import android.text.Editable;
import android.text.TextWatcher;
import android.widget.EditText;
/**
 * @author by malei on 2017/12/19.
 * 手機號實時驗證
 */
public class PhoneFormatUtils implements TextWatcher {
    private EditText numberEditText;
/**
     * 字串編輯前長度
     */
int beforeLen = 0;
/**
     * 字串編輯後長度
     */
 
int afterLen = 0;
    public PhoneFormatUtils(EditText numberEditText) {
        this.numberEditText = numberEditText;
numberEditText.addTextChangedListener(this);
beforeString = numberEditText.getText().toString();
}


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


    @Override
public void beforeTextChanged(CharSequence s, int start, int count,
                                  int after) {
        beforeLen = s.length();
}


    private boolean isChange = true;
@Override
public void afterTextChanged(Editable arg0) {
        // TODO Auto-generated method
 
if (!isChange) {
            isChange = true;
            return;
}
        String contents = numberEditText.getText().toString();
afterLen = contents.length();
        if (afterLen == 0)
            return;
//        contents = contents.replace(" ", "");
if (beforeLen > afterLen) {
            contents = subStringFormat(contents);
} else if ((beforeLen < afterLen)) {
            contents = addStringFormat(contents);
}
        if (!isChange) {
            numberEditText.setText(contents);
            if (contents.length() >= 1)
                numberEditText.setSelection(contents.length());
}
    }


    /**
     * 新增字元格式化
     *
     * @param contents
* @return
*/
private String addStringFormat(String contents) {
        // TODO Auto-generated method stub
int length = contents.length();
isChange = false;
        if (length == 1) {
            if (!contents.startsWith("1")) {
                contents = "";
                return contents;
}
            return contents;
}
        if (!contents.startsWith("1")) {
            contents = contents.substring(1);
            return contents;
}
        if (!(contents.startsWith("13") || contents.startsWith("15") || contents
                .startsWith("18"))) {
            if (length > 2) {
                contents = "1" + contents.substring(2);
} else {
                contents = "1";
}
            return contents;
}
        if (length > 11) {
            contents = contents.substring(0, 11);
}
        if (length > 3) {
            contents = contents.substring(0, 3)  + contents.substring(3);
}
        if (length > 7) {
            contents = contents.substring(0, 8) + contents.substring(8);
}
        beforeString = contents;
        return contents;
}


    /**
     * 記錄刪除字元之前字串內容，如若刪除後格式不符進行還原
     */
private String beforeString = "";
/**
     * 刪除字元格式化
     *
     * @param contents
* @return
*/
private String subStringFormat(String contents) {
        // TODO Auto-generated method stub
int length = contents.length();
isChange = false;
        if (length == 0) {
            return contents;
}
        if (length == 1) {
            if (contents.startsWith("1"))
                return contents;
            else
                return beforeString;
}
        if (length >= 2) {
            if (!(contents.startsWith("13") || contents.startsWith("15") || contents
                    .startsWith("18"))) {
                return beforeString;
}
        }
        if (length > 3) {
            contents = contents.substring(0, 3) +  contents.substring(3);
}
        if (length > 7) {
            contents = contents.substring(0, 8) +  contents.substring(8);
}
        beforeString = contents;
        return contents;
}
}