Add Horse API. Adds BUKKIT-4424

API has been added to interface with Horses and to modify their inventories. A new event, HorseJumpEvent, has been added to be fired whenever a horse jumps.

This commit fixes BUKKIT-4393.

src/main/java/org/bukkit/entity/Horse.java

@@ -1,6 +1,256 @@
 package org.bukkit.entity;
 
+import org.bukkit.inventory.HorseInventory;
+import org.bukkit.inventory.InventoryHolder;
+
 /**
  * Represents a Horse.
  */
-public interface Horse extends Animals, Vehicle {}
+public interface Horse extends Animals, Vehicle, InventoryHolder, Tameable {
+
+    /**
+     * Represents the different types of horses that may exist.
+     */
+    public enum Variant {
+        /**
+         * A normal horse
+         */
+        HORSE,
+        /**
+         * A donkey
+         */
+        DONKEY,
+        /**
+         * A mule
+         */
+        MULE,
+        /**
+         * An undead horse
+         */
+        UNDEAD_HORSE,
+        /**
+         * A skeleton horse
+         */
+        SKELETON_HORSE,
+        ;
+    }
+
+    /**
+     * Represents the base color that the horse has.
+     */
+    public enum Color {
+        /**
+         * Snow white
+         */
+        WHITE,
+        /**
+         * Very light brown
+         */
+        CREAMY,
+        /**
+         * Chestnut
+         */
+        CHESTNUT,
+        /**
+         * Light brown
+         */
+        BROWN,
+        /**
+         * Pitch black
+         */
+        BLACK,
+        /**
+         * Gray
+         */
+        GRAY,
+        /**
+         * Dark brown
+         */
+        DARK_BROWN,
+        ;
+    }
+
+    /**
+     * Represents the style, or markings, that the horse has.
+     */
+    public enum Style {
+        /**
+         * No markings
+         */
+        NONE,
+        /**
+         * White socks or stripes
+         */
+        WHITE,
+        /**
+         * Milky splotches
+         */
+        WHITEFIELD,
+        /**
+         * Round white dots
+         */
+        WHITE_DOTS,
+        /**
+         * Small black dots
+         */
+        BLACK_DOTS,
+        ;
+    }
+
+    /**
+     * Gets the horse's variant.
+     * <p>
+     * A horse's variant defines its physical appearance and capabilities.
+     * Whether a horse is a regular horse, donkey, mule, or other kind of
+     * horse is determined using the variant.
+     *
+     * @return a {@link Variant} representing the horse's variant
+     */
+    public Variant getVariant();
+
+    /**
+     * Sets the horse's variant.
+     * <p>
+     * A horse's variant defines its physical appearance and capabilities.
+     * Whether a horse is a regular horse, donkey, mule, or other kind of
+     * horse can be set using the variant.
+     * <p>
+     * Setting a horse's variant does not change its attributes such as
+     * its owner and its tamed status, but changing a mule or donkey
+     * with a chest to another variant which does not support a chest
+     * will remove the chest and its contents.
+     *
+     * @param variant a {@link Variant} for this horse
+     */
+    public void setVariant(Variant variant);
+
+    /**
+     * Gets the horse's color.
+     * <p>
+     * Colors only apply to horses, not to donkeys, mules, skeleton horses
+     * or undead horses.
+     *
+     * @return a {@link Color} representing the horse's group
+     */
+    public Color getColor();
+
+    /**
+     * Sets the horse's color.
+     * <p>
+     * Attempting to set a color for any donkey, mule, skeleton horse or
+     * undead horse will not result in a change.
+     *
+     * @param color a {@link Color} for this horse
+     */
+    public void setColor(Color color);
+
+    /**
+     * Gets the horse's style.
+     * Styles determine what kind of markings or patterns a horse has.
+     * <p>
+     * Styles only apply to horses, not to donkeys, mules, skeleton horses
+     * or undead horses.
+     *
+     * @return a {@link Style} representing the horse's style
+     */
+    public Style getStyle();
+
+    /**
+     * Sets the style of this horse.
+     * Styles determine what kind of markings or patterns a horse has.
+     * <p>
+     * Attempting to set a style for any donkey, mule, skeleton horse or
+     * undead horse will not result in a change.
+     *
+     * @param style a {@link Style} for this horse
+     */
+    public void setStyle(Style style);
+
+    /**
+     * Gets whether the horse has a chest equipped.
+     *
+     * @return true if the horse has chest storage
+     */
+    public boolean isCarryingChest();
+
+    /**
+     * Sets whether the horse has a chest equipped.
+     * Removing a chest will also clear the chest's inventory.
+     *
+     * @param chest true if the horse should have a chest
+     */
+    public void setCarryingChest(boolean chest);
+
+    /**
+     * Gets the domestication level of this horse.
+     * <p>
+     * A higher domestication level indicates that the horse is closer to
+     * becoming tame. As the domestication level gets closer to the max
+     * domestication level, the chance of the horse becoming tame increases.
+     *
+     * @return domestication level
+     */
+    public int getDomestication();
+
+    /**
+     * Sets the domestication level of this horse.
+     * <p>
+     * Setting the domestication level to a high value will increase the
+     * horse's chances of becoming tame.
+     * <p>
+     * Domestication level must be greater than zero and no greater than
+     * the max domestication level of the horse, determined with
+     * {@link #getMaxDomestication()}
+     *
+     * @param level domestication level
+     */
+    public void setDomestication(int level);
+
+    /**
+     * Gets the maximum domestication level of this horse.
+     * <p>
+     * The higher this level is, the longer it will likely take
+     * for the horse to be tamed.
+     *
+     * @return the max domestication level
+     */
+    public int getMaxDomestication();
+
+    /**
+     * Sets the maximum domestication level of this horse.
+     * <p>
+     * Setting a higher max domestication will increase the amount of
+     * domesticating (feeding, riding, etc.) necessary in order to tame it,
+     * while setting a lower max value will have the opposite effect.
+     * <p>
+     * Maximum domestication must be greater than zero.
+     *
+     * @param level the max domestication level
+     */
+    public void setMaxDomestication(int level);
+
+    /**
+     * Gets the jump strength of this horse.
+     * <p>
+     * Jump strength defines how high the horse can jump. A higher jump strength
+     * increases how high a jump will go.
+     *
+     * @return the horse's jump strength
+     */
+    public double getJumpStrength();
+
+    /**
+     * Sets the jump strength of this horse.
+     * <p>
+     * A higher jump strength increases how high a jump will go.
+     * Setting a jump strength to 0 will result in no jump.
+     * You cannot set a jump strength to a value below 0 or
+     * above 2.
+     *
+     * @param strength jump strength for this horse
+     */
+    public void setJumpStrength(double strength);
+
+    @Override
+    public HorseInventory getInventory();
+}

