path: root/projects/net.wotonomy.web/src/main/java/net/wotonomy/web/ObservableArray.java

/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2001 Michael Powers

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see http://www.gnu.org
*/

package net.wotonomy.web;

import java.util.Collection;
import java.util.Iterator;
import java.util.List;

import net.wotonomy.control.EOObserverCenter;
import net.wotonomy.control.EOObserving;
import net.wotonomy.foundation.NSMutableArray;
import net.wotonomy.foundation.NSRange;

/**
 * A package class that extends NSMutableArray but makes use of the fact that
 * wotonomy's implementation extends ArrayList to intercept insertions and
 * deletion and register and unregister objects for change notifications as
 * appropriate. Since we can't be sure of ArrayList's implementation, we're
 * forced to override each and every add and remove method, some of which
 * probably call each other. However, EOObserverCenter will only register us
 * once per object.
 */
class ObservableArray<T> extends NSMutableArray<T> {
	private static final long serialVersionUID = 1166339693880765234L;
	EOObserving observer;

	ObservableArray(EOObserving anObserver) {
		observer = anObserver;
	}

	/**
	 * Removes the last object from the array.
	 */
	@Override
	public void removeLastObject() {
		remove(count() - 1);
	}

	/**
	 * Removes the object at the specified index.
	 */
	@Override
	public void removeObjectAtIndex(int index) {
		remove(index);
	}

	/**
	 * Adds all objects in the specified collection.
	 */
	@Override
	public void addObjectsFromArray(Collection<T> aCollection) {
		addAll(aCollection);
	}

	/**
	 * Removes all objects from the array.
	 */
	@Override
	public void removeAllObjects() {
		clear();
	}

	/**
	 * Removes all objects equivalent to the specified object within the range of
	 * specified indices.
	 */
	@Override
	public void removeObject(T anObject, NSRange aRange) {
		if ((anObject == null) || (aRange == null))
			return;

		int loc = aRange.location();
		int max = aRange.maxRange();
		for (int i = loc; i < max; i++) {
			if (anObject.equals(get(i))) {
				remove(i);
				i = i - 1;
				max = max - 1;
			}
		}
	}

	/**
	 * Removes all instances of the specified object within the range of specified
	 * indices, comparing by reference.
	 */
	@Override
	public void removeIdenticalObject(T anObject, NSRange aRange) {
		if ((anObject == null) || (aRange == null))
			return;

		int loc = aRange.location();
		int max = aRange.maxRange();
		for (int i = loc; i < max; i++) {
			if (anObject == get(i)) {
				remove(i);
				i = i - 1;
				max = max - 1;
			}
		}
	}

	/**
	 * Removes all objects in the specified collection from the array.
	 */
	@Override
	public void removeObjectsInArray(Collection<T> aCollection) {
		removeAll(aCollection);
	}

	/**
	 * Removes all objects in the indices within the specified range from the array.
	 */
	@Override
	public void removeObjectsInRange(NSRange aRange) {
		if (aRange == null)
			return;

		for (int i = 0; i < aRange.length(); i++) {
			remove(aRange.location());
		}
	}

	/**
	 * Replaces objects in the current range with objects from the specified range
	 * of the specified array. If currentRange is larger than otherRange, the extra
	 * objects are removed. If otherRange is larger than currentRange, the extra
	 * objects are added.
	 */
	@Override
	public void replaceObjectsInRange(NSRange currentRange, List<T> otherArray, NSRange otherRange) {
		if ((currentRange == null) || (otherArray == null) || (otherRange == null))
			return;

		// transform otherRange if out of bounds for array
		if (otherRange.maxRange() > otherArray.size()) {
			// TODO: Test this logic.
			int loc = Math.min(otherRange.location(), otherArray.size() - 1);
			otherRange = new NSRange(loc, otherArray.size() - loc);
		}

		List<T> subList = subList(currentRange.location(), currentRange.maxRange());
		int otherIndex = otherRange.location();
		// TODO: Test this logic.
		for (int i = 0; i < subList.size(); i++) {
			if (otherIndex < otherRange.maxRange()) { // set object
				subList.set(i, otherArray.get(otherIndex));
			} else { // remove extra elements from currentRange
				subList.remove(i);
				i--;
			}
			otherIndex++;
		}
		// TODO: Test this logic.
		for (int i = otherIndex; i < otherRange.maxRange(); i++) {
			add(otherArray.get(i));
		}
	}

