Develop Reference

Android: ProgressDialog not progressing inside a Thread

I'm calling several AsyncTasks to do a job. In order to know when they are done. I have an object (synchronized) with a numerator that holds the number of current running AsyncTasks.
After deploying all of them I do the following:
final ProgressDialog pd = new ProgressDialog(this);
pd.setMessage(getString(R.string.please_wait));
pd.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
pd.setCancelable(false);
pd.setProgress(0);
pd.setMax(Utils.getAsyncs());
pd.show();
new Thread(new Runnable() {
#Override
public void run() {
while (Utils.getAsyncs() > 0)
pd.setProgress(pd.getMax() - Utils.getAsyncs());
runOnUiThread(new Runnable() {
public void run() {
pd.dismiss();
}
});
}
}).start();
When the dialog shows, it starts progressing but at some point it gets stuck til the end of everything and then dismisses (as expected).
I tried to put
pd.setProgress(pd.getMax() - Utils.getAsyncs());
also inside a runOnUiThread but that made things worse and I'm sure I'm missing something else. hence my question. Thanks
edited by request:
public static int getAsyncs() {
return asyncs;
}
edit 2: I did the following based on a comment
while (Utils.getAsyncs() > 0) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {}
runOnUiThread(new Runnable() {
public void run() {
pd.setProgress(pd.getMax() - Utils.getAsyncs());
}
});
}
and it seems to be better

In your class fields
private Handler progressHandler = new Handler();
private Runnable progressRunnable = new Runnable() {
#Override
public void run() {
progressDialog.setProgress(progressValue);
progressHandler.postDelayed(this, 1000);
}
};
When the time consuming thread is started
// Here start time consuming thread
// Here show the ProgressDialog
progressHandler.postDelayed(progressRunnable, 1000);
When the time consuming thread ends
progressHandler.removeCallbacks(progressRunnable);
/// Here dismiss the ProgressDialog.
ADDED:
Instead new Thread(new Runnable) that you probably use for your time consuming code I propose to do this:
To initialize the task :
MyTask task = new MyTask();
task.execute();
// Here show the PorgressDialog
progressHandler.postDelayed(progressRunnable, 1000);
Add this private class inside your main class:
private class MyTask extends AsyncTask<Void, Void, Void> {
#Override
protected Void doInBackground(Void... voids) {
//Here do your time consuming work
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
// This will be called on the UI thread after doInBackground returns
progressHandler.removeCallbacks(progressRunnable);
progressDialog.dismiss();
}
}

do something lik this
new Thread(new Runnable() {
public void run() {
while (prStatus < 100) {
prStatus += 1;
handler.post(new Runnable() {
public void run() {
pb_2.setProgress(prStatus);
}
});
try {
Thread.sleep(150);
} catch (InterruptedException e) {
e.printStackTrace();
}
if(prStatus == 100)
prStatus = 0;
}
}
}).start();

