private static int sSmsToMmsTextThreshold = 6; // 4

vendor/mediatek/proprietary/packages/apps/Mms/res/layout/compose_message_activity.xml

vendor/mediatek/proprietary/packages/apps/Mms/src/com/android/mms/ui/ComposeMessageActivity.java private EnhanceEditText mTextEditor;      // Text editor to type your message into //消息輸入框  private TextView mTextCounter;     // Shows the number of characters used in text editor //剩余字數顯示  private TextView mSendButtonMms;    // Press to send mms //彩信發送按鈕，TextView中加入圖片  private ImageButton mSendButtonSms;   // Press to send sms //短信發送按鈕  private void updateCounter(CharSequence text, int start, int before, int count) {    ...    int[] params = null;    int encodingType = SmsMessage.ENCODING_UNKNOWN;    encodingType = mOpComposeExt.getSmsEncodingType(encodingType, ComposeMessageActivity.this);    params = SmsMessage.calculateLength(text, false, encodingType);      /* SmsMessage.calculateLength returns an int[4] with:       *  int[0] being the number of SMS's required,       *  int[1] the number of code units used,       *  int[2] is the number of code units remaining until the next message.       *  int[3] is the encoding type that should be used for the message.       */    final int msgCount = params[0]; //已輸入短信條數    final int remainingInCurrentMessage = params[2]; //剩余字數    mWorkingMessage.setLengthRequiresMms(      msgCount >= MmsConfig.getSmsToMmsTextThreshold(), true); //轉為彩信的短信條數    MmsLog.d(TAG, "updateCounter(): message msgCount = " + msgCount        + " TextThreshold() = " + MmsConfig.getSmsToMmsTextThreshold()        + " remainingInCurrentMessage = " + remainingInCurrentMessage);    /// M: Show the counter    /// M: Update the remaining characters and number of messages required.    if (msgCount >= MmsConfig.getSmsToMmsTextThreshold()) {      mTextCounter.setVisibility(View.GONE);      return;    }    mUiHandler.postDelayed(new Runnable() {      @Override      public void run() {        if (mOpComposeExt.updateCounterUiRun(mTextEditor, remainingInCurrentMessage,            msgCount, mWorkingMessage)) {          return;        }        MmsLog.d(TAG, "updateCounter requiresMms = " + mWorkingMessage.requiresMms()            + " line count = " + mTextEditor.getLineCount());        if (mWorkingMessage.requiresMms() || mTextEditor.getLineCount() <= 1) {          mTextCounter.setVisibility(View.GONE);          return;        }        mTextCounter.setVisibility(View.VISIBLE);        String counterText = remainingInCurrentMessage + "/" + msgCount;        mTextCounter.setText(counterText);      }    }, 100);//顯示短信發送按鈕或彩信發送按鈕  private View showSmsOrMmsSendButton(boolean isMms) {    View showButton = null;    View hideButton = null;    // add for ipmessage    if (isMms) {      if (mSubCount == 0 || (isRecipientsEditorVisible()          && TextUtils.isEmpty(mRecipientsEditor.getText()))          /// M: fix bug ALPS00563318, show gray mms_send_button        /// when haven't subject, text and attachment        || ((mSubjectTextEditor == null || (mSubjectTextEditor != null            && TextUtils.isEmpty(mSubjectTextEditor.getText().toString().trim())))            && mTextEditor != null            && TextUtils.isEmpty(mTextEditor.getText().toString().trim())            && !mWorkingMessage.hasAttachment())            || !mIsSmsEnabled) {      mSendButtonMms.setCompoundDrawablesWithIntrinsicBounds(null, null, null,        getResources().getDrawable(R.drawable.ic_send_sms_unsend));    } else {      mSendButtonMms.setCompoundDrawablesWithIntrinsicBounds(null, null, null,          getResources().getDrawable(R.drawable.ic_send_ipmsg));      }      showButton = mSendButtonMms;      hideButton = mSendButtonSms;    } else {      if (!mIpCompose.onIpShowSmsOrMmsSendButton(isMms)) {        if ((mTextEditor.getText().toString().isEmpty())            || mSubCount == 0            || (isRecipientsEditorVisible()                && TextUtils.isEmpty(mRecipientsEditor.getText()))            || recipientCount() > MmsConfig.getSmsRecipientLimit()            || !mIsSmsEnabled) {          ///@}          mSendButtonSms.setImageResource(R.drawable.ic_send_sms_unsend);        } else {          mSendButtonSms.setImageResource(R.drawable.ic_send_ipmsg);        }      }      showButton = mSendButtonSms;      hideButton = mSendButtonMms;    }    if (showButton != null) {      showButton.setVisibility(View.VISIBLE);    }    if (hideButton != null) {      hideButton.setVisibility(View.GONE);    }    updateTextEditorHint();    return showButton;  }