AndroidでCountDownTimerを一時停止して、アクティビティが前面にない場合
10からカウントダウンするCountDownTimerを使用するアクティビティがあります。ユーザーが電話や何かを受け取った場合など、アクティビティがフォーカスされなくなったときにタイマーを一時停止し、ユーザーがアクティビティ？これは可能ですか？
OnTickハンドラーに何かを追加して、クラスのタイマーの進行状況を保存します（残りのミリ秒数）。
アクティビティのonPause（）メソッドで、タイマーのcancel（）を呼び出します。
アクティビティのonResume（）メソッドで、保存されたミリ秒数を残して新しいタイマーを作成します。
pause()を使用してタイマーを一時停止し、後でstart()を呼び出してcountDownTimerを開始または再開できます。
/**
* This class uses the native CountDownTimer to
* create a timer which could be paused and then
* started again from the previous point. You can
* provide implementation for onTick() and onFinish()
* then use it in your projects.
*/
public abstract class CountDownTimerPausable {
long millisInFuture = 0;
long countDownInterval = 0;
long millisRemaining = 0;
CountDownTimer countDownTimer = null;
boolean isPaused = true;
public CountDownTimerPausable(long millisInFuture, long countDownInterval) {
super();
this.millisInFuture = millisInFuture;
this.countDownInterval = countDownInterval;
this.millisRemaining = this.millisInFuture;
}
private void createCountDownTimer(){
countDownTimer = new CountDownTimer(millisRemaining,countDownInterval) {
@Override
public void onTick(long millisUntilFinished) {
millisRemaining = millisUntilFinished;
CountDownTimerPausable.this.onTick(millisUntilFinished);
}
@Override
public void onFinish() {
CountDownTimerPausable.this.onFinish();
}
};
}
/**
* Callback fired on regular interval.
*
* @param millisUntilFinished The amount of time until finished.
*/
public abstract void onTick(long millisUntilFinished);
/**
* Callback fired when the time is up.
*/
public abstract void onFinish();
/**
* Cancel the countdown.
*/
public final void cancel(){
if(countDownTimer!=null){
countDownTimer.cancel();
}
this.millisRemaining = 0;
}
/**
* Start or Resume the countdown.
* @return CountDownTimerPausable current instance
*/
public synchronized final CountDownTimerPausable start(){
if(isPaused){
createCountDownTimer();
countDownTimer.start();
isPaused = false;
}
return this;
}
/**
* Pauses the CountDownTimerPausable, so it could be resumed(start)
* later from the same point where it was paused.
*/
public void pause()throws IllegalStateException{
if(isPaused==false){
countDownTimer.cancel();
} else{
throw new IllegalStateException("CountDownTimerPausable is already in pause state, start counter before pausing it.");
}
isPaused = true;
}
public boolean isPaused() {
return isPaused;
}
}
新しいTimerを作成する必要はありません。millisUntilFinished= totalを設定するだけです。例えば
private CountDownTimer cdTimer;
private long total = 30000;
...
toggleButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View view){
if(toggleButton.isChecked()) {
startCountDownTimer();
}else{
cdTimer.cancel();
}
}
});
...
private void startCountDownTimer() {
cdTimer = new CountDownTimer(total, 1000) {
public void onTick(long millisUntilFinished) {
//update total with the remaining time left
total = millisUntilFinished;
nTimeLabel.setText("seconds remaining: " + millisUntilFinished/ 1000);
}
public void onFinish() {
nTimeLabel.setText("done!");
}
}.start();
}
砂時計 を使用してみることができます
_Hourglass hourglass = new Hourglass(50000, 1000) {
@Override
public void onTimerTick(long timeRemaining) {
// Update UI
Toast.show(MainActivity.this, String.valueOf(timeRemaining), Toast.LENGTH_SHORT).show();
}
@Override
public void onTimerFinish() {
// Timer finished
Toast.show(MainActivity.this, "Timer finished", Toast.LENGTH_SHORT).show();
}
};
_タイマーを開始するには、hourglass.startTimer();を使用します。
タイマーを一時停止および再開できるヘルパーメソッドがあります。
_hourglass.pauseTimer();
_そして
_hourglass.resumeTimer();
_これはまさにあなたが探しているものでなければなりません。ソースは this Gist。
package alt.Android.os;
import Android.os.Handler;
import Android.os.SystemClock;
import Android.os.Message;
public abstract class CountDownTimer {
/**
* Millis since Epoch when alarm should stop.
