Develop Reference

Handlers don't end after calling removeCallbacksAndMessages(null)

I have two handlers. Handler in a handler. Both of them are in a for-loop.
The overview is something like this,
for{
handler.postDelayed(runnableA{
for{
handler2.postDelayed(runnableB{
function();
}, 3000);
}
}, 1000);
}
I wanted to end handlers' work at any time when the user clicks back button. So, I created two Runnable Classes so that I can use something like runnableA.removellbacksAndMessages(null).
Handler messageHandler;
Handler countDownHandler;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toast.makeText(this, "Start Play in 5 seconds", Toast.LENGTH_SHORT).show();
countDownHandler = new Handler();
for (int i = 7; i >= 0; --i) {
final int idx = i;
Runnable countRunnable = new CountRunnable(idx, countDownView);
countDownHandler.postDelayed(countRunnable, 1000 * (7 - i));
}
}
And this is Runnable Classes.
public class CountRunnable implements Runnable {
int idx;
TextView countDownView;
public CountRunnable(int idx, TextView countDownView) {
this.idx = idx;
this.countDownView = countDownView;
}
#Override
public void run() {
int messageSize = messageItems.size();
for (int j = 0; j < messageSize; j++) {
final int jdx = j;
messageHandler = new Handler();
Runnable messageRunnable = new MessageRunnable(jdx);
messageHandler.postDelayed(messageRunnable, 3000 * jdx);
}
}
}
class MessageRunnable implements Runnable {
int jdx;
public MessageRunnable(int jdx) {
this.jdx = jdx;
}
#Override
public void run() {
addMessageView(messageItems.get(jdx));
}
}
This is onBackPressed():
#Override
public void onBackPressed() {
super.onBackPressed();
Toast.makeText(getApplicationContext(), "All Work Ended.", Toast.LENGTH_SHORT).show();
scrollFlag = true;
try {
messageHandler.removeCallbacksAndMessages(null);
} catch (Exception e) {
Log.d(TAG, "messageHandler never used");
e.printStackTrace();
}
try {
countDownHandler.removeCallbacksAndMessages(null);
} catch (Exception e) {
e.printStackTrace();
}
}
public void addMessageView(String message){
try{
mTextView.setText(message);
}catch(Exception e){
Toast.makeText(getApplicationContext(), "Abnormal End", Toast.LENGTH_SHORT).show();
}
}
But, I keep getting errors because the activity already ended but the handlers can't find the activity. So, Abnormal End Toast message shows as many as the size of inner for loop.
I can ignore this if I don't use the Toast message, but I am afraid of Memory leak or Bad formed Program or something like that.
How can I fix this problem?

The main problem is that you are creating n numbers of CountRunnables and m number MessageRunnables. Despite creating more than one numbers of handlers you are removing callbacks only for the latest-created Hanlder.
Here's what you should do:
Keep a reference of all the Handlers and Runnables and call messageHandler.removeCallbacksAndMessages(null); and countDownHandler.removeCallbacksAndMessages(null); on all of them.

How to set up ProgressBar for inputStream?

I'm trying to setup ProgressDialog to show to the user the progress of an InputStream of bytes. I'm able to show this in the console of the Android Studio by way of this below :
Log.d(TAG, "Progress, transferred " + Integer.toString(100 * bytesTransferred/osSize) + "%");
However, I'm not sure how to attach the bytesTransferred/osSize correctly to a ProgressDialog, I can use a thread to time how long the progress bar will take to fill up the progressBar with the code below:
update = new ProgressDialog(this);
update.setTitle("Transferring update");
update.setMessage("Please wait updating...");
update.setCanceledOnTouchOutside(false);
update.setProgress(0);
final int totalProgressTime = 100;
final Thread t = new Thread() {
#Override
public void run() {
int jumpTime = 0;
while(jumpTime < totalProgressTime) {
try {
sleep(1800);
jumpTime += 1;
update.setProgress(jumpTime);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
};
t.start();
update.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
update.setButton(DialogInterface.BUTTON_NEGATIVE, "Cancel", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
update.show();
}
But would be much better to show to the user the actual transfer of the bytes. This below is what I have to work with:
final int osSize;
final InputStream inputStream;
osSize = inputStream();
public void onProgress(int bytesTransferred) {
Log.d(TAG, "Progress, transferred " + Integer.toString(100 * bytesTransferred/osSize) + "%");
}
Any help would be appreciated, thanks in advance.

