src/java/com/android/internal/telephony/SmsMessageBase.java - platform/frameworks/opt/telephony - Git at Google

 /*
  * 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 com.android.internal.telephony;

 import com.android.internal.telephony.GsmAlphabet.TextEncodingDetails;
 import com.android.internal.telephony.SmsConstants;
 import com.android.internal.telephony.SmsHeader;
 import java.text.BreakIterator;
 import java.util.Arrays;

 import android.provider.Telephony;
 import android.telephony.SmsMessage;
 import android.text.Emoji;

 /**
  * Base class declaring the specific methods and members for SmsMessage.
  * {@hide}
  */
 public abstract class SmsMessageBase {
     /** {@hide} The address of the SMSC. May be null */
     protected String mScAddress;

     /** {@hide} The address of the sender */
     protected SmsAddress mOriginatingAddress;

     /** {@hide} The message body as a string. May be null if the message isn't text */
     protected String mMessageBody;

     /** {@hide} */
     protected String mPseudoSubject;

     /** {@hide} Non-null if this is an email gateway message */
     protected String mEmailFrom;

     /** {@hide} Non-null if this is an email gateway message */
     protected String mEmailBody;

     /** {@hide} */
     protected boolean mIsEmail;

     /** {@hide} */
     protected long mScTimeMillis;

     /** {@hide} The raw PDU of the message */
     protected byte[] mPdu;

     /** {@hide} The raw bytes for the user data section of the message */
     protected byte[] mUserData;

     /** {@hide} */
     protected SmsHeader mUserDataHeader;

     // "Message Waiting Indication Group"
     // 23.038 Section 4
     /** {@hide} */
     protected boolean mIsMwi;

     /** {@hide} */
     protected boolean mMwiSense;

     /** {@hide} */
     protected boolean mMwiDontStore;

     /**
      * Indicates status for messages stored on the ICC.
      */
     protected int mStatusOnIcc = -1;

     /**
      * Record index of message in the EF.
      */
     protected int mIndexOnIcc = -1;

     /** TP-Message-Reference - Message Reference of sent message. @hide */
     public int mMessageRef;

     // TODO(): This class is duplicated in SmsMessage.java. Refactor accordingly.
     public static abstract class SubmitPduBase  {
         public byte[] encodedScAddress; // Null if not applicable.
         public byte[] encodedMessage;

         @Override
         public String toString() {
             return "SubmitPdu: encodedScAddress = "
                     + Arrays.toString(encodedScAddress)
                     + ", encodedMessage = "
                     + Arrays.toString(encodedMessage);
         }
     }

     /**
      * Returns the address of the SMS service center that relayed this message
      * or null if there is none.
      */
     public String getServiceCenterAddress() {
         return mScAddress;
     }

     /**
      * Returns the originating address (sender) of this SMS message in String
      * form or null if unavailable
      */
     public String getOriginatingAddress() {
         if (mOriginatingAddress == null) {
             return null;
         }

         return mOriginatingAddress.getAddressString();
     }

     /**
      * Returns the originating address, or email from address if this message
      * was from an email gateway. Returns null if originating address
      * unavailable.
      */
     public String getDisplayOriginatingAddress() {
         if (mIsEmail) {
             return mEmailFrom;
         } else {
             return getOriginatingAddress();
         }
     }

     /**
      * Returns the message body as a String, if it exists and is text based.
      * @return message body is there is one, otherwise null
      */
     public String getMessageBody() {
         return mMessageBody;
     }

     /**
      * Returns the class of this message.
      */
     public abstract SmsConstants.MessageClass getMessageClass();

     /**
      * Returns the message body, or email message body if this message was from
      * an email gateway. Returns null if message body unavailable.
      */
     public String getDisplayMessageBody() {
         if (mIsEmail) {
             return mEmailBody;
         } else {
             return getMessageBody();
         }
     }

     /**
      * Unofficial convention of a subject line enclosed in parens empty string
      * if not present
      */
     public String getPseudoSubject() {
         return mPseudoSubject == null ? "" : mPseudoSubject;
     }

     /**
      * Returns the service centre timestamp in currentTimeMillis() format
      */
     public long getTimestampMillis() {
         return mScTimeMillis;
     }

