com.yworks.yfiles.graph

Class Mapper<K,V>

java.lang.Object

com.yworks.yfiles.graph.Mapper<K,V>

All Implemented Interfaces:

IMapper<K,V>

public final class Mapper<K,V>
extends Object
implements IMapper<K,V>

An IMapper implementation backed by a Map.

A DefaultValue can be set that is returned for keys that don't have an explicit value set.

It is legal to use null as key (provided K is a reference or nullable type), which can be assigned a value just like other keys.

Constructor Summary

Constructors

Constructor and Description
Mapper() Creates an instance using a HashMap as the backing store.
Mapper(Map<K,V> map) Creates an instance using the provided Map as the backing store.

Method Summary

Modifier and Type	Method and Description
void	clear() Calls HashMap.clear() on the backing implementation.
V	getDefaultValue() Gets the default value to return if no specific value has been set for a given key.
Iterable<Map.Entry<K,V>>	getEntries() Gets an enumerable over all entries in this (dictionary based) mapper.
V	getItem(K key) Finds the associated value for the given key in the mapping or (re-)associates the given key with the value provided, removing previous associations.
V	getValue(K key) Gets the value for a given key in the mapping.
void	removeValue(K key)
void	setDefaultValue(V value) Sets the default value to return if no specific value has been set for a given key.
void	setItem(K key, V value) Finds the associated value for the given key in the mapping or (re-)associates the given key with the value provided, removing previous associations.
void	setValue(K key, V value) Sets the value for a given key in the mapping.

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.IMapper

fromConstant, fromFunction

Constructor Detail

Mapper

public Mapper()

Creates an instance using a HashMap as the backing store.

The value for the null item is stored separately.

Mapper

public Mapper(Map<K,V> map)

Creates an instance using the provided Map as the backing store.

The value for the null item is stored separately.

Method Detail

clear

public final void clear()

Calls HashMap.clear() on the backing implementation.

getDefaultValue

public final V getDefaultValue()

Gets the default value to return if no specific value has been set for a given key.

Returns:

The DefaultValue.

See Also:

setDefaultValue(java.lang.Object)

getEntries

public final Iterable<Map.Entry<K,V>> getEntries()

Gets an enumerable over all entries in this (dictionary based) mapper.

Returns:

The Entries.

getItem

public final V getItem(K key)

Finds the associated value for the given key in the mapping or (re-)associates the given key with the value provided, removing previous associations.

In order to remove an association the removeValue(Object) method should be preferred over calling this method using a default value. This implementation simply delegates to setValue(Object, Object) and getValue(Object) respectively.

Parameters:

key - The key to use as the index.

Returns:

The value.

See Also:

removeValue(Object), getValue(Object), setValue(Object, Object), setItem(Object, Object)

getValue

public final V getValue(K key)

Description copied from interface: IMapper

Gets the value for a given key in the mapping.

Setting a value for an already existing key overwrites the previous value.

It depends on the specific implementation of the mapper whether a mapping can be removed. If an implementation provides a way to remove a mapping, that should be preferred over setting a null value. For example, Mapper provides the removeValue(java.lang.Object) method.

Specified by:

getValue in interface IMapper<K,V>

Parameters:

key - The key of the mapping.

Returns:

The value.

See Also:

IMapper.setValue(java.lang.Object, java.lang.Object)

removeValue

public final void removeValue(K key)

setDefaultValue

public final void setDefaultValue(V value)

Sets the default value to return if no specific value has been set for a given key.

Parameters:

value - The DefaultValue to set.

See Also:

getDefaultValue()

setItem

public final void setItem(K key,
                          V value)

Finds the associated value for the given key in the mapping or (re-)associates the given key with the value provided, removing previous associations.

In order to remove an association the removeValue(Object) method should be preferred over calling this method using a default value. This implementation simply delegates to setValue(Object, Object) and getValue(Object) respectively.

Parameters:

key - The key to use as the index.

value - The value.

See Also:

removeValue(Object), getValue(Object), setValue(Object, Object), getItem(Object)

setValue

public final void setValue(K key,
                           V value)

Description copied from interface: IMapper

Sets the value for a given key in the mapping.

Setting a value for an already existing key overwrites the previous value.

It depends on the specific implementation of the mapper whether a mapping can be removed. If an implementation provides a way to remove a mapping, that should be preferred over setting a null value. For example, Mapper provides the removeValue(java.lang.Object) method.

Specified by:

setValue in interface IMapper<K,V>

Parameters:

key - The key of the mapping.

value - The value.

See Also:

IMapper.getValue(java.lang.Object)