diff options
Diffstat (limited to 'src/com/android/gallery3d/util/LinkedNode.java')
-rw-r--r-- | src/com/android/gallery3d/util/LinkedNode.java | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/src/com/android/gallery3d/util/LinkedNode.java b/src/com/android/gallery3d/util/LinkedNode.java new file mode 100644 index 000000000..4cfc3cded --- /dev/null +++ b/src/com/android/gallery3d/util/LinkedNode.java @@ -0,0 +1,71 @@ +/* + * 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>(); + } +} |