Develop Reference

How to set a delay in Android

I'm making a Simon game, while doing it, I created an method that called "Computer" that is activated when the game is starting and after that, every time after the player successes to repeat the sequence.
Here is the code:
private void Computer(){
rounds.setText("Round " + index);
new CountDownTimer(500, 500) {
public void onTick(long millisUntilFinished) {
}
public void onFinish()
{
ResetArray(Player);
//Pushing buttons
Red.setClickable(false);
Blue.setClickable(false);
Green.setClickable(false);
Yellow.setClickable(false);
for (int i = 0; i < index; i++)
{
final Handler handler = new Handler();
final int temp=Game[i];
if (temp == 0)
{
Red.setImageResource(R.drawable.red1);
handler.postDelayed(new Runnable() {
#Override
public void run()
{
StartSound(red);
Red.setImageResource(R.drawable.red);
}
}, 100);
}
if (temp == 1)
{
Green.setImageResource(R.drawable.green1);
handler.postDelayed(new Runnable() {
#Override
public void run() {
StartSound(green);
Green.setImageResource(R.drawable.green);
}
}, 100);
}
if (temp == 2)
{
Blue.setImageResource(R.drawable.blue1);
handler.postDelayed(new Runnable() {
#Override
public void run() {
StartSound(blue);
Blue.setImageResource(R.drawable.blue);
}
}, 100);
}
if (temp == 3)
{
Yellow.setImageResource(R.drawable.yellow1);
handler.postDelayed(new Runnable() {
#Override
public void run() {
StartSound(yellow);
Yellow.setImageResource(R.drawable.yellow);
}
}, 100);
}
}
Red.setClickable(true);
Blue.setClickable(true);
Green.setClickable(true);
Yellow.setClickable(true);
}
}.start();
}
So basically, what iv'e done here is a short delay, of 500 milliseconds, and then it is starting with the self "pushing". This is for create some space between the beginning of the game/starting a new round.
Index- round number.
Game- an array that iv'e created, where there is 50 random numbers which presents the sequence, every round i'm adding one for the index.
Red, Green, Blue, Yellow - References for ImageButtons.
The handler delay is to give some time between the button pressing (which presented by switching the image resource to a same color but brighter, that gives the effect of pressing a button) and un-press it, without it, the changing will be so fast so the player will not be able to see any graphical change.
Basically I need a way to stop the program for a while between each pushing. I need a delayer that will delay the loop every time at it's beginning. The countdowntimer and the Handler are not suitable because the program keeps "running" after the declaring and setting those, the only effect is that the buttons are pushed together but in a delay, which is not what I need.
The result now is that the buttons are seems pushed together and I need to separate their pushing in some way.
Iv'e tried everything, and I could not find nothing.
Thanks,
Ziv.

Using a Handler and postDelayed(...) IS exactly what you need but you're a approaching it wrong.
Basically what you are doing is running through your for loop almost instantly and at each loop you're calling postDelayed(...) with a delay of 100ms.
I'll explain further - suppose index is 4 and it only takes 1ms to go through each run of the for loop. When the 4 runs of the loop are complete you'll have 4 postDelayed events with times of 100ms, 99ms, 98ms & 96ms - - to all intents and purposes, when they trigger they all appear to trigger at once.
One easy way around this with your code is to increase each delay based on the loop count...
int delayTime;
for (int i = 0; i < index; i++)
{
delaytime = (i + 1) * 100;
final Handler handler = new Handler();
final int temp=Game[i];
if (temp == 0)
{
Red.setImageResource(R.drawable.red1);
handler.postDelayed(new Runnable() {
#Override
public void run()
{
StartSound(red);
Red.setImageResource(R.drawable.red);
}
}, delayTime); // NOTE USING delayTime AS THE DELAY
}
//
// REPEAT THE ABOVE CODE FOR BLUE, GREEN & YELLOW HANDLER DELAYS
}
In other words when i=0, delayTime will be 100ms, when i=1, delayTime is 200ms etc etc

probably you want to sleep the thread for 500 milliseconds, then you can do this to slept your thread.
try {
Thread.sleep(500);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

