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Android Fragments - Only the original thread that created a view hierarchy can touch its views [duplicate]

This question already has answers here:
Android "Only the original thread that created a view hierarchy can touch its views."
(33 answers)
How do we use runOnUiThread in Android?
(13 answers)
Closed 2 years ago.
this is my main activity:
public class LearnTree extends AppCompatActivity {
private RulesFragment rulesFragment;
private TreeFragment treeFragment;
private PredictionFragment predictionFragment;
TabLayout tabLayout;
ViewPager viewPager;
private Button button;
private static ObjectOutputStream out;
private static ObjectInputStream in;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.learn_tree);
tabLayout=findViewById(R.id.tab_layout);
viewPager= findViewById((R.id.view_pager));
final ViewPagerAdapter viewPagerAdapter= new ViewPagerAdapter(getSupportFragmentManager());
viewPagerAdapter.addFragment(RulesFragment.getInstance(), "TREE RULES");
viewPagerAdapter.addFragment(TreeFragment.getInstance(), "REGRESSION TREE");
viewPagerAdapter.addFragment(PredictionFragment.getInstance(), "PREDICTION");
rulesFragment= (RulesFragment) viewPagerAdapter.getItem(0);
treeFragment= (TreeFragment) viewPagerAdapter.getItem(1);
predictionFragment= (PredictionFragment) viewPagerAdapter.getItem(2);
viewPager.setAdapter(viewPagerAdapter);
tabLayout.setupWithViewPager(viewPager);
LearnTree.PrimeThread p=new LearnTree.PrimeThread();
p.start();
}
private class PrimeThread extends Thread {
public void run() {
out= SocketObject.getOut();
in = SocketObject.getIn();
// print rules
rulesFragment.setText((String)in.readObject());
//print tree
treeFragment.setText((String)in.readObject());
}
}
}
And this is one my 3 fragments, the other 2 are almost the same:
public class RulesFragment extends Fragment {
// Store instance variables
private String title;
private int page;
private TextView rulesView;
public static RulesFragment getInstance() {
RulesFragment rulesFragment = new RulesFragment();
return rulesFragment;
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view= inflater.inflate(R.layout.rules_fragment, container, false);
rulesView= (TextView) view.findViewById(R.id.textview_treerules);
rulesView.setMovementMethod(new ScrollingMovementMethod());
return view;
}
public void setText(String text){
rulesView.setText(text);
}
}
When executing rulesFragment.setText((String)in.readObject()); I get this error: Only the original thread that created a view hierarchy can touch its views
That's because I created the textview in onCreateView but I'm editing it in setText right? The problem is that I need to edit that text multiple times during the program execution and I cannot transfer part of my code in onCreateView (to make it run like a separate thread i guess?) because I need to retrieve input from the Socket sequentially.
Is there another way to do this?
Moreover let's say I have a Spinner in the third fragment and a button "Send". When the user hits Send I'm supposed to reset every textview in each fragment to empty and I need to restart the execution in PrimeThread in LearnTree class. How can I do this? Is there a way to detect the onClick event of send button from the mainactivity?

The previous answer is very complete.
However, you could try by calling the:
Device.BeginInvokeOnMainThread(
() => { lblStatus.Text = "Updating..."; }
);

To answer your main issue, what is happening is that the thread that creates the view is the Main UI thread. For this reason, whenever you want to change something on the UI from a different thread (in your case the PrimeThread), you should execute the functions by using runOnUiThread.
This means in your code you should have:
String rules = (String)in.readObject()
String tree = (String)in.readObject()
requireActivity().runOnUiThread(new Runnable() {
#Override
public void run() {
// print rules
rulesFragment.setText(rules);
//print tree
treeFragment.setText(tree);
}
});
For your last question about having a listener for a button click, you can do it like this:
Button buttonY = (Button)findViewById(R.id.buttonYName);
// Register the onClick listener with the implementation above
buttonY.setOnClickListener(new OnClickListener() {
public void onClick(View v)
{
(LearnTree)getActivity().primeThread.start(); // Assuming this is executed in the context of a Fragment
}
});
If you want to restart the thread in the LearnTree Activity, you need to store the thread in a class variable:
public LearnTree.PrimeThread primeThread;
Or declare it as private and have a getter/setter, it's up to you.
Also, you should create your ViewPagerAdapter like this, otherwise you will get crashes:
public class ViewPagerAdapter extends FragmentPagerAdapter {
public ViewPagerAdapter(FragmentManager fragmentManager) {
super(fragmentManager);
}
#Override
public Fragment getItem(int position) {
if(position == 0) return new RulesFragment();
if(position == 1) return new TreeFragment();
if(position == 2) return new PredictionFragment();
throw new IllegalStateException("Unexpected position " + position);
}
#Override
public int getCount() {
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
if(position == 0) return "TREE RULES";
if(position == 1) return "REGRESSION TREE";
if(position == 2) return "PREDICTION";
throw new IllegalStateException("Unexpected position " + position);
}
}
To get a reference to a Fragment created by a ViewPager, use the following findFragmentByTag scheme:
Fragment fragment = supportFragmentManager.findFragmentByTag("android:switcher:" + viewPager.getId() + ":" + fragmentPosition)