*/
private final long mMillisInFuture;
/**
* The interval in millis that the user receives callbacks
*/
private final long mCountdownInterval;
private long mStopTimeInFuture;
private long mPauseTime;
private boolean mCancelled = false;
private boolean mPaused = false;
/**
* @param millisInFuture The number of millis in the future from the call
* to {@link #start()} until the countdown is done and {@link #onFinish()}
* is called.
* @param countDownInterval The interval along the way to receive
* {@link #onTick(long)} callbacks.
*/
public CountDownTimer(long millisInFuture, long countDownInterval) {
mMillisInFuture = millisInFuture;
mCountdownInterval = countDownInterval;
}
/**
* Cancel the countdown.
*
* Do not call it from inside CountDownTimer threads
*/
public final void cancel() {
mHandler.removeMessages(MSG);
mCancelled = true;
}
/**
* Start the countdown.
*/
public synchronized final CountDownTimer start() {
if (mMillisInFuture <= 0) {
onFinish();
return this;
}
mStopTimeInFuture = SystemClock.elapsedRealtime() + mMillisInFuture;
mHandler.sendMessage(mHandler.obtainMessage(MSG));
mCancelled = false;
mPaused = false;
return this;
}
/**
* Pause the countdown.
*/
public long pause() {
mPauseTime = mStopTimeInFuture - SystemClock.elapsedRealtime();
mPaused = true;
return mPauseTime;
}
/**
* Resume the countdown.
*/
public long resume() {
mStopTimeInFuture = mPauseTime + SystemClock.elapsedRealtime();
mPaused = false;
mHandler.sendMessage(mHandler.obtainMessage(MSG));
return mPauseTime;
}
/**
* Callback fired on regular interval.
* @param millisUntilFinished The amount of time until finished.
*/
public abstract void onTick(long millisUntilFinished);
/**
* Callback fired when the time is up.
*/
public abstract void onFinish();
private static final int MSG = 1;
// handles counting down
private Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
synchronized (CountDownTimer.this) {
if (!mPaused) {
final long millisLeft = mStopTimeInFuture - SystemClock.elapsedRealtime();
if (millisLeft <= 0) {
onFinish();
} else if (millisLeft < mCountdownInterval) {
// no tick, just delay until done
sendMessageDelayed(obtainMessage(MSG), millisLeft);
} else {
long lastTickStart = SystemClock.elapsedRealtime();
onTick(millisLeft);
// take into account user's onTick taking time to execute
long delay = lastTickStart + mCountdownInterval - SystemClock.elapsedRealtime();
// special case: user's onTick took more than interval to
// complete, skip to next interval
while (delay < 0) delay += mCountdownInterval;
if (!mCancelled) {
sendMessageDelayed(obtainMessage(MSG), delay);
}
}
}
}
}
};
}
これが以下のコードです。正常に動作するアクティビティで使用してください。
public class MainActivity extends AppCompatActivity {
TextView textview;
final static long INTERVAL = 1000;
final static long TIMEOUT = 11000;
static long millisecondsleft;
boolean isPause =false;
CountDownTimer countDownTimer;
CountDownTimer countDownTimeronResume;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textview=findViewById(R.id.textviewcheck);
}
@Override
protected void onResume() {
super.onResume();
if(isPause == false) {
countDownTimer = new CountDownTimer(TIMEOUT, INTERVAL) {
@Override
public void onTick(long millisUntilFinished) {
millisecondsleft = millisUntilFinished;
textview.setText(":" + String.format("%02d", millisUntilFinished / 1000));
}
@Override
public void onFinish() {
textview.setText("DONE!");
}
}.start();
} else{
countDownTimeronResume = new CountDownTimer(millisecondsleft, INTERVAL) {
@Override
public void onTick(long millisUntilFinished) {
Toast.makeText(MainActivity.this, "ONPAUSED", Toast.LENGTH_SHORT).show();
millisecondsleft = millisUntilFinished;
textview.setText(":" + String.format("%02d", millisUntilFinished / 1000));
}
@Override
public void onFinish() {
textview.setText("DONE!");
}
}.start();
}
}
@Override
protected void onPause() {
super.onPause();
if(countDownTimer!=null){
countDownTimer.cancel();
isPause = true;
}
if(countDownTimeronResume!=null){
countDownTimeronResume.cancel();
}
}
}