javafx.beans.binding.SetExpression Maven / Gradle / Ivy
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package javafx.beans.binding;
import com.sun.javafx.binding.StringFormatter;
import javafx.beans.InvalidationListener;
import javafx.beans.property.ReadOnlyBooleanProperty;
import javafx.beans.property.ReadOnlyIntegerProperty;
import javafx.beans.value.ObservableSetValue;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.collections.ObservableSet;
import javafx.collections.SetChangeListener;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Iterator;
import java.util.NoSuchElementException;
/**
* {@code SetExpression} is an
* {@link javafx.beans.value.ObservableSetValue} plus additional convenience
* methods to generate bindings in a fluent style.
*
* A concrete sub-class of {@code SetExpression} has to implement the method
* {@link javafx.beans.value.ObservableSetValue#get()}, which provides the
* actual value of this expression.
*
* If the wrapped list of a {@code SetExpression} is {@code null}, all methods implementing the {@code Set}
* interface will behave as if they were applied to an immutable empty set.
*
* @param the type of the {@code Set} elements
* @since JavaFX 2.1
*/
public abstract class SetExpression implements ObservableSetValue {
/**
* Creates a default {@code SetExpression}.
*/
public SetExpression() {
}
private static final ObservableSet EMPTY_SET = new EmptyObservableSet();
private static class EmptyObservableSet extends AbstractSet implements ObservableSet {
private static final Iterator iterator = new Iterator() {
@Override
public boolean hasNext() {
return false;
}
@Override
public Object next() {
throw new NoSuchElementException();
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
};
@Override
public Iterator iterator() {
return iterator;
}
@Override
public int size() {
return 0;
}
@Override
public void addListener(SetChangeListener setChangeListener) {
// no-op
}
@Override
public void removeListener(SetChangeListener setChangeListener) {
// no-op
}
@Override
public void addListener(InvalidationListener listener) {
// no-op
}
@Override
public void removeListener(InvalidationListener listener) {
// no-op
}
}
@Override
public ObservableSet getValue() {
return get();
}
/**
* Returns a {@code SetExpression} that wraps a
* {@link javafx.beans.value.ObservableSetValue}. If the
* {@code ObservableSetValue} is already a {@code SetExpression}, it
* will be returned. Otherwise a new
* {@link javafx.beans.binding.SetBinding} is created that is bound to
* the {@code ObservableSetValue}.
*
* @param the type of the {@code Set} elements
* @param value
* The source {@code ObservableSetValue}
* @return A {@code SetExpression} that wraps the
* {@code ObservableSetValue} if necessary
* @throws NullPointerException
* if {@code value} is {@code null}
*/
public static SetExpression setExpression(final ObservableSetValue value) {
if (value == null) {
throw new NullPointerException("Set must be specified.");
}
return value instanceof SetExpression ? (SetExpression) value
: new SetBinding() {
{
super.bind(value);
}
@Override
public void dispose() {
super.unbind(value);
}
@Override
protected ObservableSet computeValue() {
return value.get();
}
@Override
public ObservableList getDependencies() {
return FXCollections.singletonObservableList(value);
}
};
}
/**
* The size of the set
* @return the size
*/
public int getSize() {
return size();
}
/**
* An integer property that represents the size of the set.
* @return the property
*/
public abstract ReadOnlyIntegerProperty sizeProperty();
/**
* A boolean property that is {@code true}, if the set is empty.
* @return the {@code ReadOnlyBooleanProperty}
*/
public abstract ReadOnlyBooleanProperty emptyProperty();
/**
* Creates a new {@link BooleanBinding} that holds {@code true} if this set is equal to
* another {@link javafx.collections.ObservableSet}.
*
* @param other
* the other {@code ObservableSet}
* @return the new {@code BooleanBinding}
* @throws NullPointerException
* if {@code other} is {@code null}
*/
public BooleanBinding isEqualTo(final ObservableSet other) {
return Bindings.equal(this, other);
}
/**
* Creates a new {@link BooleanBinding} that holds {@code true} if this set is not equal to
* another {@link javafx.collections.ObservableSet}.
*
* @param other
* the other {@code ObservableSet}
* @return the new {@code BooleanBinding}
* @throws NullPointerException
* if {@code other} is {@code null}
*/
public BooleanBinding isNotEqualTo(final ObservableSet other) {
return Bindings.notEqual(this, other);
}
/**
* Creates a new {@link BooleanBinding} that holds {@code true} if the wrapped set is {@code null}.
*
* @return the new {@code BooleanBinding}
*/
public BooleanBinding isNull() {
return Bindings.isNull(this);
}
/**
* Creates a new {@link BooleanBinding} that holds {@code true} if the wrapped set is not {@code null}.
*
* @return the new {@code BooleanBinding}
*/
public BooleanBinding isNotNull() {
return Bindings.isNotNull(this);
}
/**
* Creates a {@link javafx.beans.binding.StringBinding} that holds the value
* of the {@code SetExpression} turned into a {@code String}. If the
* value of this {@code SetExpression} changes, the value of the
* {@code StringBinding} will be updated automatically.
*
* @return the new {@code StringBinding}
*/
public StringBinding asString() {
return (StringBinding) StringFormatter.convert(this);
}
@Override
public int size() {
final ObservableSet set = get();
return (set == null)? EMPTY_SET.size() : set.size();
}
@Override
public boolean isEmpty() {
final ObservableSet set = get();
return (set == null)? EMPTY_SET.isEmpty() : set.isEmpty();
}
@Override
public boolean contains(Object obj) {
final ObservableSet set = get();
return (set == null)? EMPTY_SET.contains(obj) : set.contains(obj);
}
@Override
public Iterator iterator() {
final ObservableSet set = get();
return (set == null)? EMPTY_SET.iterator() : set.iterator();
}
@Override
public Object[] toArray() {
final ObservableSet set = get();
return (set == null)? EMPTY_SET.toArray() : set.toArray();
}
@Override
public T[] toArray(T[] array) {
final ObservableSet set = get();
return (set == null)? (T[]) EMPTY_SET.toArray(array) : set.toArray(array);
}
@Override
public boolean add(E element) {
final ObservableSet set = get();
return (set == null)? EMPTY_SET.add(element) : set.add(element);
}
@Override
public boolean remove(Object obj) {
final ObservableSet set = get();
return (set == null)? EMPTY_SET.remove(obj) : set.remove(obj);
}
@Override
public boolean containsAll(Collection objects) {
final ObservableSet set = get();
return (set == null)? EMPTY_SET.contains(objects) : set.containsAll(objects);
}
@Override
public boolean addAll(Collection elements) {
final ObservableSet set = get();
return (set == null)? EMPTY_SET.addAll(elements) : set.addAll(elements);
}
@Override
public boolean removeAll(Collection objects) {
final ObservableSet set = get();
return (set == null)? EMPTY_SET.removeAll(objects) : set.removeAll(objects);
}
@Override
public boolean retainAll(Collection objects) {
final ObservableSet set = get();
return (set == null)? EMPTY_SET.retainAll(objects) : set.retainAll(objects);
}
@Override
public void clear() {
final ObservableSet set = get();
if (set == null) {
EMPTY_SET.clear();
} else {
set.clear();
}
}
}