| 1 | package org.farng.mp3.id3; |
| 2 | |
| 3 | import java.util.Iterator; |
| 4 | import java.util.NoSuchElementException; |
| 5 | |
| 6 | /** |
| 7 | * This is a manual iterator for an ID3v2 tag |
| 8 | * |
| 9 | * @author Eric Farng |
| 10 | * @version $Revision: 1.4 $ |
| 11 | */ |
| 12 | public class ID3v1Iterator implements Iterator { |
| 13 | |
| 14 | private static final int TITLE = 1; |
| 15 | private static final int ARTIST = 2; |
| 16 | private static final int ALBUM = 3; |
| 17 | private static final int COMMENT = 4; |
| 18 | private static final int YEAR = 5; |
| 19 | private static final int GENRE = 6; |
| 20 | private static final int TRACK = 7; |
| 21 | private ID3v1 id3v1tag; |
| 22 | private int lastIndex = 0; |
| 23 | |
| 24 | /** |
| 25 | * Creates a new ID3v1Iterator object. |
| 26 | */ |
| 27 | public ID3v1Iterator(final ID3v1 id3v1tag) { |
| 28 | this.id3v1tag = id3v1tag; |
| 29 | } |
| 30 | |
| 31 | public boolean hasNext() { |
| 32 | return hasNext(this.lastIndex); |
| 33 | } |
| 34 | |
| 35 | public Object next() { |
| 36 | return next(this.lastIndex); |
| 37 | } |
| 38 | |
| 39 | public void remove() { |
| 40 | switch (this.lastIndex) { |
| 41 | case TITLE: |
| 42 | this.id3v1tag.title = ""; |
| 43 | case ARTIST: |
| 44 | this.id3v1tag.artist = ""; |
| 45 | case ALBUM: |
| 46 | this.id3v1tag.album = ""; |
| 47 | case COMMENT: |
| 48 | this.id3v1tag.comment = ""; |
| 49 | case YEAR: |
| 50 | this.id3v1tag.year = ""; |
| 51 | case GENRE: |
| 52 | this.id3v1tag.genre = -1; |
| 53 | case TRACK: |
| 54 | if (this.id3v1tag instanceof ID3v1_1) { |
| 55 | ((ID3v1_1) this.id3v1tag).track = -1; |
| 56 | } |
| 57 | } |
| 58 | } |
| 59 | |
| 60 | private boolean hasNext(final int index) { |
| 61 | switch (index) { |
| 62 | case TITLE: |
| 63 | return (this.id3v1tag.title.length() > 0) || hasNext(index + 1); |
| 64 | case ARTIST: |
| 65 | return (this.id3v1tag.artist.length() > 0) || hasNext(index + 1); |
| 66 | case ALBUM: |
| 67 | return (this.id3v1tag.album.length() > 0) || hasNext(index + 1); |
| 68 | case COMMENT: |
| 69 | return (this.id3v1tag.comment.length() > 0) || hasNext(index + 1); |
| 70 | case YEAR: |
| 71 | return (this.id3v1tag.year.length() > 0) || hasNext(index + 1); |
| 72 | case GENRE: |
| 73 | return (this.id3v1tag.genre >= 0) || hasNext(index + 1); |
| 74 | case TRACK: |
| 75 | if (this.id3v1tag instanceof ID3v1_1) { |
| 76 | return (((ID3v1_1) this.id3v1tag).track >= 0) || hasNext(index + 1); |
| 77 | } |
| 78 | default: |
| 79 | return false; |
| 80 | } |
| 81 | } |
| 82 | |
| 83 | private Object next(final int index) { |
| 84 | switch (this.lastIndex) { |
| 85 | case 0: |
| 86 | return (this.id3v1tag.title.length() > 0) ? this.id3v1tag.title : next(index + 1); |
| 87 | case TITLE: |
| 88 | return (this.id3v1tag.artist.length() > 0) ? this.id3v1tag.artist : next(index + 1); |
| 89 | case ARTIST: |
| 90 | return (this.id3v1tag.album.length() > 0) ? this.id3v1tag.album : next(index + 1); |
| 91 | case ALBUM: |
| 92 | return (this.id3v1tag.comment.length() > 0) ? this.id3v1tag.comment : next(index + 1); |
| 93 | case COMMENT: |
| 94 | return (this.id3v1tag.year.length() > 0) ? this.id3v1tag.year : next(index + 1); |
| 95 | case YEAR: |
| 96 | return (this.id3v1tag.genre >= 0) ? new Byte(this.id3v1tag.genre) : next(index + 1); |
| 97 | case GENRE: |
| 98 | return (this.id3v1tag instanceof ID3v1_1 && (((ID3v1_1) this.id3v1tag).track >= 0)) ? |
| 99 | new Byte(((ID3v1_1) this.id3v1tag).track) : |
| 100 | null; |
| 101 | default: |
| 102 | throw new NoSuchElementException("Iteration has no more elements."); |
| 103 | } |
| 104 | } |
| 105 | } |