Fix Improper Use of Event API (#3853)

* Fix Improper Use of Event API

* Checkstyle OOOO

Author: JRoy

Essentials/src/main/java/net/ess3/api/events/AfkStatusChangeEvent.java

@@ -1,11 +1,13 @@
 package net.ess3.api.events;
 
 import net.ess3.api.IUser;
+import org.bukkit.event.HandlerList;
 
 /**
  * Fired when a player's AFK status changes.
  */
 public class AfkStatusChangeEvent extends StatusChangeEvent {
+    private static final HandlerList handlers = new HandlerList();
     private final Cause cause;
 
     @Deprecated
@@ -22,6 +24,15 @@ public Cause getCause() {
         return cause;
     }
 
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
+
     /**
      * The cause of the AFK status change.
      */

Essentials/src/main/java/net/ess3/api/events/FlyStatusChangeEvent.java

@@ -1,12 +1,24 @@
 package net.ess3.api.events;
 
 import net.ess3.api.IUser;
+import org.bukkit.event.HandlerList;
 
 /**
  * Fired when a player's flight status is toggled using /fly.
  */
 public class FlyStatusChangeEvent extends StatusChangeEvent {
+    private static final HandlerList handlers = new HandlerList();
+
     public FlyStatusChangeEvent(final IUser affected, final IUser controller, final boolean value) {
         super(affected, controller, value);
     }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
 }

Essentials/src/main/java/net/ess3/api/events/GodStatusChangeEvent.java

@@ -1,6 +1,7 @@
 package net.ess3.api.events;
 
 import net.ess3.api.IUser;
+import org.bukkit.event.HandlerList;
 
 /**
  * Fired when a user's god status is toggled.
@@ -9,7 +10,18 @@
  * and #getController methods are inverted.
  */
 public class GodStatusChangeEvent extends StatusChangeEvent {
+    private static final HandlerList handlers = new HandlerList();
+
     public GodStatusChangeEvent(final IUser affected, final IUser controller, final boolean value) {
         super(affected, controller, value);
     }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
 }

Essentials/src/main/java/net/ess3/api/events/IgnoreStatusChangeEvent.java

@@ -1,12 +1,24 @@
 package net.ess3.api.events;
 
 import net.ess3.api.IUser;
+import org.bukkit.event.HandlerList;
 
 /**
  * This event is currently unused, and is retained for ABI compatibility and potential future implementation.
  */
 public class IgnoreStatusChangeEvent extends StatusChangeEvent {
+    private static final HandlerList handlers = new HandlerList();
+
     public IgnoreStatusChangeEvent(final IUser affected, final IUser controller, final boolean value) {
         super(affected, controller, value);
     }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
 }

Essentials/src/main/java/net/ess3/api/events/JailStatusChangeEvent.java

@@ -1,6 +1,7 @@
 package net.ess3.api.events;
 
 import net.ess3.api.IUser;
+import org.bukkit.event.HandlerList;
 
 /**
  * Fired when a player's jail status changes.
@@ -9,7 +10,18 @@
  * You <i>can</i>, however, access the player's current jail when they are about to be unjailed by calling {@link IUser#getJail()}.
  */
 public class JailStatusChangeEvent extends StatusChangeEvent {
+    private static final HandlerList handlers = new HandlerList();
+
     public JailStatusChangeEvent(final IUser affected, final IUser controller, final boolean value) {
         super(affected, controller, value);
     }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
 }

Essentials/src/main/java/net/ess3/api/events/MuteStatusChangeEvent.java

@@ -1,13 +1,15 @@
 package net.ess3.api.events;
 
 import net.ess3.api.IUser;
+import org.bukkit.event.HandlerList;
 
 import java.util.Optional;
 
 /**
  * Fired when a player's mute status is changed.
  */
 public class MuteStatusChangeEvent extends StatusChangeEvent {
+    private static final HandlerList handlers = new HandlerList();
     private final Long timestamp;
     private final String reason;
 
@@ -30,4 +32,13 @@ public Optional<Long> getTimestamp() {
     public String getReason() {
         return reason;
     }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
 }

Essentials/src/main/java/net/ess3/api/events/NickChangeEvent.java

@@ -2,13 +2,15 @@
 
 import net.ess3.api.IUser;
 import org.bukkit.event.Cancellable;
+import org.bukkit.event.HandlerList;
 
 /**
  * Fired when a player's nickname is changed.
  *
  * <b>WARNING: The values of {@link NickChangeEvent#getAffected()} and {@link NickChangeEvent#getController()} are inverted due to a long-standing implementation bug.</b>
  */
 public class NickChangeEvent extends StateChangeEvent implements Cancellable {
+    private static final HandlerList handlers = new HandlerList();
     private final String newValue;
 
     public NickChangeEvent(final IUser affected, final IUser controller, final String value) {
@@ -41,4 +43,13 @@ public IUser getAffected() {
     public IUser getController() {
         return super.getController();
     }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
 }

Essentials/src/main/java/net/ess3/api/events/SignBreakEvent.java

@@ -2,14 +2,26 @@
 
 import com.earth2me.essentials.signs.EssentialsSign;
 import net.ess3.api.IUser;
+import org.bukkit.event.HandlerList;
 
 /**
  * Fired when an Essentials sign is broken.
  *
  * This is primarily intended for use with EssentialsX's sign abstraction - external plugins should not listen on this event.
  */
 public class SignBreakEvent extends SignEvent {
+    private static final HandlerList handlers = new HandlerList();
+
     public SignBreakEvent(final EssentialsSign.ISign sign, final EssentialsSign essSign, final IUser user) {
         super(sign, essSign, user);
     }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
 }

Essentials/src/main/java/net/ess3/api/events/SignCreateEvent.java

@@ -2,14 +2,26 @@
 
 import com.earth2me.essentials.signs.EssentialsSign;
 import net.ess3.api.IUser;
+import org.bukkit.event.HandlerList;
 
 /**
  * Fired when an Essentials sign is created.
  *
  * This is primarily intended for use with EssentialsX's sign abstraction - external plugins should not listen on this event.
  */
 public class SignCreateEvent extends SignEvent {
+    private static final HandlerList handlers = new HandlerList();
+
     public SignCreateEvent(final EssentialsSign.ISign sign, final EssentialsSign essSign, final IUser user) {
         super(sign, essSign, user);
     }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
 }

Essentials/src/main/java/net/ess3/api/events/SignEvent.java

@@ -6,13 +6,11 @@
 import org.bukkit.Bukkit;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
-import org.bukkit.event.HandlerList;
 
 /**
  * This handles common boilerplate for other SignEvent
  */
-public class SignEvent extends Event implements Cancellable {
-    private static final HandlerList handlers = new HandlerList();
+public abstract class SignEvent extends Event implements Cancellable {
     final ISign sign;
     final EssentialsSign essSign;
     final IUser user;
@@ -25,10 +23,6 @@ public SignEvent(final ISign sign, final EssentialsSign essSign, final IUser use
         this.user = user;
     }
 
-    public static HandlerList getHandlerList() {
-        return handlers;
-    }
-
     public ISign getSign() {
         return sign;
     }
@@ -41,11 +35,6 @@ public IUser getUser() {
         return user;
     }
 
-    @Override
-    public HandlerList getHandlers() {
-        return handlers;
-    }
-
     @Override
     public boolean isCancelled() {
         return cancelled;