Extend this:
#Override
public void run() {
int jumpTime = 0;
while(jumpTime < totalProgressTime) {
try {
sleep(1800);
jumpTime += 1;
update.setProgress(jumpTime);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
With this:
#Override
public void run() {
int jumpTime = 0;
while(jumpTime < totalProgressTime) {
try {
sleep(1800);
jumpTime += 1;
final int fJumpTime = jumpTime;
runOnUiThread(new Runnable() {
#Override
public void run() {
update.setProgress(fJumpTime);
});
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}

System.currentTimeMillis() returns same timestamp

I need to calculate time between two time. System.currentTimeMillis() returns same value everytime when it called in Thread.
My code is:
#Override
protected void onCreate(Bundle savedInstanceState) {
// Other codes..
start_sec = Math.round(System.currentTimeMillis()/1000);
fin = false;
runThread();
// Other codes..
}
private void runThread() {
new Thread() {
public void run() {
while (i++ < 61) {
if (!running) return;
try {
runOnUiThread(new Runnable() {
#Override
public void run() {
if(!fin){
int len = Math.round(System.currentTimeMillis()/1000) - start_sec;
Log.d("current time: ",String.valueOf( Math.round(System.currentTimeMillis()/1000)));
Log.d("difference is: ", String.valueOf(len));
if(len < 0 && len > 58){
fin=true;
}
timerec.getLayoutParams().width = metrics.widthPixels *(60- len)/60;
timerec.requestLayout();
}
else{
end_game();
running= true;
}
}
});
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}.start();
}
Here is the logs:
...
D/current time:: 1492337024
D/difference is:: 0
D/current time:: 1492337024
D/difference is:: 0
....
It returs same "time". What is the solution?

take time as long. and don't divide it by 1000. the time difference is fraction of seconds.that's why it is showing the same time as you are rounding it.

the difference between two cycle in a while loop is so much less than a second and when your calculating the difference by seconds (you divide current millisecond with 1000) it makes the same second and the difference is 0 seconds.
try to print difference in milliseconds (without dividing).

Try this:
#Override
protected void onCreate(Bundle savedInstanceState) {
// Other codes..
start_sec = System.currentTimeMillis();
fin = false;
runThread();
// Other codes..
}
private void runThread() {
new Thread() {
public void run() {
while (i++ < 61) {
if (!running) return;
try {
runOnUiThread(new Runnable() {
#Override
public void run() {
if(!fin){
int len = System.currentTimeMillis() - start_sec;
Log.d("current time: ",String.valueOf( System.currentTimeMillis()));
Log.d("difference is: ", String.valueOf(len));
if(len < 0 && len > 58){
fin=true;
}
timerec.getLayoutParams().width = metrics.widthPixels *(60- len)/60;
timerec.requestLayout();
}
else{
end_game();
running= true;
}
}
});
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}.start();
}

Math.round() causes the problem.
long len = System.currentTimeMillis()/1000 - start_sec;
Log.d("current time: ",String.valueOf(System.currentTimeMillis()/1000));
Log.d("difference is: ", String.valueOf(len));
This code works altought dividing.

Issues using android studio to get time of travel between two points

For the last week, I have been using Android Studio to write code that achieves the following goals:
Wait for the user to be within a certain distance of the start waypoint
Once at start waypoint, begin a timer that logs gps data and current time
Stops timer when the end waypoint is crossed
At the moment, I have the start and end waypoints hard coded but I seem to run into an error that I have been trying to trace with the step through function on my IDE but can't seem to find it. Below is the code I have been using:
void StartTimer (View view){
//Location l = null;
boolean hasLoc = false; //are we at the start?
float speed = 0;
float topSpeed = 0;
while(hasLoc == false && cancel == false){
float d = l.distanceTo(t);
if(d < 2.0)
hasLoc = true;
//if(!l.equals(lm.getLastKnownLocation("")))
String msg = "Latitude: " + l.getLatitude() + "\nLongitude: "+ l.getLongitude();
Toast.makeText(getBaseContext(), msg, Toast.LENGTH_LONG).show();
}
hasLoc = false;
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
public void run() {
// Actions to do after 10 seconds
buzzer();
}
}, 10000);
while(l.distanceTo(tf) > 2.0 && cancel == false){
float cSpeed = l.getSpeed();
if(cSpeed>topSpeed)
topSpeed = cSpeed;
String msg = "Current Speed: "+cSpeed+"Top Speed: "+topSpeed;
Toast.makeText(getBaseContext(), msg, Toast.LENGTH_LONG).show();
}
cancel = false;
}
When I run the code, the phone I test it one will run it but it won't respond, which leads me to believe there is an unsatisfied loop that I have not considered.
Any suggestions would be helpful, thank you in advance for advice!

