I'm trying to make a stopwatch in Java and don't know how to pause and continue my timer. Here is what I have done so far.
startButton.addActionListener(this);
stopButton.addActionListener(this);
pauseButton.addActionListener(this);
public void actionPerformed(ActionEvent e) {
Calendar aCalendar = Calendar.getInstance();
if (e.getSource() == startButton){
start = aCalendar.getTimeInMillis();
startButton.setBackground(Color.GREEN);
stopButton.setBackground(null);
pauseButton.setBackground(null);
} else if (e.getSource() == stopButton) {
stopButton.setBackground(Color.RED);
startButton.setBackground(null);
pauseButton.setBackground(null);
aJLabel.setText("Elapsed time is: " +
(double) (aCalendar.getTimeInMillis() - start) / 1000 );
} else if (e.getSource() == pauseButton) {
pauseButton.setBackground(Color.YELLOW);
stopButton.setBackground(null);
startButton.setBackground(null);
}
}
As you can see, I've only changed the colors for my pause button. I don't really know how to pause the thread by having the user click on the button. All examples I've found of thread.sleep() were with a specific time.
You can use the swing.Timer (not util.Timer) like this:
int interval = 100; // set milliseconds for each loop
Timer timer = new Timer(interval, (evt) -> repeatingProccess());
// create the method repeatingProccess() with your
// code that makes the clock tick
startButton.addActionListener(e -> timer.start());
stopButton.addActionListener( e -> {
timer.stop();
// here refresh your clock with some code...
};
pauseButton.addActionListener(e -> timer.stop());
You write a method called repeatingProccess() and it works in its own thread again and again every interval milliseconds. For a clock that counts seconds you can do this:
int interval = 1000;
int seconds = 0;
public void repeatingProccess() {
seconds++ ;
}
note:
The second will not be exactly 1000 milliseconds but around 1001 because of the time needed to run seconds++ but you can fix that as well by getting System time before and after and substracting the difference from your clock. You should use the Calendar API for this.
Related
I'm trying to make an image twinkle with RaffleImage(); while I'm executing the timer, my character is immune to any collision, I want it to be immune only for 2 seconds, so the timer get execute only for 2 seconds and then get finished.
I've tried subtracting System.currentTimeMillis() but any variable I create from this method, have always the same value, making me get a zero from that subtracting.
Do you know how I can stop or pause the timer after any elapsed time in seconds?
immuneTimer = new Timer(50, new ActionListener() {
#Override
public synchronized void actionPerformed(ActionEvent e) {
long initMillis = System.currentTimeMillis();
if (System.currentTimeMillis() - initMillis > 2000 ) { // this substract gives me 0
initImages();
setImmune(false); // so this never reached
immuneTimer.stop();
} else {
raffleImage(); //its executing like forever;
}
}
});
The Swing timer fires a an ActionEvent. From the event you can use getSource() to get the source of the event. Cast that source to the swing timer object and use that to turn it off.
To know when to turn it off you need to have a variable count the number of times the swing timer is invoked. When the variable reaches that amount, turn it off.
int elapsedTime = 0;
int timerDelay = 50;
int max = 2000;
public void actionPerformed(ActionEvent ae) {
elapsedTime += timerDelay; // you could use getDelay here but it
// is in milliseconds.
if (elapsedTime >= max) {
Timer s = (Timer)ae.getSource();
s.stop();
}
// rest of code
}
I have the follow problem:
i'm writing an chat bot in java and i want to call a method even x minutes.
So i read an "Timer.Schedule" is what i need. So i write the following method:
public function timerMethod()
{
int time = 10;
...
new java.util.Timer().schedule(
new java.util.TimerTask() {
#Override
public void run() {
timerMethod();
}
}, 1000 * 60 * time // 1MSec * 1Sec * xMin
);
}
At the beginning the loop works fine but after a few hours (i think it's after 10-15 hours) the loop dont work anymore...
I dont know why i dont work and dont get any error message :(
Can someone help me pleace???
So you want code to run for x minutes, correct?
If so, convert the time you want the code to run for into milliseconds like this : 1 minute = 60000 ms. There is a method called System.currentTimeMillis(), this will return a value of miliseconds from the EPOCH date (Jan 1, 1970).
