blob: 4cfc3cdede167d40ee833e6c1d80e2df14bc2852 [file] [log] [blame]
/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed 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 com.android.gallery3d.util;
public class LinkedNode {
private LinkedNode mPrev;
private LinkedNode mNext;
public LinkedNode() {
mPrev = mNext = this;
}
public void insert(LinkedNode node) {
node.mNext = mNext;
mNext.mPrev = node;
node.mPrev = this;
mNext = node;
}
public void remove() {
if (mNext == this) throw new IllegalStateException();
mPrev.mNext = mNext;
mNext.mPrev = mPrev;
mPrev = mNext = null;
}
@SuppressWarnings("unchecked")
public static class List<T extends LinkedNode> {
private LinkedNode mHead = new LinkedNode();
public void insertLast(T node) {
mHead.mPrev.insert(node);
}
public T getFirst() {
return (T) (mHead.mNext == mHead ? null : mHead.mNext);
}
public T getLast() {
return (T) (mHead.mPrev == mHead ? null : mHead.mPrev);
}
public T nextOf(T node) {
return (T) (node.mNext == mHead ? null : node.mNext);
}
public T previousOf(T node) {
return (T) (node.mPrev == mHead ? null : node.mPrev);
}
}
public static <T extends LinkedNode> List<T> newList() {
return new List<T>();
}
}