LocateableList.java

package org.geogebra.common.kernel;

import java.util.ArrayList;

import org.geogebra.common.kernel.algos.AlgoElement;
import org.geogebra.common.kernel.geos.GeoElement;
import org.geogebra.common.kernel.kernelND.GeoPointND;

/**
 * List of Locateables linked to a point
 * 
 * @author ggb3D
 *
 */

public class LocateableList extends ArrayList<Locateable> {

	/**
	 * 
	 */
	private static final long serialVersionUID = 9060255316180319972L;
	private transient GeoPointND point;

	/**
	 * constructor
	 * 
	 * @param point
	 *            point
	 */
	public LocateableList(GeoPointND point) {
		super();
		this.point = point;
	}

	/**
	 * Tells this point that the given Locateable has this point as start point.
	 * 
	 * @param l
	 *            locateable
	 */
	public void registerLocateable(Locateable l) {
		if (contains(l)) {
			return;
		}

		// add only locateables that are not already
		// part of the updateSet of this point
		AlgoElement parentAlgo = l.toGeoElement().getParentAlgorithm();
		if (parentAlgo == null
				|| !(((GeoElement) point).algoUpdateSetContains(parentAlgo))) {
			// add the locatable
			add(l);
		}
	}

	/**
	 * Tells this point that the given Locatable no longer has this point as
	 * start point.
	 * 
	 * @param l
	 *            locateable
	 */
	public void unregisterLocateable(Locateable l) {
		remove(l);
	}

	/**
	 * Tells Locateables that their start point is removed and calls
	 * super.remove()
	 */
	public void doRemove() {

		// copy locateableList into array
		Object[] locs = toArray();
		clear();

		// tell all locateables
		for (int i = 0; i < locs.length; i++) {
			Locateable loc = (Locateable) locs[i];
			loc.removeStartPoint(point);
			loc.toGeoElement().updateCascade();
		}

	}

}