I can't find a none blocking way to invoke my callback method from the main thread as my second thread exits.
I tried to use the loading.isAlive() in a while loop but it freeze the screen.
public class MainActivity extends AppCompatActivity {
private ProgressBar progressBar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
progressBar = findViewById(R.id.load_opening_screen);
Thread loading = new LoadingBarThread();
loading.start();
}
private class LoadingBarThread extends Thread {
#Override
public void run() {
for (int i=0;i<=100;i++) {
progressBar.setProgress(i);
try {
Thread.sleep(40);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
private void callback(){
// start a new activity for example
}
}
I would like to start a new activity as the ProgressBar reaches 100.
Use a Handler object and at the end of your run() function, post a Runnable to that Handler. Have the Runnable call the callback method. Handler will execute it on the thread its attached to (whatever thread it was created on).
So your new class looks like:
private class LoadingBarThread extends Thread {
Handler handler = new Handler();
#Override
public void run() {
for (int i=0;i<=100;i++) {
progressBar.setProgress(i);
try {
Thread.sleep(40);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
handler.post(new Runnable() {
public void run() {
callback();
}
});
}
}
Related
I am running a recursive handler which runs some code. I am posting the handler using a HandlerThread. I want to run the next recursive call only after the completion of the previous call.
Is it possible to do so? If not what are the alternatives.
HandlerThread ht = new HandlerThread();
ht.start();
Handler h = new Handler(ht.getLooper());
h.post(new Runnable() {
#override
public void run(){
//Some code
h.postDelay(this,1000);
}
});
Your code should work, but if you want a complete example how to run something recursively using HandlerThread, here it is:
public class Main2Activity extends AppCompatActivity {
private MyWorkerThread mWorkerThread;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
mWorkerThread = new MyWorkerThread("myWorkerThread");
final Runnable task = new Runnable() {
#Override
public void run() {
Log.d("TAG", "Done.");
mWorkerThread.postTask(this);
}
};
mWorkerThread.start();
mWorkerThread.prepareHandler();
mWorkerThread.postTask(task);
}
#Override
protected void onDestroy() {
mWorkerThread.quit();
super.onDestroy();
}
}
class MyWorkerThread extends HandlerThread {
private Handler mWorkerHandler;
public MyWorkerThread(String name) {
super(name);
}
public void postTask(Runnable task){
mWorkerHandler.postDelayed(task, 1000); // set timeout which needed
}
public void prepareHandler(){
mWorkerHandler = new Handler(getLooper());
}
}
Don't forget to call handlerThread.quit() in onDestroy
I am updating progress bar with the help of handler of MainActivity
but it gives the error :Can't create handler inside thread that has not called Looper.prepare()
Error
public class MainActivity extends AppCompatActivity {
ProgressBar progressBar;
Handler handler;
Thread thread;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
progressBar = (ProgressBar) findViewById(R.id.progressBar);
thread = new Thread(new MyThread());
thread.start();
handler = new Handler() {
#Override
public void handleMessage(Message msg) {
progressBar.setProgress(msg.arg1);
}
};
}
class MyThread implements Runnable {
#Override
public void run() {
Message message = Message.obtain();
for (int i = 0; i < 100; i++) {
message.arg1 = i;
handler.sendMessage(message);
try {
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}
The error is because you are updating your UI from a different thread. So what you should be doing is like call the update method on main ui thread
handler = new Handler() {
#Override
public void handleMessage(Message msg) {
runOnUiThread(new Runnable() {
#Override
public void run() {
// Do something on UiThread
// update progress
}
});
};
You should run progress bar only on Main Looper.
Add
handler = new Handler(context.getMainLooper()) {
.....
}
Should work.
I have to update the list after optimizing the running apps ....
m_optimizeBtn.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
launchProgressRing(OptimizationActivity.this);
listAdaptor.notifyDataSetChanged();
}
});
}
Killing the running process in a seprate thread....
public void launchProgressRing(Context ctx){
final ProgressDialog opt_proDialog=new ProgressDialog(ctx);
opt_proDialog.setTitle("Please wait...");
opt_proDialog.setMessage("Optimizing power draining apps...");
opt_proDialog.setIndeterminate(true);
opt_proDialog.show();
opt_proDialog.setCancelable(false);
new Thread(new Runnable()
{
#Override
public void run()
{
//TODO: optimize apps
m_cPowerDrainingApps.killBgRunningProcesses(runningAppsList);
try
{
Thread.sleep(1500);
} catch (InterruptedException e)
{
e.printStackTrace();
}
runOnUiThread(new Runnable()
{
#Override
public void run()
{
opt_proDialog.dismiss();
}
});
}
}).start();
}
listAdaptor.notifyDataSetChanged() is not working ,don't know why ???
