1 /* 2 * Copyright (C) 2008 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 17 package com.android.email.mail.internet; 18 19 import java.util.regex.Matcher; 20 import java.util.regex.Pattern; 21 22 public class EmailHtmlUtil { 23 24 // Regex that matches characters that have special meaning in HTML. '<', '>', '&' and 25 // multiple continuous spaces. 26 private static final Pattern PLAIN_TEXT_TO_ESCAPE = Pattern.compile("[<>&]| {2,}|\r?\n"); 27 28 /** 29 * Escape some special character as HTML escape sequence. 30 * 31 * @param text Text to be displayed using WebView. 32 * @return Text correctly escaped. 33 */ 34 public static String escapeCharacterToDisplay(String text) { 35 Pattern pattern = PLAIN_TEXT_TO_ESCAPE; 36 Matcher match = pattern.matcher(text); 37 38 if (match.find()) { 39 StringBuilder out = new StringBuilder(); 40 int end = 0; 41 do { 42 int start = match.start(); 43 out.append(text.substring(end, start)); 44 end = match.end(); 45 int c = text.codePointAt(start); 46 if (c == ' ') { 47 // Escape successive spaces into series of " ". 48 for (int i = 1, n = end - start; i < n; ++i) { 49 out.append(" "); 50 } 51 out.append(' '); 52 } else if (c == '\r' || c == '\n') { 53 out.append("<br>"); 54 } else if (c == '<') { 55 out.append("<"); 56 } else if (c == '>') { 57 out.append(">"); 58 } else if (c == '&') { 59 out.append("&"); 60 } 61 } while (match.find()); 62 out.append(text.substring(end)); 63 text = out.toString(); 64 } 65 return text; 66 } 67 } 68
