Added cause to PlayerTeleportEvent

By: Nathan Adams <dinnerbone@dinnerbone.com>

paper-api/src/main/java/org/bukkit/event/player/PlayerTeleportEvent.java

@@ -8,11 +8,52 @@ import org.bukkit.event.Event;
  * Holds information for player teleport events
  */
 public class PlayerTeleportEvent extends PlayerMoveEvent {
+    private TeleportCause cause = TeleportCause.UNKNOWN;
+
     public PlayerTeleportEvent(Player player, Location from, Location to) {
         super(Type.PLAYER_TELEPORT, player, from, to);
     }
 
+    public PlayerTeleportEvent(Player player, Location from, Location to, TeleportCause cause) {
+        super(Type.PLAYER_TELEPORT, player, from, to);
+
+        this.cause = cause;
+    }
+
     public PlayerTeleportEvent(final Event.Type type, Player player, Location from, Location to) {
         super(type, player, from, to);
     }
+
+    public PlayerTeleportEvent(final Event.Type type, Player player, Location from, Location to, TeleportCause cause) {
+        super(type, player, from, to);
+
+        this.cause = cause;
+    }
+
+    /**
+     * Gets the cause of this teleportation event
+     * @return Cause of the event
+     */
+    public TeleportCause getCause() {
+        return cause;
+    }
+
+    public enum TeleportCause {
+        /**
+         * Indicates the teleporation was caused by a player throwing an Ender Pearl
+         */
+        ENDER_PEARL,
+        /**
+         * Indicates the teleportation was caused by a player executing a command
+         */
+        COMMAND,
+        /**
+         * Indicates the teleportation was caused by a plugin
+         */
+        PLUGIN,
+        /**
+         * Indicates the teleportation was caused by an event not covered by this enum
+         */
+        UNKNOWN;
+    }
 }