Wsrtjtyk

I'm a new in RxJava in Android development. I had changed in project AsyncTask to RxJava and got a ConcurrentModificationException. Yes, I used collection (sparseArray) but it doesn't matter 'cause exeption was thrown in findViewById.setVisibility. Only when I try to invoke setVisibility. I confused, what I do wrong? I have a TextView in fragment. At first I set up OnClickListener, in listener I init Single.fromCallable, then I set up OnDragListener

TextView tv;



tv.setOnClickListener(v -> {

          if (isClickEnable) {

              tv.setBackgroundResource(R.drawable.cheap_dark);

              cheapInObservable(tv);



          }



});



tv.setOnDragListener(new MyDragListener());



private void cheapInObservable(TextView tView) {

        Single.fromCallable( () ->  tView).subscribeOn(Schedulers.io())

              .delay(250, TimeUnit.MILLISECONDS, AndroidSchedulers.mainThread())

              .doOnSuccess(this::onSuccessCheapIn)

              .subscribe();

    }

And in this code I get exeption:

private class MyDragListener implements View.OnDragListener {



        @Override

        public boolean onDrag(View v, DragEvent event) {

            View dragView = (View)event.getLocalState();

            switch (event.getAction()) {

                case DragEvent.ACTION_DRAG_ENDED:

                    if(!event.getResult()) {

                        if(dragView == v) {

                            dragView.setVisibility(View.VISIBLE);

                            activity.findViewById(sparseCheaps.get(dragView.getId())).

                                     setVisibility(View.VISIBLE);



                        }

                    }

                    break;





private void onSuccessCheapIn(TextView tv) {

            tv.setVisibility(View.INVISIBLE);

            TextView tvd = activity.findViewById(sparseCheaps.get(tv.getId()));

            tvd.setVisibility(View.VISIBLE);

            AnimatorSet set = new AnimatorSet();

            tvd.animate().rotation(0);

            int up = activity.findViewById(R.id.guidelineGlowUp).getTop();

            int left = getXcoord(tvd);

            set.setDuration(400).playTogether(ObjectAnimator.ofFloat(tvd, TextView.TRANSLATION_X,

                    tvd.getX(), left),

                    ObjectAnimator.ofFloat(tvd, TextView.TRANSLATION_Y, tvd.getY(), up - 3));



            set.setInterpolator(new AccelerateInterpolator((float) 0.4));



            set.addListener(new AnimatorListenerAdapter() {

                @Override

                public void onAnimationEnd(Animator animation) {

                    isAnimationCheaps = false;

                    super.onAnimationEnd(animation);

                }

            });



            set.start();

        }

I've found out that only the exeption is thrown when I use setVisibility. If I use AsyncTask instead of Rx it works without exception

StackTrace is:

java.util.ConcurrentModificationException

        at java.util.HashMap$HashIterator.nextEntry(HashMap.java:795)

        at java.util.HashMap$KeyIterator.next(HashMap.java:822)

        at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1154)

        at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1156)

        at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1156)

        at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1156)

        at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1156)

        at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1156)

        at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1156)

        at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1156)

        at android.view.ViewRootImpl.handleDragEvent(ViewRootImpl.java:4322)

        at android.view.ViewRootImpl.access$1100(ViewRootImpl.java:103)

        at android.view.ViewRootImpl$ViewRootHandler.handleMessage(ViewRootImpl.java:3407)

        at android.os.Handler.dispatchMessage(Handler.java:107)

        at android.os.Looper.loop(Looper.java:194)

        at android.app.ActivityThread.main(ActivityThread.java:5370)

        at java.lang.reflect.Method.invokeNative(Native Method)

        at java.lang.reflect.Method.invoke(Method.java:525)

        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)

        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)

        at dalvik.system.NativeStart.main(Native Method)