com.yworks.yfiles.graph

Class LookupChain

java.lang.Object

com.yworks.yfiles.graph.LookupChain

All Implemented Interfaces:

IContextLookup

public class LookupChain
extends Object
implements IContextLookup

An implementation of a chain of IContextLookupChainLinks.

Field Summary

Fields inherited from interface com.yworks.yfiles.graph.IContextLookup

EMPTY_CONTEXT_LOOKUP

Constructor Summary

Constructors

Constructor and Description
LookupChain()

Method Summary

Modifier and Type	Method and Description
<TContext,TResult> IContextLookupChainLink	add(Class<TContext> contextType, Class<TResult> resultType, BiFunction<TContext,TResult,TResult> wrapperFactory) A convenience method that adds a IContextLookupChainLink to the given chain that is based on a BiFunction.
<TContext,TResult> IContextLookupChainLink	add(Class<TContext> contextType, Class<TResult> resultType, BiFunction<TContext,TResult,TResult> wrapperFactory, boolean decorateNull) A convenience method that adds a IContextLookupChainLink to the given chain that is based on a BiFunction.
<TContext,TResult> IContextLookupChainLink	add(Class<TContext> contextType, Class<TResult> resultType, Function<TContext,TResult> factory) A convenience method that adds a IContextLookupChainLink to the given chain that is based on a Function.
<TContext,TResult> IContextLookupChainLink	add(Class<TContext> contextType, Class<TResult> resultType, Function<TContext,TResult> factory, boolean nullIsFallback) A convenience method that adds a IContextLookupChainLink to the given chain that is based on a Function.
void	add(IContextLookupChainLink lookup) Adds the given link to the end of the chain.
<TResult> IContextLookupChainLink	addConstant(Class<TResult> resultType, TResult result) Convenience method that can be used instead of the add(IContextLookupChainLink) method to easily add a lookup implementation for a given type that always yields a constant result.
void	addPropertyChangedListener(IEventHandler<PropertyChangedEventArgs> propertyChangedEvent) Adds the given listener for the PropertyChanged event that occurs when the lookup of this instance has changed for some or all of the types or items.
Object	lookup(Object item, Class type) Performs the actual lookup operation.
void	notifyChange() Can be called by client code to trigger the PropertyChanged event manually.
protected void	onPropertyChanged(PropertyChangedEventArgs eventArgs) Notifies client code that the lookup of this instance might have changed.
void	remove(IContextLookupChainLink link) Removes the link that has previously been added to this instance from this chain.
void	removePropertyChangedListener(IEventHandler<PropertyChangedEventArgs> propertyChangedEvent) Removes the given listener for the PropertyChanged event that occurs when the lookup of this instance has changed for some or all of the types or items.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.yworks.yfiles.graph.IContextLookup

lookup, lookup, lookup, safeLookup

Constructor Detail

LookupChain

public LookupChain()

Method Detail

add

public final <TContext,TResult> IContextLookupChainLink add(Class<TContext> contextType,
                                                            Class<TResult> resultType,
                                                            BiFunction<TContext,TResult,TResult> wrapperFactory)

A convenience method that adds a IContextLookupChainLink to the given chain that is based on a BiFunction.

Depending on decorateNull, null results of the underlying chain will be passed to the wrapperFactory, or simply yielded as the final result.

Type Parameters:

TContext - The type of the context.

TResult - The type of the result.

Parameters:

wrapperFactory - The wrapper factory that will be called for queries to TResult to wrap the result of the query to the remainder of the chain.

Returns:

The link that has been registered with the chain.

add

public <TContext,TResult> IContextLookupChainLink add(Class<TContext> contextType,
                                                      Class<TResult> resultType,
                                                      BiFunction<TContext,TResult,TResult> wrapperFactory,
                                                      boolean decorateNull)

A convenience method that adds a IContextLookupChainLink to the given chain that is based on a BiFunction.

Depending on decorateNull, null results of the underlying chain will be passed to the wrapperFactory, or simply yielded as the final result.

Type Parameters:

TContext - The type of the context.

