How to make a countdown? - java

I'm trying to create a countdown. I don't see how exactly I can make a countdown. Can anyone help?

The code does what you tell it. You say in onStart:
end.add(Calendar.MINUTE, 4);
end.add(Calendar.SECOND, 5);
which tells the system you want a countdown starting at 4 minutes and 4 seconds. Instead, do:
end.add(Calendar.SECOND, 45);
EDIT
Took a while to understand what you meant. First, go to github and copy TickTockView into your own project. Remove the dependency to the original project. Open the file and in onDraw, change:
if (mCircleDuration == DURATION_TOTAL && mStartTime != null) {
long totalTime = mEndTime.getTimeInMillis() - mStartTime.getTimeInMillis();
float percentage = (((float) mTimeRemaining) / ((float) totalTime));
angle = 360f * percentage;
}
to:
if (mCircleDuration == DURATION_TOTAL && mStartTime != null) {
long totalTime = mEndTime.getTimeInMillis() - mStartTime.getTimeInMillis();
float percentage = (((float) mTimeRemaining) / ((float) 45000));//45000(ms) = 45 seconds
angle = 360f * percentage;
}
In your xml file where the circle is defined, add:
app:tickCircleDuration="total_time"
And by doing that, you only need to change totalTime in onDraw in the TickTockView. Remember to update the package name in the XML file to point to the place you saved the file, not the original project.
For reference, this is the file you should copy

The good way is to use CountDownTimer class provided by Android for downward counting in time. I have recently used it in my game and is simple in use. First you
CountDownTimer timer = new CountDownTimer(45000, 1000) {
// 45000 milliseconds countdown and 1000 milliseconds decrement at each tick.
public void onTick(long millisUntilFinished) {
//you can change your UI here based on time
}
public void onFinish() {
// you can define something to happen when timer ends.
}
};
timer.start();

Change the below code into
Calendar end = Calendar.getInstance();
end.add(Calendar.MINUTE, 4);
end.add(Calendar.SECOND, 5);
into
Calendar end = Calendar.getInstance();
end.add(Calendar.MINUTE, 0);//O minute
end.add(Calendar.SECOND, 45);//45 second

Related

Double (chess like) timer

I am thinking about making an android app to support a game of mine, and I can't find info on how to do it. Here is an app explanation:
The app should have two timers (both set for x minutes). When first player starts his turn (by a button click) his time starts running out. when first player makes his move, he should click his time to stop it, and player two starts his turn.
NOW, the problem I can't find a solution for - When player one takes his turn, time that he loses should pass to the other player's timer.
Example: Both players start with a 5 minute timer. If player one takes 30 second for his turn, his time should go down to 04:30, at which time he clicked on his timer. During that time, for each second he lost, the other player gained time on his timer, so at the beginning of his turn, his time is 05:30. The time goes back and forth, and the player whose timer runs out loses the game.
Any idea how to do this?
I am still stuck to the idea on how to make it, so I have no code to share.
Thank you all for your answers, and effort in helping me, if you have a question I haven't covered, I will gladly answer it.
First, you will need to instantiate class of CountDownTimer everytime you click on button.
For reference check here: https://developer.android.com/reference/android/os/CountDownTimer.html
You have two parameters long millisInFuture, long countDownInterval
Before you start, you will need to create two global variables one for first player, and one for second player like this:
long firstPlayerRemainingTime = 5 * 60 * 1000; // start time 5 minutes
long secondPlayerRemainingTime = 5 * 60 * 1000;
long limitedTime = 30 * 1000; // 30 seconds
CountDownTimer mCountDownTimer;
Now we have came to the most important part and that is logic inside onClickListener method
I don't know if there are two buttons or one, but I will go with two buttons:
btnFirstPlayer.setTag(1); // start timer
btnFirstPlayer.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (btnFirstPlayer.getTag() == 1) {
startTimer();
} else {
stopTimer();
}
});
private void startTimer() {
long startTime = firstPlayerRemainingTime;
btnFirstPlayer.setTag(2); // stop timer
btnFirstPlayer.setText("Stop");
mCountDownTimer = new CountDownTimer(firstPlayerRemainingTime, 1000) {
public void onTick(long millisUntilFinished) {
firstPlayerRemainingTime = millisUntilFinished;
tvPlayerOneTimer.setText("" + firstPlayerRemainingTime / 1000)
// Here you would like to check if 30 seconds has passed
if ((startTime / 1000) - (limitedTime / 1000)
== (firstPlayerRemainingTime / 1000)) {
stopTimer();
}
// Here you would like to increase the time of the second player
secondPlayerRemainingTime = ++1000;
}
public void onFinish() {
mTextField.setText("done!");
}
}.start();
}
}
private void stopTimer() {
btnFirstPlayer.setTag(1);
btnFirstPlayer.setText("Start");
mCountDownTimer.cancel();
// I guess here starts second player move
}
The same logic would go for second player. Let me know if this helped you or if I need to explain anything.

