1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184
/* * @(#)ComponentOrientation.java 1.19 06/07/27 * * Copyright 2006 Sun Microsystems, Inc. All rights reserved. * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */ /* * (C) Copyright IBM Corp. 1998 - All Rights Reserved * * The original version of this source code and documentation is copyrighted * and owned by IBM, Inc. These materials are provided under terms of a * License Agreement between IBM and Sun. This technology is protected by * multiple US and International patents. This notice and attribution to IBM * may not be removed. * */ package java.awt; import java.util.Locale; import java.util.ResourceBundle; /** * The ComponentOrientation class encapsulates the language-sensitive * orientation that is to be used to order the elements of a component * or of text. It is used to reflect the differences in this ordering * between Western alphabets, Middle Eastern (such as Hebrew), and Far * Eastern (such as Japanese). * <p> * Fundamentally, this governs items (such as characters) which are laid out * in lines, with the lines then laid out in a block. This also applies * to items in a widget: for example, in a check box where the box is * positioned relative to the text. * <p> * There are four different orientations used in modern languages * as in the following table.<br> * <pre> * LT RT TL TR * A B C C B A A D G G D A * D E F F E D B E H H E B * G H I I H G C F I I F C * </pre><br> * (In the header, the two-letter abbreviation represents the item direction * in the first letter, and the line direction in the second. For example, * LT means "items left-to-right, lines top-to-bottom", * TL means "items top-to-bottom, lines left-to-right", and so on.) * <p> * The orientations are: * <ul> * <li>LT - Western Europe (optional for Japanese, Chinese, Korean) * <li>RT - Middle East (Arabic, Hebrew) * <li>TR - Japanese, Chinese, Korean * <li>TL - Mongolian * </ul> * Components whose view and controller code depends on orientation * should use the <code>isLeftToRight()</code> and * <code>isHorizontal()</code> methods to * determine their behavior. They should not include switch-like * code that keys off of the constants, such as: * <pre> * if (orientation == LEFT_TO_RIGHT) { * ... * } else if (orientation == RIGHT_TO_LEFT) { * ... * } else { * // Oops * } * </pre> * This is unsafe, since more constants may be added in the future and * since it is not guaranteed that orientation objects will be unique. */ public final class ComponentOrientation implements java.io.Serializable { /* * serialVersionUID */ private static final long serialVersionUID = -4113291392143563828L; // Internal constants used in the implementation private static final int UNK_BIT = 1; private static final int HORIZ_BIT = 2; private static final int LTR_BIT = 4; /** * Items run left to right and lines flow top to bottom * Examples: English, French. */ public static final ComponentOrientation LEFT_TO_RIGHT = new ComponentOrientation(HORIZ_BIT|LTR_BIT); /** * Items run right to left and lines flow top to bottom * Examples: Arabic, Hebrew. */ public static final ComponentOrientation RIGHT_TO_LEFT = new ComponentOrientation(HORIZ_BIT); /** * Indicates that a component's orientation has not been set. * To preserve the behavior of existing applications, * isLeftToRight will return true for this value. */ public static final ComponentOrientation UNKNOWN = new ComponentOrientation(HORIZ_BIT|LTR_BIT|UNK_BIT); /** * Are lines horizontal? * This will return true for horizontal, left-to-right writing * systems such as Roman. */ public boolean isHorizontal() { return (orientation & HORIZ_BIT) != 0; } /** * HorizontalLines: Do items run left-to-right?<br> * Vertical Lines: Do lines run left-to-right?<br> * This will return true for horizontal, left-to-right writing * systems such as Roman. */ public boolean isLeftToRight() { return (orientation & LTR_BIT) != 0; } /** * Returns the orientation that is appropriate for the given locale. * @param locale the specified locale */ public static ComponentOrientation getOrientation(Locale locale) { // A more flexible implementation would consult a ResourceBundle // to find the appropriate orientation. Until pluggable locales // are introduced however, the flexiblity isn't really needed. // So we choose efficiency instead. String lang = locale.getLanguage(); if( "iw".equals(lang) || "ar".equals(lang) || "fa".equals(lang) || "ur".equals(lang) ) { return RIGHT_TO_LEFT; } else { return LEFT_TO_RIGHT; } } /** * Returns the orientation appropriate for the given ResourceBundle's * localization. Three approaches are tried, in the following order: * <ol> * <li>Retrieve a ComponentOrientation object from the ResourceBundle * using the string "Orientation" as the key. * <li>Use the ResourceBundle.getLocale to determine the bundle's * locale, then return the orientation for that locale. * <li>Return the default locale's orientation. * </ol> * * @deprecated As of J2SE 1.4, use {@link #getOrientation(java.util.Locale)}. */ @Deprecated public static ComponentOrientation getOrientation(ResourceBundle bdl) { ComponentOrientation result = null; try { result = (ComponentOrientation)bdl.getObject("Orientation"); } catch (Exception e) { } if (result == null) { result = getOrientation(bdl.getLocale()); } if (result == null) { result = getOrientation(Locale.getDefault()); } return result; } private int orientation; private ComponentOrientation(int value) { orientation = value; } }