1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except 5 * in compliance with the License. You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software distributed under the License 10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 11 * or implied. See the License for the specific language governing permissions and limitations under 12 * the License. 13 */ 14 package android.support.v17.leanback.widget; 15 16 import static android.support.v17.leanback.widget.ObjectAdapter.NO_ID; 17 18 /** 19 * The base class for all rows. A commonly used subclass is the {@link ListRow}. Custom 20 * subclasses may define other types of rows. 21 */ 22 public class Row { 23 24 private static final int FLAG_ID_USE_MASK = 1; 25 private static final int FLAG_ID_USE_HEADER = 1; 26 private static final int FLAG_ID_USE_ID = 0; 27 28 private int mFlags = FLAG_ID_USE_HEADER; 29 private HeaderItem mHeaderItem; 30 private long mId = NO_ID; 31 32 /** 33 * Constructor for a Row. 34 * 35 * @param id The id of the row. 36 * @param headerItem The {@link HeaderItem} for this Row, or null if there 37 * is no header. 38 */ Row(long id, HeaderItem headerItem)39 public Row(long id, HeaderItem headerItem) { 40 setId(id); 41 setHeaderItem(headerItem); 42 } 43 44 /** 45 * Constructor for a Row. 46 * 47 * @param headerItem The {@link HeaderItem} for this Row, or null if there 48 * is no header. 49 */ Row(HeaderItem headerItem)50 public Row(HeaderItem headerItem) { 51 setHeaderItem(headerItem); 52 } 53 54 /** 55 * Constructor for a Row. 56 */ Row()57 public Row() { 58 } 59 60 /** 61 * Returns the {@link HeaderItem} that represents metadata for the row. 62 * 63 * @return The HeaderItem for this row, or null if unset. 64 */ getHeaderItem()65 public final HeaderItem getHeaderItem() { 66 return mHeaderItem; 67 } 68 69 /** 70 * Sets the {@link HeaderItem} that represents metadata for the row. 71 * 72 * @param headerItem The HeaderItem for this Row, or null if there is no 73 * header. 74 */ setHeaderItem(HeaderItem headerItem)75 public final void setHeaderItem(HeaderItem headerItem) { 76 mHeaderItem = headerItem; 77 } 78 79 /** 80 * Sets the id for this row. 81 * 82 * @param id The id of the row. 83 */ setId(long id)84 public final void setId(long id) { 85 mId = id; 86 setFlags(FLAG_ID_USE_ID, FLAG_ID_USE_MASK); 87 } 88 89 /** 90 * Returns a unique identifier for this row. This id can come from one of 91 * three places: 92 * <ul> 93 * <li>If {@link #setId(long)} is ever called on this row, it will return 94 * this id. 95 * <li>If {@link #setId(long)} has not been called but the header item is 96 * not null, the result of {@link HeaderItem#getId()} is returned. 97 * <li>Otherwise {@link ObjectAdapter#NO_ID NO_ID} is returned. 98 * </ul> 99 */ getId()100 public final long getId() { 101 if ( (mFlags & FLAG_ID_USE_MASK) == FLAG_ID_USE_HEADER) { 102 HeaderItem header = getHeaderItem(); 103 if (header != null) { 104 return header.getId(); 105 } 106 return NO_ID; 107 } else { 108 return mId; 109 } 110 } 111 setFlags(int flags, int mask)112 final void setFlags(int flags, int mask) { 113 mFlags = (mFlags & ~mask) | (flags & mask); 114 } 115 getFlags()116 final int getFlags() { 117 return mFlags; 118 } 119 120 /** 121 * Returns true if this Row can be rendered in a visible row view, false otherwise. For example 122 * {@link ListRow} is rendered by {@link ListRowPresenter}. {@link PageRow}, 123 * {@link SectionRow}, {@link DividerRow} are rendered as invisible row views. 124 * @return True if this Row can be rendered in a visible row view, false otherwise. 125 */ isRenderedAsRowView()126 public boolean isRenderedAsRowView() { 127 return true; 128 } 129 } 130