ParameterDriversList.java
/* Copyright 2002-2019 CS Systèmes d'Information
* Licensed to CS Systèmes d'Information (CS) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* CS licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.orekit.utils;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import org.orekit.time.AbsoluteDate;
/** Class managing several {@link ParameterDriver parameter drivers},
* taking care of duplicated names.
* <p>
* Once parameter drivers sharing the same name have been added to
* an instance of this class, they are permanently bound together and
* also bound to the {@link #getDrivers() delegating driver} that
* manages them. This means that if drivers {@code d1}, {@code d2}...
* {@code dn} are added to the list and both correspond to parameter
* name "P", then {@link #getDrivers()} will return a list containing
* a delegating driver {@code delegateD} for the same name "P".
* Afterwards, whenever either {@link ParameterDriver#setValue(double)}
* or {@link ParameterDriver#setReferenceDate(AbsoluteDate)} is called
* on any of the {@code n+1} instances {@code d1}, {@code d2}... {@code dn}
* or {@code delegateD}, the call will be automatically forwarded to the
* {@code n} remaining instances, hence ensuring they remain consistent
* with each other.
* </p>
* @author Luc Maisonobe
* @since 8.0
*/
public class ParameterDriversList {
/** Managed drivers. */
private final List<DelegatingDriver> delegating;
/** Creates an empty list.
*/
public ParameterDriversList() {
this.delegating = new ArrayList<DelegatingDriver>();
}
/** Add a driver.
* <p>
* If the driver is already present, it will not be added.
* If another driver managing the same parameter is present,
* both drivers will be managed together, existing drivers
* being set to the value of the last driver added (i.e.
* each addition overrides the parameter value).
* </p>
* @param driver driver to add
*/
public void add(final ParameterDriver driver) {
final DelegatingDriver existingHere = findByName(driver.getName());
final DelegatingDriver alreadyBound = getAssociatedDelegatingDriver(driver);
if (existingHere != null) {
if (alreadyBound != null) {
// ensure we don't get intermixed change forwarders that call each other recursively
existingHere.setForwarder(alreadyBound.getForwarder());
} else {
// this is a new driver for an already managed parameter
existingHere.add(driver);
}
} else {
if (alreadyBound != null) {
// the driver is new here, but already bound to other drivers in other lists
delegating.add(alreadyBound);
} else {
// this is the first driver we have for this parameter name
final DelegatingDriver created = new DelegatingDriver(driver);
final ChangesForwarder forwarder = new ChangesForwarder(created);
created.setForwarder(forwarder);
delegating.add(created);
}
}
}
/** Get a {@link DelegatingDriver delegating driver} bound to a driver.
* @param driver driver to check
* @return a {@link DelegatingDriver delegating driver} bound to a driver, or
* null if this driver is not associated with any {@link DelegatingDriver delegating driver}
* @since 9.1
*/
private DelegatingDriver getAssociatedDelegatingDriver(final ParameterDriver driver) {
for (final ParameterObserver observer : driver.getObservers()) {
if (observer instanceof ChangesForwarder) {
return ((ChangesForwarder) observer).getDelegatingDriver();
}
}
return null;
}
/** Find a {@link DelegatingDriver delegating driver} by name.
* @param name name to check
* @return a {@link DelegatingDriver delegating driver} managing this parameter name
* @since 9.1
*/
public DelegatingDriver findByName(final String name) {
for (final DelegatingDriver d : delegating) {
if (d.getName().equals(name)) {
return d;
}
}
return null;
}
/** Sort the parameters lexicographically.
*/
public void sort() {
Collections.sort(delegating, new Comparator<DelegatingDriver>() {
/** {@inheritDoc} */
@Override
public int compare(final DelegatingDriver d1, final DelegatingDriver d2) {
return d1.getName().compareTo(d2.getName());
}
});
}
/** Filter parameters to keep only one type of selection status.
* @param selected if true, only {@link ParameterDriver#isSelected()
* selected} parameters will be kept, the other ones will be removed
*/
public void filter(final boolean selected) {
for (final Iterator<DelegatingDriver> iterator = delegating.iterator(); iterator.hasNext();) {
if (iterator.next().isSelected() != selected) {
iterator.remove();
}
}
}
/** Get the number of parameters with different names.
* @return number of parameters with different names
*/
public int getNbParams() {
return delegating.size();
}
/** Get delegating drivers for all parameters.
* <p>
* The delegating drivers are <em>not</em> the same as
* the drivers added to the list, but they delegate to them.
* </p>
* <p>
* All delegating drivers manage parameters with different names.
* </p>
* @return unmodifiable view of the list of delegating drivers
*/
public List<DelegatingDriver> getDrivers() {
return Collections.unmodifiableList(delegating);
}
/** Specialized driver delegating to several other managing
* the same parameter name.
*/
public static class DelegatingDriver extends ParameterDriver {
/** Drivers managing the same parameter. */
private final List<ParameterDriver> drivers;
/** Observer for propagating changes between all drivers. */
private ChangesForwarder forwarder;
/** Simple constructor.