Your while loops are clogging up the CPU's execution which is what is causing it to not respond. Instead you should place your code inside a thread and call Thread.sleep(1000); inside the thread, this way the the while loop is paused for 1 second after every execution of the code inside it.
Something like this:
new Thread(new Runnable() {
#Override
public void run() {
while (hasLoc == false && cancel == false) {
float d = l.distanceTo(t);
if (d < 2.0)
hasLoc = true;
String msg = "Latitude: " + l.getLatitude() + "\nLongitude: " + l.getLongitude();
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
runOnUiThread(new Runnable() {
#Override
public void run() {
Toast.makeText(getBaseContext(), msg, Toast.LENGTH_LONG).show();
}
});
}
hasLoc = false;
new Handler().postDelayed(new Runnable() {
public void run() {
// Actions to do after 10 seconds
buzzer();
}
}, 10000);
while (l.distanceTo(tf) > 2.0 && cancel == false) {
float cSpeed = l.getSpeed();
if (cSpeed > topSpeed)
topSpeed = cSpeed;
String msg = "Current Speed: " + cSpeed + "Top Speed: " + topSpeed;
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
runOnUiThread(new Runnable() {
#Override
public void run() {
Toast.makeText(getBaseContext(), msg, Toast.LENGTH_LONG).show();
}
});
}
cancel = false;
}
}).start();

How can i make a text in android-studio to be animated?

For example if i display in a TextView the text "Uploading" now i want it to display the text as "Uploading..." and the 3 points to be delete and show again like it's processing doing something and not just static text.
I have this in the MainActivity onTouch event:
#Override
public boolean onTouchEvent(MotionEvent event)
{
float eventX = event.getX();
float eventY = event.getY();
float lastdownx = 0;
float lastdowny = 0;
switch (event.getAction())
{
case MotionEvent.ACTION_DOWN:
lastdownx = eventX;
lastdowny = eventY;
Thread t = new Thread(new Runnable()
{
#Override
public void run()
{
byte[] response = null;
if (connectedtoipsuccess == true)
{
if (is_start == true)
{
uploadTimerBool = true;
timers.StartTimer(timerValueRecord, "Recording Time: ");
response = Get(iptouse + "start");
is_start = false;
} else
{
timers.StopTimer(timerValueRecord);
textforthespeacch = "Recording stopped and preparing the file to be shared on youtube";
MainActivity.this.runOnUiThread(new Runnable()
{
#Override
public void run()
{
status1.setText("Preparing the file");
}
});
MainActivity.this.initTTS();
response = Get(iptouse + "stop");
is_start = true;
startuploadstatusthread = true;
servercheckCounter = 0;
}
if (response != null)
{
try
{
a = new String(response, "UTF-8");
MainActivity.this.runOnUiThread(new Runnable()
{
#Override
public void run()
{
if (a.equals("Recording started"))
{
status1.setText("Recording");
}
if (a.equals("Recording stopped and preparing the file to be shared on youtube"))
{
status1.setText("Recording Stopped");
}
}
});
textforthespeacch = a;
MainActivity.this.initTTS();
} catch (UnsupportedEncodingException e)
{
e.printStackTrace();
}
Logger.getLogger("MainActivity(inside thread)").info(a);
}
}
}
});
t.start();
return true;
case MotionEvent.ACTION_MOVE:
break;
case MotionEvent.ACTION_UP:
break;
default:
return false;
}
return true;
}
This line:
status1.setText("Preparing the file");
Instead displaying only static text "Preparing the file" i was wondering how to make that it will display something like moving points like "Preparing the file..." then "Preparing the file.." and "Preparing the file." and again "Preparing the file..." then "Preparing the file.." and so on.

Use this awesome library, exactly what you are looking for:
https://github.com/tajchert/WaitingDots
Add this to dependencies
compile 'pl.tajchert:waitingdots:0.2.0'
and you can use the methos. The description is in the link

Handler handler = new Handler();
for (int i = 100; i <= 3500; i=i+100) {
handler.postDelayed(new Runnable() {
#Override
public void run() {
if(i%300 == 0){
textView.setText("Uploading.");
}else if(i%200 == 0){
textView.setText("Uploading..");
}else if(i%100 == 0){
textView.setText("Uploading...");
}
}
}, i);
}