android 自定义TextView实现秒级数字时钟

package com.jinhui.humitureshow.view

import android.content.Context
import android.os.Handler
import android.os.Looper
import android.os.Message
import android.util.AttributeSet
import android.widget.TextView
import com.jinhui.humitureshow.R
import java.util.*

/**
 * Description: 自定义时间显示TextView，时间取决于当前Android设备的时间
 *
 * Creator: Shawn
 * Data&Time: 2019/1/17 & 13:52
 */
class TimeTextView : TextView {

    private val handler: TimeHandler =
        TimeHandler(this)

    constructor(context: Context) : this(context, null)

    constructor(context: Context, set: AttributeSet?) : this(context, set, 0)

    constructor(context: Context, set: AttributeSet?, defStyleAttr: Int) : this(context, set, defStyleAttr, 0)

    constructor(context: Context, set: AttributeSet?, defStyleAttr: Int, defStyleRes: Int) : super(
        context,
        set,
        defStyleAttr,
        defStyleRes
    ) {
        init(context)
    }

    /**
     * 获取当前时间并启动时钟更新线程
     *
     * @param context Context
     */
    private fun init(context: Context) {
        updateClock(context)

        Thread(Runnable { handler.startScheduleUpdate() }).start()
    }

    /**
     * 更新时钟
     */
    private fun updateClock(context: Context) {
        val calendar = Calendar.getInstance(TimeZone.getDefault())
        val year = calendar.get(Calendar.YEAR)
        val month = calendar.get(Calendar.MONTH) + 1
        val day = calendar.get(Calendar.DAY_OF_MONTH)
        val hour = calendar.get(Calendar.HOUR_OF_DAY)
        val minute = calendar.get(Calendar.MINUTE)
        val second = calendar.get(Calendar.SECOND)
        val dayStr = formatInt(day)

        val monthStr = formatInt(month)

        val hourStr = formatInt(hour)

        val minuteStr = formatInt(minute)

        val secondStr = formatInt(second)

        val weekStr = getWeak(calendar)

        this.text = context.getString(R.string.time_example, year, monthStr, dayStr, weekStr, hourStr, minuteStr, secondStr)
    }

    /**
     * 获取当前星期
     * @param calendar Calendar
     * @return String
     */
    private fun getWeak(calendar: Calendar): String {
        val week = calendar.get(Calendar.WEEK_OF_MONTH)
        return when (week) {
            1 -> "日"
            2 -> "一"
            3 -> "二"
            4 -> "三"
            5 -> "四"
            6 -> "五"
            else -> "六"
        }
    }

    /**
     * 格式化 个位数格式
     * @param number Int
     */
    private fun formatInt(number: Int): String {
        return when (number < 10) {
            true -> "0$number"
            else -> "$number"
        }
    }

    companion object {
        private class TimeHandler(private val timeTextView: TimeTextView) : Handler(Looper.getMainLooper()) {

            private var mStopped = false

            fun post() {
                //每隔1秒发送一次消息
                sendMessageDelayed(obtainMessage(0), 1000)
            }

            override fun handleMessage(msg: Message?) {
                super.handleMessage(msg)
                if (!mStopped) {
                    timeTextView.updateClock(timeTextView.context)
                    //实现实时更新
                    post()
                }
            }

            fun startScheduleUpdate() {
                mStopped = false
                post()
            }

//            fun stopScheduleUpdate() {
//                mStopped = true
//            }
        }
    }

}