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| 1 | /* | ||
| 2 | * Copyright (c) 1997, 1998, Oracle and/or its affiliates. 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. Oracle designates this | ||
| 8 | * particular file as subject to the "Classpath" exception as provided | ||
| 9 | * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | ||
| 22 | * or visit www.oracle.com if you need additional information or have any | ||
| 23 | * questions. | ||
| 24 | */ | ||
| 25 | |||
| 26 | /* | ||
| 27 | * (C) Copyright Taligent, Inc. 1996 - 1997, All Rights Reserved | ||
| 28 | * (C) Copyright IBM Corp. 1996 - 1998, All Rights Reserved | ||
| 29 | * | ||
| 30 | * The original version of this source code and documentation is | ||
| 31 | * copyrighted and owned by Taligent, Inc., a wholly-owned subsidiary | ||
| 32 | * of IBM. These materials are provided under terms of a License | ||
| 33 | * Agreement between Taligent and Sun. This technology is protected | ||
| 34 | * by multiple US and International patents. | ||
| 35 | * | ||
| 36 | * This notice and attribution to Taligent may not be removed. | ||
| 37 | * Taligent is a registered trademark of Taligent, Inc. | ||
| 38 | * | ||
| 39 | */ | ||
| 40 | |||
| 41 | package java.awt.font; | ||
| 42 | import java.lang.String; | ||
| 43 | |||
| 44 | /** | ||
| 45 | * The <code>TextHitInfo</code> class represents a character position in a | ||
| 46 | * text model, and a <b>bias</b>, or "side," of the character. Biases are | ||
| 47 | * either <EM>leading</EM> (the left edge, for a left-to-right character) | ||
| 48 | * or <EM>trailing</EM> (the right edge, for a left-to-right character). | ||
| 49 | * Instances of <code>TextHitInfo</code> are used to specify caret and | ||
| 50 | * insertion positions within text. | ||
| 51 | * <p> | ||
| 52 | * For example, consider the text "abc". TextHitInfo.trailing(1) | ||
| 53 | * corresponds to the right side of the 'b' in the text. | ||
| 54 | * <p> | ||
| 55 | * <code>TextHitInfo</code> is used primarily by {@link TextLayout} and | ||
| 56 | * clients of <code>TextLayout</code>. Clients of <code>TextLayout</code> | ||
| 57 | * query <code>TextHitInfo</code> instances for an insertion offset, where | ||
| 58 | * new text is inserted into the text model. The insertion offset is equal | ||
| 59 | * to the character position in the <code>TextHitInfo</code> if the bias | ||
| 60 | * is leading, and one character after if the bias is trailing. The | ||
| 61 | * insertion offset for TextHitInfo.trailing(1) is 2. | ||
| 62 | * <p> | ||
| 63 | * Sometimes it is convenient to construct a <code>TextHitInfo</code> with | ||
| 64 | * the same insertion offset as an existing one, but on the opposite | ||
| 65 | * character. The <code>getOtherHit</code> method constructs a new | ||
| 66 | * <code>TextHitInfo</code> with the same insertion offset as an existing | ||
| 67 | * one, with a hit on the character on the other side of the insertion offset. | ||
| 68 | * Calling <code>getOtherHit</code> on trailing(1) would return leading(2). | ||
| 69 | * In general, <code>getOtherHit</code> for trailing(n) returns | ||
| 70 | * leading(n+1) and <code>getOtherHit</code> for leading(n) | ||
| 71 | * returns trailing(n-1). | ||
| 72 | * <p> | ||
| 73 | * <strong>Example</strong>:<p> | ||
| 74 | * Converting a graphical point to an insertion point within a text | ||
| 75 | * model | ||
| 76 | * <blockquote><pre> | ||
| 77 | * TextLayout layout = ...; | ||
| 78 | * Point2D.Float hitPoint = ...; | ||
| 79 | * TextHitInfo hitInfo = layout.hitTestChar(hitPoint.x, hitPoint.y); | ||