Thread not behaving as expected after rewrite

I'm writing an android app to measure display lag on tvs using the mirror function on the video out. After many revisions, my code got too complex for its own good, so I scraped it and did a rewrite. My issue is that it is not behaving as expected. The square is not blinking, and the time is 0.0 and the rating is excellent. i have tested changing the ui via the thread by making the square turn different colors, that worked fine. Can someone tell me what the issue is and how to fix it? The way the app works is that you hook the device to a tv and it mirrors the display. then it changes the color of a square in the app and dose a time stamp, then it wait till the camera detects a change then dose another time stamp. using both time stamps you can figure out the delay of the tv. I have it in a loop because the camera only captures at 15ish fps, so I need to run the test multiple times to get an accurate result. The issue is that it always shows up as 0.0ms, that is an impossible number because the lag on most consumer tvs is 9ms. I get the RGB values from each camera frame.
class lagTestThread extends Thread {
#Override
public void run () {
long lagStartTime;
long lagEndTime;
long tempResult;
final double rating;
int x;
long testResult = 0;
int cnt;
for (cnt = 0; cnt >= 100; cnt++){
runOnUiThread(new Runnable() {
#Override
public void run() {
lagSquare.setBackgroundColor(Color.rgb(000, 000, 000));
}
});
while (redVal >= 10.0 && blueVal >= 10.0 && greenVal >= 10.0) {
x = 0;
}
redVal = 0;
blueVal = 0;
greenVal = 0;
lagStartTime = System.nanoTime(); //start lagTimer start
runOnUiThread(new Runnable() {
#Override
public void run() {
lagSquare.setBackgroundColor(Color.rgb(255, 255, 255));
}
});
while (redVal <= 100.0 && blueVal <= 100.0 && greenVal <= 100.0) {
x = 0;
}
lagEndTime = System.nanoTime(); //start lagTimer end
runOnUiThread(new Runnable() {
#Override
public void run() {
lagSquare.setBackgroundColor(Color.rgb(000, 000, 000));
}
});
tempResult = (lagEndTime - lagStartTime);
if (tempResult <= testResult && tempResult != 0) {
testResult = tempResult;
}
}
rating = ((double) testResult) / 1000000.0;
final String finalResultString = String.valueOf(rating);
runOnUiThread(new Runnable() {
#Override
public void run() {
lagTime.setText(finalResultString);
if (rating <= 17.0) {
lagRating.setText("Excellent");
} else if (rating <= 34.0) {
lagRating.setText("Great");
} else if (rating <= 51.0) {
lagRating.setText("Average");
} else {
lagRating.setText("Bad");
}
}
});
}
}
I call it like this
public void startTest(View view) {
lagTestThread lagTest = new lagTestThread();
lagTest.start();
}
redVal, blueVal, greenVal declaration
#Override
public Mat onCameraFrame(CameraBridgeViewBase.CvCameraViewFrame inputFrame) {
double[] rgb = inputFrame.rgba().get(100, 100);
redVal = rgb[0];
blueVal = rgb[2];
greenVal = rgb[1];
Log.i("", "red:" + rgb[0] + " green:" + rgb[1] + " blue:" + rgb[2]);
return rgbMat;
}

The runOnUiThread() causes the Runnable to be posted to the UI thread, at which point the function returns immediately. The Runnable executes at some later time.
Your code is posting events to the UI thread and checking the system time, which means you're calculating how long it takes to post events to the UI thread, not how long it takes them to run. Also, because all the events are queued up behind one another, it's likely they will all execute in the same frame, so you will only see the result of the last setBackgroundColor() call.
If you really want to divorce your display and timing code from the UI thread, you should consider doing this with a SurfaceView, which can be updated independently of the UI thread. (The down side of SurfaceView is that it's a lot more complicated to work with than a custom View.)

