J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2000-2007 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 | * <code>DocumentFilter</code>, as the name implies, is a filter for the |
| 29 | * <code>Document</code> mutation methods. When a <code>Document</code> |
| 30 | * containing a <code>DocumentFilter</code> is modified (either through |
| 31 | * <code>insert</code> or <code>remove</code>), it forwards the appropriate |
| 32 | * method invocation to the <code>DocumentFilter</code>. The |
| 33 | * default implementation allows the modification to |
| 34 | * occur. Subclasses can filter the modifications by conditionally invoking |
| 35 | * methods on the superclass, or invoking the necessary methods on |
| 36 | * the passed in <code>FilterBypass</code>. Subclasses should NOT call back |
| 37 | * into the Document for the modification |
| 38 | * instead call into the superclass or the <code>FilterBypass</code>. |
| 39 | * <p> |
| 40 | * When <code>remove</code> or <code>insertString</code> is invoked |
| 41 | * on the <code>DocumentFilter</code>, the <code>DocumentFilter</code> |
| 42 | * may callback into the |
| 43 | * <code>FilterBypass</code> multiple times, or for different regions, but |
| 44 | * it should not callback into the <code>FilterBypass</code> after returning |
| 45 | * from the <code>remove</code> or <code>insertString</code> method. |
| 46 | * <p> |
| 47 | * By default, text related document mutation methods such as |
| 48 | * <code>insertString</code>, <code>replace</code> and <code>remove</code> |
| 49 | * in <code>AbstractDocument</code> use <code>DocumentFilter</code> when |
| 50 | * available, and <code>Element</code> related mutation methods such as |
| 51 | * <code>create</code>, <code>insert</code> and <code>removeElement</code> in |
| 52 | * <code>DefaultStyledDocument</code> do not use <code>DocumentFilter</code>. |
| 53 | * If a method doesn't follow these defaults, this must be explicitly stated |
| 54 | * in the method documentation. |
| 55 | * |
| 56 | * @see javax.swing.text.Document |
| 57 | * @see javax.swing.text.AbstractDocument |
| 58 | * @see javax.swing.text.DefaultStyledDocument |
| 59 | * |
| 60 | * @since 1.4 |
| 61 | */ |
| 62 | public class DocumentFilter { |
| 63 | /** |
| 64 | * Invoked prior to removal of the specified region in the |
| 65 | * specified Document. Subclasses that want to conditionally allow |
| 66 | * removal should override this and only call supers implementation as |
| 67 | * necessary, or call directly into the <code>FilterBypass</code> as |
| 68 | * necessary. |
| 69 | * |
| 70 | * @param fb FilterBypass that can be used to mutate Document |
| 71 | * @param offset the offset from the beginning >= 0 |
| 72 | * @param length the number of characters to remove >= 0 |
| 73 | * @exception BadLocationException some portion of the removal range |
| 74 | * was not a valid part of the document. The location in the exception |
| 75 | * is the first bad position encountered. |
| 76 | */ |
| 77 | public void remove(FilterBypass fb, int offset, int length) throws |
| 78 | BadLocationException { |
| 79 | fb.remove(offset, length); |
| 80 | } |
| 81 | |
| 82 | /** |
| 83 | * Invoked prior to insertion of text into the |
| 84 | * specified Document. Subclasses that want to conditionally allow |
| 85 | * insertion should override this and only call supers implementation as |
| 86 | * necessary, or call directly into the FilterBypass. |
| 87 | * |
| 88 | * @param fb FilterBypass that can be used to mutate Document |
| 89 | * @param offset the offset into the document to insert the content >= 0. |
| 90 | * All positions that track change at or after the given location |
| 91 | * will move. |
| 92 | * @param string the string to insert |
| 93 | * @param attr the attributes to associate with the inserted |
| 94 | * content. This may be null if there are no attributes. |
| 95 | * @exception BadLocationException the given insert position is not a |
| 96 | * valid position within the document |
