UnicodeEncoder.java

/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 * 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 io.appium.android.bootstrap.utils;

import java.nio.charset.Charset;

import io.appium.android.bootstrap.Logger;


public class UnicodeEncoder {
  private static final Charset M_UTF7 = Charset.forName("x-IMAP-mailbox-name");
  private static final Charset ASCII  = Charset.forName("US-ASCII");


  public static String encode(final String text) {
    byte[] encoded = text.getBytes(M_UTF7);
    String ret = new String(encoded, ASCII);
    if (ret.charAt(ret.length()-1) != text.charAt(text.length()-1) && !ret.endsWith("-")) {
      // in some cases there is a problem and the closing tag is not added
      // to the encoded text (for instance, with `ü`)
      //
      // but first, sometimes it is just that the original string is too long
      // and things get confused
      if (text.length() >= 2) {
        Logger.debug("Encoding error. Splitting text and trying again.");
        int middle = text.length() / 2;
        ret = encode(text.substring(0, middle)) + encode(text.substring(middle));
      } else {
        Logger.debug("Closing tag missing. Adding.");
        ret = ret + "-";
      }
    }
    return ret;
  }

  public static boolean needsEncoding(final String text) {
    char[] chars = text.toCharArray();
    for (int i = 0; i < chars.length; i++) {
      int cp = Character.codePointAt(chars, i);
      if (cp > 0x7F || cp == '&') {
        // Selenium uses a Unicode PUA to cover certain special characters
        // see https://code.google.com/p/selenium/source/browse/java/client/src/org/openqa/selenium/Keys.java
        // these should juse be passed through as is.
        return !(cp >= 0xE000 && cp <= 0xE040);
      }
    }
    return false;
  }
}