| 80 | * int insPoint = hitInfo.getInsertionIndex(); | ||
| 81 | * // insPoint is relative to layout; may need to adjust for use | ||
| 82 | * // in a text model | ||
| 83 | * </pre></blockquote> | ||
| 84 | * | ||
| 85 | * @see TextLayout | ||
| 86 | */ | ||
| 87 | |||
| 88 | public final class TextHitInfo { | ||
| 89 | private int charIndex; | ||
| 90 | private boolean isLeadingEdge; | ||
| 91 | |||
| 92 | /** | ||
| 93 | * Constructs a new <code>TextHitInfo</code>. | ||
| 94 | * @param charIndex the index of the character hit | ||
| 95 | * @param isLeadingEdge <code>true</code> if the leading edge of the | ||
| 96 | * character was hit | ||
| 97 | */ | ||
| 98 | private TextHitInfo(int charIndex, boolean isLeadingEdge) { | ||
| 99 | this.charIndex = charIndex; | ||
| 100 | this.isLeadingEdge = isLeadingEdge; | ||
| 101 | } | ||
| 102 | |||
| 103 | /** | ||
| 104 | * Returns the index of the character hit. | ||
| 105 | * @return the index of the character hit. | ||
| 106 | */ | ||
| 107 | public int getCharIndex() { | ||
| 108 | return charIndex; | ||
| 109 | } | ||
| 110 | |||
| 111 | /** | ||
| 112 | * Returns <code>true</code> if the leading edge of the character was | ||
| 113 | * hit. | ||
| 114 | * @return <code>true</code> if the leading edge of the character was | ||
| 115 | * hit; <code>false</code> otherwise. | ||
| 116 | */ | ||
| 117 | public boolean isLeadingEdge() { | ||
| 118 | return isLeadingEdge; | ||
| 119 | } | ||
| 120 | |||
| 121 | /** | ||
| 122 | * Returns the insertion index. This is the character index if | ||
| 123 | * the leading edge of the character was hit, and one greater | ||
| 124 | * than the character index if the trailing edge was hit. | ||
| 125 | * @return the insertion index. | ||
| 126 | */ | ||
| 127 | public int getInsertionIndex() { | ||
| 128 | return isLeadingEdge ? charIndex : charIndex + 1; | ||
| 129 | } | ||
| 130 | |||
| 131 | /** | ||
| 132 | * Returns the hash code. | ||
| 133 | * @return the hash code of this <code>TextHitInfo</code>, which is | ||
| 134 | * also the <code>charIndex</code> of this <code>TextHitInfo</code>. | ||
| 135 | */ | ||
| 136 | public int hashCode() { | ||
| 137 | return charIndex; | ||
| 138 | } | ||
| 139 | |||
| 140 | /** | ||
| 141 | * Returns <code>true</code> if the specified <code>Object</code> is a | ||
| 142 | * <code>TextHitInfo</code> and equals this <code>TextHitInfo</code>. | ||
| 143 | * @param obj the <code>Object</code> to test for equality | ||
| 144 | * @return <code>true</code> if the specified <code>Object</code> | ||
| 145 | * equals this <code>TextHitInfo</code>; <code>false</code> otherwise. | ||
| 146 | */ | ||
| 147 | public boolean equals(Object obj) { | ||
| 148 | return (obj instanceof TextHitInfo) && equals((TextHitInfo)obj); | ||
| 149 | } | ||
| 150 | |||
| 151 | /** | ||
| 152 | * Returns <code>true</code> if the specified <code>TextHitInfo</code> | ||
| 153 | * has the same <code>charIndex</code> and <code>isLeadingEdge</code> | ||
| 154 | * as this <code>TextHitInfo</code>. This is not the same as having | ||
| 155 | * the same insertion offset. | ||
| 156 | * @param hitInfo a specified <code>TextHitInfo</code> | ||
| 157 | * @return <code>true</code> if the specified <code>TextHitInfo</code> | ||
| 158 | * has the same <code>charIndex</code> and <code>isLeadingEdge</code> | ||
| 159 | * as this <code>TextHitInfo</code>. | ||
| 160 | */ | ||
| 161 | public boolean equals(TextHitInfo hitInfo) { | ||
| 162 | return hitInfo != null && charIndex == hitInfo.charIndex && | ||
| 163 | isLeadingEdge == hitInfo.isLeadingEdge; | ||
| 164 | } | ||
| 165 | |||
| 166 | /** | ||
