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 17 package com.example.android.listviewdragginganimation; 18 19 import android.content.Context; 20 import android.widget.ArrayAdapter; 21 22 import java.util.HashMap; 23 import java.util.List; 24 25 public class StableArrayAdapter extends ArrayAdapter<String> { 26 27 final int INVALID_ID = -1; 28 29 HashMap<String, Integer> mIdMap = new HashMap<String, Integer>(); 30 31 public StableArrayAdapter(Context context, int textViewResourceId, List<String> objects) { 32 super(context, textViewResourceId, objects); 33 for (int i = 0; i < objects.size(); ++i) { 34 mIdMap.put(objects.get(i), i); 35 } 36 } 37 38 @Override 39 public long getItemId(int position) { 40 if (position < 0 || position >= mIdMap.size()) { 41 return INVALID_ID; 42 } 43 String item = getItem(position); 44 return mIdMap.get(item); 45 } 46 47 @Override 48 public boolean hasStableIds() { 49 return true; 50 } 51 } 52