Class Visitor<TNode, TComponent>

This class tries to serve three goals

As a base class for visitor patterns. Users can add visitor methods and provide code for different types of visited items.
As building block for enumerators. Visitor methods can yield an enumeration.
As a tool set to implement transformations on scenes. Transformations operate on scenes and alter their structure.

Visitors derived from this class may implement their own Visit methods for all kinds of scene graph elements. Visitor methods can be defined for scene nodes (although many implementations will most likely NOT have a very big inheritance tree for nodes) as well as for scene components. A Visitor method can be any instance method (not static) taking one parameter either derived from INode or derived from IComponent. To mark such a method as a Visitor method it needs to be decorated with the VisitMethodAttribute attribute. Visitor methods can have arbitrary names and don't necessarily need to be virtual.

Inheritance

System.Object

Visitor<TNode, TComponent>

AABBCalculator

OBBCalculator

SceneRendererForward

SceneInteractionHandler

SceneFinderBase<TSceneElementType, TNode, TComponent>

ViseratorBase<TItem, TNode, TComponent>

Inherited Members

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.ToString()

Namespace: Fusee.Xene

Assembly: Fusee.Xene.dll

Syntax

public class Visitor<TNode, TComponent>
    where TNode : class, INode where TComponent : class, IComponent

Type Parameters

Name	Description
TNode
TComponent

Fields

IgnoreInactiveComponents

Set this to true if the visitor should skip inactive Components.

Declaration

public bool IgnoreInactiveComponents

Field Value

Type	Description
System.Boolean

VisitorModules

Declaration

public List<IVisitorModule> VisitorModules

Field Value

Type	Description
System.Collections.Generic.List<IVisitorModule>

Properties

CurrentComponent

Returns the currently visited component during a traversal.

Declaration

protected TComponent CurrentComponent { get; }

Property Value

Type	Description
TComponent	The current component.

CurrentNode

Returns currently visited node during a traversal.

Declaration

protected TNode CurrentNode { get; }

Property Value

Type	Description
TNode	The current node.

YieldEnumeration

Gets a value indicating whether the current enumeration should yield.

Declaration

protected bool YieldEnumeration { get; }

Property Value

Type	Description
System.Boolean	`true` if the current enumeration should yield; otherwise, `false`.

YieldOnCurrentComponent

Can be called in derived visitors. Set this property to true during traversals to make the visitor yield the current component when used as an enumerator.

Declaration

protected bool YieldOnCurrentComponent { get; set; }

Property Value

Type	Description
System.Boolean	`true` if the enumeration should yield the current component; otherwise, `false`.

YieldOnCurrentNode

Can be called in derived visitors. Set this property to true during traversals to make the visitor yield the current node when used as an enumerator.

Declaration

protected bool YieldOnCurrentNode { get; set; }

Property Value

Type	Description
System.Boolean	`true` if the enumeration should yield the current node; otherwise, `false`.

Methods

EnumInit(IEnumerator<TNode>)

Enumerator Building Block to be called in derived Visitors acting as enumerators. Use this to initialize the traversing enumeration on a list of (root) nodes.

Declaration

protected void EnumInit(IEnumerator<TNode> nodes)

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerator<TNode>	nodes	The list of nodes.

EnumMoveNext()

This method implements a re-entrant (in terms of yield, not multi-threading) non-recursive traversal over combined node and component trees. Call this method in derived classes implementing enumerators, like in the various find extension methods or the Viserator<TItem, TState, TNode, TComponent>

Declaration

protected bool EnumMoveNext()

Returns

Type	Description
System.Boolean	`true` if the enumerator was successfully advanced to the next element; `false` if the enumerator has passed the end of node-component-tree.

EnumMoveNextNoComponent()

Continue a currently active enumeration. Call all registered Visit methods. Visitor methods may set YieldOnCurrentComponent or YieldOnCurrentNode to true to signal the enumeration to yield.

Declaration

protected bool EnumMoveNextNoComponent()

Returns

Type	Description
System.Boolean	true if the enumeration is not finished yet (i.e. if components/nodes are still unvisited). false otherwise.

InitState()

Method is called when traversal starts to initialize the traversal state. Override this method in derived classes to initialize any state.

Declaration

protected virtual void InitState()

PopState()

Method is called when going up one hierarchy level while traversing. Override this method to perform pop on any self-defined state.

Declaration

protected virtual void PopState()

PushState()

Method is called when going down one hierarchy level while traversing. Override this method to push any self-defined state.

Declaration

protected virtual void PushState()

Traverse(TNode)

Start traversing a scene graph starting with the given root node. Performs a recursive depth-first traversal from the specified root.

Declaration

public void Traverse(TNode rootNode)

Parameters

Type	Name	Description
TNode	rootNode	The root node where to start the traversal.

Traverse(IEnumerable<TNode>)

Start traversing a list of nodes. Performs a recursive depth-first traversal over the list starting with the first node in the list.

Declaration

public void Traverse(IEnumerable<TNode> children)

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<TNode>	children	The list of nodes to traverse over.