What I suggest is to use AsyncTask to do the job. AsyncTask has two good methods for you:
doInBackground: which you can put most of the background tasks in there
onPostExecute : which you can put the logic of what needs to be done when the background task has finished its job.
So your code should look like this:
public class BackgroundTask extends AsyncTask<Void,Void,Void>{
private ListAdapter mAdapter;
public BackgroundTask(ListAdapter adapter)
{
mAdapter = adapter
}
public Void doInBackground (Void... params)
{
//define m_cPowerDrainingApps somewhere
m_cPowerDrainingApps.killBgRunningProcesses(runningAppsList);
try
{
Thread.sleep(1500);
} catch (InterruptedException e)
{
e.printStackTrace();
}
}
public Void onPostExecute (Void... params)
{
//do your UI things
mAdapter.notifyDataSetChanged();
}
}
and then run this with:
new BackgroundTask(listAdapter).execute()
Use a Handler and its postDelayed method to invalidate the list's adapter as follows:
final Handler handler = new Handler()
handler.postDelayed( new Runnable() {
#Override
public void run() {
adapter.notifyDataSetChanged();
handler.postDelayed( this, 60 * 1000 );
}
}, 60 * 1000 );
You must only update UI in the main (UI) thread.
I want to make a callback function in the ShipInfoManager to inform the MainActivity to do some action.
If I put onEvent() into Runnable, it runs.
However If I put it like this, it shows an error.
Is there any way to fire the callback after loading data?
Or, is there any way to do the callback like Android's API's LocatioManger's requestLocationUpdates, giving a callback when the data/variables is changed?
Thank you for any replies!
MyCallback Interface:
interface MyCallback {
void callbackCall();
}
ShipInfoManager class:
public class ShipInfoManager {
Context mContext;
public ShipInfoManager(Context _mContext) {
this.mContext = _mContext;
reloadData();
startTimer();
}
MyCallback callback;
void onEvent() {
callback.callbackCall();
}
private void startTimer() {
/* RUN EVERY MIN */
final Handler handler = new Handler();
Timer timer = new Timer();
TimerTask doAsynchronousTask = new TimerTask() {
#Override
public void run() {
handler.post(new Runnable() {
#SuppressWarnings("unchecked")
public void run() {
try {
reloadData();
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
};
// TEMP SUSPEND FROM PREVENTING RELOAD //
timer.schedule(doAsynchronousTask, 0, 5000);
}
/* JSON handling and extraction */
private void reloadData() {
//Do sth to reload the data
//After reload, I want to fire the callback
onEvent();
}
}
It looks like you haven't any listeners to your callback and you're not checking for this.
You should replace your ShipInfoManager with this:
public class ShipInfoManager {
public interface MyCallback {
void callbackCall();
}
public void setCustomEventListener(MyCallback eventListener) {
callback = eventListener;
}
Context mContext;
public ShipInfoManager(Context _mContext) {
this.mContext = _mContext;
reloadData();
startTimer();
}
MyCallback callback;
void onEvent() {
// Check if we have listeners
if (callback != null)
callback.callbackCall();
}
private void startTimer() {
/* RUN EVERY MIN */
final Handler handler = new Handler();
Timer timer = new Timer();
TimerTask doAsynchronousTask = new TimerTask() {
#Override
public void run() {
handler.post(new Runnable() {
#SuppressWarnings("unchecked")
public void run() {
try {
reloadData();
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
};
// TEMP SUSPEND FROM PREVENTING RELOAD //
timer.schedule(doAsynchronousTask, 0, 5000);
}
/* JSON handling and extraction */
private void reloadData() {
//Do sth to reload the data
//After reload, I want to fire the callback
onEvent();
}
}
Inside your Activity or Fragment you should have something like:
public class MainActivity extends ActionBarActivity implements ShipInfoManager.MyCallback {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ShipInfoManager s = new ShipInfoManager(this);
s.setCustomEventListener(this);
}
#Override
public void callbackCall() {
}
}
I changed my MainActivity like this. It works now.