     /**
      * Returns true if message is an email.
      *
      * @return true if this message came through an email gateway and email
      *         sender / subject / parsed body are available
      */
     public boolean isEmail() {
         return mIsEmail;
     }

     /**
      * @return if isEmail() is true, body of the email sent through the gateway.
      *         null otherwise
      */
     public String getEmailBody() {
         return mEmailBody;
     }

     /**
      * @return if isEmail() is true, email from address of email sent through
      *         the gateway. null otherwise
      */
     public String getEmailFrom() {
         return mEmailFrom;
     }

     /**
      * Get protocol identifier.
      */
     public abstract int getProtocolIdentifier();

     /**
      * See TS 23.040 9.2.3.9 returns true if this is a "replace short message"
      * SMS
      */
     public abstract boolean isReplace();

     /**
      * Returns true for CPHS MWI toggle message.
      *
      * @return true if this is a CPHS MWI toggle message See CPHS 4.2 section
      *         B.4.2
      */
     public abstract boolean isCphsMwiMessage();

     /**
      * returns true if this message is a CPHS voicemail / message waiting
      * indicator (MWI) clear message
      */
     public abstract boolean isMWIClearMessage();

     /**
      * returns true if this message is a CPHS voicemail / message waiting
      * indicator (MWI) set message
      */
     public abstract boolean isMWISetMessage();

     /**
      * returns true if this message is a "Message Waiting Indication Group:
      * Discard Message" notification and should not be stored.
      */
     public abstract boolean isMwiDontStore();

     /**
      * returns the user data section minus the user data header if one was
      * present.
      */
     public byte[] getUserData() {
         return mUserData;
     }

     /**
      * Returns an object representing the user data header
      *
      * {@hide}
      */
     public SmsHeader getUserDataHeader() {
         return mUserDataHeader;
     }

     /**
      * TODO(cleanup): The term PDU is used in a seemingly non-unique
      * manner -- for example, what is the difference between this byte
      * array and the contents of SubmitPdu objects.  Maybe a more
      * illustrative term would be appropriate.
      */

     /**
      * Returns the raw PDU for the message.
      */
     public byte[] getPdu() {
         return mPdu;
     }

     /**
      * For an SMS-STATUS-REPORT message, this returns the status field from
      * the status report.  This field indicates the status of a previously
      * submitted SMS, if requested.  See TS 23.040, 9.2.3.15 TP-Status for a
      * description of values.
      *
      * @return 0 indicates the previously sent message was received.
      *         See TS 23.040, 9.9.2.3.15 for a description of other possible
      *         values.
      */
     public abstract int getStatus();

     /**
      * Return true iff the message is a SMS-STATUS-REPORT message.
      */
     public abstract boolean isStatusReportMessage();

     /**
      * Returns true iff the <code>TP-Reply-Path</code> bit is set in
      * this message.
      */
     public abstract boolean isReplyPathPresent();

     /**
      * Returns the status of the message on the ICC (read, unread, sent, unsent).
      *
      * @return the status of the message on the ICC.  These are:
      *         SmsManager.STATUS_ON_ICC_FREE
      *         SmsManager.STATUS_ON_ICC_READ
      *         SmsManager.STATUS_ON_ICC_UNREAD
      *         SmsManager.STATUS_ON_ICC_SEND
      *         SmsManager.STATUS_ON_ICC_UNSENT
      */
     public int getStatusOnIcc() {
         return mStatusOnIcc;
     }

     /**
      * Returns the record index of the message on the ICC (1-based index).
      * @return the record index of the message on the ICC, or -1 if this
      *         SmsMessage was not created from a ICC SMS EF record.
      */
     public int getIndexOnIcc() {
         return mIndexOnIcc;
     }

     protected void parseMessageBody() {
         // originatingAddress could be null if this message is from a status
         // report.
         if (mOriginatingAddress != null && mOriginatingAddress.couldBeEmailGateway()) {
             extractEmailAddressFromMessageBody();
         }
     }

     /**
      * Try to parse this message as an email gateway message
      * There are two ways specified in TS 23.040 Section 3.8 :
      *  - SMS message "may have its TP-PID set for Internet electronic mail - MT
      * SMS format: [<from-address><space>]<message> - "Depending on the
      * nature of the gateway, the destination/origination address is either
      * derived from the content of the SMS TP-OA or TP-DA field, or the
      * TP-OA/TP-DA field contains a generic gateway address and the to/from
      * address is added at the beginning as shown above." (which is supported here)
      * - Multiple addresses separated by commas, no spaces, Subject field delimited
      * by '()' or '##' and '#' Section 9.2.3.24.11 (which are NOT supported here)
      */
     protected void extractEmailAddressFromMessageBody() {