Wait for thread to finish and then move to next position

i am trying to display a Toast on the screen and when Toast fades off then move to the next question. I have tried with Thread but cannot seem to manage.
My code:
next.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (getUserSelection()){
position = position + 3;
if (position < questionsArray.size()) {
curName = questionsArray.get(position).getName();
curArray = questionsArray.get(position).getAnswers();
curIscorrect = questionsArray.get(position).getIscorrect();
setupQuestionView(curName, curArray, curIscorrect);
} else {
StringGenerator.showToast(QuestionsActivity.this, "Your score : " + score + "/" + (questionsArray.size() / 3));
}
}else {
StringGenerator.showToast(QuestionsActivity.this, getString(R.string.noanswerselected));
}
}
});
and the getUserSelectionMethod:
private boolean getUserSelection() {
correct = (RadioButton)findViewById(group.getCheckedRadioButtonId());
if (correct == null){
return false;
}else {
correctAnswerText = correct.getText().toString();
if (map.get(correctAnswerText).equals(Constants.CORRECTANSWER)) {
score++;
setCorrectMessage();
return true;
} else {
setWrongMessage();
return true;
}
}
}
private void setCorrectMessage() {
correctToast = new Toast(QuestionsActivity.this);
correctToastView = getLayoutInflater().inflate(R.layout.correct, (ViewGroup) findViewById(R.id.correctRootLayout));
correctText = (TextView)correctToastView.findViewById(R.id.correctTextView);
correctText.setText(getString(R.string.correctAnswer));
correctToast.setDuration(Toast.LENGTH_SHORT);
correctToast.setView(correctToastView);
correctToast.show();
correctThread = new Thread(new Runnable() {
#Override
public void run() {
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
correctToast.cancel();
}
});
correctThread.start();
}
private void setWrongMessage() {
wrongToast = new Toast(QuestionsActivity.this);
wrongToastView = getLayoutInflater().inflate(R.layout.wrong, (ViewGroup) findViewById(R.id.wrongRootLayout));
wrongText = (TextView)wrongToastView.findViewById(R.id.wrongTextView);
wrongText.setText(getString(R.string.wrongAnswer));
wrongToast.setDuration(Toast.LENGTH_SHORT);
wrongToast.setView(wrongToastView);
wrongToast.show();
wrongThread = new Thread(new Runnable() {
#Override
public void run() {
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
wrongToast.cancel();
}
});
wrongThread.start();
}
Any suggestion on how to do this?

You can determine the toast visibility:
toast.getView().getWindowToken()
If the result is null, than your toast isn't visible anymore, and than you can run any code you want.

as stated in this answer you can start a thread that waits the duration of the Toast:
Thread thread = new Thread(){
#Override
public void run() {
try {
Thread.sleep(3500); // 3.5seconds!
// Do the stuff you want to be done after the Toast disappeared
} catch (InterruptedException e) {
e.printStackTrace();
}
}
};
Toast.LENGTH_SHORT and Toast.LENGTH_LONG are only flags so you have to either hard code the duration or keep them in a constant. The durations are 3.5s (long) and 2s (short).
If you want to manipulate some of your views, you cannot do this in another thread than the "main" UI thread. So you have to implement a kind of callback/polling mechanism to get notified when the SleepThread has finished.
Check this answer to read about a couple of ways to do this. Probably the easiest of them to understand and implement is this:
After you started your Thread you can check if it is still alive and running by calling thread.isAlive(). In this way you can do a while loop that runs while the thread is running:
// start your thread
while(thread.isAlive()){}
// continue the work. The other thread has finished.
Please note that this is NOT the most elegant way to do this! Check the other possibilities in the answer I've mentioned above for more elegant solutions (especially the last one with the listeners is very interesting and worth reading!)

That's because the Thread class is purely executed in the background and you need to manipulate the view in the Main thread. To solve your issue just replace the Thread with AsynTask.
AsyncTask<Void,Void,Void> a = new AsyncTask<Void, Void, Void>() {
#Override
protected Void doInBackground(Void... params) {
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
correctToast.cancel();
}
};
a.execute();
If you look at my code you can see my onPostExecute, this method is called in the Main Thread.

My Error was because i was trying to acess UI Elements through another Thread so modifying the code like this:
Thread thread = new Thread(new Runnable() {
#Override
public void run() {
try {
Thread.sleep(500);
QuestionsActivity.this.runOnUiThread(new Runnable() {
#Override
public void run() {
moveToNextQuestion();
}
});
} catch (InterruptedException e) {
e.printStackTrace();
}
}
});
thread.start();
did the trick. I hope my answer helps someone!!!