AsyncTaskLoader not calling onFinishedLoad after orientation change

Some background information:
I am using a Activity>ParentFragment(Holds ViewPager)>Child fragments.
Child Fragments are added dynamically with add, remove buttons.
I am using MVP architecture
Actual Problem:
In child fragment, we have listview that populates using an asynctaskloader via a presenter.
Child Fragment:
//Initialize Views
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
root = inflater.inflate(R.layout.fragment_search_view_child, container, false);
.......
mSearchViewPresenter= new SearchViewPresenter(
getActivity(),
new GoogleSuggestLoader(getContext()),
getActivity().getLoaderManager(),
this, id
);
SearchList list=new SearchList();
//requestList from presenter
searchListAdapter =new SearchViewListAdapter(getActivity(), list, this);
listView.setAdapter(searchListAdapter);
......
return root;
}
#Override
public void onResume(){
super.onResume();
mSearchViewPresenter.start();
searchBar.addTextChangedListener(textWatcher);
}
In the presenter class we have:
public SearchViewPresenter(#NonNull Context context, #NonNull GoogleSuggestLoader googleloader,#NonNull LoaderManager loaderManager,
#NonNull SearchViewContract.View tasksView, #NonNull String id) {
// mLoader = checkNotNull(loader, "loader cannot be null!");
mLoaderManager = checkNotNull(loaderManager, "loader manager cannot be null");
// mTasksRepository = checkNotNull(tasksRepository, "tasksRepository cannot be null");
mSearchView = checkNotNull(tasksView, "tasksView cannot be null!");
mSearchView.setPresenter(this);
searchList=new SearchList();
this.googleLoader=googleloader;
this.context=context;
this.id=loaderID;
// this.id=Integer.parseInt(id);
}
#Override
public void start() {
Log.d("start>initloader","log");
mLoaderManager.restartLoader(1, null, this);
}
//TODO implement these when you are ready to use loader to cache local browsing history
#Override
public android.content.Loader<List<String>> onCreateLoader(int i, Bundle bundle) {
int loaderid=googleLoader.getId();
Log.d("Loader: ", "created");
googleLoader=new GoogleSuggestLoader(context);
googleLoader.setUrl("");
googleLoader.setUrl(mSearchView.provideTextQuery());
return googleLoader;
}
#Override
public void onLoadFinished(android.content.Loader<List<String>> loader, List<String> data) {
Log.d("Loader: ", "loadFinished");
searchList.clear();
for (int i = 0; i < data.size(); ++i) {
searchList.addListItem(data.get(i), null, LIST_TYPE_SEARCH, android.R.drawable.btn_plus);
Log.d("data Entry: ",i+ " is: "+searchList.getText(i));
}
mSearchView.updateSearchList(searchList);
}
#Override
public void onLoaderReset(android.content.Loader<List<String>> loader) {
}
Also we have this code in the presenter that is triggered by a edittext box on the fragment view being edited.
#Override
public void notifyTextEntry() {
//DETERMINE HOW TO GIVE LIST HERE
// Dummy List
Log.d("notifyTextEntry","log");
if(googleLoader==null)googleLoader=new GoogleSuggestLoader(context);
googleLoader.setUrl(mSearchView.provideTextQuery());
// mLoaderManager.getLoader(id).abandon();
mLoaderManager.getLoader(1).forceLoad();
mLoaderManager.getLoader(1).onContentChanged();
Log.d("length ", searchList.length().toString());
// googleLoader.onContentChanged();
}
Lastly we have the loader here:
public class GoogleSuggestLoader extends AsyncTaskLoader<List<String>>{
/** Query URL */
private String mUrl;
private static final String BASE_URL="https://suggestqueries.google.com/complete/search?client=firefox&oe=utf-8&q=";
private List<String> suggestions =new ArrayList<>();
public GoogleSuggestLoader(Context context) {
super(context);
this.mUrl=BASE_URL;
}
public void setUrl(String mUrl){
this.mUrl=BASE_URL+mUrl;
};
#Override
protected void onStartLoading() {forceLoad(); }
#Override
public List<String> loadInBackground() {
if (mUrl == null) {
return null;
}
try {
suggestions = new ArrayList<>();
Log.d("notifyinsideLoader","log");
String result=GoogleSuggestParser.parseTemp(mUrl);
if(result!=null) {
JSONArray json = new JSONArray(result);
if (json != null) {
JSONArray inner=new JSONArray((json.getString(1)));
if(inner!=null){
for (int i = 0; i < inner.length(); ++i) {
//only show 3 results
if(i==3)break;
Log.d("notifyinsideLoader",inner.getString(i));
suggestions.add(inner.getString(i));
}
}
}
}
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
return suggestions;
}
}
So the problem:
The code loads the data fine to the listview on the fragment. When orientation changes loader is not calling onLoadFinished. I have tested the loader and it is processing the data fine.
I have already tried forceload and onContentChanged in the presenter to no avail.
If you need anymore info or if I should just use something else like RxJava let me know. But I would really like to get this working.
Before you ask I have seen similar problems like: AsyncTaskLoader: onLoadFinished not called after orientation change however I am using the same id so this problem should not exist.

