J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1998-2006 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 | |
| 26 | /* |
| 27 | * (C) Copyright IBM Corp. 1998 - All Rights Reserved |
| 28 | * |
| 29 | * The original version of this source code and documentation is copyrighted |
| 30 | * and owned by IBM, Inc. These materials are provided under terms of a |
| 31 | * License Agreement between IBM and Sun. This technology is protected by |
| 32 | * multiple US and International patents. This notice and attribution to IBM |
| 33 | * may not be removed. |
| 34 | * |
| 35 | */ |
| 36 | |
| 37 | package java.awt; |
| 38 | |
| 39 | import java.util.Locale; |
| 40 | import java.util.ResourceBundle; |
| 41 | |
| 42 | /** |
| 43 | * The ComponentOrientation class encapsulates the language-sensitive |
| 44 | * orientation that is to be used to order the elements of a component |
| 45 | * or of text. It is used to reflect the differences in this ordering |
| 46 | * between Western alphabets, Middle Eastern (such as Hebrew), and Far |
| 47 | * Eastern (such as Japanese). |
| 48 | * <p> |
| 49 | * Fundamentally, this governs items (such as characters) which are laid out |
| 50 | * in lines, with the lines then laid out in a block. This also applies |
| 51 | * to items in a widget: for example, in a check box where the box is |
| 52 | * positioned relative to the text. |
| 53 | * <p> |
| 54 | * There are four different orientations used in modern languages |
| 55 | * as in the following table.<br> |
| 56 | * <pre> |
| 57 | * LT RT TL TR |
| 58 | * A B C C B A A D G G D A |
| 59 | * D E F F E D B E H H E B |
| 60 | * G H I I H G C F I I F C |
| 61 | * </pre><br> |
| 62 | * (In the header, the two-letter abbreviation represents the item direction |
| 63 | * in the first letter, and the line direction in the second. For example, |
| 64 | * LT means "items left-to-right, lines top-to-bottom", |
| 65 | * TL means "items top-to-bottom, lines left-to-right", and so on.) |
| 66 | * <p> |
| 67 | * The orientations are: |
| 68 | * <ul> |
| 69 | * <li>LT - Western Europe (optional for Japanese, Chinese, Korean) |
| 70 | * <li>RT - Middle East (Arabic, Hebrew) |
| 71 | * <li>TR - Japanese, Chinese, Korean |
| 72 | * <li>TL - Mongolian |
| 73 | * </ul> |
| 74 | * Components whose view and controller code depends on orientation |
| 75 | * should use the <code>isLeftToRight()</code> and |
| 76 | * <code>isHorizontal()</code> methods to |
| 77 | * determine their behavior. They should not include switch-like |
| 78 | * code that keys off of the constants, such as: |
| 79 | * <pre> |
| 80 | * if (orientation == LEFT_TO_RIGHT) { |
| 81 | * ... |
| 82 | * } else if (orientation == RIGHT_TO_LEFT) { |
| 83 | * ... |
| 84 | * } else { |
| 85 | * // Oops |
| 86 | * } |
| 87 | * </pre> |
| 88 | * This is unsafe, since more constants may be added in the future and |
| 89 | * since it is not guaranteed that orientation objects will be unique. |
| 90 | */ |
| 91 | public final class ComponentOrientation implements java.io.Serializable |
| 92 | { |
| 93 | /* |
| 94 | * serialVersionUID |
| 95 | */ |
| 96 | private static final long serialVersionUID = -4113291392143563828L; |
| 97 | |
| 98 | // Internal constants used in the implementation |
| 99 | private static final int UNK_BIT = 1; |
| 100 | private static final int HORIZ_BIT = 2; |
| 101 | private static final int LTR_BIT = 4; |
| 102 | |
| 103 | /** |
| 104 | * Items run left to right and lines flow top to bottom |
| 105 | * Examples: English, French. |
| 106 | */ |