Android - Cannot make a static reference to a non static method

I refactoring my threads in order to avoid memory leaks, and I got 2 errors regarding handler and startActivityForResult being called from within the thread ( dealing with GoogleDrive)
I have in my DownloadActivity :
public class DownloadActivity extends Activity {
....
private void getFolderId(){
getFolderIdThread = new GetFolderIdThread();
getFolderIdThread.start();
}
private static class GetFolderIdThread extends Thread {
private Boolean mRunning = false;
#Override
public void run() {
mRunning = true;
fResultList = new ArrayList<File>();
Files f1 = mService.files();
Files.List request = null;
aFolderId = null;
do {
try {
request = f1.list();
String aQuery = "'root' in parents and mimeType='application/vnd.google-apps.folder' and title='"+ aFolderName + "'";
request.setQ(aQuery);
FileList fileList = request.execute();
fResultList.addAll(fileList.getItems());
request.setPageToken(fileList.getNextPageToken());
} catch (UserRecoverableAuthIOException e) {
startActivityForResult(e.getIntent(), REQUEST_AUTHORIZATION); <= THIS RAISES THE ERROR
} catch (IOException e) {
e.printStackTrace();
if (request != null){
request.setPageToken(null);
}
}
} while (request.getPageToken() !=null && request.getPageToken().length() > 0);
if (fResultList.size() == 0) {
Log.d(TAG, "cannot find the training folder at root level");
Message msg = handler.obtainMessage(); <= THIS RAISES THE ERROR
Bundle bundle = new Bundle();
bundle.putInt("msgKey", DownloadActivity.NO_TRAININGS_FOLDER);
msg.setData(bundle);
handler.sendMessage(msg); <= THIS RAISES THE ERROR
} else {
File folder = fResultList.get(0);
aFolderId = folder.getId();
getFolderContents(); <= THIS RAISES THE ERROR
}
}
public void close() {
mRunning = false;
}
}
I have the handler defined in my activity
Handler handler = new Handler() {
#Override
public void handleMessage(Message msg) {
...
}
}
and the onActivityResult
protected void onActivityResult(final int requestCode, final int resultCode, final Intent data) {
switch (requestCode) {
case REQUEST_ACCOUNT_PICKER:
....
break;
}
}
what are my options to bypass this error ?

Your GetFolderIdThread class is static and a static nested class cannot reference non-static methods and fields in the instance of the outer class that created it. Such a nested class can only access static methods and fields in your Activity. Remove static from the class definition and I think your problem will resolve.
You also need to post your call to startActivityForResult on the UI thread. Of course you should be able to use your handler for that, something like:
handler.post(new Runnable()
{
public void run()
{
startActivityForResult(e.getIntent(), REQUEST_AUTHORIZATION);
}
});
Make sure your thread can gracefully complete as well when you do that because it will continue to run.

Update UI from running thread

I want to write a download manager app, in the activity I add a progress bar which show the current progress to the user, now if user touch the back button and re-open the activity again this ProgressBar won't be updated.
To avoid from this problem I create a single thread with unique name for each download that keep progress runnable and check if that thread is running in onResume function, if it is then clone it to the current thread and re-run the new thread again but it won't update my UI either, Any ideas !?
#Override
public void onResume()
{
super.onResume();
Set<Thread> threadSet = Thread.getAllStackTraces().keySet();
Thread[] threadArray = threadSet.toArray(new Thread[threadSet.size()]);
for (int i = 0; i < threadArray.length; i++)
if (threadArray[i].getName().equals(APPLICATION_ID))
{
mBackground = new Thread(threadArray[i]);
mBackground.start();
downloadProgressBar.setVisibility(View.VISIBLE);
Toast.makeText(showcaseActivity.this
, "Find that thread - okay", Toast.LENGTH_LONG).show();
}
}
private void updateProgressBar()
{
Runnable runnable = new updateProgress();
mBackground = new Thread(runnable);
mBackground.setName(APPLICATION_ID);
mBackground.start();
}
private class updateProgress implements Runnable
{
public void run()
{
while (Thread.currentThread() == mBackground)
try
{
Thread.sleep(1000);
Message setMessage = new Message();
setMessage.what = mDownloadReceiver.getProgressPercentage();
mHandler.sendMessage(setMessage);
}
catch (InterruptedException e)
{
Thread.currentThread().interrupt();
}
catch (Exception e)
{/* Do Nothing */}
}
}
private Handler mHandler = new Handler()
{
#Override
public void handleMessage(Message getMessage)
{
downloadProgressBar.setIndeterminate(false);
downloadProgressBar.setProgress(getMessage.what);
if (getMessage.what == 100)
downloadProgressBar.setVisibility(View.GONE);
}
};
Download button code:
downloadBtn.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View arg0)
{
downloadProgressBar.setVisibility(View.VISIBLE);
downloadProgressBar.setIndeterminate(true);
downloadProgressBar.setMax(100);
Intent intent = new Intent(showcaseActivity.this, downloadManagers.class);
intent.putExtra("url", "http://test.com/t.zip");
intent.putExtra("receiver", mDownloadReceiver);
startService(intent);
updateProgressBar();
}
});