Thank you for your suggestion and reply!!!!!
public class MainActivity extends ActionBarActivity {
ShipInfoManager mShipInfo;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mShipInfo = new ShipInfoManager(this);
Log.i("Show Ship List Size", String.valueOf(mShipInfo.get_shipsList().size()));
Log.i("Show Ship - 6", String.valueOf(mShipInfo.getShip(6).getShip_name()));
mShipInfo.callback = new ShipInfoManager.MyCallback() {
#Override
public void callbackCall() {
Log.i("Call Back", "it is called");
}
};
}
I get this error "Can't create handler inside thread that has not called Looper.prepare()"
Can you tell me how to fix it?
public class PaymentActivity extends BaseActivity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.payment);
final Button buttonBank = (Button) findViewById(R.id.buttonBank);
buttonBank.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
progressDialog = ProgressDialog.show(PaymentActivity.this, "",
"Redirecting to payment gateway...", true, true);
new Thread() {
public void run() {
try {
startPayment("Bank");
} catch (Exception e) {
alertDialog.setMessage(e.getMessage());
handler.sendEmptyMessage(1);
progressDialog.cancel();
}
}
}.start();
}
});
StartPayment Method:
private void startPayment(String id) {
Bundle b = getIntent().getExtras();
final Sail sail = b.getParcelable(Constant.SAIL);
final Intent bankIntent = new Intent(this, BankActivity.class);
try {
Reservation reservation = RestService.createReservation(
sail.getId(),
getSharedPreferences(Constant.PREF_NAME_CONTACT, 0));
bankIntent.putExtra(Constant.RESERVATION, reservation);
// <workingWithDB> Storing Reservation info in Database
DBAdapter db = new DBAdapter(this);
db.open();
#SuppressWarnings("unused")
long rowid;
rowid = db.insertRow(sail.getId(), sail.getFrom(),
sail.getTo(), sail.getShip(), sail.getDateFrom().getTime(),
sail.getPrice().toString(), reservation.getId().floatValue());
db.close();
// </workingWithDB>
String html = PaymentService.getRedirectHTML(id, reservation);
bankIntent.putExtra(Constant.BANK, html);
} catch (Exception e) {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
AlertDialog alertDialog = builder.create();
alertDialog.setMessage(e.getMessage());
alertDialog.show();
}
startActivity(bankIntent);
}
You should know that when you try to modify your UI , the only thread who can do that is the UiThread.
So if you want to modify your UI in another thread, try to use the method: Activity.runOnUiThread(new Runnable);
Your code should be like this :
new Thread() {
public void run() {
YourActivity.this.runOnUiThread(new Runnable(){
#Override
public void run(){
try {
startPayment("Bank");//Edit,integrate this on the runOnUiThread
} catch (Exception e) {
alertDialog.setMessage(e.getMessage());
handler.sendEmptyMessage(1);
progressDialog.cancel();
}
});
}
}
}.start();
I assume you create a Handler in startPayment() method. You can't do that, as handlers can be created on th UI thread only. Just create it in your activity class.
Instead of new Thread() line, try giving
this.runOnUiThread(new Runnable() {
you cant change any UI in thread you can use runOnUIThread or AsyncTask for more detail about this click here
I've found that most thread handling can be replaced by AsyncTasks like this:
public class TestStuff extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button buttonBank = (Button) findViewById(R.id.button);
buttonBank.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
new StartPaymentAsyncTask(TestStuff.this).execute((Void []) null);
}
});
}
private class StartPaymentAsyncTask extends AsyncTask<Void, Void, String> {
private ProgressDialog dialog;
private final Context context;
public StartPaymentAsyncTask(Context context) {
this.context = context;
}
#Override
protected void onPreExecute() {
dialog = new ProgressDialog(context);
// setup your dialog here
dialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
dialog.setMessage(context.getString(R.string.doing_db_work));
dialog.setCancelable(false);
dialog.show();
}
#Override
protected String doInBackground(Void... ignored) {
String returnMessage = null;
try {
startPayment("Bank");
} catch (Exception e) {
returnMessage = e.getMessage();
}
return returnMessage;
}
#Override
protected void onPostExecute(String message) {
dialog.dismiss();
if (message != null) {
// process the error (show alert etc)
Log.e("StartPaymentAsyncTask", String.format("I received an error: %s", message));
} else {
Log.i("StartPaymentAsyncTask", "No problems");
}
}
}
public void startPayment(String string) throws Exception {
SystemClock.sleep(2000); // pause for 2 seconds for dialog
Log.i("PaymentStuff", "I am pretending to do some work");
throw new Exception("Oh dear, database error");
}
}
I pass in the Application Context to the Async so it can create dialogs from it.
The advantage of doing it this way is you know exactly which methods are run in your UI and which are in a separate background thread. Your main UI thread isn't delayed, and the separation into small async tasks is quite nice.
The code assumes your startPayment() method does nothing with the UI, and if it does, move it into the onPostExecute of the AsyncTask so it's done in the UI thread.
Try
final Handler handlerTimer = new Handler(Looper.getMainLooper());
handlerTimer.postDelayed(new Runnable() {
public void run() {
......
}
}, time_interval});