J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | package javax.swing.text; |
| 26 | |
| 27 | /** |
| 28 | * Represents a location within a document. It is intended to abstract away |
| 29 | * implementation details of the document and enable specification of |
| 30 | * positions within the document that are capable of tracking of change as |
| 31 | * the document is edited. |
| 32 | * <p> |
| 33 | * A {@code Position} object points at a location between two characters. |
| 34 | * As the surrounding content is altered, the {@code Position} object |
| 35 | * adjusts its offset automatically to reflect the changes. If content is |
| 36 | * inserted or removed before the {@code Position} object's location, then the |
| 37 | * {@code Position} increments or decrements its offset, respectively, |
| 38 | * so as to point to the same location. If a portion of the document is removed |
| 39 | * that contains a {@code Position}'s offset, then the {@code Position}'s |
| 40 | * offset becomes that of the beginning of the removed region. For example, if |
| 41 | * a {@code Position} has an offset of 5 and the region 2-10 is removed, then |
| 42 | * the {@code Position}'s offset becomes 2. |
| 43 | * <p> |
| 44 | * {@code Position} with an offset of 0 is a special case. It never changes its |
| 45 | * offset while document content is altered. |
| 46 | * |
| 47 | * @author Timothy Prinzing |
| 48 | */ |
| 49 | public interface Position { |
| 50 | |
| 51 | /** |
| 52 | * Fetches the current offset within the document. |
| 53 | * |
| 54 | * @return the offset >= 0 |
| 55 | */ |
| 56 | public int getOffset(); |
| 57 | |
| 58 | /** |
| 59 | * A typesafe enumeration to indicate bias to a position |
| 60 | * in the model. A position indicates a location between |
| 61 | * two characters. The bias can be used to indicate an |
| 62 | * interest toward one of the two sides of the position |
| 63 | * in boundary conditions where a simple offset is |
| 64 | * ambiguous. |
| 65 | */ |
| 66 | public static final class Bias { |
| 67 | |
| 68 | /** |
| 69 | * Indicates to bias toward the next character |
| 70 | * in the model. |
| 71 | */ |
| 72 | public static final Bias Forward = new Bias("Forward"); |
| 73 | |
| 74 | /** |
| 75 | * Indicates a bias toward the previous character |
| 76 | * in the model. |
| 77 | */ |
| 78 | public static final Bias Backward = new Bias("Backward"); |
| 79 | |
| 80 | /** |
| 81 | * string representation |
| 82 | */ |
| 83 | public String toString() { |
| 84 | return name; |
| 85 | } |
| 86 | |
| 87 | private Bias(String name) { |
| 88 | this.name = name; |
| 89 | } |
| 90 | |
| 91 | private String name; |
| 92 | } |
| 93 | } |