Calculating time passed in libgdx with getDeltaTime()

i am trying to calculate the time passed in my libGDX application like this
float timeSpent= 0;
public void render(){
timeSpent = timeSpent + Gdx.graphics.getDeltaTime();
}
by the above code i feel like the time is almost passing double the normal rate
but if i get delta time directly from java's nano time method like this
float prevTime;
float timeSpent = 0;
public void show(){
prevTime = System.nanoTime();
}
public void render(){
float p = System.nanoTime();
timeSpent += (p-prevTime)/1000000000f;
prevTime = p;
}
it seems to work fine, i know that libgdx also get delta time from subtracting
nano time method.
i am not able to figure out what am i doing wrong in the first method.
thank you
You can calculate the passed time from the start of your application by simply saving a date when it starts, and just subtract it from the current date. No need to accumulate the deltas in each frame.
You can further simplify the code by using TimeUtils:
// save at start
long start = TimeUtils.millis();
// query whenever you want
long diffInMillis = TimeUtils.timeSinceMillis(startTime);

Mp3 player with timer in java [fast forward]

I'm making fast forward button in my Mp3 player. I wrote already code for this, but have problem how to implement timer to jump 5% forward? I mean when I press button timer should jump 5% forward of total long song. This is my fastForward method.
public void FastForward(){
try {
//songTotalLength = fis.available();
fis.skip((long) ((songTotalLength * 0.05)));
} catch (IOException e) {
e.printStackTrace();
}
}
And here is the button method:
private void jButton3ActionPerformed(ActionEvent e) {
mp3.FastForward();
if(mp3.player.isComplete()){
bar = 100;
}
jProgressBar1.setValue((int)bar);
bar+=5;
}
And this one is for timer:
private void setTime(float t) {
int mili = (int) (t / 1000);
int sec = (mili / 1000) % 60;
int min = (mili / 1000) / 60;
start.set(Calendar.MINUTE, 0);
start.set(Calendar.SECOND, 0);
end.set(Calendar.MINUTE, 0 + min);
end.set(Calendar.SECOND, 0 + sec);
timer = new javax.swing.Timer(1000, new TimerListener());
percent = (float)100/(min*60+sec);
}
You're already redundantly tracking progress in two variables fis and bar. For the sake of good design, use one of those to determine elapsed time rather than using yet another variable for the same purpose.
but have problem how to implement timer to jump 5% forward?
You seem to have mistaken the purpose of a Timer. According to the Timer class documentation, it:
Fires one or more ActionEvents at specified intervals.
So the timer is not meant to keep track of how much time has elapsed. It will simply invoke the actionPerformed(ActionEvent) method of your TimerListener once per second (every 1000 milliseconds) as you have it configured.
For a more complete answer, please post the code for your TimerListener class.
Notes
It seems that your setTime(float) method is meant to be called repeatedly, so this method should not be initializing the timer variable. Rather initialize the timer once and leave it alone to do its job.
I'm assuming you intended the supplied float parameter t to represent microseconds.
The float data type has only 7 digits of precision. This could be fine since you're interested only in minutes and seconds, otherwise float is only good for up to about four months of seconds before losing accuracy.
It seems like you wanted your button click handler to do this (increment bar sooner):
private void jButton3ActionPerformed(ActionEvent e) {
mp3.FastForward();
bar+=5; // increment bar before checking complete, and before setting progress
if(mp3.player.isComplete()){
bar = 100;
}
jProgressBar1.setValue((int)bar);
}

