Interface IHierarchyCapability

Namespace

KeenEyes.Capabilities

Assembly

KeenEyes.Abstractions.dll

Capability interface for entity hierarchy operations.

public interface IHierarchyCapability

Examples

public void Install(IPluginContext context)
{
    if (context.TryGetCapability<IHierarchyCapability>(out var hierarchy))
    {
        var children = hierarchy.GetChildren(parentEntity);
        foreach (var child in children)
        {
            // Process child entities
        }
    }
}

Remarks

This capability provides access to parent-child relationship management for entities. Plugins and systems that need to traverse or manipulate entity hierarchies should request this capability via GetCapability<T>() rather than casting to the concrete World type.

Common use cases include UI systems that need to render children, transform propagation systems, and scene graph traversal.

Methods

AddChild(Entity, Entity)

Adds a child entity to a parent entity.

void AddChild(Entity parent, Entity child)

Parameters

parent Entity

The parent entity.

child Entity

The entity to add as a child.

Exceptions

InvalidOperationException

Thrown when either entity is not alive, or when the relationship would create a circular hierarchy.

DespawnRecursive(Entity)

Destroys an entity and all its descendants recursively.

int DespawnRecursive(Entity entity)

Parameters

entity Entity

The entity to destroy along with all its descendants.

Returns

int

The number of entities destroyed.

GetAncestors(Entity)

Gets all ancestors of an entity (parent, grandparent, etc.).

IEnumerable<Entity> GetAncestors(Entity entity)

Parameters

entity Entity

The entity to get ancestors for.

Returns

IEnumerable<Entity>

An enumerable of all ancestor entities, starting with the immediate parent.

GetChildren(Entity)

Gets all immediate children of an entity.

IEnumerable<Entity> GetChildren(Entity entity)

Parameters

entity Entity

The entity to get children for.

Returns

IEnumerable<Entity>

An enumerable of child entities.

GetDescendants(Entity)

Gets all descendants of an entity (children, grandchildren, etc.).

IEnumerable<Entity> GetDescendants(Entity entity)

Parameters

entity Entity

The entity to get descendants for.

Returns

IEnumerable<Entity>

An enumerable of all descendant entities in breadth-first order.

GetParent(Entity)

Gets the parent of an entity.

Entity GetParent(Entity entity)

Parameters

entity Entity

The entity to get the parent for.

Returns

Entity

The parent entity, or Null if the entity has no parent.

GetRoot(Entity)

Gets the root entity of the hierarchy containing the given entity.

Entity GetRoot(Entity entity)

Parameters

entity Entity

The entity to find the root for.

Returns

Entity

The root entity (topmost ancestor with no parent). If the entity itself has no parent, returns the entity itself.

RemoveChild(Entity, Entity)

Removes a specific child from a parent entity.

bool RemoveChild(Entity parent, Entity child)

Parameters

parent Entity

The parent entity.

child Entity

The child entity to remove from the parent.

Returns

bool

True if the child was removed; false otherwise.

SetParent(Entity, Entity)

Sets the parent of an entity, establishing a parent-child relationship.

void SetParent(Entity child, Entity parent)

Parameters

child Entity

The entity to become a child.

parent Entity

The entity to become the parent. Pass Null to remove the parent.

Exceptions

InvalidOperationException

Thrown when the child entity is not alive, or when setting the parent would create a circular relationship.