Class StringBinding

java.lang.Object

javafx.beans.binding.StringExpression

javafx.beans.binding.StringBinding

All Implemented Interfaces:

Binding<String>, Observable, ObservableObjectValue<String>, ObservableStringValue, ObservableValue<String>

public abstract class StringBinding
extends StringExpression
implements Binding<String>

Base class that provides most of the functionality needed to implement a Binding of a String.

StringBinding provides a simple invalidation-scheme. An extending class can register dependencies by calling bind(Observable...). If One of the registered dependencies becomes invalid, this StringBinding is marked as invalid. With unbind(Observable...) listening to dependencies can be stopped.

To provide a concrete implementation of this class, the method computeValue() has to be implemented to calculate the value of this binding based on the current state of the dependencies. It is called when get() is called for an invalid binding.

See DoubleBinding for an example how this base class can be extended.

Since:

JavaFX 2.0

See Also:

• Binding
• StringExpression

Constructor Summary

Constructors

Constructor	Description
StringBinding()	Creates a default StringBinding.

Method Summary

Modifier and Type	Method	Description
void	addListener(InvalidationListener listener)	Adds an InvalidationListener which will be notified whenever the Observable becomes invalid.
void	addListener(ChangeListener<? super String> listener)	Adds a ChangeListener which will be notified whenever the value of the ObservableValue changes.
protected final void	bind(Observable... dependencies)	Start observing the dependencies for changes.
protected abstract String	computeValue()	Calculates the current value of this binding.
void	dispose()	A default implementation of dispose() that is empty.
final String	get()	Returns the result of computeValue().
ObservableList<?>	getDependencies()	A default implementation of getDependencies() that returns an empty ObservableList.
final void	invalidate()	Mark a binding as invalid.
final boolean	isValid()	Checks if a binding is valid.
protected void	onInvalidating()	The method onInvalidating() can be overridden by extending classes to react, if this binding becomes invalid.
void	removeListener(InvalidationListener listener)	Removes the given listener from the list of listeners, that are notified whenever the value of the Observable becomes invalid.
void	removeListener(ChangeListener<? super String> listener)	Removes the given listener from the list of listeners that are notified whenever the value of the ObservableValue changes.
String	toString()	Returns a string representation of this StringBinding object.
protected final void	unbind(Observable... dependencies)	Stop observing the dependencies for changes.

Methods declared in class StringExpression

concat, getValue, getValueSafe, greaterThan, greaterThan, greaterThanOrEqualTo, greaterThanOrEqualTo, isEmpty, isEqualTo, isEqualTo, isEqualToIgnoreCase, isEqualToIgnoreCase, isNotEmpty, isNotEqualTo, isNotEqualTo, isNotEqualToIgnoreCase, isNotEqualToIgnoreCase, isNotNull, isNull, length, lessThan, lessThan, lessThanOrEqualTo, lessThanOrEqualTo, stringExpression

