Correctly clone packet listeners.

ProtocolLib/src/main/java/com/comphenix/protocol/async/NullPacketListener.java

@@ -67,7 +67,7 @@ class NullPacketListener implements PacketListener {
 	
 	private ListeningWhitelist cloneWhitelist(ListenerPriority priority, ListeningWhitelist whitelist) {
 		if (whitelist != null) 
-			return new ListeningWhitelist(priority, whitelist.getWhitelist(), whitelist.getGamePhase());
+			return ListeningWhitelist.newBuilder(whitelist).priority(priority).build();
 		else 
 			return null;
 	}

ProtocolLib/src/main/java/com/comphenix/protocol/events/ListeningWhitelist.java

@@ -18,11 +18,13 @@
 package com.comphenix.protocol.events;
 
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.EnumSet;
 import java.util.Set;
 
 import com.comphenix.protocol.injector.GamePhase;
+
 import com.google.common.base.Objects;
 import com.google.common.collect.Sets;
 
@@ -32,16 +34,22 @@ import com.google.common.collect.Sets;
  * @author Kristian 
  */
 public class ListeningWhitelist {
-	
 	/**
 	 * A whitelist with no packets - indicates that the listener shouldn't observe any packets.
 	 */
 	public static final ListeningWhitelist EMPTY_WHITELIST = new ListeningWhitelist(ListenerPriority.LOW);
 
-	private ListenerPriority priority;
-	private Set<Integer> whitelist;
-	private GamePhase gamePhase;
-	private Set<ListenerOptions> options = EnumSet.noneOf(ListenerOptions.class);
+	private final ListenerPriority priority;
+	private final Set<Integer> whitelist;
+	private final GamePhase gamePhase;
+	private final Set<ListenerOptions> options;
+
+	private ListeningWhitelist(Builder builder) {
+		this.priority = builder.priority;
+		this.whitelist = builder.whitelist;
+		this.gamePhase = builder.gamePhase;
+		this.options = builder.options;
+	}
 	
 	/**
 	 * Creates a packet whitelist for a given priority with a set of packet IDs.
@@ -60,8 +68,9 @@ public class ListeningWhitelist {
 	 */
 	public ListeningWhitelist(ListenerPriority priority, Set<Integer> whitelist, GamePhase gamePhase) {
 		this.priority = priority;
-		this.whitelist = whitelist;
+		this.whitelist = safeSet(whitelist);
 		this.gamePhase = gamePhase;
+		this.options = EnumSet.noneOf(ListenerOptions.class);
 	}
 
 	/**
@@ -73,6 +82,7 @@ public class ListeningWhitelist {
 		this.priority = priority;
 		this.whitelist = Sets.newHashSet(whitelist);
 		this.gamePhase = GamePhase.PLAYING;
+		this.options = EnumSet.noneOf(ListenerOptions.class);
 	}
 
 	/**
@@ -85,6 +95,7 @@ public class ListeningWhitelist {
 		this.priority = priority;
 		this.whitelist = Sets.newHashSet(whitelist);
 		this.gamePhase = gamePhase;
+		this.options = EnumSet.noneOf(ListenerOptions.class);
 	}
 
 	/**
@@ -92,15 +103,13 @@ public class ListeningWhitelist {
 	 * @param priority - the listener priority.
 	 * @param whitelist - list of packet IDs to observe/enable.
 	 * @param gamePhase - which game phase to receieve notifications on.
+	 * @param options - every special option associated with this whitelist.
 	 */
 	public ListeningWhitelist(ListenerPriority priority, Integer[] whitelist, GamePhase gamePhase, ListenerOptions... options) {
 		this.priority = priority;
 		this.whitelist = Sets.newHashSet(whitelist);
 		this.gamePhase = gamePhase;
-		
-		if (options != null) {
-			this.options.addAll(Arrays.asList(options));
-		}
+		this.options = safeEnumSet(Arrays.asList(options), ListenerOptions.class);
 	}
 
 	/**
@@ -144,7 +153,7 @@ public class ListeningWhitelist {
 	}
 
 	@Override
-	public int hashCode(){
+	public int hashCode() {
 		return Objects.hashCode(priority, whitelist, gamePhase, options);
 	}
 
