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Top Description Fields Constructors Methods
javafx.beans.binding

public abstract Class LongBinding

extends LongExpression
implements NumberBinding
Class Inheritance
All Implemented Interfaces
javafx.beans.binding.NumberBinding, javafx.beans.binding.NumberExpression, javafx.beans.value.ObservableNumberValue, javafx.beans.value.ObservableValue, javafx.beans.Observable, javafx.beans.binding.Binding
Known Direct Subclasses
javafx.beans.property.LongPropertyBase.ValueWrapper, com.sun.javafx.binding.SelectBinding.AsLong
Imports
javafx.beans.InvalidationListener, .Observable, javafx.beans.value.ChangeListener, javafx.collections.FXCollections, .ObservableList, com.sun.javafx.binding.BindingHelperObserver, .ExpressionHelper
Base class that provides most of the functionality needed to implement a Binding of a long value.

LongBinding provides a simple invalidation-scheme. An extending class can register dependencies by calling bind(Observable...). If One of the registered dependencies becomes invalid, this LongBinding 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, NumberBinding, javafx.beans.binding.LongExpression

Field Summary

Modifier and TypeField and Description
private ExpressionHelper<Number>
helper

private BindingHelperObserver
observer

Invalidation listener used for observing dependencies.

private boolean
valid

private long
value

Constructor Summary

AccessConstructor and Description
public
LongBinding()

Creates a default LongBinding.

Method Summary

Modifier and TypeMethod and Description
public void
addListener(InvalidationListener listener)

Implements javafx.beans.Observable.addListener.

Adds an InvalidationListener which will be notified whenever the Observable becomes invalid.

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

Implements javafx.beans.value.ObservableValue.addListener.

Adds a ChangeListener which will be notified whenever the value of the ObservableValue changes.

protected final void
bind(Observable...
the dependencies to observe
dependencies)

Start observing the dependencies for changes.

protected abstract long

Returns:

the current value
computeValue()

Calculates the current value of this binding.

public void
dispose()

Implements javafx.beans.binding.Binding.dispose.

A default implementation of dispose() that is empty.

public final long

Returns:

the current value
get()

Implements javafx.beans.value.ObservableLongValue.get.

Returns the result of computeValue().

public ObservableList<?>

Returns:

an empty ObservableList
getDependencies()

Implements javafx.beans.binding.Binding.getDependencies.

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

public final void
invalidate()

Implements javafx.beans.binding.Binding.invalidate.

Mark a binding as invalid.

public final boolean
isValid()

Implements javafx.beans.binding.Binding.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.

public void
removeListener(InvalidationListener listener)

Implements javafx.beans.Observable.removeListener.

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

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

Implements javafx.beans.value.ObservableValue.removeListener.

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

public String

Returns:

a string representation of this LongBinding object.
toString()

Overrides java.lang.Object.toString.

Returns a string representation of this LongBinding object.

protected final void
unbind(Observable...
the dependencies to stop observing
dependencies)

Stop observing the dependencies for changes.

Inherited from javafx.beans.binding.LongExpression:
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Field Detail

helperback to summary
private ExpressionHelper<Number> helper
observerback to summary
private BindingHelperObserver observer

Invalidation listener used for observing dependencies. This is never cleared once created as there is no way to determine when all dependencies that were previously bound were removed in one or more calls to unbind(Observable...).

validback to summary
private boolean valid
valueback to summary
private long value

Constructor Detail

LongBindingback to summary
public LongBinding()

Creates a default LongBinding.

Method Detail

addListenerback to summary
public void addListener(InvalidationListener listener)

Implements javafx.beans.Observable.addListener.

Doc from javafx.beans.Observable.addListener.

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.

Annotations
@Override
addListenerback to summary
public void addListener(ChangeListener<? super Number> listener)

Implements javafx.beans.value.ObservableValue.addListener.

Doc from javafx.beans.value.ObservableValue.addListener.

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.

Annotations
@Override
bindback to summary
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:Observable[]

the dependencies to observe

computeValueback to summary
protected abstract long computeValue()

Calculates the current value of this binding.

Classes extending LongBinding have to provide an implementation of computeValue.

Returns:long

the current value

disposeback to summary
public void dispose()

Implements javafx.beans.binding.Binding.dispose.

A default implementation of dispose() that is empty.

Annotations
@Override
getback to summary
public final long get()

Implements javafx.beans.value.ObservableLongValue.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().

Returns:long

the current value

Annotations
@Override
getDependenciesback to summary
public ObservableList<?> getDependencies()

Implements javafx.beans.binding.Binding.getDependencies.

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

Returns:ObservableList<?>

an empty ObservableList

Annotations
@Override
invalidateback to summary
public final void invalidate()

Implements javafx.beans.binding.Binding.invalidate.

Doc from javafx.beans.binding.Binding.invalidate.

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

Annotations
@Override
isValidback to summary
public final boolean isValid()

Implements javafx.beans.binding.Binding.isValid.

Doc from javafx.beans.binding.Binding.isValid.

Checks if a binding is valid.

Annotations
@Override
onInvalidatingback to summary
protected void onInvalidating()

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

removeListenerback to summary
public void removeListener(InvalidationListener listener)

Implements javafx.beans.Observable.removeListener.

Doc from javafx.beans.Observable.removeListener.

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.

Annotations
@Override
removeListenerback to summary
public void removeListener(ChangeListener<? super Number> listener)

Implements javafx.beans.value.ObservableValue.removeListener.

Doc from javafx.beans.value.ObservableValue.removeListener.

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.

Annotations
@Override
toStringback to summary
public String toString()

Overrides java.lang.Object.toString.

Returns a string representation of this LongBinding object.

Returns:String

a string representation of this LongBinding object.

Annotations
@Override
unbindback to summary
protected final void unbind(Observable... dependencies)

Stop observing the dependencies for changes.

Parameters
dependencies:Observable[]

the dependencies to stop observing