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 class WebBackForwardList implements Cloneable, Serializable { 27 28 /** 29 * @hide 30 */ WebBackForwardList()31 public WebBackForwardList() { 32 } 33 34 /** 35 * Return the current history item. This method returns null if the list is 36 * empty. 37 * @return The current history item. 38 */ getCurrentItem()39 public synchronized WebHistoryItem getCurrentItem() { 40 throw new MustOverrideException(); 41 } 42 43 /** 44 * Get the index of the current history item. This index can be used to 45 * directly index into the array list. 46 * @return The current index from 0...n or -1 if the list is empty. 47 */ getCurrentIndex()48 public synchronized int getCurrentIndex() { 49 throw new MustOverrideException(); 50 } 51 52 /** 53 * Get the history item at the given index. The index range is from 0...n 54 * where 0 is the first item and n is the last item. 55 * @param index The index to retrieve. 56 */ getItemAtIndex(int index)57 public synchronized WebHistoryItem getItemAtIndex(int index) { 58 throw new MustOverrideException(); 59 } 60 61 /** 62 * Get the total size of the back/forward list. 63 * @return The size of the list. 64 */ getSize()65 public synchronized int getSize() { 66 throw new MustOverrideException(); 67 } 68 69 /** 70 * Clone the entire object to be used in the UI thread by clients of 71 * WebView. This creates a copy that should never be modified by any of the 72 * webkit package classes. 73 */ clone()74 protected synchronized WebBackForwardList clone() { 75 throw new MustOverrideException(); 76 } 77 78 } 79