| 97 | */ |
| 98 | public void insertString(FilterBypass fb, int offset, String string, |
| 99 | AttributeSet attr) throws BadLocationException { |
| 100 | fb.insertString(offset, string, attr); |
| 101 | } |
| 102 | |
| 103 | /** |
| 104 | * Invoked prior to replacing a region of text in the |
| 105 | * specified Document. Subclasses that want to conditionally allow |
| 106 | * replace should override this and only call supers implementation as |
| 107 | * necessary, or call directly into the FilterBypass. |
| 108 | * |
| 109 | * @param fb FilterBypass that can be used to mutate Document |
| 110 | * @param offset Location in Document |
| 111 | * @param length Length of text to delete |
| 112 | * @param text Text to insert, null indicates no text to insert |
| 113 | * @param attrs AttributeSet indicating attributes of inserted text, |
| 114 | * null is legal. |
| 115 | * @exception BadLocationException the given insert position is not a |
| 116 | * valid position within the document |
| 117 | */ |
| 118 | public void replace(FilterBypass fb, int offset, int length, String text, |
| 119 | AttributeSet attrs) throws BadLocationException { |
| 120 | fb.replace(offset, length, text, attrs); |
| 121 | } |
| 122 | |
| 123 | |
| 124 | /** |
| 125 | * Used as a way to circumvent calling back into the Document to |
| 126 | * change it. Document implementations that wish to support |
| 127 | * a DocumentFilter must provide an implementation that will |
| 128 | * not callback into the DocumentFilter when the following methods |
| 129 | * are invoked from the DocumentFilter. |
| 130 | * @since 1.4 |
| 131 | */ |
| 132 | public static abstract class FilterBypass { |
| 133 | /** |
| 134 | * Returns the Document the mutation is occuring on. |
| 135 | * |
| 136 | * @return Document that remove/insertString will operate on |
| 137 | */ |
| 138 | public abstract Document getDocument(); |
| 139 | |
| 140 | /** |
| 141 | * Removes the specified region of text, bypassing the |
| 142 | * DocumentFilter. |
| 143 | * |
| 144 | * @param offset the offset from the beginning >= 0 |
| 145 | * @param length the number of characters to remove >= 0 |
| 146 | * @exception BadLocationException some portion of the removal range |
| 147 | * was not a valid part of the document. The location in the |
| 148 | * exception is the first bad position encountered. |
| 149 | */ |
| 150 | public abstract void remove(int offset, int length) throws |
| 151 | BadLocationException; |
| 152 | |
| 153 | /** |
| 154 | * Inserts the specified text, bypassing the |
| 155 | * DocumentFilter. |
| 156 | * @param offset the offset into the document to insert the |
| 157 | * content >= 0. All positions that track change at or after the |
| 158 | * given location will move. |
| 159 | * @param string the string to insert |
| 160 | * @param attr the attributes to associate with the inserted |
| 161 | * content. This may be null if there are no attributes. |
| 162 | * @exception BadLocationException the given insert position is not a |
| 163 | * valid position within the document |
| 164 | */ |
| 165 | public abstract void insertString(int offset, String string, |
| 166 | AttributeSet attr) throws |
| 167 | BadLocationException; |
| 168 | |
| 169 | /** |
| 170 | * Deletes the region of text from <code>offset</code> to |
| 171 | * <code>offset + length</code>, and replaces it with |
| 172 | * <code>text</code>. |
| 173 | * |
| 174 | * @param offset Location in Document |
| 175 | * @param length Length of text to delete |
| 176 | * @param string Text to insert, null indicates no text to insert |
| 177 | * @param attrs AttributeSet indicating attributes of inserted text, |
| 178 | * null is legal. |
| 179 | * @exception BadLocationException the given insert is not a |
| 180 | * valid position within the document |
| 181 | */ |
| 182 | public abstract void replace(int offset, int length, String string, |
| 183 | AttributeSet attrs) throws |
| 184 | BadLocationException; |
| 185 | } |
| 186 | } |