1 /*
2  * Copyright (C) 2006 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package android.webkit;
18 
19 import java.io.Serializable;
20 
21 /**
22  * This class contains the back/forward list for a WebView.
23  * WebView.copyBackForwardList() will return a copy of this class used to
24  * inspect the entries in the list.
25  */
26 public abstract class WebBackForwardList implements Cloneable, Serializable {
27     /**
28      * Return the current history item. This method returns null if the list is
29      * empty.
30      * @return The current history item.
31      */
getCurrentItem()32     public abstract WebHistoryItem getCurrentItem();
33 
34     /**
35      * Get the index of the current history item. This index can be used to
36      * directly index into the array list.
37      * @return The current index from 0...n or -1 if the list is empty.
38      */
getCurrentIndex()39     public abstract int getCurrentIndex();
40 
41     /**
42      * Get the history item at the given index. The index range is from 0...n
43      * where 0 is the first item and n is the last item.
44      * @param index The index to retrieve.
45      */
getItemAtIndex(int index)46     public abstract WebHistoryItem getItemAtIndex(int index);
47 
48     /**
49      * Get the total size of the back/forward list.
50      * @return The size of the list.
51      */
getSize()52     public abstract int getSize();
53 
54     /**
55      * Clone the entire object to be used in the UI thread by clients of
56      * WebView. This creates a copy that should never be modified by any of the
57      * webkit package classes.
58      */
clone()59     protected abstract WebBackForwardList clone();
60 }
61