         /* Some carriers may use " /" delimiter as below
          *
          * 1. [x@y][ ]/[subject][ ]/[body]
          * -or-
          * 2. [x@y][ ]/[body]
          */
          String[] parts = mMessageBody.split("( /)|( )", 2);
          if (parts.length < 2) return;
          mEmailFrom = parts[0];
          mEmailBody = parts[1];
          mIsEmail = Telephony.Mms.isEmailAddress(mEmailFrom);
     }

     /**
      * Find the next position to start a new fragment of a multipart SMS.
      *
      * @param currentPosition current start position of the fragment
      * @param byteLimit maximum number of bytes in the fragment
      * @param msgBody text of the SMS in UTF-16 encoding
      * @return the position to start the next fragment
      */
     public static int findNextUnicodePosition(
             int currentPosition, int byteLimit, CharSequence msgBody) {
         int nextPos = Math.min(currentPosition + byteLimit / 2, msgBody.length());
         // Check whether the fragment ends in a character boundary. Some characters take 4-bytes
         // in UTF-16 encoding. Many carriers cannot handle
         // a fragment correctly if it does not end at a character boundary.
         if (nextPos < msgBody.length()) {
             BreakIterator breakIterator = BreakIterator.getCharacterInstance();
             breakIterator.setText(msgBody.toString());
             if (!breakIterator.isBoundary(nextPos)) {
                 int breakPos = breakIterator.preceding(nextPos);
                 while (breakPos + 4 <= nextPos
                         && Emoji.isRegionalIndicatorSymbol(
                             Character.codePointAt(msgBody, breakPos))
                         && Emoji.isRegionalIndicatorSymbol(
                             Character.codePointAt(msgBody, breakPos + 2))) {
                     // skip forward over flags (pairs of Regional Indicator Symbol)
                     breakPos += 4;
                 }
                 if (breakPos > currentPosition) {
                     nextPos = breakPos;
                 } else if (Character.isHighSurrogate(msgBody.charAt(nextPos - 1))) {
                     // no character boundary in this fragment, try to at least land on a code point
                     nextPos -= 1;
                 }
             }
         }
         return nextPos;
     }

     /**
      * Calculate the TextEncodingDetails of a message encoded in Unicode.
      */
     public static TextEncodingDetails calcUnicodeEncodingDetails(CharSequence msgBody) {
         TextEncodingDetails ted = new TextEncodingDetails();
         int octets = msgBody.length() * 2;
         ted.codeUnitSize = SmsConstants.ENCODING_16BIT;
         ted.codeUnitCount = msgBody.length();
         if (octets > SmsConstants.MAX_USER_DATA_BYTES) {
             // If EMS is not supported, break down EMS into single segment SMS
             // and add page info " x/y".
             // In the case of UCS2 encoding type, we need 8 bytes for this
             // but we only have 6 bytes from UDH, so truncate the limit for
             // each segment by 2 bytes (1 char).
             int maxUserDataBytesWithHeader = SmsConstants.MAX_USER_DATA_BYTES_WITH_HEADER;
             if (!SmsMessage.hasEmsSupport()) {
                 // make sure total number of segments is less than 10
                 if (octets <= 9 * (maxUserDataBytesWithHeader - 2)) {
                     maxUserDataBytesWithHeader -= 2;
                 }
             }

             int pos = 0;  // Index in code units.
             int msgCount = 0;
             while (pos < msgBody.length()) {
                 int nextPos = findNextUnicodePosition(pos, maxUserDataBytesWithHeader,
                         msgBody);
                 if (nextPos == msgBody.length()) {
                     ted.codeUnitsRemaining = pos + maxUserDataBytesWithHeader / 2 -
                             msgBody.length();
                 }
                 pos = nextPos;
                 msgCount++;
             }
             ted.msgCount = msgCount;
         } else {
             ted.msgCount = 1;
             ted.codeUnitsRemaining = (SmsConstants.MAX_USER_DATA_BYTES - octets) / 2;
         }

         return ted;
     }
 }
	/*
	* 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 com.android.internal.telephony;

	import com.android.internal.telephony.GsmAlphabet.TextEncodingDetails;
	import com.android.internal.telephony.SmsConstants;
	import com.android.internal.telephony.SmsHeader;
	import java.text.BreakIterator;
	import java.util.Arrays;

	import android.provider.Telephony;
	import android.telephony.SmsMessage;
	import android.text.Emoji;