You can use a while loop like this:
`
int msTime = 60000; //1 Minute = 60000 MS
int doUntil = ms + System.currentTimeMillis(); //1 minute
while(System.currentTimeMillis() != doUntil)
{
//Code here
System.out.println(¨Hello World¨); //This will print Ḧello World for 60000ms
}
Mmm well first you can stop instantiating multiple times the java.util.Timer() variable. You only need one as an attribute of the class. The timerTask is the only one there that should be reinstantiated.
private Timer timer = new Timer();
Now, surround your code inside the run function with try/catch:
public void run() {
try {
timerMethod();
} catch(InterruptedException e) {
e.printStackTrace();
}
}
Are you calling that timerMethod just once? You can add to this code some prints too in order to check whenever you reschedule your function and when you run your method.
In my platforming game, I have a swing timer that ticks the following method every 17 milliseconds. It is here that I run the various events that I need to run. My plan was to sleep the timer for 1 second whenever the player died.
My problem is that I don't really have a firm understanding of how to sleep a swing timer. Every example that I look at involves using a Thread which is not what I am doing. When I do the following I get a IllegalMonitorStateException error.
public void actionPerformed(ActionEvent e)
{
if (!louis.isDead)
{
if (louis.right)
{
louis.moveR();
}
if (louis.left)
{
louis.moveL();
}
if (!louis.left && !louis.right)
louis.friction();
louis.gravity();
louis.checkCol(charMap, mapX, mapY);
mapX -= louis.moveX();
mapY -= louis.moveY();
louis.checkDeath(charMap, mapX, mapY);
}
else
{
try {
time.wait(1000);
} catch (InterruptedException e1) {e1.printStackTrace();}
mapX = initMapX;
mapY = initMapY;
louis = new Player(spawnX, spawnY);
}
repaint();
}
Thanks in advance
My problem is that I don't really have a firm understanding of how to sleep a swing timer.
You don't. You don't sleep anything in Swing, not unless you want to put your entire GUI asleep. Instead why not simply record the start time, check the elapsed time with each tick, and then activate whatever code you want activated when the elapsed time is greater than your cut-off?
Not sure what you're trying to do, but perhaps something in this sort of range (code not tested)
private static final long TOTAL_DEATH_TIME = 1000L; // total time of your delay
private long deathInitTime = -1L; // start time of death throes
public void actionPerformed(ActionEvent e) {
if (!louis.isDead) {
// .... etc... unchanged from your code
} else {
// he's dead
if (deathInitTime < 0) {
// if dead but just now dead, initialize deathInitTime
deathInitTime = System.currentTimeMillis();
} else {
// he's been dead
// check how long he's been dead
long deathTime = System.currentTimeMillis() - deathInitTime;
if (deathTime > TOTAL_DEATH_TIME) {
// if he's been dead long enough, call this code
mapX = initMapX;
mapY = initMapY;
louis = new Player(spawnX, spawnY);
deathInitTime = -1L; // and re-initialize deathInitTime
}
}
}
repaint();
}
How can I get the time left in a util.Timer?
What I want to do is to add a progressbar that displays time left until the timer starts over.
This is what I've got this far:
int seconds = 8;
java.util.Timer timer = new Timer();
timer.schedule( new TimerTask(){
public void run(){
// Do something
// Add a progressbar that displays time left until the timer "starts over".
},0,(long) (seconds*1000));
You would need a second timer to refresh the gui in a specific interval.
Another way to achieve this, would be to activate a single timer every second and update the counting in the ui. If the time is up, call your specific action.
A simple expample with console output only:
TimerTask task = new TimerTask()
{
int seconds = 8;
int i = 0;
#Override
public void run()
{
i++;
if(i % seconds == 0)
System.out.println("Timer action!");
else
System.out.println("Time left:" + (seconds - (i %seconds)) );
}
};
Timer timer = new Timer();
timer.schedule(task, 0, 1000);
It's output would be:
Time left:7
Time left:6
Time left:5
Time left:4
Time left:3
Time left:2
Time left:1
Timer action!
Time left:7
Time left:6
Time left:5
Time left:4
Time left:3
Time left:2
Time left:1
Timer action!
Time left:7
Time left:6
...
Then simply change the System.out's with your code to update the progress bar. Remember: java.util.Timer starts its own Thread. Swing is not thread safe, so you need to put every gui changing code into SwingUtilities.invokeLater()!