Running a counter thread in the background during a game

I am wondering the best way to keep a timer going in the background while a game is played.
I am programming a version of the HiLo game (in Java), which gives a user a certain amount of time to determine a number. If a guess is not correct, the game will tell the user whether the name is too high or too low.
I'm keeping track of time using System.currentTimeMillis() and seeing how much time has elapsed. This seems to work well, and so far I have been checking to see how much time has elapsed each time a new number is entered. For example, currently the app output looks like this:
Welcome to HiLo!
You have 10 seconds to guess a number I'm thinking of between 1 and 100.
> 67
Too high.
> 29
Too low.
Half of your time is gone! Only 5 seconds remains!
> 37
Too high.
> 33
Oops! Time is up - try again.
As you can see, currently, it can only check when I enter a new number how much time is passed.
I have tried creating a thread to start with a timer, however, when I start it, it keeps counting until the time is exhausted, without going on to the thread.run(int guess) which will be run when there is a new guess. I want to be able to still make guesses while the counter runs. Here is my attempt at a new implementation for thread.start():
public void start(int time_sent) throws InterruptedException {
time = time_sent;
startTime = (System.currentTimeMillis() / 1000);
while (1==1) {
long elapsed = ((System.currentTimeMillis() / 1000) - (startTime));
if (elapsed >= (time)) {
System.out.println("Oops! Time is up - try again.");
System.exit(0);
}
else if (elapsed >= (time/2) && !halfWarning) {
System.out.println("Half of your time is gone! Only " + (time/2) + " seconds remains!");
halfWarning = true;
}
}
}
How can I continue running this counter in the background?

This is one more approach:
public void game() {
Scanner scanner = new Scanner(System.in);
int time = 10; // sec
message("You have " + time + " seconds to guess...");
new Thread(new Background(System.currentTimeMillis() / 1000, time)).start();
while (true) {
String s = scanner.next();
if (s.equals("55")) {
message("You win");
System.exit(0);
} else {
message("try again...");
}
}
}
private void message(String str) {
System.out.println(str);
System.out.print("> "); // monit
}
You start 1 thread with behavior implemented in Background class. Next you enter while loop to capture user inputs. The Background thread works in background...
private class Background implements Runnable {
private long startTime;
private long time;
private boolean halfWarning;
private Background(long startTime, long time) {
this.startTime = startTime;
this.time = time;
}
#Override
public void run() {
while (true) {
long now = System.currentTimeMillis() / 1000;
long elapsed = now - startTime;
if (elapsed >= (time / 2) && !halfWarning) {
message("\n Half of your time is gone! Only " + (time / 2) + " seconds remains!");
halfWarning = true;
}
if (elapsed >= time) {
message("\n Oops! Time is up - try again.");
System.exit(0);
}
try {
Thread.sleep(100);
} catch (InterruptedException e) {
//ignore
}
}
}
}

Use a ScheduledExecutorService to execute concurrent actions in the future:
ScheduledExecutorService ses = Executors.newSingleThreadScheduledExecutor();
ScheduledFuture<?> half = ses.schedule(new Runnable() {
#Override
public void run() {
System.out.println("Half of your time is gone!");
}
}, time / 2, TimeUnit.SECONDS);
ScheduledFuture<?> full = ses.schedule(new Runnable() {
#Override
public void run() {
System.out.println("Oops! Time is up - try again.");
// System.exit(0) ?
}
}, time, TimeUnit.SECONDS);
// check
if (input == toGuess) {
half.cancel();
full.cancel();
}

You could have a Timer thread that prints out these messages and shuts down the listening program.

It might inspire you :
public static class Game extends TimerTask {
private long start;
private long end;
public Game(long end) {
super();
this.start = System.currentTimeMillis();
this.end = end;
}
#Override
public void run() {
while (System.currentTimeMillis() - start < end)
System.out.println(System.currentTimeMillis());
}
}
public static void main(String[] args) {
TimerTask task = new Game(10000);
Timer timer = new Timer();
timer.schedule(task,0);
}

For loop display numbers in label [duplicate]

The idea of my program is to select one name from a list that saved before in other JFrame. I'd like to print in the label all names one after the other with small delay between them, and after that stop at one of them. The problem is that lbl.setText("String"); doesn't work if there is more than one setText code.
Here is the part of my code :
public void actionPerformed(ActionEvent e)
{
if (RandomNames.size != 0)
{
for (int i = 0; i < 30; i++)
{
int rand = (int)(Math.random() * RandomNames.size);
stars.setText(RandomNames.list.get(rand));
try
{
Thread.sleep(100);
}
catch (InterruptedException err)
{
err.printStackTrace();
}
}
int rand2 = (int)(Math.random() * RandomNames.size);
stars.setText(RandomNames.list.get(rand2));
RandomNames.list.remove(rand2);
RandomNames.size = RandomNames.list.size();
}
if (RandomNames.list.size() == 0)
{
last.setText("\u062A\u0645 \u0638\u0647\u0648\u0631 \u062C\u0645\u064A\u0639 \u0627\u0644\u0623\u0633\u0645\u0627\u0621 \u0627\u0644\u062A\u064A \u0641\u064A \u0627\u0644\u0642\u0627\u0626\u0645\u0629 !");
}
}

