1 /* 2 * Copyright (C) 2011 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.android.providers.contacts.util; 18 19 import android.text.TextUtils; 20 21 import java.util.ArrayList; 22 import java.util.List; 23 24 /** 25 * Builds a selection clause by concatenating several clauses with AND. 26 */ 27 public class SelectionBuilder { 28 private static final String[] EMPTY_STRING_ARRAY = new String[0]; 29 private final List<String> mWhereClauses; 30 31 /** 32 * @param baseSelection The base selection to start with. This is typically 33 * the user supplied selection arg. Pass null if no base selection is 34 * required. 35 */ 36 public SelectionBuilder(String baseSelection) { 37 mWhereClauses = new ArrayList<String>(); 38 addClause(baseSelection); 39 } 40 41 /** 42 * Adds a new clause to the selection. Nothing is added if the supplied clause 43 * is null or empty. 44 */ 45 public SelectionBuilder addClause(String clause) { 46 if (!TextUtils.isEmpty(clause)) { 47 mWhereClauses.add(clause); 48 } 49 return this; 50 } 51 52 /** 53 * Returns a combined selection clause with AND of all clauses added using 54 * {@link #addClause(String)}. Returns null if no clause has been added or 55 * only null/empty clauses have been added till now. 56 */ 57 public String build() { 58 if (mWhereClauses.size() == 0) { 59 return null; 60 } 61 return DbQueryUtils.concatenateClauses(mWhereClauses.toArray(EMPTY_STRING_ARRAY)); 62 } 63 } 64
