1 /* 2 * Copyright (C) 2009 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 com.android.quicksearchbox.util.QuietlyCloseable; 19 20 import android.database.DataSetObserver; 21 22 import java.util.Collection; 23 24 /** 25 * A sequence of suggestions, with a current position. 26 */ 27 public interface SuggestionCursor extends Suggestion, QuietlyCloseable { 28 29 /** 30 * Gets the query that the user typed to get this suggestion. 31 */ 32 String getUserQuery(); 33 34 /** 35 * Gets the number of suggestions in this result. 36 * 37 * @return The number of suggestions, or {@code 0} if this result represents a failed query. 38 */ 39 int getCount(); 40 41 /** 42 * Moves to a given suggestion. 43 * 44 * @param pos The position to move to. 45 * @throws IndexOutOfBoundsException if {@code pos < 0} or {@code pos >= getCount()}. 46 */ 47 void moveTo(int pos); 48 49 /** 50 * Moves to the next suggestion, if there is one. 51 * 52 * @return {@code false} if there is no next suggestion. 53 */ 54 boolean moveToNext(); 55 56 /** 57 * Gets the current position within the cursor. 58 */ 59 int getPosition(); 60 61 /** 62 * Frees any resources used by this cursor. 63 */ 64 void close(); 65 66 /** 67 * Register an observer that is called when changes happen to this data set. 68 * 69 * @param observer gets notified when the data set changes. 70 */ 71 void registerDataSetObserver(DataSetObserver observer); 72 73 /** 74 * Unregister an observer that has previously been registered with 75 * {@link #registerDataSetObserver(DataSetObserver)} 76 * 77 * @param observer the observer to unregister. 78 */ 79 void unregisterDataSetObserver(DataSetObserver observer); 80 81 /** 82 * Return the extra columns present in this cursor, or null if none exist. 83 */ 84 Collection<String> getExtraColumns(); 85 } 86