1/* 2 * Copyright (C) 2013 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package android.support.v4.text; 18 19import android.support.annotation.NonNull; 20import android.support.annotation.Nullable; 21import android.support.v4.view.ViewCompat; 22 23import java.util.Locale; 24 25public class TextUtilsCompat { 26 27 /** 28 * Html-encode the string. 29 * @param s the string to be encoded 30 * @return the encoded string 31 */ 32 @NonNull 33 public static String htmlEncode(@NonNull String s) { 34 StringBuilder sb = new StringBuilder(); 35 char c; 36 for (int i = 0; i < s.length(); i++) { 37 c = s.charAt(i); 38 switch (c) { 39 case '<': 40 sb.append("<"); //$NON-NLS-1$ 41 break; 42 case '>': 43 sb.append(">"); //$NON-NLS-1$ 44 break; 45 case '&': 46 sb.append("&"); //$NON-NLS-1$ 47 break; 48 case '\'': 49 //http://www.w3.org/TR/xhtml1 50 // The named character reference ' (the apostrophe, U+0027) was introduced in 51 // XML 1.0 but does not appear in HTML. Authors should therefore use ' instead 52 // of ' to work as expected in HTML 4 user agents. 53 sb.append("'"); //$NON-NLS-1$ 54 break; 55 case '"': 56 sb.append("""); //$NON-NLS-1$ 57 break; 58 default: 59 sb.append(c); 60 } 61 } 62 return sb.toString(); 63 } 64 65 /** 66 * Return the layout direction for a given Locale 67 * 68 * @param locale the Locale for which we want the layout direction. Can be null. 69 * @return the layout direction. This may be one of: 70 * {@link ViewCompat#LAYOUT_DIRECTION_LTR} or 71 * {@link ViewCompat#LAYOUT_DIRECTION_RTL}. 72 * 73 * Be careful: this code will need to be updated when vertical scripts will be supported 74 */ 75 public static int getLayoutDirectionFromLocale(@Nullable Locale locale) { 76 if (locale != null && !locale.equals(ROOT)) { 77 final String scriptSubtag = ICUCompat.getScript( 78 ICUCompat.addLikelySubtags(locale.toString())); 79 if (scriptSubtag == null) return getLayoutDirectionFromFirstChar(locale); 80 81 if (scriptSubtag.equalsIgnoreCase(ARAB_SCRIPT_SUBTAG) || 82 scriptSubtag.equalsIgnoreCase(HEBR_SCRIPT_SUBTAG)) { 83 return ViewCompat.LAYOUT_DIRECTION_RTL; 84 } 85 } 86 87 return ViewCompat.LAYOUT_DIRECTION_LTR; 88 } 89 90 /** 91 * Fallback algorithm to detect the locale direction. Rely on the fist char of the 92 * localized locale name. This will not work if the localized locale name is in English 93 * (this is the case for ICU 4.4 and "Urdu" script) 94 * 95 * @param locale 96 * @return the layout direction. This may be one of: 97 * {@link ViewCompat#LAYOUT_DIRECTION_LTR} or 98 * {@link ViewCompat#LAYOUT_DIRECTION_RTL}. 99 * 100 * Be careful: this code will need to be updated when vertical scripts will be supported 101 */ 102 private static int getLayoutDirectionFromFirstChar(Locale locale) { 103 switch(Character.getDirectionality(locale.getDisplayName(locale).charAt(0))) { 104 case Character.DIRECTIONALITY_RIGHT_TO_LEFT: 105 case Character.DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC: 106 return ViewCompat.LAYOUT_DIRECTION_RTL; 107 108 case Character.DIRECTIONALITY_LEFT_TO_RIGHT: 109 default: 110 return ViewCompat.LAYOUT_DIRECTION_LTR; 111 } 112 } 113 114 public static final Locale ROOT = new Locale("", ""); 115 116 private static String ARAB_SCRIPT_SUBTAG = "Arab"; 117 private static String HEBR_SCRIPT_SUBTAG = "Hebr"; 118} 119