	/**
	* Base class declaring the specific methods and members for SmsMessage.
	* {@hide}
	*/
	public abstract class SmsMessageBase {
	/** {@hide} The address of the SMSC. May be null */
	protected String mScAddress;

	/** {@hide} The address of the sender */
	protected SmsAddress mOriginatingAddress;

	/** {@hide} The message body as a string. May be null if the message isn't text */
	protected String mMessageBody;

	/** {@hide} */
	protected String mPseudoSubject;

	/** {@hide} Non-null if this is an email gateway message */
	protected String mEmailFrom;

	/** {@hide} Non-null if this is an email gateway message */
	protected String mEmailBody;

	/** {@hide} */
	protected boolean mIsEmail;

	/** {@hide} */
	protected long mScTimeMillis;

	/** {@hide} The raw PDU of the message */
	protected byte[] mPdu;

	/** {@hide} The raw bytes for the user data section of the message */
	protected byte[] mUserData;

	/** {@hide} */
	protected SmsHeader mUserDataHeader;

	// "Message Waiting Indication Group"
	// 23.038 Section 4
	/** {@hide} */
	protected boolean mIsMwi;

	/** {@hide} */
	protected boolean mMwiSense;

	/** {@hide} */
	protected boolean mMwiDontStore;

	/**
	* Indicates status for messages stored on the ICC.
	*/
	protected int mStatusOnIcc = -1;

	/**
	* Record index of message in the EF.
	*/
	protected int mIndexOnIcc = -1;

	/** TP-Message-Reference - Message Reference of sent message. @hide */
	public int mMessageRef;

	// TODO(): This class is duplicated in SmsMessage.java. Refactor accordingly.
	public static abstract class SubmitPduBase {
	public byte[] encodedScAddress; // Null if not applicable.
	public byte[] encodedMessage;

	@Override
	public String toString() {
	return "SubmitPdu: encodedScAddress = "
	+ Arrays.toString(encodedScAddress)
	+ ", encodedMessage = "
	+ Arrays.toString(encodedMessage);
	}
	}

	/**
	* Returns the address of the SMS service center that relayed this message
	* or null if there is none.
	*/
	public String getServiceCenterAddress() {
	return mScAddress;
	}

	/**
	* Returns the originating address (sender) of this SMS message in String
	* form or null if unavailable
	*/
	public String getOriginatingAddress() {
	if (mOriginatingAddress == null) {
	return null;
	}

	return mOriginatingAddress.getAddressString();
	}

	/**
	* Returns the originating address, or email from address if this message
	* was from an email gateway. Returns null if originating address
	* unavailable.
	*/
	public String getDisplayOriginatingAddress() {
	if (mIsEmail) {
	return mEmailFrom;
	} else {
	return getOriginatingAddress();
	}
	}

	/**
	* Returns the message body as a String, if it exists and is text based.
	* @return message body is there is one, otherwise null
	*/
	public String getMessageBody() {
	return mMessageBody;
	}

	/**
	* Returns the class of this message.
	*/
	public abstract SmsConstants.MessageClass getMessageClass();

	/**
	* Returns the message body, or email message body if this message was from
	* an email gateway. Returns null if message body unavailable.
	*/
	public String getDisplayMessageBody() {
	if (mIsEmail) {
	return mEmailBody;
	} else {
	return getMessageBody();
	}
	}

	/**
	* Unofficial convention of a subject line enclosed in parens empty string
	* if not present
	*/
	public String getPseudoSubject() {
	return mPseudoSubject == null ? "" : mPseudoSubject;
	}

	/**
	* Returns the service centre timestamp in currentTimeMillis() format
	*/
	public long getTimestampMillis() {
	return mScTimeMillis;
	}