Modifier and Type	Method	Description
StringExpression	concat(Object other)	Returns a StringExpression that holds the value of this StringExpression concatenated with another Object.
String	getValue()	Returns the current value of this ObservableValue
final String	getValueSafe()	Returns usually the value of this StringExpression.
BooleanBinding	greaterThan(String other)	Creates a new BooleanBinding that holds true if this StringExpression is greater than a constant value.
BooleanBinding	greaterThan(ObservableStringValue other)	Creates a new BooleanBinding that holds true if this StringExpression is greater than another ObservableStringValue.
BooleanBinding	greaterThanOrEqualTo(String other)	Creates a new BooleanBinding that holds true if this StringExpression is greater than or equal to a constant value.
BooleanBinding	greaterThanOrEqualTo(ObservableStringValue other)	Creates a new BooleanBinding that holds true if this StringExpression is greater than or equal to another ObservableStringValue.
BooleanBinding	isEmpty()	Creates a new BooleanBinding that holds true if this StringExpression is empty.
BooleanBinding	isEqualTo(String other)	Creates a new BooleanBinding that holds true if this StringExpression is equal to a constant value.
BooleanBinding	isEqualTo(ObservableStringValue other)	Creates a new BooleanBinding that holds true if this and another ObservableStringValue are equal.
BooleanBinding	isEqualToIgnoreCase(String other)	Creates a new BooleanBinding that holds true if this StringExpression is equal to a constant value ignoring case.
BooleanBinding	isEqualToIgnoreCase(ObservableStringValue other)	Creates a new BooleanBinding that holds true if this and another ObservableStringValue are equal ignoring case.
BooleanBinding	isNotEmpty()	Creates a new BooleanBinding that holds true if this StringExpression is not empty.
BooleanBinding	isNotEqualTo(String other)	Creates a new BooleanBinding that holds true if this StringExpression is not equal to a constant value.
BooleanBinding	isNotEqualTo(ObservableStringValue other)	Creates a new BooleanBinding that holds true if this and another ObservableStringValue are not equal.
BooleanBinding	isNotEqualToIgnoreCase(String other)	Creates a new BooleanBinding that holds true if this StringExpression is not equal to a constant value ignoring case.
BooleanBinding	isNotEqualToIgnoreCase(ObservableStringValue other)	Creates a new BooleanBinding that holds true if this and another ObservableStringValue are not equal ignoring case.
BooleanBinding	isNotNull()	Creates a new BooleanBinding that holds true if this StringExpression is not null.
BooleanBinding	isNull()	Creates a new BooleanBinding that holds true if this StringExpression is null.
IntegerBinding	length()	Creates a new IntegerBinding that holds the length of this StringExpression.
BooleanBinding	lessThan(String other)	Creates a new BooleanBinding that holds true if this StringExpression is less than a constant value.
BooleanBinding	lessThan(ObservableStringValue other)	Creates a new BooleanBinding that holds true if this StringExpression is less than another ObservableStringValue.
BooleanBinding	lessThanOrEqualTo(String other)	Creates a new BooleanBinding that holds true if this StringExpression is less than or equal to a constant value.
BooleanBinding	lessThanOrEqualTo(ObservableStringValue other)	Creates a new BooleanBinding that holds true if this StringExpression is less than or equal to another ObservableStringValue.
static StringExpression	stringExpression(ObservableValue<?> value)	Returns a StringExpression that wraps a ObservableValue.

Methods declared in class Object

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

Methods declared in interface Observable

subscribe

Modifier and Type	Method	Description
default Subscription	subscribe(Runnable invalidationSubscriber)	Creates a Subscription on this Observable which calls invalidationSubscriber whenever it becomes invalid.

Methods declared in interface ObservableValue

flatMap, map, orElse, subscribe, subscribe, when

Modifier and Type	Method	Description
default <U> ObservableValue<U>	flatMap(Function<? super String, ? extends ObservableValue<? extends U>> mapper)	Returns an ObservableValue that holds the value of an ObservableValue produced by applying the given mapping function on this value.
default <U> ObservableValue<U>	map(Function<? super String, ? extends U> mapper)	Returns an ObservableValue that holds the result of applying the given mapping function on this value.
default ObservableValue<String>	orElse(String constant)	Returns an ObservableValue that holds this value, or the given constant if it is null.
default Subscription	subscribe(BiConsumer<? super String, ? super String> changeSubscriber)	Creates a Subscription on this ObservableValue which calls the given changeSubscriber with the old and new value whenever its value changes.
default Subscription	subscribe(Consumer<? super String> valueSubscriber)	Creates a Subscription on this ObservableValue which immediately provides the current value to the given valueSubscriber, followed by any subsequent values whenever its value changes.
default ObservableValue<String>	when(ObservableValue<Boolean> condition)	Returns an ObservableValue that holds this value and is updated only when condition holds true.

Constructor Details

StringBinding

public StringBinding()

Creates a default StringBinding.

Method Details

addListener

public void addListener(InvalidationListener listener)

Description copied from interface: Observable

Adds an InvalidationListener which will be notified whenever the Observable becomes invalid. If the same listener is added more than once, then it will be notified more than once. That is, no check is made to ensure uniqueness.