If you're not doing any long running tasks, every time your timer reachs the 8 seconds mark, you may want to use javax.swing.Timer directly. It uses the EDT and not its own Thread, so you don't need to synchronize your calls to Swing components with SwingUtilities.invokeLater().
Also see:
javax.swing.Timer vs java.util.Timer inside of a Swing application
All you need to do is declare a long variable timeleft in your MainActivity.
long timeleft;
Then, when you create a new Timer, set the "onTick" override to update the timeleft variable each "onTick" (which in the following example is 1000 milliseconds )
timer = new CountDownTimer(time, 1000) {
#Override
public void onTick(long millisecondsUntilFinished) {
timeleft = millisecondsUntilFinished;
}
}
Your app can access then the variable timeleft every time you need to check how much time is left.
hi guys i am new to java... :(
i just want my button(start) to start a timer but i want to stop the timer automatically with 'if' so for example... when a user enters a time and the timer get's to the timer it stops... so far my coding is like this...
private void startTimerActionPerformed(java.awt.event.ActionEvent evt) {
javax.swing.Timer tm = new javax.swing.Timer(100, new ActionListener()
{
public void actionPerformed (ActionEvent evt) {
AddOneActionPerformed(evt);
}
});
tm.start();
int getTM,getM,getTS,getS,Secs,tenSec,Mins,tenMin;
getTM = Integer.parseInt(enterTenMins.getText());
getM = Integer.parseInt(enterOneMins.getText());
getTS = Integer.parseInt(enterTenSecs.getText());
getS = Integer.parseInt(enterOneSecs.getText());
tenMin = Integer.parseInt(tenMins.getText());
Mins = Integer.parseInt(oneMins.getText());
tenSec = Integer.parseInt(tenSecs.getText());
Secs = Integer.parseInt(oneSecs.getText());
}
and AddOneActionPerformed(evt) is
private void AddOneActionPerformed(java.awt.event.ActionEvent evt) {
int dd,Secs,tenSec,Mins,tenMin;
tenMin = Integer.parseInt(tenMins.getText());
Mins = Integer.parseInt(oneMins.getText());
tenSec = Integer.parseInt(tenSecs.getText());
Secs = Integer.parseInt(oneSecs.getText());
dd= Integer.parseInt(digitValue.getText());
dd= dd+1;
if (dd==10)
dd = 0;
if (Secs == 10)
Secs = 0;
if (dd==0)
Secs=Secs +1;
if (tenSec>=6)
tenSec = 0;
if (Secs==10)
tenSec=tenSec +1;
if (Mins==10)
Mins = 0;
if (tenSec==6)
Mins=Mins+1;
if (tenMin>=6)
tenMin=0;
if (Mins==10)
tenMin=tenMin+1;
String ss = Integer.toString(dd);
digitValue.setText(ss);
String ff = Integer.toString(Secs);
oneSecs.setText(ff);
String gg = Integer.toString(tenSec);
tenSecs.setText(gg);
String hh = Integer.toString(Mins);
oneMins.setText(hh);
String jj = Integer.toString(tenMin);
tenMins.setText(jj);
showDigitActionPerformed(evt);
showOneSecsActionPerformed(evt);
showTenSecsActionPerformed(evt);
showOneMinsActionPerformed(evt);
showTenMinsActionPerformed(evt);
}
You can get the Timer instance from the ActionEvent's getSource() method, and then call stop on it. So,...
// for your Timer's ActionListener
#Override
public void actionPerformed(ActionEvent evt) {
if (someStoppingConditionIsTrue) {
Timer timer = (Timer) evt.getSource();
timer.stop();
} else {
// code to call repeatedly
}
}
Note that you've got two separate issues going on, and should solve them separately. The code above is a way to stop a Timer from within its own ActionListener using some condition. Your other question is how to get user input to allow you to change that condition, and that will involve separate code that is independent of the Timer code above.
Consider in addtion:
Use two JSpinners to for the user's to input minutes and seconds.
Give your class an int totalTime field.
Set this value in your startTimerActionPerformed method.
Have the Timer's ActionListener decrement this value based on measured elapsed time using the differences in calls to System.getSystemTime().
Calculate get the difference between the totalTime and elapsedTime (it will be in milliseconds), say called timeLeft
Calculate your minutes and seconds from timeLeft.
Then display these values in a JLabel using a formatted String, say something like String.format("%02d:%02d", minutes, seconds).
When the timeLeft == 0, that's when you stop your Timer.