Module io.github.mmm.value.observable

Package io.github.mmm.value.observable

Class AbstractWritableObservableValue<V>

java.lang.Object

io.github.mmm.event.AbstractEventSource<ObservableEvent<V>,ObservableEventListener<? super V>>

io.github.mmm.value.observable.AbstractObservableValue<V>

io.github.mmm.value.observable.AbstractWritableObservableValue<V>

Type Parameters:

V - type of the observable value.

All Implemented Interfaces:

EventSource<ObservableEvent<V>,ObservableEventListener<? super V>>, ObservableValue<V>, WritableObservableValue<V>, ReadableValue<V>, WritableValue<V>, Supplier<V>

public abstract class AbstractWritableObservableValue<V>
extends AbstractObservableValue<V>
implements WritableObservableValue<V>

Abstract base implementation of WritableObservableValue that handles bindings.

Since:

1.0.0

Constructor Summary

Constructors

Constructor	Description
AbstractWritableObservableValue()

Method Summary

Modifier and Type	Method	Description
protected void	bindInternal(ObservableValue<? extends V> observable)	Internal method of bindOneWay(ObservableValue).
void	bindOneWay(ObservableValue<? extends V> observable)	Creates a unidirection binding for this object. ATTENTION: An unidirectional binding is very strict.
void	bindTwoWay(WritableObservableValue<V> other)	Create a bidirectional binding between this object and the given one.
protected abstract V	doGet()
protected abstract void	doSet(V newValue)
V	get()
boolean	isBoundOneWay()
protected boolean	isValueEqual(V newValue, V oldValue)	Null-safe check if two values are considered equal (unchanged).
protected void	requireWritable()
void	set(V value)
protected void	setWithChange(V oldValue, V value)	Internal method called from set(Object) if the value actually changed.
void	unbindOneWay()	Removes the unidirectional binding from this object.
void	unbindTwoWay(WritableObservableValue<V> other)	Removes a bidirectional binding between this object and the given one.

Methods inherited from class io.github.mmm.value.observable.AbstractObservableValue

addListener, fireChange, fireEvent, fireEvent, fireEventFor, fireEventFor, fireEventWithOldValue, hasChangeAwareListeners, invalidate, removeListener, toString, toString

Methods inherited from class io.github.mmm.event.AbstractEventSource

getEventAdapter, hasListeners

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.github.mmm.event.EventSource

addListener, addListener, addWeakListener, removeListener

Methods inherited from interface io.github.mmm.value.observable.ObservableValue

toString

Methods inherited from interface io.github.mmm.value.ReadableValue

getSafe

Constructor Details

AbstractWritableObservableValue

public AbstractWritableObservableValue()

Method Details

get

public V get()

Specified by:

get in interface ReadableValue<V>

Specified by:

get in interface Supplier<V>

doGet

protected abstract V doGet()

Returns:

the internal value.

bindOneWay

public void bindOneWay(ObservableValue<? extends V> observable)

Description copied from interface: WritableObservableValue

Creates a unidirection binding for this object.
ATTENTION:
An unidirectional binding is very strict. It makes this object to appear exactly as the ObservableValue it is bound to. After creating the unidirectional binding, calls to WritableValue.set(Object) will fail. This is very different to an bidirectional binding.

Specified by:

bindOneWay in interface WritableObservableValue<V>

Parameters:

observable - the ObservableValue this object should be bound to.

See Also:

• WritableObservableValue.unbindOneWay()
• WritableObservableValue.isBoundOneWay()

bindInternal

protected void bindInternal(ObservableValue<? extends V> observable)

Internal method of bindOneWay(ObservableValue). Do not call.

Parameters:

observable - the ObservableValue to bind.

See Also:

• bindOneWay(ObservableValue)

unbindOneWay

public void unbindOneWay()

Description copied from interface: WritableObservableValue

Removes the unidirectional binding from this object. If this object is not bound, this method has no effect.

Specified by:

unbindOneWay in interface WritableObservableValue<V>

See Also:

• WritableObservableValue.bindOneWay(ObservableValue)

isBoundOneWay

public boolean isBoundOneWay()

Specified by:

isBoundOneWay in interface WritableObservableValue<V>

Returns:

true if this object is bound, false otherwise.

See Also:

• WritableObservableValue.bindOneWay(ObservableValue)

bindTwoWay

public void bindTwoWay(WritableObservableValue<V> other)

Description copied from interface: WritableObservableValue

Create a bidirectional binding between this object and the given one. After a bidirectional binding, WritableValue.set(Object) on this object will propagate its value to the bound one and vice versa. Bidirectional bindings exists independently of unidirectional bindings. However, it is bad practice to combine both. It is possible to have multiple bidirectional bindings for the same object.

Specified by:

bindTwoWay in interface WritableObservableValue<V>

Parameters:

other - the other WritableObservableValue to bind bidirectional.

See Also:

• WritableObservableValue.unbindTwoWay(WritableObservableValue)

unbindTwoWay

public void unbindTwoWay(WritableObservableValue<V> other)

Description copied from interface: WritableObservableValue

Removes a bidirectional binding between this object and the given one. If no bidirectional binding between these objects exists, this method has no effect. It is possible to unbind in inverse order. So to unbind two bidirectional bound objects it does not matter if you call unbindBidirectional on the first with the second as argument or vice versa.

Specified by:

unbindTwoWay in interface WritableObservableValue<V>

Parameters:

other - the other WritableObservableValue to unbind bidirectional.

See Also:

• WritableObservableValue.bindTwoWay(WritableObservableValue)

set

public void set(V value)

Specified by:

set in interface WritableValue<V>

isValueEqual

protected boolean isValueEqual(V newValue,
 V oldValue)

Null-safe check if two values are considered equal (unchanged).

Parameters:

newValue - the new value.

oldValue - the old value.

Returns:

true if equal (unchanged), false otherwise (changed),

setWithChange

protected void setWithChange(V oldValue,
 V value)

Internal method called from set(Object) if the value actually changed.

Parameters:

oldValue - the old value.

value - the new value.

requireWritable

protected void requireWritable()
                        throws IllegalStateException

Throws:

IllegalStateException - if this property is not writable.

doSet

protected abstract void doSet(V newValue)

Parameters:

newValue - the new value to set.

See Also:

• set(Object)