src/main/java/org/bukkit/event/entity/HorseJumpEvent.java

@@ -0,0 +1,78 @@
+package org.bukkit.event.entity;
+
+import org.bukkit.entity.Horse;
+import org.bukkit.event.Cancellable;
+import org.bukkit.event.HandlerList;
+
+/**
+ * Called when a horse jumps.
+ */
+public class HorseJumpEvent extends EntityEvent implements Cancellable {
+    private static final HandlerList handlers = new HandlerList();
+    private boolean cancelled;
+    private float power;
+
+    public HorseJumpEvent(final Horse horse, final float power) {
+        super(horse);
+        this.power = power;
+    }
+
+    public boolean isCancelled() {
+        return cancelled;
+    }
+
+    public void setCancelled(boolean cancel) {
+        cancelled = cancel;
+    }
+
+    @Override
+    public Horse getEntity() {
+        return (Horse) entity;
+    }
+
+    /**
+     * Gets the power of the jump.
+     * <p>
+     * Power is a value that defines how much of the horse's jump strength
+     * should be used for the jump. Power is effectively multiplied times
+     * the horse's jump strength to determine how high the jump is;
+     * 0 represents no jump strength while 1 represents full jump strength.
+     * Setting power to a value above 1 will use additional jump strength
+     * that the horse does not usually have.
+     * <p>
+     * Power does not affect how high the horse is capable of jumping,
+     * only how much of its jumping capability will be used in this jump.
+     * To set the horse's overall jump strength, see
+     * {@link Horse#setJumpStrength(double)}.
+     *
+     * @return jump strength
+     */
+    public float getPower() {
+        return power;
+    }
+
+    /**
+     * Sets the power of the jump.
+     * <p>
+     * Jump power can be set to a value above 1.0 which will increase
+     * the strength of this jump above the horse's actual jump strength.
+     * <p>
+     * Setting the jump power to 0 will result in the jump animation
+     * still playing, but the horse not leaving the ground. Only
+     * canceling this event will result in no jump animation at all.
+     *
+     * @param power power of the jump
+     */
+    public void setPower(float power) {
+        this.power = power;
+    }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
+}

src/main/java/org/bukkit/inventory/HorseInventory.java

@@ -0,0 +1,32 @@
+package org.bukkit.inventory;
+
+public interface HorseInventory extends Inventory {
+
+    /**
+     * Gets the item in the horse's saddle slot.
+     *
+     * @return the saddle item
+     */
+    ItemStack getSaddle();
+
+    /**
+     * Gets the item in the horse's armor slot.
+     *
+     * @return the armor item
+     */
+    ItemStack getArmor();
+
+    /**
+     * Sets the item in the horse's saddle slot.
+     *
+     * @param stack the new item
+     */
+    void setSaddle(ItemStack stack);
+
+    /**
+     * Sets the item in the horse's armor slot.
+     *
+     * @param stack the new item
+     */
+    void setArmor(ItemStack stack);
+}