167 lines
3.1 KiB
Java
167 lines
3.1 KiB
Java
/*
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Copyright 2006 Rene Grothmann, modified by Eric Hakenholz
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This file is part of C.a.R. software.
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C.a.R. is a free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, version 3 of the License.
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C.a.R. is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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package rene.util.list;
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/**
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* A class for a list of things. The list is forward and backward chained.
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*
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* @see rene.list.ListElement
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*/
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public class ListClass {
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ListElement First, Last; // Pointer to start and end of list.
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/**
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* Generate an empty list.
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*/
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public ListClass() {
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First = null;
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Last = null;
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}
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/**
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* Append a node to the list
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*/
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public void append(final ListElement l) {
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if (Last == null)
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init(l);
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else {
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Last.next(l);
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l.previous(Last);
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Last = l;
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l.next(null);
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l.list(this);
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}
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}
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public void prepend(final ListElement l)
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// prepend a node to the list
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{
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if (First == null)
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init(l);
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else {
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First.previous(l);
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l.next(First);
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First = l;
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l.previous(null);
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l.list(this);
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}
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}
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/*
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* @param l ListElement to be inserted.
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*
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* @param after If null, it works like prepend.
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*/
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public void insert(final ListElement l, final ListElement after) {
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if (after == Last)
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append(l);
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else if (after == null)
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prepend(l);
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else {
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after.next().previous(l);
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l.next(after.next());
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after.next(l);
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l.previous(after);
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l.list(this);
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}
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}
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/**
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* initialize the list with a single element.
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*/
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public void init(final ListElement l) {
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Last = First = l;
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l.previous(null);
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l.next(null);
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l.list(this);
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}
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/**
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* Remove a node from the list. The node really should be in the list, which
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* is not checked.
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*/
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public void remove(final ListElement l) {
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if (First == l) {
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First = l.next();
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if (First != null)
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First.previous(null);
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else
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Last = null;
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} else if (Last == l) {
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Last = l.previous();
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if (Last != null)
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Last.next(null);
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else
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First = null;
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} else {
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l.previous().next(l.next());
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l.next().previous(l.previous());
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}
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l.next(null);
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l.previous(null);
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l.list(null);
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}
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/**
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* Empty the list.
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*/
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public void removeall() {
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First = null;
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Last = null;
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}
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/** remove everything after e */
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public void removeAfter(final ListElement e) {
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e.next(null);
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Last = e;
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}
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/**
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* @return First ListElement.
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*/
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public ListElement first() {
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return First;
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}
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/**
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* @return Last ListElement.
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*/
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public ListElement last() {
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return Last;
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}
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/**
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* Prints the class
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*/
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@Override
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public String toString() {
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ListElement e = First;
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String s = "";
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while (e != null) {
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s = s + e.content().toString() + ", ";
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e = e.next();
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}
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return s;
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}
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}
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