javafx.beans.binding.MapExpression Maven / Gradle / Ivy
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* accompanied this code).
*
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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.ObservableMapValue;
import javafx.beans.value.ObservableValue;
import javafx.collections.FXCollections;
import javafx.collections.MapChangeListener;
import javafx.collections.ObservableList;
import javafx.collections.ObservableMap;
import java.util.*;
/**
* {@code MapExpression} is an
* {@link javafx.beans.value.ObservableMapValue} plus additional convenience
* methods to generate bindings in a fluent style.
*
* A concrete sub-class of {@code MapExpression} has to implement the method
* {@link javafx.beans.value.ObservableMapValue#get()}, which provides the
* actual value of this expression.
*
* If the wrapped list of a {@code MapExpression} is {@code null}, all methods implementing the {@code Map}
* interface will behave as if they were applied to an immutable empty list.
*
* @param the type of the key elements
* @param the type of the value elements
* @since JavaFX 2.1
*/
public abstract class MapExpression implements ObservableMapValue {
private static final ObservableMap EMPTY_MAP = new EmptyObservableMap();
private static class EmptyObservableMap extends AbstractMap implements ObservableMap {
@Override
public Set> entrySet() {
return Collections.emptySet();
}
@Override
public void addListener(MapChangeListener mapChangeListener) {
// no-op
}
@Override
public void removeListener(MapChangeListener mapChangeListener) {
// no-op
}
@Override
public void addListener(InvalidationListener listener) {
// no-op
}
@Override
public void removeListener(InvalidationListener listener) {
// no-op
}
}
@Override
public ObservableMap getValue() {
return get();
}
/**
* Returns a {@code MapExpression} that wraps a
* {@link javafx.beans.value.ObservableMapValue}. If the
* {@code ObservableMapValue} is already a {@code MapExpression}, it
* will be returned. Otherwise a new
* {@link javafx.beans.binding.MapBinding} is created that is bound to
* the {@code ObservableMapValue}.
*
* @param the type of the key elements
* @param the type of the value elements
* @param value
* The source {@code ObservableMapValue}
* @return A {@code MapExpression} that wraps the
* {@code ObservableMapValue} if necessary
* @throws NullPointerException
* if {@code value} is {@code null}
*/
public static MapExpression mapExpression(final ObservableMapValue value) {
if (value == null) {
throw new NullPointerException("Map must be specified.");
}
return value instanceof MapExpression ? (MapExpression) value
: new MapBinding() {
{
super.bind(value);
}
@Override
public void dispose() {
super.unbind(value);
}
@Override
protected ObservableMap computeValue() {
return value.get();
}
@Override
public ObservableList getDependencies() {
return FXCollections.singletonObservableList(value);
}
};
}
/**
* The size of the map
* @return the size
*/
public int getSize() {
return size();
}
/**
* An integer property that represents the size of the map.
* @return the property
*/
public abstract ReadOnlyIntegerProperty sizeProperty();
/**
* A boolean property that is {@code true}, if the map is empty.
* @return the {@code ReadOnlyBooleanProperty}
*/
public abstract ReadOnlyBooleanProperty emptyProperty();
/**
* Creates a new {@link ObjectBinding} that contains the mapping of the specified key.
*
* @param key the key of the mapping
* @return the {@code ObjectBinding}
*/
public ObjectBinding valueAt(K key) {
return Bindings.valueAt(this, key);
}
/**
* Creates a new {@link ObjectBinding} that contains the mapping of the specified key.
*
* @param key the key of the mapping
* @return the {@code ObjectBinding}
* @throws NullPointerException if {@code key} is {@code null}
*/
public ObjectBinding valueAt(ObservableValue key) {
return Bindings.valueAt(this, key);
}
/**
* Creates a new {@link BooleanBinding} that holds {@code true} if this map is equal to
* another {@link javafx.collections.ObservableMap}.
*
* @param other
* the other {@code ObservableMap}
* @return the new {@code BooleanBinding}
* @throws NullPointerException
* if {@code other} is {@code null}
*/
public BooleanBinding isEqualTo(final ObservableMap other) {
return Bindings.equal(this, other);
}
/**
* Creates a new {@link BooleanBinding} that holds {@code true} if this map is not equal to
* another {@link javafx.collections.ObservableMap}.
*
* @param other
* the other {@code ObservableMap}
* @return the new {@code BooleanBinding}
* @throws NullPointerException
* if {@code other} is {@code null}
*/
public BooleanBinding isNotEqualTo(final ObservableMap other) {
return Bindings.notEqual(this, other);
}
/**
* Creates a new {@link BooleanBinding} that holds {@code true} if the wrapped map 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 map 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 MapExpression} turned into a {@code String}. If the
* value of this {@code MapExpression} 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 ObservableMap map = get();
return (map == null)? EMPTY_MAP.size() : map.size();
}
@Override
public boolean isEmpty() {
final ObservableMap map = get();
return (map == null)? EMPTY_MAP.isEmpty() : map.isEmpty();
}
@Override
public boolean containsKey(Object obj) {
final ObservableMap map = get();
return (map == null)? EMPTY_MAP.containsKey(obj) : map.containsKey(obj);
}
@Override
public boolean containsValue(Object obj) {
final ObservableMap map = get();
return (map == null)? EMPTY_MAP.containsValue(obj) : map.containsValue(obj);
}
@Override
public V put(K key, V value) {
final ObservableMap map = get();
return (map == null)? (V) EMPTY_MAP.put(key, value) : map.put(key, value);
}
@Override
public V remove(Object obj) {
final ObservableMap map = get();
return (map == null)? (V) EMPTY_MAP.remove(obj) : map.remove(obj);
}
@Override
public void putAll(Map elements) {
final ObservableMap map = get();
if (map == null) {
EMPTY_MAP.putAll(elements);
} else {
map.putAll(elements);
}
}
@Override
public void clear() {
final ObservableMap map = get();
if (map == null) {
EMPTY_MAP.clear();
} else {
map.clear();
}
}
@Override
public Set keySet() {
final ObservableMap map = get();
return (map == null)? EMPTY_MAP.keySet() : map.keySet();
}
@Override
public Collection values() {
final ObservableMap map = get();
return (map == null)? EMPTY_MAP.values() : map.values();
}
@Override
public Set> entrySet() {
final ObservableMap map = get();
return (map == null)? EMPTY_MAP.entrySet() : map.entrySet();
}
@Override
public V get(Object key) {
final ObservableMap map = get();
return (map == null)? (V) EMPTY_MAP.get(key) : map.get(key);
}
}