        this.breeder = breeder;
+        this.bredWith = bredWith;
+
+        setExperience(experience);
+    }
+
+    @Override
+    public LivingEntity getEntity() {
+        return (LivingEntity) entity;
+    }
+
+    /**
+     * Gets the parent creating this entity.
+     *
+     * @return The "birth" parent
+     */
+    public LivingEntity getMother() {
+        return mother;
+    }
+
+    /**
+     * Gets the other parent of the newly born entity.
+     *
+     * @return the other parent
+     */
+    public LivingEntity getFather() {
+        return father;
+    }
+
+    /**
+     * Gets the Entity responsible for breeding. Breeder is null for spontaneous
+     * conception.
+     *
+     * @return The Entity who initiated breeding.
+     */
+    public LivingEntity getBreeder() {
+        return breeder;
+    }
+
+    /**
+     * The ItemStack that was used to initiate breeding, if present.
+     *
+     * @return ItemStack used to initiate breeding.
+     */
+    public ItemStack getBredWith() {
+        return bredWith;
+    }
+
+    /**
+     * Get the amount of experience granted by breeding.
+     *
+     * @return experience amount
+     */
+    public int getExperience() {
+        return experience;
+    }
+
+    /**
+     * Set the amount of experience granted by breeding.
+     *
+     * @param experience experience amount
+     */
+    public void setExperience(int experience) {
+        Validate.isTrue(experience >= 0, "Experience cannot be negative");
+        this.experience = experience;
+    }
+
+    @Override
+    public boolean isCancelled() {
+        return cancel;
+    }
+
+    @Override
+    public void setCancelled(boolean cancel) {
+        this.cancel = cancel;
+    }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
+}