Add asynchronous pre-login event; Addresses BUKKIT-1213

By: Wesley Wolfe <weswolf@aol.com>

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

@@ -0,0 +1,108 @@
+package org.bukkit.event.player;
+
+import java.net.InetAddress;
+
+import org.bukkit.event.Event;
+import org.bukkit.event.HandlerList;
+
+/**
+ * Stores details for players attempting to log in.<br>
+ * This event is asynchronous, and not run using main thread.
+ */
+public class AsyncPlayerPreLoginEvent extends Event {
+    private static final HandlerList handlers = new HandlerList();
+    private PlayerPreLoginEvent.Result result;
+    private String message;
+    private final String name;
+    private final InetAddress ipAddress;
+
+    public AsyncPlayerPreLoginEvent(final String name, final InetAddress ipAddress) {
+        super(true);
+        this.result = PlayerPreLoginEvent.Result.ALLOWED;
+        this.message = "";
+        this.name = name;
+        this.ipAddress = ipAddress;
+    }
+
+    /**
+     * Gets the current result of the login, as an enum
+     *
+     * @return Current Result of the login
+     */
+    public PlayerPreLoginEvent.Result getResult() {
+        return result;
+    }
+
+    /**
+     * Sets the new result of the login, as an enum
+     *
+     * @param result New result to set
+     */
+    public void setResult(final PlayerPreLoginEvent.Result result) {
+        this.result = result;
+    }
+
+    /**
+     * Gets the current kick message that will be used if getResult() != Result.ALLOWED
+     *
+     * @return Current kick message
+     */
+    public String getKickMessage() {
+        return message;
+    }
+
+    /**
+     * Sets the kick message to display if getResult() != Result.ALLOWED
+     *
+     * @param message New kick message
+     */
+    public void setKickMessage(final String message) {
+        this.message = message;
+    }
+
+    /**
+     * Allows the player to log in
+     */
+    public void allow() {
+        result = PlayerPreLoginEvent.Result.ALLOWED;
+        message = "";
+    }
+
+    /**
+     * Disallows the player from logging in, with the given reason
+     *
+     * @param result New result for disallowing the player
+     * @param message Kick message to display to the user
+     */
+    public void disallow(final PlayerPreLoginEvent.Result result, final String message) {
+        this.result = result;
+        this.message = message;
+    }
+
+    /**
+     * Gets the player's name.
+     *
+     * @return the player's name
+     */
+    public String getName() {
+        return name;
+    }
+
+    /**
+     * Gets the player IP address.
+     *
+     * @return The IP address
+     */
+    public InetAddress getAddress() {
+        return ipAddress;
+    }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
+}