	/**
	 * Clears the current array and then populates it with the contents of the
	 * specified collection.
	 */
	@Override
	public void setArray(Collection<T> aCollection) {
		clear();
		addAll(aCollection);
	}

	/**
	 * Removes all objects equivalent to the specified object.
	 */
	@Override
	public void removeObject(Object anObject) {
		remove(anObject);
	}

	/**
	 * Removes all occurences of the specified object, comparing by reference.
	 */
	@Override
	public void removeIdenticalObject(T anObject) {
		EOObserverCenter.removeObserver(observer, anObject);
		super.removeIdenticalObject(anObject);
	}

	/**
	 * Inserts the specified object into this array at the specified index.
	 */
	@Override
	public void insertObjectAtIndex(T anObject, int anIndex) {
		add(anIndex, anObject);
	}

	/**
	 * Replaces the object at the specified index with the specified object.
	 */
	@Override
	public void replaceObjectAtIndex(int anIndex, T anObject) {
		set(anIndex, anObject);
	}

	/**
	 * Adds the specified object to the end of this array.
	 */
	@Override
	public void addObject(T anObject) {
		add(anObject);
	}

	// interface List: mutators

	@Override
	public void add(int index, T element) {
		EOObserverCenter.addObserver(observer, element);
		super.add(index, element);
	}

	@Override
	public boolean add(T o) {
		EOObserverCenter.addObserver(observer, o);
		return super.add(o);
	}

	@Override
	public boolean addAll(Collection<? extends T> coll) {
		Iterator<? extends T> it = coll.iterator();
		while (it.hasNext()) {
			EOObserverCenter.addObserver(observer, it.next());
		}
		return super.addAll(coll);
	}

	@Override
	public boolean addAll(int index, Collection<? extends T> c) {
		Iterator<? extends T> it = c.iterator();
		while (it.hasNext()) {
			EOObserverCenter.addObserver(observer, it.next());
		}
		return super.addAll(index, c);
	}

	@Override
	public void clear() {
		Iterator<T> it = iterator();
		while (it.hasNext()) {
			EOObserverCenter.removeObserver(observer, it.next());
		}
		super.clear();
	}

	@Override
	public T remove(int index) {
		EOObserverCenter.removeObserver(observer, get(index));
		return super.remove(index);
	}

	@Override
	public boolean remove(Object o) {
		EOObserverCenter.removeObserver(observer, o);
		return super.remove(o);
	}

	@Override
	public boolean removeAll(Collection<?> coll) {
		Iterator<?> it = coll.iterator();
		while (it.hasNext()) {
			EOObserverCenter.removeObserver(observer, it.next());
		}
		return super.removeAll(coll);
	}

	@Override
	public boolean retainAll(Collection<?> coll) {
		throw new UnsupportedOperationException();
	}

	@Override
	public T set(int index, T element) {
		EOObserverCenter.removeObserver(observer, get(index));
		EOObserverCenter.addObserver(observer, element);
		return super.set(index, element);
	}
}

/*
 * $Log$ Revision 1.2 2006/02/19 01:44:02 cgruber Add xmlrpc files Remove jclark
 * and replace with dom4j and javax.xml.sax stuff Re-work dependencies and
 * imports so it all compiles.
 *
 * Revision 1.1 2006/02/16 13:22:22 cgruber Check in all sources in
 * eclipse-friendly maven-enabled packages.
 *
 * Revision 1.1 2003/01/18 23:31:32 mpowers Needed for WODisplayGroup.
 *
 * Revision 1.2 2002/10/24 21:15:36 mpowers New implementations of NSArray and
 * subclasses.
 *
 * Revision 1.1 2001/02/20 16:38:55 mpowers MasterDetailAssociations now observe
 * their controlled display group's objects for changes to that the parent
 * object will be marked as updated. Before, only inserts and deletes to an
 * object's items are registered. Also, moved ObservableArray to package access.
 *
 * Revision 1.1 2001/01/24 14:37:24 mpowers Contributing a delegate useful for
 * debugging.
 *
 *
 */