1 /* 2 * Copyright (C) 2010 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 package com.android.quicksearchbox; 17 18 import org.json.JSONException; 19 20 import java.util.Collection; 21 import java.util.HashSet; 22 23 /** 24 * Abstract SuggestionExtras supporting flattening to JSON. 25 */ 26 public abstract class AbstractSuggestionExtras implements SuggestionExtras { 27 28 private final SuggestionExtras mMore; 29 30 protected AbstractSuggestionExtras(SuggestionExtras more) { 31 mMore = more; 32 } 33 34 public Collection<String> getExtraColumnNames() { 35 HashSet<String> columns = new HashSet<String>(); 36 columns.addAll(doGetExtraColumnNames()); 37 if (mMore != null) { 38 columns.addAll(mMore.getExtraColumnNames()); 39 } 40 return columns; 41 } 42 43 protected abstract Collection<String> doGetExtraColumnNames(); 44 45 public String getExtra(String columnName) { 46 String extra = doGetExtra(columnName); 47 if (extra == null && mMore != null) { 48 extra = mMore.getExtra(columnName); 49 } 50 return extra; 51 } 52 53 protected abstract String doGetExtra(String columnName); 54 55 public String toJsonString() throws JSONException { 56 return new JsonBackedSuggestionExtras(this).toString(); 57 } 58 59 } 60