Java tutorial
/* * Copyright (C) 2008 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.text.util; import android.widget.MultiAutoCompleteTextView; import java.util.ArrayList; import java.util.Collection; /** * This class works as a Tokenizer for MultiAutoCompleteTextView for * address list fields, and also provides a method for converting * a string of addresses (such as might be typed into such a field) * into a series of Rfc822Tokens. */ public class Rfc822Tokenizer implements MultiAutoCompleteTextView.Tokenizer { /** * This constructor will try to take a string like * "Foo Bar (something) <foo\@google.com>, * blah\@google.com (something)" * and convert it into one or more Rfc822Tokens, output into the supplied * collection. * * It does *not* decode MIME encoded-words; charset conversion * must already have taken place if necessary. * It will try to be tolerant of broken syntax instead of * returning an error. * */ public static void tokenize(CharSequence text, Collection<Rfc822Token> out) { StringBuilder name = new StringBuilder(); StringBuilder address = new StringBuilder(); StringBuilder comment = new StringBuilder(); int i = 0; int cursor = text.length(); while (i < cursor) { char c = text.charAt(i); if (c == ',' || c == ';') { i++; while (i < cursor && text.charAt(i) == ' ') { i++; } crunch(name); if (address.length() > 0) { out.add(new Rfc822Token(name.toString(), address.toString(), comment.toString())); } else if (name.length() > 0) { out.add(new Rfc822Token(null, name.toString(), comment.toString())); } name.setLength(0); address.setLength(0); comment.setLength(0); } else if (c == '"') { i++; while (i < cursor) { c = text.charAt(i); if (c == '"') { i++; break; } else if (c == '\\') { if (i + 1 < cursor) { name.append(text.charAt(i + 1)); } i += 2; } else { name.append(c); i++; } } } else if (c == '(') { int level = 1; i++; while (i < cursor && level > 0) { c = text.charAt(i); if (c == ')') { if (level > 1) { comment.append(c); } level--; i++; } else if (c == '(') { comment.append(c); level++; i++; } else if (c == '\\') { if (i + 1 < cursor) { comment.append(text.charAt(i + 1)); } i += 2; } else { comment.append(c); i++; } } } else if (c == '<') { i++; while (i < cursor) { c = text.charAt(i); if (c == '>') { i++; break; } else { address.append(c); i++; } } } else if (c == ' ') { name.append('\0'); i++; } else { name.append(c); i++; } } crunch(name); if (address.length() > 0) { out.add(new Rfc822Token(name.toString(), address.toString(), comment.toString())); } else if (name.length() > 0) { out.add(new Rfc822Token(null, name.toString(), comment.toString())); } } /** * This method will try to take a string like * "Foo Bar (something) <foo\@google.com>, * blah\@google.com (something)" * and convert it into one or more Rfc822Tokens. * It does *not* decode MIME encoded-words; charset conversion * must already have taken place if necessary. * It will try to be tolerant of broken syntax instead of * returning an error. */ public static Rfc822Token[] tokenize(CharSequence text) { ArrayList<Rfc822Token> out = new ArrayList<Rfc822Token>(); tokenize(text, out); return out.toArray(new Rfc822Token[out.size()]); } private static void crunch(StringBuilder sb) { int i = 0; int len = sb.length(); while (i < len) { char c = sb.charAt(i); if (c == '\0') { if (i == 0 || i == len - 1 || sb.charAt(i - 1) == ' ' || sb.charAt(i - 1) == '\0' || sb.charAt(i + 1) == ' ' || sb.charAt(i + 1) == '\0') { sb.deleteCharAt(i); len--; } else { i++; } } else { i++; } } for (i = 0; i < len; i++) { if (sb.charAt(i) == '\0') { sb.setCharAt(i, ' '); } } } /** * {@inheritDoc} */ public int findTokenStart(CharSequence text, int cursor) { /* * It's hard to search backward, so search forward until * we reach the cursor. */ int best = 0; int i = 0; while (i < cursor) { i = findTokenEnd(text, i); if (i < cursor) { i++; // Skip terminating punctuation while (i < cursor && text.charAt(i) == ' ') { i++; } if (i < cursor) { best = i; } } } return best; } /** * {@inheritDoc} */ public int findTokenEnd(CharSequence text, int cursor) { int len = text.length(); int i = cursor; while (i < len) { char c = text.charAt(i); if (c == ',' || c == ';') { return i; } else if (c == '"') { i++; while (i < len) { c = text.charAt(i); if (c == '"') { i++; break; } else if (c == '\\' && i + 1 < len) { i += 2; } else { i++; } } } else if (c == '(') { int level = 1; i++; while (i < len && level > 0) { c = text.charAt(i); if (c == ')') { level--; i++; } else if (c == '(') { level++; i++; } else if (c == '\\' && i + 1 < len) { i += 2; } else { i++; } } } else if (c == '<') { i++; while (i < len) { c = text.charAt(i); if (c == '>') { i++; break; } else { i++; } } } else { i++; } } return i; } /** * Terminates the specified address with a comma and space. * This assumes that the specified text already has valid syntax. * The Adapter subclass's convertToString() method must make that * guarantee. */ public CharSequence terminateToken(CharSequence text) { return text + ", "; } }