	/**
	* Returns true if message is an email.
	*
	* @return true if this message came through an email gateway and email
	* sender / subject / parsed body are available
	*/
	public boolean isEmail() {
	return mIsEmail;
	}

	/**
	* @return if isEmail() is true, body of the email sent through the gateway.
	* null otherwise
	*/
	public String getEmailBody() {
	return mEmailBody;
	}

	/**
	* @return if isEmail() is true, email from address of email sent through
	* the gateway. null otherwise
	*/
	public String getEmailFrom() {
	return mEmailFrom;
	}

	/**
	* Get protocol identifier.
	*/
	public abstract int getProtocolIdentifier();

	/**
	* See TS 23.040 9.2.3.9 returns true if this is a "replace short message"
	* SMS
	*/
	public abstract boolean isReplace();

	/**
	* Returns true for CPHS MWI toggle message.
	*
	* @return true if this is a CPHS MWI toggle message See CPHS 4.2 section
	* B.4.2
	*/
	public abstract boolean isCphsMwiMessage();

	/**
	* returns true if this message is a CPHS voicemail / message waiting
	* indicator (MWI) clear message
	*/
	public abstract boolean isMWIClearMessage();

	/**
	* returns true if this message is a CPHS voicemail / message waiting
	* indicator (MWI) set message
	*/
	public abstract boolean isMWISetMessage();

	/**
	* returns true if this message is a "Message Waiting Indication Group:
	* Discard Message" notification and should not be stored.
	*/
	public abstract boolean isMwiDontStore();

	/**
	* returns the user data section minus the user data header if one was
	* present.
	*/
	public byte[] getUserData() {
	return mUserData;
	}

	/**
	* Returns an object representing the user data header
	*
	* {@hide}
	*/
	public SmsHeader getUserDataHeader() {
	return mUserDataHeader;
	}

	/**
	* TODO(cleanup): The term PDU is used in a seemingly non-unique
	* manner -- for example, what is the difference between this byte
	* array and the contents of SubmitPdu objects. Maybe a more
	* illustrative term would be appropriate.
	*/

	/**
	* Returns the raw PDU for the message.
	*/
	public byte[] getPdu() {
	return mPdu;
	}

	/**
	* For an SMS-STATUS-REPORT message, this returns the status field from
	* the status report. This field indicates the status of a previously
	* submitted SMS, if requested. See TS 23.040, 9.2.3.15 TP-Status for a
	* description of values.
	*
	* @return 0 indicates the previously sent message was received.
	* See TS 23.040, 9.9.2.3.15 for a description of other possible
	* values.
	*/
	public abstract int getStatus();

	/**
	* Return true iff the message is a SMS-STATUS-REPORT message.
	*/
	public abstract boolean isStatusReportMessage();

	/**
	* Returns true iff the <code>TP-Reply-Path</code> bit is set in
	* this message.
	*/
	public abstract boolean isReplyPathPresent();

	/**
	* Returns the status of the message on the ICC (read, unread, sent, unsent).
	*
	* @return the status of the message on the ICC. These are:
	* SmsManager.STATUS_ON_ICC_FREE
	* SmsManager.STATUS_ON_ICC_READ
	* SmsManager.STATUS_ON_ICC_UNREAD
	* SmsManager.STATUS_ON_ICC_SEND
	* SmsManager.STATUS_ON_ICC_UNSENT
	*/
	public int getStatusOnIcc() {
	return mStatusOnIcc;
	}

	/**
	* Returns the record index of the message on the ICC (1-based index).
	* @return the record index of the message on the ICC, or -1 if this
	* SmsMessage was not created from a ICC SMS EF record.
	*/
	public int getIndexOnIcc() {
	return mIndexOnIcc;
	}

	protected void parseMessageBody() {
	// originatingAddress could be null if this message is from a status
	// report.
	if (mOriginatingAddress != null && mOriginatingAddress.couldBeEmailGateway()) {
	extractEmailAddressFromMessageBody();
	}
	}

	/**
	* Try to parse this message as an email gateway message
	* There are two ways specified in TS 23.040 Section 3.8 :
	* - SMS message "may have its TP-PID set for Internet electronic mail - MT
	* SMS format: [<from-address><space>]<message> - "Depending on the
	* nature of the gateway, the destination/origination address is either
	* derived from the content of the SMS TP-OA or TP-DA field, or the
	* TP-OA/TP-DA field contains a generic gateway address and the to/from
	* address is added at the beginning as shown above." (which is supported here)
	* - Multiple addresses separated by commas, no spaces, Subject field delimited
	* by '()' or '##' and '#' Section 9.2.3.24.11 (which are NOT supported here)
	*/
	protected void extractEmailAddressFromMessageBody() {