@@ -180,14 +189,14 @@ public class ListeningWhitelist {
 	}
 
 	@Override
-	public boolean equals(final Object obj){
-	    if(obj instanceof ListeningWhitelist){
+	public boolean equals(final Object obj) {
+		if (obj instanceof ListeningWhitelist) {
 			final ListeningWhitelist other = (ListeningWhitelist) obj;
 			return Objects.equal(priority, other.priority)
 					&& Objects.equal(whitelist, other.whitelist)
 					&& Objects.equal(gamePhase, other.gamePhase)
 					&& Objects.equal(options, other.options);
-	    } else{
+		} else {
 			return false;
 		}
 	}
@@ -197,11 +206,125 @@ public class ListeningWhitelist {
 		if (this == EMPTY_WHITELIST)
 			return "EMPTY_WHITELIST";
 		else
-			return Objects.toStringHelper(this)
-				.add("priority", priority)
-				.add("packets", whitelist)
-				.add("gamephase", gamePhase)
-				.add("options", options).
+			return Objects.toStringHelper(this).
+				add("priority", priority).
+				add("packets", whitelist).
+				add("gamephase", gamePhase).
+				add("options", options).
 				toString();
 	}
+	
+	/**
+	 * Construct a new builder of whitelists.
+	 * @return New whitelist builder.
+	 */
+	public static Builder newBuilder() {
+		return new Builder(null);
+	}
+	
+	/**
+	 * Construct a new builder of whitelists initialized to the same values as the template.
+	 * @param template - the template object.
+	 * @return New whitelist builder.
+	 */
+	public static Builder newBuilder(ListeningWhitelist template) {
+		return new Builder(template);
+	}
+	
+	/**
+	 * Construct a copy of a given enum.
+	 * @param options - the options to copy, or NULL to indicate the empty set.
+	 * @return A copy of the enum set.
+	 */
+	private static <T extends Enum<T>> EnumSet<T> safeEnumSet(Collection<T> options, Class<T> enumClass) {
+		if (options != null) {
+			return EnumSet.copyOf(options);
+		} else {
+			return EnumSet.noneOf(enumClass);
+		}
+	}
+	
+	/**
+	 * Construct a copy of a given set.
+	 * @param list - the set to copy.
+	 * @return The copied set.
+	 */
+	private static <T> Set<T> safeSet(Collection<T> set) {
+		if (set != null)
+			return Sets.newHashSet(set);
+		else
+			return Collections.emptySet();
+	}
+
+	/**
+	 * Represents a builder of whitelists.
+	 * @author Kristian
+	 */
+	public static class Builder {
+		private ListenerPriority priority;
+		private Set<Integer> whitelist;
+		private GamePhase gamePhase;
+		private Set<ListenerOptions> options;
+		
+		/**
+		 * Construct a new listening whitelist template.
+		 * @param template - the template.
+		 */
+		private Builder(ListeningWhitelist template) {
+			if (template != null) {
+				priority(template.getPriority());
+				gamePhase(template.getGamePhase());
+				whitelist(template.getWhitelist());
+				options(template.getOptions());
+			}
+		}
+		
+		/**
+		 * Set the priority to use when constructing new whitelists.
+		 * @param priority - the priority.
+		 * @return This builder, for chaining.
+		 */
+		public Builder priority(ListenerPriority priority) {
+			this.priority = priority;
+			return this;
+		}
+		
+		/**
+		 * Set the whitelist of packet IDs to copy when constructing new whitelists.
+		 * @param whitelist - the whitelist of packets.
+		 * @return This builder, for chaining.
+		 */
+		public Builder whitelist(Collection<Integer> whitelist) {
+			this.whitelist = safeSet(whitelist);
+			return this;
+		}
+		
+		/**
+		 * Set the gamephase to use when constructing new whitelists.
+		 * @param gamePhase - the gamephase.
+		 * @return This builder, for chaining.
+		 */
+		public Builder gamePhase(GamePhase gamePhase) {
+			this.gamePhase = gamePhase;
+			return this;
+		}
+		
+		/**
+		 * Set the options to copy when constructing new whitelists.
+		 * @param options - the options.
+		 * @return This builder, for chaining.
+		 */
+		public Builder options(Set<ListenerOptions> options) {
+			this.options = safeSet(options);
+			return this;
+		}
+		
+		/**
+		 * Construct a new whitelist from the values in this builder.
+		 * @return The new whitelist.
+		 */
+		public ListeningWhitelist build() {
+			return new ListeningWhitelist(this);
+		}
+	}
 }