Develop Reference

Button to trigger every 5 seconds

My app needs tracking of real time so I need a button that needs to trigger every 5 seconds but I have no idea how to do it. Can you teach me how?
I want that in every 5 seconds that AsyncTask will be triggered.
btnStart.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
HashMap postLoc = new HashMap();
postLoc.put("txtLat", tvLat.getText().toString());
postLoc.put("txtLng", tvLong.getText().toString());
postLoc.put("txtOwner", pref.getString("username","").toString());
PostResponseAsyncTask taskLoc = new PostResponseAsyncTask(getActivity(), postLoc,false, new AsyncResponse() {
#Override
public void processFinish(String s) {
Log.d(TAG, tvLat.getText().toString());
Log.d(TAG, tvLong.getText().toString());
Intent i = new Intent(getActivity(),GPS_Service.class);
getActivity().startService(i);
}
});
taskLoc.execute("http://carkila.esy.es/carkila/locationUpdate.php");
}
});

I think this code might be useful to trigger the code every 5 second
Timer timer;
TimerTask timerTask;
final Handler handler = new Handler();
#Override
public void onCreate() {
super.onCreate();
startTimer();
}
public void startTimer() {
//set a new Timer
timer = new Timer();
//initialize the TimerTask's job
initializeTimerTask();
timer.schedule(timerTask, 0, 5000);
}
public void initializeTimerTask() {
timerTask = new TimerTask() {
public void run() {
handler.post(new Runnable() {
public void run() {
//code to run after every 5 seconds
}
});
}
};
}

Create a method like this and call the method on button click and also call the method by using a handler like this:
mRunnable = new Runnable() {
public void run() {
public void toBecalled_Every_5_Second();
mHandler.postDelayed(mRunnable, 5000);
}
};
mHandler.postDelayed(mRunnable, 5000);
public void toBecalled_Every_5_Second(){
PostResponseAsyncTask taskLoc = new PostResponseAsyncTask(getActivity(), postLoc,false, new AsyncResponse() {
#Override
public void processFinish(String s) {
Log.d(TAG, tvLat.getText().toString());
Log.d(TAG, tvLong.getText().toString());
Intent i = new Intent(getActivity(),GPS_Service.class);
getActivity().startService(i);
}
});
taskLoc.execute("http://carkila.esy.es/carkila/locationUpdate.php");
}
so it will call the method every 5 second and the a sync task will execute....

I would like to have a CountDownTimer which will trigger the button click function after every 5 seconds.
CountDownTimer mTimer = new CountDownTimer(50000, 1000) {
public void onTick(long millisUntilFinished) {
// Do nothing
}
public void onFinish() {
btnStart.performClick();
this.start(); // Restart
}
}.start();

You can use Timer with TimerTask and Handler to update the result to main thread i.e your UI.
Something like this:
Timer timer;
TimerTask timerTask;
//we are going to use a handler to be able to run in our TimerTask
final Handler handler = new Handler();
private void initializeTimerTask() {
timerTask = new TimerTask() {
public void run() {
//use a handler to run process
handler.post(new Runnable() {
public void run() {
/**************************/
/** Do your process here **/
/**************************/
}
});
}
};
}
private void startTimer() {
//set a new Timer
timer = new Timer();
//initialize the TimerTask's job
initializeTimerTask();
//schedule the timer, start run TimerTask then run every 5000ms i.e 5 seconds.
timer.schedule(timerTask, 0, 5000); //
}
private void stopTimerTask() {
//stop the timer, if it's not already null
if (timer != null) {
timer.cancel();
timer = null;
}
}
Insert your processing code in Handler.post(). Then start the trigger by calling startTimer(). To stop the trigger, just call stopTimerTask().

How to get runOnUiThread to run continuously in Android

Using Android studio, I am trying to make an app that gets data from a web-service and display the data and updates the view every 5 sec or when the data on the web-service changes. With this I am trying to change the colours on some button based on an int, the int changes and the color on the button changes when I apply buttons(); to another button and then presses it but I want it to update by itself.
When I used a while loop the app gets stuck
MainActivity.this.runOnUiThread(new Runnable() {
#Override
public void run() {
buttons();
}
});
The runOnUiThread is placed in the onCreate.