| 167 | * Returns a <code>String</code> representing the hit for debugging | ||
| 168 | * use only. | ||
| 169 | * @return a <code>String</code> representing this | ||
| 170 | * <code>TextHitInfo</code>. | ||
| 171 | */ | ||
| 172 | public String toString() { | ||
| 173 | return "TextHitInfo[" + charIndex + (isLeadingEdge ? "L" : "T")+"]"; | ||
| 174 | } | ||
| 175 | |||
| 176 | /** | ||
| 177 | * Creates a <code>TextHitInfo</code> on the leading edge of the | ||
| 178 | * character at the specified <code>charIndex</code>. | ||
| 179 | * @param charIndex the index of the character hit | ||
| 180 | * @return a <code>TextHitInfo</code> on the leading edge of the | ||
| 181 | * character at the specified <code>charIndex</code>. | ||
| 182 | */ | ||
| 183 | public static TextHitInfo leading(int charIndex) { | ||
| 184 | return new TextHitInfo(charIndex, true); | ||
| 185 | } | ||
| 186 | |||
| 187 | /** | ||
| 188 | * Creates a hit on the trailing edge of the character at | ||
| 189 | * the specified <code>charIndex</code>. | ||
| 190 | * @param charIndex the index of the character hit | ||
| 191 | * @return a <code>TextHitInfo</code> on the trailing edge of the | ||
| 192 | * character at the specified <code>charIndex</code>. | ||
| 193 | */ | ||
| 194 | public static TextHitInfo trailing(int charIndex) { | ||
| 195 | return new TextHitInfo(charIndex, false); | ||
| 196 | } | ||
| 197 | |||
| 198 | /** | ||
| 199 | * Creates a <code>TextHitInfo</code> at the specified offset, | ||
| 200 | * associated with the character before the offset. | ||
| 201 | * @param offset an offset associated with the character before | ||
| 202 | * the offset | ||
| 203 | * @return a <code>TextHitInfo</code> at the specified offset. | ||
| 204 | */ | ||
| 205 | public static TextHitInfo beforeOffset(int offset) { | ||
| 206 | return new TextHitInfo(offset-1, false); | ||
| 207 | } | ||
| 208 | |||
| 209 | /** | ||
| 210 | * Creates a <code>TextHitInfo</code> at the specified offset, | ||
| 211 | * associated with the character after the offset. | ||
| 212 | * @param offset an offset associated with the character after | ||
| 213 | * the offset | ||
| 214 | * @return a <code>TextHitInfo</code> at the specified offset. | ||
| 215 | */ | ||
| 216 | public static TextHitInfo afterOffset(int offset) { | ||
| 217 | return new TextHitInfo(offset, true); | ||
| 218 | } | ||
| 219 | |||
| 220 | /** | ||
| 221 | * Creates a <code>TextHitInfo</code> on the other side of the | ||
| 222 | * insertion point. This <code>TextHitInfo</code> remains unchanged. | ||
| 223 | * @return a <code>TextHitInfo</code> on the other side of the | ||
| 224 | * insertion point. | ||
| 225 | */ | ||
| 226 | public TextHitInfo getOtherHit() { | ||
| 227 | if (isLeadingEdge) { | ||
| 228 | return trailing(charIndex - 1); | ||
| 229 | } else { | ||
| 230 | return leading(charIndex + 1); | ||
| 231 | } | ||
| 232 | } | ||
| 233 | |||
| 234 | /** | ||
| 235 | * Creates a <code>TextHitInfo</code> whose character index is offset | ||
| 236 | * by <code>delta</code> from the <code>charIndex</code> of this | ||
| 237 | * <code>TextHitInfo</code>. This <code>TextHitInfo</code> remains | ||
| 238 | * unchanged. | ||
| 239 | * @param delta the value to offset this <code>charIndex</code> | ||
| 240 | * @return a <code>TextHitInfo</code> whose <code>charIndex</code> is | ||
| 241 | * offset by <code>delta</code> from the <code>charIndex</code> of | ||
| 242 | * this <code>TextHitInfo</code>. | ||
| 243 | */ | ||
| 244 | public TextHitInfo getOffsetHit(int delta) { | ||
| 245 | return new TextHitInfo(charIndex + delta, isLeadingEdge); | ||
| 246 | } | ||
| 247 | } | ||