Improve death events

This adds the ability to cancel the death events and to modify the sound
an entity makes when dying. (In cases were no sound should it will be
called with shouldPlaySound set to false allowing unsilencing of silent
entities)

It makes handling of entity deaths a lot nicer as you no longer need
to listen on the damage event and calculate if the entity dies yourself
to cancel the death which has the benefit of also receiving the dropped
items and experience which is otherwise only properly possible by using
internal code.

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

@@ -6,15 +6,25 @@ import org.bukkit.entity.LivingEntity;
 import org.bukkit.event.HandlerList;
 import org.bukkit.inventory.ItemStack;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * Thrown whenever a LivingEntity dies
  */
-public class EntityDeathEvent extends EntityEvent {
+public class EntityDeathEvent extends EntityEvent implements org.bukkit.event.Cancellable {  // Paper - make cancellable
     private static final HandlerList handlers = new HandlerList();
     private final DamageSource damageSource;
     private final List<ItemStack> drops;
     private int dropExp = 0;
+    // Paper start - make cancellable
+    private boolean cancelled;
+    private double reviveHealth = 0;
+    private boolean shouldPlayDeathSound;
+    @Nullable private org.bukkit.Sound deathSound;
+    @Nullable private org.bukkit.SoundCategory deathSoundCategory;
+    private float deathSoundVolume;
+    private float deathSoundPitch;
+    // Paper end
 
     public EntityDeathEvent(@NotNull final LivingEntity entity, @NotNull DamageSource damageSource, @NotNull final List<ItemStack> drops) {
         this(entity, damageSource, drops, 0);
@@ -87,4 +97,133 @@ public class EntityDeathEvent extends EntityEvent {
     public static HandlerList getHandlerList() {
         return handlers;
     }
+
+    // Paper start - make cancellable
+    @Override
+    public boolean isCancelled() {
+        return cancelled;
+    }
+
+    @Override
+    public void setCancelled(boolean cancel) {
+        cancelled = cancel;
+    }
+
+    /**
+     * Get the amount of health that the entity should revive with after cancelling the event.
+     * Set to the entity's max health by default.
+     *
+     * @return The amount of health
+     */
+    public double getReviveHealth() {
+        return reviveHealth;
+    }
+
+    /**
+     * Set the amount of health that the entity should revive with after cancelling the event.
+     * Revive health value must be between 0 (exclusive) and the entity's max health (inclusive).
+     *
+     * @param reviveHealth The amount of health
+     * @throws IllegalArgumentException Thrown if the health is {@literal <= 0 or >} max health
+     */
+    public void setReviveHealth(double reviveHealth) throws IllegalArgumentException {
+        double maxHealth = ((LivingEntity) entity).getAttribute(org.bukkit.attribute.Attribute.MAX_HEALTH).getValue();
+        if ((maxHealth != 0 && reviveHealth <= 0) || (reviveHealth > maxHealth)) {
+            throw new IllegalArgumentException("Health must be between 0 (exclusive) and " + maxHealth + " (inclusive), but was " + reviveHealth);
+        }
+        this.reviveHealth = reviveHealth;
+    }
+
+    /**
+     * Whether or not the death sound should play when the entity dies. If the event is cancelled it does not play!
+     *
+     * @return Whether or not the death sound should play. Event is called with this set to false if the entity is silent.
+     */
+    public boolean shouldPlayDeathSound() {
+        return shouldPlayDeathSound;
+    }
+
+    /**
+     * Set whether or not the death sound should play when the entity dies. If the event is cancelled it does not play!
+     *
+     * @param playDeathSound Enable or disable the death sound
+     */
+    public void setShouldPlayDeathSound(boolean playDeathSound) {
+        this.shouldPlayDeathSound = playDeathSound;
+    }
+
+    /**
+     * Get the sound that the entity makes when dying
+     *
+     * @return The sound that the entity makes
+     */
+    @Nullable
+    public org.bukkit.Sound getDeathSound() {
+        return deathSound;
+    }
+
+    /**
+     * Set the sound that the entity makes when dying
+     *
+     * @param sound The sound that the entity should make when dying
+     */
+    public void setDeathSound(@Nullable org.bukkit.Sound sound) {
+        deathSound = sound;
+    }
+
+    /**
+     * Get the sound category that the death sound should play in
+     *
+     * @return The sound category
+     */
+    @Nullable
+    public org.bukkit.SoundCategory getDeathSoundCategory() {
+        return deathSoundCategory;
+    }
+
+    /**
+     * Set the sound category that the death sound should play in.
+     *
+     * @param soundCategory The sound category
+     */
+    public void setDeathSoundCategory(@Nullable org.bukkit.SoundCategory soundCategory) {
+        this.deathSoundCategory = soundCategory;
+    }
+
+    /**
+     * Get the volume that the death sound will play at.
+     *
+     * @return The volume the death sound will play at
+     */
+    public float getDeathSoundVolume() {
+        return deathSoundVolume;
+    }
+
+    /**
+     * Set the volume the death sound should play at. If the event is cancelled this will not play the sound!
+     *
+     * @param volume The volume the death sound should play at
+     */
+    public void setDeathSoundVolume(float volume) {
+        this.deathSoundVolume = volume;
+    }
+
+    /**
+     * Get the pitch that the death sound will play with.
+     *
+     * @return The pitch the death sound will play with
+     */
+    public float getDeathSoundPitch() {
+        return deathSoundPitch;
+    }
+
+    /**
+     * Set the pitch that the death sound should play with.
+     *
+     * @param pitch The pitch the death sound should play with
+     */
+    public void setDeathSoundPitch(float pitch) {
+        this.deathSoundPitch = pitch;
+    }
+    // Paper end
 }

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

@@ -63,6 +63,19 @@ public class PlayerDeathEvent extends EntityDeathEvent {
         return (Player) entity;
     }
 
+    // Paper start - improve death events
+    /**
+     * Clarity method for getting the player. Not really needed except
+     * for reasons of clarity.
+     *
+     * @return Player who is involved in this event
+     */
+    public @NotNull Player getPlayer() {
+        return this.getEntity();
+    }
+
+    // Paper end - improve death events
+
     // Paper start - adventure
     /**
      * Set the death message that will appear to everyone on the server.