| 107 | public static final ComponentOrientation LEFT_TO_RIGHT = |
| 108 | new ComponentOrientation(HORIZ_BIT|LTR_BIT); |
| 109 | |
| 110 | /** |
| 111 | * Items run right to left and lines flow top to bottom |
| 112 | * Examples: Arabic, Hebrew. |
| 113 | */ |
| 114 | public static final ComponentOrientation RIGHT_TO_LEFT = |
| 115 | new ComponentOrientation(HORIZ_BIT); |
| 116 | |
| 117 | /** |
| 118 | * Indicates that a component's orientation has not been set. |
| 119 | * To preserve the behavior of existing applications, |
| 120 | * isLeftToRight will return true for this value. |
| 121 | */ |
| 122 | public static final ComponentOrientation UNKNOWN = |
| 123 | new ComponentOrientation(HORIZ_BIT|LTR_BIT|UNK_BIT); |
| 124 | |
| 125 | /** |
| 126 | * Are lines horizontal? |
| 127 | * This will return true for horizontal, left-to-right writing |
| 128 | * systems such as Roman. |
| 129 | */ |
| 130 | public boolean isHorizontal() { |
| 131 | return (orientation & HORIZ_BIT) != 0; |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | * HorizontalLines: Do items run left-to-right?<br> |
| 136 | * Vertical Lines: Do lines run left-to-right?<br> |
| 137 | * This will return true for horizontal, left-to-right writing |
| 138 | * systems such as Roman. |
| 139 | */ |
| 140 | public boolean isLeftToRight() { |
| 141 | return (orientation & LTR_BIT) != 0; |
| 142 | } |
| 143 | |
| 144 | /** |
| 145 | * Returns the orientation that is appropriate for the given locale. |
| 146 | * @param locale the specified locale |
| 147 | */ |
| 148 | public static ComponentOrientation getOrientation(Locale locale) { |
| 149 | // A more flexible implementation would consult a ResourceBundle |
| 150 | // to find the appropriate orientation. Until pluggable locales |
| 151 | // are introduced however, the flexiblity isn't really needed. |
| 152 | // So we choose efficiency instead. |
| 153 | String lang = locale.getLanguage(); |
| 154 | if( "iw".equals(lang) || "ar".equals(lang) |
| 155 | || "fa".equals(lang) || "ur".equals(lang) ) |
| 156 | { |
| 157 | return RIGHT_TO_LEFT; |
| 158 | } else { |
| 159 | return LEFT_TO_RIGHT; |
| 160 | } |
| 161 | } |
| 162 | |
| 163 | /** |
| 164 | * Returns the orientation appropriate for the given ResourceBundle's |
| 165 | * localization. Three approaches are tried, in the following order: |
| 166 | * <ol> |
| 167 | * <li>Retrieve a ComponentOrientation object from the ResourceBundle |
| 168 | * using the string "Orientation" as the key. |
| 169 | * <li>Use the ResourceBundle.getLocale to determine the bundle's |
| 170 | * locale, then return the orientation for that locale. |
| 171 | * <li>Return the default locale's orientation. |
| 172 | * </ol> |
| 173 | * |
| 174 | * @deprecated As of J2SE 1.4, use {@link #getOrientation(java.util.Locale)}. |
| 175 | */ |
| 176 | @Deprecated |
| 177 | public static ComponentOrientation getOrientation(ResourceBundle bdl) |
| 178 | { |
| 179 | ComponentOrientation result = null; |
| 180 | |
| 181 | try { |
| 182 | result = (ComponentOrientation)bdl.getObject("Orientation"); |
| 183 | } |
| 184 | catch (Exception e) { |
| 185 | } |
| 186 | |
| 187 | if (result == null) { |
| 188 | result = getOrientation(bdl.getLocale()); |
| 189 | } |
| 190 | if (result == null) { |
| 191 | result = getOrientation(Locale.getDefault()); |
| 192 | } |
| 193 | return result; |
| 194 | } |
| 195 | |
| 196 | private int orientation; |
| 197 | |
| 198 | private ComponentOrientation(int value) |
| 199 | { |
| 200 | orientation = value; |
| 201 | } |
| 202 | } |