TResult - The type of the result.

Parameters:

wrapperFactory - The wrapper factory that will be called for queries to TResult to wrap the result of the query to the remainder of the chain.

decorateNull - if set to true null return values of the remainder of the chain will be passed to the wrapper factory so that it can decorate the null, otherwise null will be yielded as the final result.

Returns:

The link that has been registered with the chain.

add

public final <TContext,TResult> IContextLookupChainLink add(Class<TContext> contextType,
                                                            Class<TResult> resultType,
                                                            Function<TContext,TResult> factory)

A convenience method that adds a IContextLookupChainLink to the given chain that is based on a Function.

Depending on nullIsFallback, null return values of the factory will be interpreted as the final result or indicate to the implementation that the chain should be queried for the result.

Type Parameters:

TContext - The type of the context.

TResult - The type of the result.

Parameters:

factory - The factory that will be called for queries to TResult.

Returns:

The link that has been registered with the chain.

add

public <TContext,TResult> IContextLookupChainLink add(Class<TContext> contextType,
                                                      Class<TResult> resultType,
                                                      Function<TContext,TResult> factory,
                                                      boolean nullIsFallback)

A convenience method that adds a IContextLookupChainLink to the given chain that is based on a Function.

Depending on nullIsFallback, null return values of the factory will be interpreted as the final result or indicate to the implementation that the chain should be queried for the result.

Type Parameters:

TContext - The type of the context.

TResult - The type of the result.

Parameters:

factory - The factory that will be called for queries to TResult.

nullIsFallback - If set to true, null return values of the factory method will be interpreted as the final result, otherwise the request will propagate down the chain.

Returns:

The link that has been registered with the chain.

add

public final void add(IContextLookupChainLink lookup)

Adds the given link to the end of the chain.

Parameters:

lookup - The link to add.

See Also:

remove(IContextLookupChainLink)

addConstant

public <TResult> IContextLookupChainLink addConstant(Class<TResult> resultType,
                                                     TResult result)

Convenience method that can be used instead of the add(IContextLookupChainLink) method to easily add a lookup implementation for a given type that always yields a constant result.

Note that in order to work correctly, the type parameter (TResult) should be specified instead of being inferred by the compiler, because the parameter is used to compare with the query type in the IContextLookup.lookup(Object, Class) call.

Type Parameters:

TResult - The type of the query, which is a base type or the type of the result.

Parameters:

result - The constant value to yield if the chain is queried for an implementation of type TResult.

Returns:

The IContextLookupChainLink instance that has been added to the chain.

addPropertyChangedListener

public final void addPropertyChangedListener(IEventHandler<PropertyChangedEventArgs> propertyChangedEvent)

Adds the given listener for the PropertyChanged event that occurs when the lookup of this instance has changed for some or all of the types or items.

Parameters:

propertyChangedEvent - The listener to add.

See Also:

removePropertyChangedListener(IEventHandler)

lookup

public final Object lookup(Object item,
                           Class type)

Performs the actual lookup operation.

This call will traverse the chain to satisfy the query.

Specified by:

lookup in interface IContextLookup

Parameters:

item - The item to use as the context.

type - The type of the query.

Returns:

The result of the query.

See Also:

ILookup.lookup(Class)

notifyChange

public void notifyChange()

Can be called by client code to trigger the PropertyChanged event manually.

onPropertyChanged

protected void onPropertyChanged(PropertyChangedEventArgs eventArgs)

Notifies client code that the lookup of this instance might have changed.

Parameters:

eventArgs - The arguments

remove

public final void remove(IContextLookupChainLink link)

Removes the link that has previously been added to this instance from this chain.

Parameters:

link - The link to remove.

removePropertyChangedListener

public final void removePropertyChangedListener(IEventHandler<PropertyChangedEventArgs> propertyChangedEvent)

Removes the given listener for the PropertyChanged event that occurs when the lookup of this instance has changed for some or all of the types or items.

Parameters:

propertyChangedEvent - The listener to remove.

See Also:

addPropertyChangedListener(IEventHandler)