Don't use a loop or Thread.sleep. Just use a javax.swing.Timer. The following will cause 30 iterations occurring every 1000 milliseconds. You can adjust the code in the actionPerformed accordingly to what you wish to happen every so many milliseconds.
int count = 0;
...
Timer timer = new Timer(1000, new ActionListener(){
#Override
public void actionPerformed(ActionEvent e){
if (count == 30) {
((Timer)e.getSource()).stop();
} else {
int rand = (int) (Math.random()* RandomNames.size);
stars.setText(RandomNames.list.get(rand));
count++;
}
}
});
timer.start();
If you want you can just set up the Timer in the constructor, and start() it in the actionPerformed of another button's listener.
See more at How to use Swing Timers

Threading issue, fields doesn't update

Asycntask's onprogressupdate is always being called, :
#Override
protected void onProgressUpdate(Integer... values) {
pbSubStatus.incrementProgressBy(values[1]);
rawNum = values[0];
...
}
And on outer class:
private double getCurrentTime() {
return currentTime;
}
private void doSomethingOnThread() {
LinearLayout layout = (LinearLayout) findViewById(R.id.main);
sMeter = new Meter(context);
layout.addView(sMeter);
final Handler mHandler = new Handler();
new Thread() {
#Override
public void run() {
while (running) {
previousTime = getCurrentTime();
previousNum = getRawNum();
try {
Thread.sleep(1500);
} catch (InterruptedException e) {
e.printStackTrace();
}
currentTime=getCurrentTime();
currentNum = getRawNum();
mHandler.post(mUpdateResults);
}
}
}.start();
}
final Runnable mUpdateResults = new Runnable() {
public void run() {
updateResultsInUi();
}
};
private void updateResultsInUi() {
if(previousNum>currentNum){
return;//TODO
}else{
int temp=currentNum-previousNum;//Problem here, both num are same.
double timeTemp=currentTime-previousTime;
someField= (float)( temp/timeTemp);
}
sMeter.setTarget(someField);//this should be last line to be executed in this snippt
}
So the problem is previousNum and currentNum are always returning the same number. I want the thread to wait 1.5 sec to get a new (getRawNum()) from the onProgressupdate. But I don't understand they they are returning the same number. Thanks for any advice.

I don't think this section is doing what you want:
while (running) {
previousTime = getCurrentTime();
previousNum = getRawNum();
try {
Thread.sleep(1500);
} catch (InterruptedException e) {
e.printStackTrace();
}
currentTime=getCurrentTime();
currentNum = getRawNum();
mHandler.post(mUpdateResults);
}
For instance, let's say this starts executing at time=0. At the end of the first iteration you will have:
previousTime = 0
currentTime = 1500
...however, the loop will immediately start its second iteration, and then you will have:
previousTime = 1500
currentTime = 1500
...then it will sleep for another 1500 milliseconds and set currentTime to 3000, and then immediately start the next iteration, setting previousTime to 3000 as well.
So the problem is that for the vast majority of the time, your code is leaving currentTime and previousTime set to the same value. The only time they have different values is for the extremely small span of time in between when one iteration ends and the next iteration begins.
A quick way to work around this problem is as follows:
currentTime = getCurrentTime();
currentNum = getRawNum();
while (running) {
try {
Thread.sleep(1500);
} catch (InterruptedException e) {
e.printStackTrace();
}
previousTime = curentTime;
previousNum = currentNum;
currentTime=getCurrentTime();
currentNum = getRawNum();
mHandler.post(mUpdateResults);
}
A better approach might be to refactor your code to use something like a circular buffer to keep track of the last n samples and sample timestamps. Then you can simply query for a new sample at regular intervals, and when updating the UI you just compare the most recent thing in the buffer against the one that came immediately before it.
And as for fields in your UI not updating, make sure that the code you have that tries to update them is running on the main thread.