Add partially working blocking and deletion (for both client and server)

Additionally had to refactor several classes "a little bit".
(Whenever one bug seemed fixed, another one appeared...)

common/src/main/java/envoy/event/GroupCreation.java

@@ -17,14 +17,14 @@ public final class GroupCreation extends Event<String> {
 	private static final long serialVersionUID = 0L;
 
 	/**
-	 * @param value            the name of this group at creation time
+	 * @param name             the name of this group at creation time
 	 * @param initialMemberIDs the IDs of all {@link User}s that should be group
 	 *                         members from the beginning on (excluding the creator
 	 *                         of this group)
 	 * @since Envoy Common v0.1-beta
 	 */
-	public GroupCreation(String value, Set<Long> initialMemberIDs) {
-		super(value);
+	public GroupCreation(String name, Set<Long> initialMemberIDs) {
+		super(name);
 		this.initialMemberIDs = initialMemberIDs != null ? initialMemberIDs : new HashSet<>();
 	}
 

common/src/main/java/envoy/event/GroupCreationResult.java

@@ -1,5 +1,7 @@
 package envoy.event;
 
+import envoy.data.Group;
+
 /**
  * Used to communicate with a client that his request to create a group might
  * have been rejected as it might be disabled on his current server.
@@ -7,15 +9,23 @@ package envoy.event;
  * @author Leon Hofmeister
  * @since Envoy Common v0.2-beta
  */
-public class GroupCreationResult extends Event<Boolean> {
+public class GroupCreationResult extends Event<Group> {
 
 	private static final long serialVersionUID = 1L;
 
 	/**
-	 * Creates a new {@code GroupCreationResult}.
+	 * Creates a new {@code GroupCreationResult} that implies the failure of this
+	 * {@link GroupCreationResult}.
 	 *
-	 * @param success whether the GroupCreation sent before was successful
 	 * @since Envoy Common v0.2-beta
 	 */
-	public GroupCreationResult(boolean success) { super(success); }
+	public GroupCreationResult() { super(null); }
+
+	/**
+	 * Creates a new {@code GroupCreationResult}.
+	 *
+	 * @param resultGroup the group the server created
+	 * @since Envoy Common v0.2-beta
+	 */
+	public GroupCreationResult(Group resultGroup) { super(resultGroup); }
 }

common/src/main/java/envoy/event/GroupResize.java

@@ -33,13 +33,12 @@ public final class GroupResize extends Event<User> {
 	 */
 	public GroupResize(User user, Group group, ElementOperation operation) {
 		super(user);
-		this.operation	= operation;
-		if (group.getContacts().contains(user)) {
-			if (operation.equals(ADD))
-				throw new IllegalArgumentException(String.format("Cannot add %s to %s!", user, group));
-		} else if (operation.equals(REMOVE))
-			throw new IllegalArgumentException(String.format("Cannot remove %s from %s!", user, group));
-		groupID	= group.getID();
+		this.operation = operation;
+		final var contained = group.getContacts().contains(user);
+		if (contained && operation.equals(ADD))
+			throw new IllegalArgumentException(String.format("Cannot add %s to %s!", user, group));
+		else if (operation.equals(REMOVE) && !contained) throw new IllegalArgumentException(String.format("Cannot remove %s from %s!", user, group));
+		groupID = group.getID();
 	}
 
 	/**
@@ -72,5 +71,5 @@ public final class GroupResize extends Event<User> {
 	}
 
 	@Override
-	public String toString() { return String.format("GroupResize[userid=%d,groupid=%d,operation=%s]", get(), groupID, operation); }
+	public String toString() { return String.format("GroupResize[user=%s,groupid=%d,operation=%s]", get(), groupID, operation); }
 }

common/src/main/java/envoy/event/contact/ContactsChangedSinceLastLogin.java

@@ -9,7 +9,7 @@ import envoy.event.Event.Valueless;
  * @author Leon Hofmeister
  * @since Envoy Common v0.3-beta
  */
-public class ContactDeletionSinceLastLogin extends Valueless {
+public class ContactsChangedSinceLastLogin extends Valueless {
 
 	private static final long serialVersionUID = 1L;
 }

common/src/main/java/envoy/event/contact/UserOperation.java

@@ -1,35 +1,38 @@
 package envoy.event.contact;
 
-import envoy.data.Contact;
+import envoy.data.User;
 import envoy.event.*;
 
 /**
  * Signifies the modification of a contact list.
  *
  * @author Maximilian Käfer
- * @since Envoy Common v0.2-alpha
+ * @since Envoy Common v0.3-beta
  */
-public final class ContactOperation extends Event<Contact> {
+public final class UserOperation extends Event<User> {
 
 	private final ElementOperation operationType;
 
 	private static final long serialVersionUID = 1L;
 
 	/**
-	 * Initializes a {@link ContactOperation}.
+	 * Initializes a {@link UserOperation}.
 	 *
 	 * @param contact       the user on which the operation is performed
 	 * @param operationType the type of operation to perform
-	 * @since Envoy Common v0.2-alpha
+	 * @since Envoy Common v0.3-beta
 	 */
-	public ContactOperation(Contact contact, ElementOperation operationType) {
+	public UserOperation(User contact, ElementOperation operationType) {
 		super(contact);
 		this.operationType = operationType;
 	}
 
 	/**
 	 * @return the type of operation to perform
-	 * @since Envoy Common v0.2-alpha
+	 * @since Envoy Common v0.3-beta
 	 */
 	public ElementOperation getOperationType() { return operationType; }
+
+	@Override
+	public String toString() { return String.format("%s[contact=%s, operation=%s]", UserOperation.class.getSimpleName(), value, operationType); }
 }