Extend time of an Countdowntimer

Why is this Code not working ?
This code should extend the Countdowntimer to 10 sec (everytime when point is 20 , 40 , 60) etc.But when I start it and my score is by 20 it shows in a TextView a right value of time.But then it is gone in 1 sec and the Countdowntimer got the old value and continue.Someone a idea ?
int bonus_time = 1 , sec = 10000 , point == 0;
points_timer =new CountDownTimer(sec,1000) {
#Override
public void onTick(long millisUntilFinished)
{
if ( point == (bonus_time * 20))
{
++bonus_time;
millisUntilFinished += 10000;
sec += 10000;
}
++point;
}
#Override
public void onFinish()
{
bonus_time = 1;
}
};
When you create a timer with the sec variable for its time, it does not magically connect the two so when the value of sec changes the timer's time changes, it just uses the value of sec once when you make the timer.
Same goes for changing millisUntilFinished, it's a parameter you got from a callback, by changing its value you are not doing anything.
The only way to change a timer's time is to create a new one. This is my suggestion:
// GLOBAL VARIABLES
CountDownTimer points_timer;
int bonus_time = 1 , sec = 10000 , point == 0;
public void createTimer()
{
points_timer =new CountDownTimer(sec,1000) {
#Override
public void onTick(long millisUntilFinished)
{
sec = millisUntilFinished;
if ( point == (bonus_time * 20))
{
++bonus_time;
//millisUntilFinished += 10000;
sec += 10000;
createTimer();
}
++point;
}
#Override
public void onFinish()
{
bonus_time = 1;
}
};
}
The creation of the timer is surrounded by a function, and that function is called each time the bonus is gained to recreate the timer with the new value of sec.
You should also call that method once in place of your previous code, to initially create the timer.
Hope this works..
There is no way to extend a CountDownTimer, no method in the class provides this.
Your attempt to add time to sec is useless, I even wonder how it can compile. Anyway, in Java integers are passed by value, so once you passed 1000, you passed it and can't change that value.
The only alernative is to re-create a new timer and use it instead of the old one. Or recode everything, a timer of your own that you can extend.
in
public void onTick(long millisUntilFinished)
you do
millisUntilFinished += 10000;
you can not assign to primitive parameter and expect that it changes anything outside of that method (eg. scope of millisUntilFinished is onTick method and nothing more)

How to increment time every second in Libgdx

I try to add time to my game that will increment every second.
How to fix that?
I add my code below
float timer;
timer += delta;
if(timer<=delta+1000)//every one sec
{
time = time+1;
timePoint.setSentence(""+time/100);
timer = 0f;
}
as your note, delta is Gdx.graphics.getDeltaTime().
'time' is string.
but looks like the time increment slowly. means that when time already run about 1,5 sec,
'time' still increase 1.
I divide by 100 because if not it will increase more faster/sec,
i also use TimeUtils class from libgdx but it produced similar result.
Thanks before.
This should work. Note that time/100 results in 0 for 0-99 and 1 for 100-199. That's probably not the effect you wanted.
float timer;
timer += delta;
if (timer >= 1) {
time++;
timePoint.setSentence(""+time);
timer -= 1;
}
The problem was that you set the timer back to 0. If it was 1.1f for example (because the last delta was 0.1f), then you basically lose 100ms. Don't reset the timer to 0f, but decrease it by 1f instead.
I would do it like this:
float time = 0f;
In render:
time += delta;
timePoint.setSentence(Integer.toString((int)time));
delta is giving the ellapsed time in seconds, so for 30FPS it is 1/30 seconds. So you only need to add it to your time. To print the difference (i guess the setSentence is printing the text) you only need to cast it to int, so that it cuts the fraction digits.
Hope it helps.
EDIT: If you need the timer and the time variable somewhere you need to store them in 2 different variables.
For that i would do it like this:
float timer = 0f;
int time = 0;
And in render:
timer+=delta;
if (timer >= 1f) {
time++;
timePoint.setSentence(Integer.toString(time));
timer-=1f;
}
By doing this you are not loosing the few milli seconds you would loose if you reset the timer.
This means, that if timer goes from 0.99f to 1.05f in one renderloop and you reset the timer to 0f, you loose 0.05 seconds. If this happens every second you loose 1 second every 20 seconds (if i am not wrong^^)
Like in pure java:
Timer timer = new Timer();
timer.schedule(new incrementYourValue(), 0, 1000); //1000 is time in mili sec
//0 is the time waited before the beginning.
Had similar problem but for me using delta time was kinda overkill. Instead I used Libgdx Timer that "Executes tasks in the future on the main loop thread". Using Timer from java.util may cause Concurrency problems in libgdx.
import com.badlogic.gdx.utils.Timer;
public class Scheduler {
public Scheduler(Runnable runnable, float periodInSeconds) {
Timer timer = new Timer();
timer.scheduleTask(new Timer.Task() {
#Override
public void run() {
runnable.run();
}
}, 0, periodInSeconds);
}}
And usage:
new Scheduler(() -> updateSth(), 1f);

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