The answer was on this page AsyncTaskLoader doesn't call onLoadFinished
but details were not given as to how to move to this.
So let me explain here for anyone else with this problem in future.
Support library is meant for fragments. So the class that is in charge of callbacks has to be importing AND implementing the correct methods from the support library. Same as if you are using MVP your presenter must extend from support loadermanager.
i.e: import android.support.v4.app.LoaderManager; Then implement correct callbacks.
Like
#Override
public android.support.v4.content.Loader<List<String>> onCreateLoader(int i, Bundle bundle) {
...
return new loader
}
and
#Override
public void onLoadFinished(android.support.v4.content.Loader<List<String>> loader, List<String> data) {
//do something here to your UI with data
}
Secondly: The loader itself must be extending from support asynctaskloader.
i.e: import android.support.v4.content.AsyncTaskLoader;

Android viewpager AsyncTask finish when page changed

I have view pager. My viewpager contains 3 fragments. In the first fragment I have an AsyncTask class. I parsed JSON with AsyncTask and I can show it in listview. (everything is ok)
I have one problem AsyncTask which I have in the first fragment does not finish when I go to the next fragments. When I am in the second fragment my AsyncTask is also running. How can I write code to cancel my AsyncTask when viewpager's page changed?
This is my source (this is the first fragment source; another fragment source is the same but the only difference is the Server Url):
public class StradaChefs1 extends Fragment {
public static CustomerStatistic stat;
private ConnectionDetector con;
private AlertDialogManager alert = new AlertDialogManager();
#SuppressLint("ClickableViewAccessibility")
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.strada_chefs_1, container,
false);
stat = new CustomerStatistic();
con = new ConnectionDetector(getActivity());
if (!con.isConnectingToInternet()) {
alert.showAlertDialog(getActivity(),
"You have not internet connection");
} else {
stat.execute("my urlllllllll"); // geo
}
return rootView;
}
public class CustomerStatistic extends AsyncTask<String, Void, String> {
ProgressDialog pDialog;
#Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = ProgressDialog.show(getActivity(), "Please Wait... ",
"Loading... ");
pDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
pDialog.setCancelable(false);
pDialog.show();
}
#Override
protected String doInBackground(String... params) {
return Utils.getJSONString(params[0]);
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
try {
JSONArray mainJson = new JSONArray(result);
String first = mainJson.getString(0);
JSONObject jobject = new JSONObject(first);
String image = jobject.getString("image");
String String_title = jobject.getString("title");
String String_name = jobject.getString("name");
String String_desc = jobject.getString("description");
String second = mainJson.getString(1);
} catch (JSONException e) {
e.printStackTrace();
}
if (pDialog != null) {
pDialog.dismiss();
pDialog = null;
}
}
}
#Override
public void onResume() {
Log.e("DEBUG", "onResume of HomeFragment");
super.onResume();
}
#Override
public void onStop() {
super.onStop();
if (stat != null && stat.equals(AsyncTask.Status.RUNNING)) {
stat.cancel(true);
Toast.makeText(getActivity(), "finished", Toast.LENGTH_SHORT)
.show();
}
}
}
This is a viewpager java code
public class TabbedActivity1 extends Fragment {
private StradaChefs1 mfragment1;
private StradaChefs2 mfragment2;
private StradaChefs3 mfragment3;
private StradaChefs4 mfragment4;
SectionsPagerAdapter mSe;
public static final String TAG = TabbedActivity1.class.getSimpleName();
ViewPager mViewPager;
private ArrayList<Fragment> fragmentList;
public static TabbedActivity1 newInstance() {
return new TabbedActivity1();
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.activity_item_one_1, container, false);
mSe=new SectionsPagerAdapter(getChildFragmentManager());
mViewPager = (ViewPager) v.findViewById(R.id.pager1);
CirclePageIndicator circle=(CirclePageIndicator)v.findViewById(R.id.circleindicator1);
mViewPager.setAdapter(mSe);
circle.setViewPager(mViewPager);
mfragment1 = new StradaChefs1();
mfragment2 = new StradaChefs2();
mfragment3 = new StradaChefs3();
mfragment4 = new StradaChefs4();
fragmentList = new ArrayList<Fragment>();
fragmentList.add(mfragment1);
fragmentList.add(mfragment2);
fragmentList.add(mfragment3);
fragmentList.add(mfragment4);
mViewPager.setPageTransformer(false, new PageTransformer() {
#Override
public void transformPage(View page, float position) {
page.setRotationY(position * -40);
}
});
return v;
}
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
return fragmentList.get(position);
}
#Override
public int getCount() {
return 4;
}
#Override
public CharSequence getPageTitle(int position) {
return null;
}
}
}
How can I solve this problem?

