Android自定义DigitalClock控件实现商品倒计时

package com.veally.timesale;

import java.util.Calendar;

import android.content.Context;
import android.database.ContentObserver;
import android.os.Handler;
import android.os.SystemClock;
import android.provider.Settings;
import android.util.AttributeSet;
import android.widget.DigitalClock;

/**
 * Custom digital clock
 * @author veally@foxmail.com
 */
public class CustomDigitalClock extends DigitalClock {

 Calendar mCalendar;
 private final static String m12 = "h:mm aa";
 private final static String m24 = "k:mm";
 private FormatChangeObserver mFormatChangeObserver;

 private Runnable mTicker;
 private Handler mHandler;
 private long endTime;
 private ClockListener mClockListener;

 private boolean mTickerStopped = false;

 @SuppressWarnings("unused")
 private String mFormat;

 public CustomDigitalClock(Context context) {
 super(context);
 initClock(context);
 }

 public CustomDigitalClock(Context context, AttributeSet attrs) {
 super(context, attrs);
 initClock(context);
 }

 private void initClock(Context context) {

 if (mCalendar == null) {
 mCalendar = Calendar.getInstance();
 }

 mFormatChangeObserver = new FormatChangeObserver();
 getContext().getContentResolver().registerContentObserver(Settings.System.CONTENT_URI, true, mFormatChangeObserver);

 setFormat();
 }

 @Override
 protected void onAttachedToWindow() {
 mTickerStopped = false;
 super.onAttachedToWindow();
 mHandler = new Handler();

 /**
 * requests a tick on the next hard-second boundary
 */
 mTicker = new Runnable() {
 public void run() {
 if (mTickerStopped)
  return;
 long currentTime = System.currentTimeMillis();
 if (currentTime / 1000 == endTime / 1000 - 5 * 60) {
  mClockListener.remainFiveMinutes();
 }
 long distanceTime = endTime - currentTime;
 distanceTime /= 1000;
 if (distanceTime == 0) {
  setText("00:00:00");
  onDetachedFromWindow();
  mClockListener.timeEnd();
 } else if (distanceTime < 0) {
  setText("00:00:00");
 } else {
  setText(dealTime(distanceTime));
 }
 invalidate();
 long now = SystemClock.uptimeMillis();
 long next = now + (1000 - now % 1000);
 mHandler.postAtTime(mTicker, next);
 }
 };
 mTicker.run();
 }

 /**
 * deal time string
 * 
 * @param time
 * @return
 */
 public static String dealTime(long time) {
 StringBuffer returnString = new StringBuffer();
 long day = time / (24 * 60 * 60);
 long hours = (time % (24 * 60 * 60)) / (60 * 60);
 long minutes = ((time % (24 * 60 * 60)) % (60 * 60)) / 60;
 long second = ((time % (24 * 60 * 60)) % (60 * 60)) % 60;
 String dayStr = String.valueOf(day);
 String hoursStr = timeStrFormat(String.valueOf(hours));
 String minutesStr = timeStrFormat(String.valueOf(minutes));
 String secondStr = timeStrFormat(String.valueOf(second));

 returnString.append(hoursStr).append(":").append(minutesStr).append(":").append(secondStr);
 return returnString.toString();
 }

 /**
 * format time
 * 
 * @param timeStr
 * @return
 */
 private static String timeStrFormat(String timeStr) {
 switch (timeStr.length()) {
 case 1:
 timeStr = "0" + timeStr;
 break;
 }
 return timeStr;
 }

 @Override
 protected void onDetachedFromWindow() {
 super.onDetachedFromWindow();
 mTickerStopped = true;
 }

 /**
 * Clock end time from now on.
 * 
 * @param endTime
 */
 public void setEndTime(long endTime) {
 this.endTime = endTime;
 }

 /**
 * Pulls 12/24 mode from system settings
 */
 private boolean get24HourMode() {
 return android.text.format.DateFormat.is24HourFormat(getContext());
 }

 private void setFormat() {
 if (get24HourMode()) {
 mFormat = m24;
 } else {
 mFormat = m12;
 }
 }

 private class FormatChangeObserver extends ContentObserver {
 public FormatChangeObserver() {
 super(new Handler());
 }

 @Override
 public void onChange(boolean selfChange) {
 setFormat();
 }
 }

 public void setClockListener(ClockListener clockListener) {
 this.mClockListener = clockListener;
 }

 public interface ClockListener{
 void timeEnd();
 void remainFiveMinutes();
 }

}

remainTime.setEndTime(mItems.get(position).getRemainTime());
 remainTime.setClockListener(new CustomDigitalClock.ClockListener() { // register the clock's listener

 @Override
 public void timeEnd() {
 // The clock time is ended.
 }

 @Override
 public void remainFiveMinutes() {
 // The clock time is remain five minutes.
 }
 });