package com.fuban.user.utils;

import android.text.InputFilter;
import android.text.Spanned;
import android.text.TextUtils;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * author：Created by ZHT on 2017/12/25 10:38
 * email：526309416@qq.com
 * desc：输入大小限制(整数 /首位不能输入0)
 */
public class IntegerInputFilter implements InputFilter {
    private Pattern mPattern;
    //输入的最大金额
    private static double MAX_VALUE = Integer.MAX_VALUE;

    public IntegerInputFilter(int maxValue) {
        MAX_VALUE = maxValue;
        mPattern = Pattern.compile("([0-9])*");
    }

    /**
     * @param source 新输入的字符串
     * @param start  新输入的字符串起始下标，一般为0
     * @param end    新输入的字符串终点下标，一般为source长度-1
     * @param dest   输入之前文本框内容
     * @param dstart 原内容起始坐标，一般为0
     * @param dend   原内容终点坐标，一般为dest长度-1
     * @return 输入内容
     */

    @Override
    public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
        String sourceText = source.toString();
        String destText = dest.toString().trim();
        //验证删除等按键
        if (TextUtils.isEmpty(sourceText)) {
            return "";
        }

        Matcher matcher = mPattern.matcher(source);
        if (!matcher.matches()) {
            return "";
        }
        if (destText.length() == 0 && sourceText.equals("0")) {
            return "";
        }
        //验证输入金额的大小
        double sumText = Double.parseDouble(destText + sourceText);

        if (MAX_VALUE > 0 && sumText > MAX_VALUE) {
            return dest.subSequence(dstart, dend);
        }
        return dest.subSequence(dstart, dend) + sourceText;
    }
}