I'd strongly recommend reading the Android Developer blog post on Painless Threading. As it states, the easiest way to update your UI from another thread is using Activity.runOnUiThread.

remove toast and also destroy or force stop thread

hi i am working on custom toast , and i am able to do that, but after when i move to next activity the thread is running or active of back activity , so what should i do for removing that thread or stop this thread.
my code is given below :
public void customToast(int x, int y, String str) {
if (Util.tipson == true) {
toast = new Toast(getApplicationContext());
toast.setDuration(Toast.LENGTH_SHORT);
toast.setGravity(Gravity.TOP, x, y);
LayoutInflater li = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
toastView = li.inflate(R.layout.toastlayout, null);
toast.setView(toastView);
TextView text = (TextView) toastView.findViewById(R.id.text);
text.setText(str);
// toast.show();
fireLongToast();
}
}
private void fireLongToast() {
t = new Thread() {
public void run() {
int count = 0;
try {
while (true && count < 40) {
try {
toast.show();
sleep(100);
count++;
} catch (Exception e) {
// TODO: handle exception
}
// do some logic that breaks out of the while loop
}
toast = null;
toastView = null;
} catch (Exception e) {
Log.e("LongToast", "", e);
}
}
};
t.start();
}

You Need to stop your thread by yourself. Since java doesn't allow you to use stop() function.
Write class for your Thread as this
public class YourThread extends Thread {
private volatile boolean stopped = false;
public void run() {
int count = 0;
try {
while (true && count < 40 && !stopped) {
try {
toast.show();
sleep(100);
count++;
} catch (Exception e) {
// TODO: handle exception
}
// do some logic that breaks out of the while loop
}
toast = null;
toastView = null;
} catch (Exception e) {
Log.e("LongToast", "", e);
}
}
public void stopThread() {
stopped = true;
}
}
Now when your Activity which has the Thread Finishes stop Your thread
#Override
protected void onDestroy() {
if(isFinishing())
yourThreadVariable.stopThread();
}

Dont know for sure, but you can call the function join of thread in onDestroy of your activity.

To stop the thread you can just use interrupt(). But for better solution I would say not to use Thread. Just create a Handler with Runnable and manage your Runnable using Handler, that would be a nice way as Android has given Handler for managing one or more Runnables.
Creating a Runnable
Runnable runnable = new Runnable() {
#Override
public void run() {
// put your code stuff here
}
};
To start Runnable use
handler.postDelayed(runnable, your_time_in_millis);
To stop Runnable use
handler.removeCallbacks(runnable);

Does finishing the activity have any effect?

I would like to suggest Lalit Poptani method too and implement this:
protected void onStop(){
handler.removeCallbacks(runnable);
super.onStop();
}
The documentation for the method:
onStop,Called when the activity is no longer visible to the user, because another activity has been resumed and is covering this one. This may happen either because a new activity is being started, an existing one is being brought in front of this one, or this one is being destroyed.
http://developer.android.com/reference/android/app/Activity.html