UndoOwner.java revision f59152cf00520d1bd36949b44faca2e1fcf6d28f
1/* 2 * Copyright (C) 2013 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 17package android.content; 18 19/** 20 * Representation of an owner of {@link UndoOperation} objects in an {@link UndoManager}. 21 * 22 * @hide 23 */ 24public class UndoOwner { 25 final String mTag; 26 final UndoManager mManager; 27 28 Object mData; 29 int mOpCount; 30 31 // For saving/restoring state. 32 int mStateSeq; 33 int mSavedIdx; 34 35 UndoOwner(String tag, UndoManager manager) { 36 if (tag == null) { 37 throw new NullPointerException("tag can't be null"); 38 } 39 if (manager == null) { 40 throw new NullPointerException("manager can't be null"); 41 } 42 mTag = tag; 43 mManager = manager; 44 } 45 46 /** 47 * Return the unique tag name identifying this owner. This is the tag 48 * supplied to {@link UndoManager#getOwner(String, Object) UndoManager.getOwner} 49 * and is immutable. 50 */ 51 public String getTag() { 52 return mTag; 53 } 54 55 /** 56 * Return the actual data object of the owner. This is the data object 57 * supplied to {@link UndoManager#getOwner(String, Object) UndoManager.getOwner}. An 58 * owner may have a null data if it was restored from a previously saved state with 59 * no getOwner call to associate it with its data. 60 */ 61 public Object getData() { 62 return mData; 63 } 64} 65