Note that the same actual InvalidationListener instance may be safely registered for different Observables.

The Observable stores a strong reference to the listener which will prevent the listener from being garbage collected and may result in a memory leak. It is recommended to either unregister a listener by calling removeListener after use or to use an instance of WeakInvalidationListener avoid this situation.

Specified by:

addListener in interface Observable

Parameters:

listener - The listener to register

See Also:

• Observable.removeListener(InvalidationListener)

removeListener

public void removeListener(InvalidationListener listener)

Description copied from interface: Observable

Removes the given listener from the list of listeners, that are notified whenever the value of the Observable becomes invalid.

If the given listener has not been previously registered (i.e. it was never added) then this method call is a no-op. If it had been previously added then it will be removed. If it had been added more than once, then only the first occurrence will be removed.

Specified by:

removeListener in interface Observable

Parameters:

listener - The listener to remove

See Also:

• Observable.addListener(InvalidationListener)

addListener

public void addListener(ChangeListener<? super String> listener)

Description copied from interface: ObservableValue

Adds a ChangeListener which will be notified whenever the value of the ObservableValue changes. If the same listener is added more than once, then it will be notified more than once. That is, no check is made to ensure uniqueness.

Note that the same actual ChangeListener instance may be safely registered for different ObservableValues.

The ObservableValue stores a strong reference to the listener which will prevent the listener from being garbage collected and may result in a memory leak. It is recommended to either unregister a listener by calling removeListener after use or to use an instance of WeakChangeListener avoid this situation.

Specified by:

addListener in interface ObservableValue<String>

Parameters:

listener - The listener to register

See Also:

• ObservableValue.removeListener(ChangeListener)

removeListener

public void removeListener(ChangeListener<? super String> listener)

Description copied from interface: ObservableValue

Removes the given listener from the list of listeners that are notified whenever the value of the ObservableValue changes.

If the given listener has not been previously registered (i.e. it was never added) then this method call is a no-op. If it had been previously added then it will be removed. If it had been added more than once, then only the first occurrence will be removed.

Specified by:

removeListener in interface ObservableValue<String>

Parameters:

listener - The listener to remove

See Also:

• ObservableValue.addListener(ChangeListener)

bind

protected final void bind(Observable... dependencies)

Start observing the dependencies for changes. If the value of one of the dependencies changes, the binding is marked as invalid.

Parameters:

dependencies - the dependencies to observe

unbind

protected final void unbind(Observable... dependencies)

Stop observing the dependencies for changes.

Parameters:

dependencies - the dependencies to stop observing

dispose

public void dispose()

A default implementation of dispose() that is empty.

Specified by:

dispose in interface Binding<String>

getDependencies

public ObservableList<?> getDependencies()

A default implementation of getDependencies() that returns an empty ObservableList.

Specified by:

getDependencies in interface Binding<String>

Returns:

an empty ObservableList

get

public final String get()

Returns the result of computeValue(). The method computeValue() is only called if the binding is invalid. The result is cached and returned if the binding did not become invalid since the last call of get().

Specified by:

get in interface ObservableObjectValue<String>

Returns:

the current value

onInvalidating

protected void onInvalidating()

The method onInvalidating() can be overridden by extending classes to react, if this binding becomes invalid. The default implementation is empty.

invalidate

public final void invalidate()

Description copied from interface: Binding

Mark a binding as invalid. This forces the recalculation of the value of the Binding next time it is request.

Specified by:

invalidate in interface Binding<String>

isValid

public final boolean isValid()

Description copied from interface: Binding

Checks if a binding is valid.

Specified by:

isValid in interface Binding<String>

Returns:

true if the Binding is valid, false otherwise

computeValue

protected abstract String computeValue()

Calculates the current value of this binding.

Classes extending StringBinding have to provide an implementation of computeValue.

Returns:

the current value

toString

public String toString()

Returns a string representation of this StringBinding object.

Overrides:

toString in class Object

Returns:

a string representation of this StringBinding object.