	/* Some carriers may use " /" delimiter as below
	*
	* 1. [x@y][ ]/[subject][ ]/[body]
	* -or-
	* 2. [x@y][ ]/[body]
	*/
	String[] parts = mMessageBody.split("( /)\|( )", 2);
	if (parts.length < 2) return;
	mEmailFrom = parts[0];
	mEmailBody = parts[1];
	mIsEmail = Telephony.Mms.isEmailAddress(mEmailFrom);
	}

	/**
	* Find the next position to start a new fragment of a multipart SMS.
	*
	* @param currentPosition current start position of the fragment
	* @param byteLimit maximum number of bytes in the fragment
	* @param msgBody text of the SMS in UTF-16 encoding
	* @return the position to start the next fragment
	*/
	public static int findNextUnicodePosition(
	int currentPosition, int byteLimit, CharSequence msgBody) {
	int nextPos = Math.min(currentPosition + byteLimit / 2, msgBody.length());
	// Check whether the fragment ends in a character boundary. Some characters take 4-bytes
	// in UTF-16 encoding. Many carriers cannot handle
	// a fragment correctly if it does not end at a character boundary.
	if (nextPos < msgBody.length()) {
	BreakIterator breakIterator = BreakIterator.getCharacterInstance();
	breakIterator.setText(msgBody.toString());
	if (!breakIterator.isBoundary(nextPos)) {
	int breakPos = breakIterator.preceding(nextPos);
	while (breakPos + 4 <= nextPos
	&& Emoji.isRegionalIndicatorSymbol(
	Character.codePointAt(msgBody, breakPos))
	&& Emoji.isRegionalIndicatorSymbol(
	Character.codePointAt(msgBody, breakPos + 2))) {
	// skip forward over flags (pairs of Regional Indicator Symbol)
	breakPos += 4;
	}
	if (breakPos > currentPosition) {
	nextPos = breakPos;
	} else if (Character.isHighSurrogate(msgBody.charAt(nextPos - 1))) {
	// no character boundary in this fragment, try to at least land on a code point
	nextPos -= 1;
	}
	}
	}
	return nextPos;
	}

	/**
	* Calculate the TextEncodingDetails of a message encoded in Unicode.
	*/
	public static TextEncodingDetails calcUnicodeEncodingDetails(CharSequence msgBody) {
	TextEncodingDetails ted = new TextEncodingDetails();
	int octets = msgBody.length() * 2;
	ted.codeUnitSize = SmsConstants.ENCODING_16BIT;
	ted.codeUnitCount = msgBody.length();
	if (octets > SmsConstants.MAX_USER_DATA_BYTES) {
	// If EMS is not supported, break down EMS into single segment SMS
	// and add page info " x/y".
	// In the case of UCS2 encoding type, we need 8 bytes for this
	// but we only have 6 bytes from UDH, so truncate the limit for
	// each segment by 2 bytes (1 char).
	int maxUserDataBytesWithHeader = SmsConstants.MAX_USER_DATA_BYTES_WITH_HEADER;
	if (!SmsMessage.hasEmsSupport()) {
	// make sure total number of segments is less than 10
	if (octets <= 9 * (maxUserDataBytesWithHeader - 2)) {
	maxUserDataBytesWithHeader -= 2;
	}
	}

	int pos = 0; // Index in code units.
	int msgCount = 0;
	while (pos < msgBody.length()) {
	int nextPos = findNextUnicodePosition(pos, maxUserDataBytesWithHeader,
	msgBody);
	if (nextPos == msgBody.length()) {
	ted.codeUnitsRemaining = pos + maxUserDataBytesWithHeader / 2 -
	msgBody.length();
	}
	pos = nextPos;
	msgCount++;
	}
	ted.msgCount = msgCount;
	} else {
	ted.msgCount = 1;
	ted.codeUnitsRemaining = (SmsConstants.MAX_USER_DATA_BYTES - octets) / 2;
	}

	return ted;
	}
	}