Events

GroupManager fires events when group state changes. External plugins can listen for these events by implementing the GroupEventListener interface.

Registering a Listener

import com.groupmanager.api.GroupEventListener;
import com.groupmanager.api.GroupManagerProvider;
import com.groupmanager.api.GroupService;

GroupService api = GroupManagerProvider.get();

api.registerEventListener(new GroupEventListener() {
    @Override
    public void onGroupCreated(UUID groupId, UUID leaderUuid) {
        // Handle group creation
    }
});

Unregistering

api.unregisterEventListener(myListener);

tip

Always unregister your listeners in your plugin's shutdown() method to avoid memory leaks.

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Event Types

All methods in GroupEventListener have default (no-op) implementations, so you only need to override the events you care about.

onGroupCreated(UUID groupId, UUID leaderUuid)

Fired when a new group is created (permanent or temporary).

Parameter	Type	Description
groupId	UUID	The new group's ID
leaderUuid	UUID	UUID of the group leader

@Override
public void onGroupCreated(UUID groupId, UUID leaderUuid) {
    log("Group " + groupId + " created by " + leaderUuid);
}

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onGroupDissolved(UUID groupId)

Fired when a group is dissolved (disbanded or all members left).

Parameter	Type	Description
groupId	UUID	The dissolved group's ID

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onMemberJoined(UUID groupId, UUID playerUuid)

Fired when a player joins a group (via accepting an invitation or API call).

Parameter	Type	Description
groupId	UUID	The group's ID
playerUuid	UUID	UUID of the player who joined

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onMemberLeft(UUID groupId, UUID playerUuid)

Fired when a player voluntarily leaves a group.

Parameter	Type	Description
groupId	UUID	The group's ID
playerUuid	UUID	UUID of the player who left

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onMemberKicked(UUID groupId, UUID playerUuid, UUID kickedBy)

Fired when a member is kicked from a group by the leader.

Parameter	Type	Description
groupId	UUID	The group's ID
playerUuid	UUID	UUID of the kicked player
kickedBy	UUID	UUID of the leader who kicked them

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onLeadershipTransferred(UUID groupId, UUID oldLeaderUuid, UUID newLeaderUuid)

Fired when group leadership is transferred to a different member.

Parameter	Type	Description
groupId	UUID	The group's ID
oldLeaderUuid	UUID	UUID of the previous leader
newLeaderUuid	UUID	UUID of the new leader

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onGroupMembersChanged(UUID groupId)

Generic event fired whenever the group's member list changes (join, leave, kick). This is a convenience event — it fires in addition to the more specific events above.

Parameter	Type	Description
groupId	UUID	The group's ID

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Complete Example

public class MyGamePlugin extends JavaPlugin {

    private GroupEventListener groupListener;

    @Override
    public void start() {
        GroupService api = GroupManagerProvider.get();
        if (api == null) return;

        groupListener = new GroupEventListener() {
            @Override
            public void onGroupCreated(UUID groupId, UUID leaderUuid) {
                getLogger().at(Level.INFO).log("Group created: " + groupId);
            }

            @Override
            public void onMemberJoined(UUID groupId, UUID playerUuid) {
                // Update team assignments
                updateTeamForGroup(groupId);
            }

            @Override
            public void onMemberLeft(UUID groupId, UUID playerUuid) {
                // Remove from team
                removeFromTeam(playerUuid);
            }

            @Override
            public void onGroupDissolved(UUID groupId) {
                // Clean up team data
                cleanupTeam(groupId);
            }
        };

        api.registerEventListener(groupListener);
    }

    @Override
    public void shutdown() {
        GroupService api = GroupManagerProvider.get();
        if (api != null && groupListener != null) {
            api.unregisterEventListener(groupListener);
        }
    }
}