Android 商品倒计时（DigitalClock实现倒计时 ）

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.
}
});