Class EntityManager

Collects every Entity instance present in a Scene. As a collection, it supports common operations such as adding and removing entities.

Inheritance

object

IdentifiableObject

DependencyObject

AttachableObject

SceneManager

EntityManager

Implements

IDependencyObject

Inherited Members

SceneManager.Managers

SceneManager.Scene

SceneManager.OnLoaded()

SceneManager.OnAttached()

SceneManager.OnDeactivated()

SceneManager.OnDestroy()

AttachableObject.AttachableStateChanged

AttachableObject.IsEnabled

AttachableObject.State

AttachableObject.IsLoaded

AttachableObject.IsAttached

AttachableObject.IsActivated

AttachableObject.IsStarted

AttachableObject.IsDestroyed

AttachableObject.ShouldBeActivated

AttachableObject.Destroy()

AttachableObject.DependencyBroken()

DependencyObject.Dependencies

DependencyObject.OnDependencyRemoved

IdentifiableObject.Id

IdentifiableObject.IdHasChanged(Guid)

Namespace: Evergine.Framework.Managers

Assembly: Evergine.Framework.dll

Syntax

public class EntityManager : SceneManager, IDependencyObject

Constructors

EntityManager()

Initializes a new instance of the EntityManager class.

Declaration

public EntityManager()

Exceptions

Type	Condition
ArgumentNullException	Thrown if adapter or scene is null.

Properties

AllEntities

Gets every Entity instance. The is traversed through every Entity including its children.

Declaration

public IEnumerable<Entity> AllEntities { get; }

Property Value

Type	Description
IEnumerable<Entity>	Every Entity instance.

Exceptions

Type	Condition
ObjectDisposedException	EntityManager has been disposed.

Count

Gets how many Entity instances have been added to this instance.

Declaration

public int Count { get; }

Property Value

Type	Description
int	The number of Entity instances added to this instance.

EntityGraph

Gets the Entity instances (see if you prefer a collection of object). IMPORTANT NOTE: Only the parents are contained within the returned value (i.e. only the instances subject to an Add() call). Children will not be considered here. See if you are also looking for children.

Declaration

public IEnumerable<Entity> EntityGraph { get; }

Property Value

Type	Description
IEnumerable<Entity>	The Entity instances.

Exceptions

Type	Condition
ObjectDisposedException	EntityManager has been disposed.

Methods

Add(Entity)

Adds a new Entity to this instance.

Declaration

public virtual void Add(Entity entity)

Parameters

Type	Name	Description
Entity	entity	The Entity to add.

Exceptions

Type	Condition
ArgumentNullException	Thrown if the entity is null.
InvalidOperationException	Thrown if there is already an entity added to this instance with the same name.

Add(IEnumerable<Entity>)

Adds a list of Entity to EntityManager.

Declaration

public virtual void Add(IEnumerable<Entity> newEntities)

Parameters

Type	Name	Description
IEnumerable<Entity>	newEntities	The Entity list to add.

Exceptions

Type	Condition
ArgumentNullException	If newEntities are null.
InvalidOperationException	If there is already an entity added to this instance with the same name.

Contains(Entity)

Determines whether this instance contains the specified Entity through its Name property.

Declaration

public bool Contains(Entity entity)

Parameters

Type	Name	Description
Entity	entity	The Entity to check.

Returns

Type	Description
bool	true if this instance contains the specified Entity; otherwise, false.

Exceptions

Type	Condition
ArgumentNullException	If the entity is null.

Detach(Entity)

Detaches a specific entity.

Declaration

public bool Detach(Entity entity)

Parameters

Type	Name	Description
Entity	entity	The entity to detach.

Returns

Type	Description
bool	Indicates whether an entity was detached.

Remarks

The entity is disposed when it is detached from this instance.

Exceptions

Type	Condition
ArgumentNullException	Thrown if entity is null.

Find(Guid)

Looks for an Entity entity in the EntityGraph, through its name.

Declaration

public Entity Find(Guid entityId)

Parameters

Type	Name	Description
Guid	entityId	The entity Id to find.

Returns

Type	Description
Entity	The Entity with the specified entityId, or null if no entity was found.

Exceptions

Type	Condition
ArgumentNullException	If the entity id is an empty Guid.

Find(string, Entity)

Finds the first entity in the EntityGraph with the given entity path.

Declaration

public Entity Find(string entityPath, Entity sourceEntity = null)

Parameters

Type	Name	Description
string	entityPath	Path of the entity to look for. If sourceEntity is not null, the path is relative to it.
Entity	sourceEntity	The source entity for a relative path.

Returns

Type	Description
Entity	The Entity with the specified entityPath, or null if no entity is found.

Exceptions

Type	Condition
ArgumentNullException	If the name is null or empty.

FindAllByTag(string)

Finds all entities with the same tag in the .

Declaration

public IEnumerable<Entity> FindAllByTag(string tag)

Parameters

Type	Name	Description
string	tag	The tag.