using run on UI thread will cause your UI to freeze , try using a timer task instead .
example :
#Override
public void StopTimerTask() {
if (timer != null) {
timer.cancel();
timer = null;
}
}
public void StartTimer() {
timer = new Timer();
initializeTimerTask();
int UpdateTime = Integer.valueOf(UserSettings.getString("Update", "60000"));
timer.schedule(doAsynchronousTask, 0, YOURTIME);
}
public void initializeTimerTask() {
doAsynchronousTask = new TimerTask() {
#Override
public void run() {
myHandler.post(new Runnable() {
public void run() {
YOUR LOGIC HERE
}
});
}
};
}

doing this where u just put another class into main activity was succesful only problem is that it have to be in my main class
public class updategui extends TimerTask {
Activity context;
Timer timer;
public updategui(Activity context, int seconds) {
this.context = context;
timer = new Timer();
timer.schedule(this,
seconds * 1000, // initial delay
seconds * 1000); // subsequent rate
}
#Override
public void run() {
if(context == null || context.isFinishing()) {
this.cancel();
return;
}
context.runOnUiThread(new Runnable() {
#Override
public void run() {
try {
buttons();
} catch (Exception e) {
e.printStackTrace();
}
}
});
}}

Displaying a stopwatch in an android app in a textView

I have setup a stop watch using the com.apache.commons library and the stop watch seems to work fine. What I don't know how to do is display this stopwatch in a textView in my app. In general, I have no idea how that would work, i.e. How exactly would a stopwatch be displayed in a textView, given that the time on a stopwatch keeps changing constantly? At the moment, I have the code below and it updated the text in the textView every second for about 2 seconds and then I got a weird error. I'm not even sure if this is the right way to go about doing this. Please help!
Timer timer = new Timer();
TimerTask timerTask;
timerTask = new TimerTask() {
#Override
public void run() {
timeText.setText(time.toString());
}
};
timer.schedule(timerTask, 0, 1000);
The error I got after 2 seconds (and it successfully updated the time) was :
"only the original thread that created a view hierarchy can touch its views"

You can only update a TextView on the UI thread.
runOnUiThread(new Runnable() {
#Override
public void run() {
//stuff that updates ui
}
});
Your code becomes
Timer timer = new Timer();
TimerTask timerTask;
timerTask = new TimerTask()
{
#Override
public void run()
{
runOnUiThread(new Runnable()
{
#Override
public void run()
{
timeText.setText(time.toString());
}
});
}
};
timer.schedule(timerTask, 0, 1000);
You may have to do myActivityObject.runOnUiThread() if you're getting an error there.
See this for more detail.

To update a view from another thread, you should use handler.
private void startTimerThread() {
Handler handler = new Handler();
Runnable runnable = new Runnable() {
private long startTime = System.currentTimeMillis();
public void run() {
//Change the condition for while loop depending on your program logic
while (true) {
try {
Thread.sleep(1000);
}
catch (InterruptedException e) {
e.printStackTrace();
}
handler.post(new Runnable(){
public void run() {
timeText.setText(time.toString());
}
});
}
}
};
new Thread(runnable).start();
}

Delay actions in android

I want to change the image in imageView after 5 seconds from app start.
This is the code that I tried so far:
public class MainActivity extends Activity {
ImageView screen;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
screen=(ImageView)findViewById(R.id.imageView1);
screen.setImageResource(R.drawable.ic_launcher);
}
}

You can use a Handler, such as:
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
// change image
}
}, 5000); // 5000ms delay
As Sam says in the comments, you could also do this (because all Views have their own handler):
screen.postDelayed(new Runnable() {
#Override
public void run() {
// change image
}
}, 5000); // 5000ms delay
See the Handler Documentation.

you can try thread like this:
new Thread(){
public void run(){
//sleep(5000);
//refreshSthHere();
}
}.start();

You can use Handler like Tom Leese said or Java Timer
new Timer().schedule(new TimerTask() {
#Override
public void run() {
// this code will be executed after 2 seconds
}
}, 2000);

Create a Timer to send HTTP request Periodically - Android

I want to end HTTP request from a Android device to a web server and check a particular data of a database periodically (once a minute). I couldn't implement a timer for this.
Thanks

public class MyActivity extends Activity {
Timer t ;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
t = new Timer();
t.schedule(new TimerTask() {
public void run() {
//Your code will be here
}
}, 1000);
}
}

Try AlarmManager running Service. I wouldn't recommend sending request each minute thou, unless it's happening only when user manually triggered this.

TimerTask doAsynchronousTask;
final Handler handler = new Handler();
Timer timer = new Timer();
doAsynchronousTask = new TimerTask() {
#Override
public void run() {
handler.post(new Runnable() {
public void run() {
if(isOnline){// check net connection
//what u want to do....
}
}
});
}
};
timer.schedule(doAsynchronousTask, 0, 10000);// execute in every 10 s

The most easy method is to loop a Handler:
private Handler iSender = new Handler() {
#Override
public void handleMessage(final Message msg) {
//Do your code here
iSender.sendEmptyMessageDelayed(0, 60*1000);
}
};
To start the loop call this sentence:
iSender.sendEmptyMessage(0);