Dragengine.Utils.ElementResolver Class Reference

Resolve element links. More...

Inheritance diagram for Dragengine.Utils.ElementResolver:

Classes
class	Request
	Resolve request. More...
class	ResolveException
	Resolve failure. More...

Public Member Functions
void	add (UniqueID id, Block ablock)
	Add resolve request. More...
Request	getAt (int index)
	Pending request at index. More...
int	getCount ()
	Number of pending requests. More...
ElementResolver	new ()
	Create resolver. More...

Detailed Description

Resolve element links.

Helper class to resolve element identifiers read from file readers. While loading elements from files the elements referenced by identifiers very well can not be present yet in the game world since they show up in the file at a later time. To support such links the UniqueID of an element is saved. Once read it has to be resolved once all elements are present in the game world. The best time for this is during a call to Element.enterFrame(). An instance of this class has to be placed in elements requiring resolving behavior. To resolve an encountered element add a resolve request to the instance of this class with a block to use. The following code example shows how to use this class.

class MyElement extends Element
   private var ElementResolver pElementResolver
   private var Element pElementInHands
   
   public func new()
      this.pElementResolver = ElementResolver.new()
   end
   
   public func void readFromFile( FileReader reader )
      ...
      if hasElementInHands
         this.pElementResolver.add( UniqueID.readFromFile( reader ), block Element resolved
            this.pElementInHands = resolved
         end )
      end
   end
   
   public func addToGameWorld()
      // request enterFrame() to be called once. works fine for both creating or loading
      // elemente. in case of creating new elements there are simply no request to resolve
      this.getGameWorld().addEnterFrameOnce( this )
   end
   
   public func void enterFrame()
      // resolve all elements. once finished all request are removed. if a resolve request
      // fails the block is called with a null element. it is the responsibility of the
      // block to handle this situation.
      this.pElementResolver.resolve( this.getGameWorld() )
   end
end

BehaviorsElement Behaviors

This class is also able to resolve BehaviorElement behaviors. During saving you have to store both the BehaviorElement UniqueID as well as the behavior instance index. The DefaultECBehavior class provides this information. While resolving the block is called with BehaviorInstance as parameter. In general you will change this to parameter type to match the behavior stored.

class MyElement extends Element
   private var ElementResolver pElementResolver
   private var MyBehavior.Instance pElementInHands
   
   public func new()
      this.pElementResolver = ElementResolver.new()
   end
   
   public func void readFromFile( FileReader reader )
      ...
      if hasElementInHands
         var UniqueID id = UniqueID.readFromFile( reader )
         var int index = reader.readUShort()
         this.pElementResolver.addBehavior( id, index, block MyBehavior.Instance behavior
            this.pElementInHands = behavior
         end )
      end
   end
   
   public func addToGameWorld()
      // request enterFrame() to be called once. works fine for both creating or loading
      // elemente. in case of creating new elements there are simply no request to resolve
      this.getGameWorld().addEnterFrameOnce( this )
   end
   
   public func void enterFrame()
      // resolve all elements. once finished all request are removed. if a resolve request
      // fails the block is called with a null element. it is the responsibility of the
      // block to handle this situation.
      this.pElementResolver.resolve( this.getGameWorld() )
   end
end

Member Function Documentation

add()

void Dragengine.Utils.ElementResolver.add	(	UniqueID	id,
		Block	ablock
	)

Add resolve request.

Add request to resolve element by identifier. Once resolved ablock is called with the resolved element as parameter. If resolving fails ablock is called with null as parameter.

getAt()

Request Dragengine.Utils.ElementResolver.getAt

(

int

index

)

Pending request at index.

getCount()

int Dragengine.Utils.ElementResolver.getCount

(

)

Number of pending requests.

new()

ElementResolver Dragengine.Utils.ElementResolver.new

(

)

Create resolver.

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The documentation for this class was generated from the following file:

• ElementResolver.ds