Returns

Type	Description
IEnumerable<Entity>	All entities with the same tag in the .

FindComponentFromEntityPath<T>(string, bool)

Returns the first component inside the first entity with the given entity path.

Declaration

public T FindComponentFromEntityPath<T>(string entityPath, bool isExactType = true) where T : Component

Parameters

Type	Name	Description
string	entityPath	Entity path.
bool	isExactType	If set to true [is exact type].

Returns

Type	Description
T	Component inside the entity.

Type Parameters

Name	Description
T	Component type.

FindComponentsFromEntityPath<T>(string, bool)

Returns the components inside the first entity with the given entity path.

Declaration

public IEnumerable<T> FindComponentsFromEntityPath<T>(string entityPath, bool isExactType = true) where T : Component

Parameters

Type	Name	Description
string	entityPath	Entity Path.
bool	isExactType	If set to true [is exact type].

Returns

Type	Description
IEnumerable<T>	Components collection.

Type Parameters

Name	Description
T	Component Type.

FindComponentsOfType(Type, bool, string)

Iterate through the entire entity hierarchy and return all component instances of the specified type.

Declaration

public IEnumerable<Component> FindComponentsOfType(Type type, bool isExactType = true, string tag = null)

Parameters

Type	Name	Description
Type	type	The component type.
bool	isExactType	Whether to match the exact type.
string	tag	Filter entities by this tag.

Returns

Type	Description
IEnumerable<Component>	The component enumerable.

Remarks

This method is extremely slow; try not to use it inside an Update method.

FindComponentsOfType<T>(bool, string)

Iterate through the entire entity hierarchy and return all component instances of the specified type.

Declaration

public IEnumerable<T> FindComponentsOfType<T>(bool isExactType = true, string tag = null) where T : Component

Parameters

Type	Name	Description
bool	isExactType	Whether to match the exact type.
string	tag	Filter entities by this tag.

Returns

Type	Description
IEnumerable<T>	The component enumerable.

Type Parameters

Name	Description
T	The component type.

Remarks

This method is extremely slow; try not to use it inside an Update method.

FindFirstComponentOfType(Type, bool, string)

Iterate through the entire entity hierarchy and return the first component instance of the specified type.

Declaration

public Component FindFirstComponentOfType(Type type, bool isExactType = true, string tag = null)

Parameters

Type	Name	Description
Type	type	The component type.
bool	isExactType	Whether to match the exact type.
string	tag	Filter entities by this tag.

Returns

Type	Description
Component	The component.

Remarks

This method is extremely slow, try to avoid using it inside an Update method.

FindFirstComponentOfType<T>(bool, string)

Iterate through the entire entity hierarchy and return the first component instance of the specified type.

Declaration

public T FindFirstComponentOfType<T>(bool isExactType = true, string tag = null) where T : Component

Parameters

Type	Name	Description
bool	isExactType	if set to true [is exact type].
string	tag	Filter entities by this tag.

Returns

Type	Description
T	The component.

Type Parameters

Name	Description
T	The component type.

Remarks

This method is extremely slow, try to avoid using it inside an Update method.

GetEntityTagCollection(string)

Gets a collection of entities filtered by the specified tag.

Declaration

public virtual EntityManager.EntityTagCollection GetEntityTagCollection(string tag)

Parameters

Type	Name	Description
string	tag	The tag.

Returns

Type	Description
EntityManager.EntityTagCollection	The entity tag collection.

OnActivated()

Invoked when the object is activated once it is attached.

Declaration

protected override void OnActivated()

Overrides

SceneManager.OnActivated()

OnDetach()

Invoked when the object is detached.

Declaration

protected override void OnDetach()

Overrides

SceneManager.OnDetach()

Remove(Entity)

Removes a specific entity.

Declaration

public virtual bool Remove(Entity entity)

Parameters

Type	Name	Description
Entity	entity	The entity to remove.

Returns

Type	Description
bool	Whether an entity was removed.

Remarks

The entity is disposed when it is removed from this instance.

Exceptions

Type	Condition
ArgumentNullException	If the entity is null.

Start()

Invoked to start the object.

Declaration

protected override void Start()

Overrides

SceneManager.Start()

Events

EntityAdded

Occurs when an Entity is added.

Declaration

public event EventHandler<Entity> EntityAdded

Event Type

Type	Description
EventHandler<Entity>

EntityDetached

Occurs when an Entity is detached.

Note that even when removing an entity, the entity is detached first. Therefore, this event will be fired for removed entities as well.

Declaration

public event EventHandler<Entity> EntityDetached

Event Type

Type	Description
EventHandler<Entity>

Implements

IDependencyObject

Extension Methods

EntityHierarchyExtensions.MoveEntityAfter(EntityManager, Guid, Guid?)

EntityHierarchyExtensions.MoveEntityBefore(EntityManager, Guid, Guid?)

ReflectionHelper.GetMemberAssembly(object)

ReflectionHelper.GetTypeName(object)