* @param driver first driver in the series
*/
DelegatingDriver(final ParameterDriver driver) {
super(driver.getName(), driver.getReferenceValue(),
driver.getScale(), driver.getMinValue(), driver.getMaxValue());
drivers = new ArrayList<ParameterDriver>();
drivers.add(driver);
setValue(driver.getValue());
setReferenceDate(driver.getReferenceDate());
setSelected(driver.isSelected());
}
/** Set the changes forwarder.
* @param forwarder new changes forwarder
* @since 9.1
*/
void setForwarder(final ChangesForwarder forwarder) {
// remove the previous observer if any
if (this.forwarder != null) {
removeObserver(this.forwarder);
for (final ParameterDriver driver : drivers) {
driver.removeObserver(this.forwarder);
}
}
// add the new observer
this.forwarder = forwarder;
addObserver(forwarder);
for (final ParameterDriver driver : drivers) {
driver.addObserver(forwarder);
}
}
/** Get the changes forwarder.
* @return changes forwarder
*/
ChangesForwarder getForwarder() {
return forwarder;
}
/** Add a driver.
* @param driver driver to add
*/
private void add(final ParameterDriver driver) {
for (final ParameterDriver d : drivers) {
if (d == driver) {
// the driver is already known, don't add it again
return;
}
}
setValue(driver.getValue());
setReferenceDate(driver.getReferenceDate());
// if any of the drivers is selected, all must be selected
if (isSelected()) {
driver.setSelected(true);
} else {
setSelected(driver.isSelected());
}
driver.addObserver(forwarder);
drivers.add(driver);
}
/** Get the raw drivers to which this one delegates.
* <p>
* These raw drivers all manage the same parameter name.
* </p>
* @return raw drivers to which this one delegates
*/
public List<ParameterDriver> getRawDrivers() {
return Collections.unmodifiableList(drivers);
}
}
/** Local observer for propagating changes, avoiding infinite recursion. */
private static class ChangesForwarder implements ParameterObserver {
/** DelegatingDriver we are associated with. */
private final DelegatingDriver delegating;
/** Root of the current update chain. */
private ParameterDriver root;
/** Depth of the current update chain. */
private int depth;
/** Simple constructor.
* @param delegating delegatingDriver we are associated with
*/
ChangesForwarder(final DelegatingDriver delegating) {
this.delegating = delegating;
}
/** Get the {@link DelegatingDriver} associated with this instance.
* @return {@link DelegatingDriver} associated with this instance
* @since 9.1
*/
DelegatingDriver getDelegatingDriver() {
return delegating;
}
/** {@inheritDoc} */
@Override
public void valueChanged(final double previousValue, final ParameterDriver driver) {
updateAll(driver, d -> {
d.setValue(driver.getValue());
});
}
/** {@inheritDoc} */
@Override
public void referenceDateChanged(final AbsoluteDate previousReferenceDate, final ParameterDriver driver) {
updateAll(driver, d -> d.setReferenceDate(driver.getReferenceDate()));
}
/** {@inheritDoc} */
@Override
public void nameChanged(final String previousName, final ParameterDriver driver) {
updateAll(driver, d -> d.setName(driver.getName()));
}
/** {@inheritDoc} */
@Override
public void selectionChanged(final boolean previousSelection, final ParameterDriver driver) {
updateAll(driver, d -> d.setSelected(driver.isSelected()));
}
/** {@inheritDoc} */
@Override
public void referenceValueChanged(final double previousReferenceValue, final ParameterDriver driver) {
updateAll(driver, d -> d.setReferenceValue(driver.getReferenceValue()));
}
/** {@inheritDoc} */
@Override
public void minValueChanged(final double previousMinValue, final ParameterDriver driver) {
updateAll(driver, d -> d.setMinValue(driver.getMinValue()));
}
/** {@inheritDoc} */
@Override
public void maxValueChanged(final double previousMaxValue, final ParameterDriver driver) {
updateAll(driver, d -> d.setMaxValue(driver.getMaxValue()));
}
/** {@inheritDoc} */
@Override
public void scaleChanged(final double previousScale, final ParameterDriver driver) {
updateAll(driver, d -> d.setScale(driver.getScale()));
}
/** Update all bound parameters.
* @param driver driver triggering the update
* @param updater updater to use
*/
private void updateAll(final ParameterDriver driver, final Updater updater) {
final boolean firstCall = depth++ == 0;
if (firstCall) {
root = driver;
}
if (driver == getDelegatingDriver()) {
// propagate change downwards, which will trigger recursive calls
for (final ParameterDriver d : delegating.drivers) {
if (d != root) {
updater.update(d);
}
}
} else if (firstCall) {
// first call started from an underlying driver, propagate change upwards
updater.update(getDelegatingDriver());
}
if (--depth == 0) {
// this is the end of the root call
root = null;
}
}
}
/** Interface for updating parameters. */
@FunctionalInterface
private interface Updater {
/** Update a driver.
* @param driver driver to update
*/
void update(ParameterDriver driver);
}
}