银行卡输入特效 4个加一空格

private static final char kongge = ' ';
private TextWatcher textWatcher=new TextWatcher() {

    //改变之前text长度
 int beforeTextLength = 0;
 //改变之前的文字
 private CharSequence beforeChar;
 //改变之后text长度
 int onTextLength = 0;
 //是否改变空格或光标
 boolean isChanged = false;
 // 记录光标的位置
 int location = 0;
    private char[] tempChar;
    private StringBuffer buffer = new StringBuffer();
 //已有空格数量
 int konggeNumberB = 0;

 @Override
 public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        beforeTextLength = s.length();
        if (buffer.length() > 0) {
            buffer.delete(0, buffer.length());
 }
        konggeNumberB = 0;
        for (int i = 0; i < s.length(); i++) {
            if (s.charAt(i) == ' ') {
                konggeNumberB++;
 }
        }
    }

    @Override
 public void onTextChanged(CharSequence s, int start, int before, int count) {

        onTextLength = s.length();
 buffer.append(s.toString());
        if (onTextLength == beforeTextLength || onTextLength <= 3
 || isChanged) {
            isChanged = false;
            return;
 }
        isChanged = true;

 }

    @Override
 public void afterTextChanged(Editable s) {
        if (isChanged) {
            location = yourCardNumEd.getSelectionEnd();
            int index = 0;
            while (index < buffer.length()) {
                if (buffer.charAt(index) == kongge) {
                    buffer.deleteCharAt(index);
 } else {
                    index++;
 }
            }
            index = 0;
            int konggeNumberC = 0;
            while (index < buffer.length()) {
                if ((index == 4 || index == 9 || index == 14 || index == 19)) {
                    buffer.insert(index, kongge);
 konggeNumberC++;
 }
                index++;
 }
            if (konggeNumberC > konggeNumberB) {
                location += (konggeNumberC - konggeNumberB);
 }
            
            tempChar = new char[buffer.length()];
 buffer.getChars(0, buffer.length(), tempChar, 0);
 String str = buffer.toString();
            if (location > str.length()) {
                location = str.length();
 } else if (location < 0) {
                location = 0;
 }

            yourCardNumEd.setText(str);
 Editable etable = yourCardNumEd.getText();
            if (location>20){
                ToastUtil.ToastShow("最多才能输入20位");
                return;
 }
            
            Selection.setSelection(etable, location);
           
 isChanged = false;
 }
    }

};