The FragmentPagerAdapter keeps additional fragments, besides the one shown, in resumed state, so you can't use onPause and onResume for starting/stopping the AsyncTask. The solution is to implement a custom OnPageChangeListener and create a new method for when the fragment is shown.
1) Create LifecycleManager Interface The interface will have two methods and each ViewPager’s Fragment will implement it. These methods Are as follows:
public interface FragmentLifecycle {
public void onPauseFragment();
public void onResumeFragment();
}
2) Let each Fragment implement the interface
3) Implement interface methods in each fragment - in onPauseFragment stop the AsyncTask, in onResumeFragment start it
4) Call interface methods on ViewPager page change You can set OnPageChangeListener on ViewPager and get callback each time when ViewPager shows another page
5) Implement OnPageChangeListener to call your custom Lifecycle methods
Listener knows the new position and can call the interface method on new Fragment with the help of PagerAdapter. I can here call onResumeFragment() for new fragment and onPauseFragment() on the current one.
I need to store also the current fragment’s position (initially the current position is equal to 0), since I don’t know whether the user scrolled from left to right or from right to left. See what I mean in code:
private OnPageChangeListener pageChangeListener = new OnPageChangeListener() {
int currentPosition = 0;
#Override
public void onPageSelected(int newPosition) {
FragmentLifecycle fragmentToShow = (FragmentLifecycle)pageAdapter.getItem(newPosition);
fragmentToShow.onResumeFragment();
FragmentLifecycle fragmentToHide = (FragmentLifecycle)pageAdapter.getItem(currentPosition);
fragmentToHide.onPauseFragment();
currentPosition = newPosition;
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) { }
public void onPageScrollStateChanged(int arg0) { }
};
I didn't write the code. Full tutorial here

When you start the asynctask set the flag isRunning=true
when you are trying to jump from one fragment to other it mean
as per fragment lifecycle your are pausing and stoping your current fragment
so in onStop method of fragment you can check isRunning flag of asynctask is true if yes the
cancel the asyntask
its my logic hope it will help you to achieve your requirement

FragmentPagerAdapter not restoring fragments upon Orientation Change

EDIT: I found out that the Activity is saving the instance, but the Fragments saved data is not making it up to the Activity savedInstanceState. I'm saving the current time in the outState, but its not making its way all the way up, as the activity has nothing in its SavedInstanceState for the time and returns 'null' for the time if I print it to the logcat....
I am building an application that has the a countup and countdown timer built in. The basic hosting activity for the timers is a FragmentActivity which hosts a FragementPagerAdapter that inflates two fragments within the code (I do not give an id to the fragments within the XML as they are not defined as fragments within the .xml). Everything works great until an orientation change and then the activity looks like it looses contact with the old fragments and just chooses to create new ones. This means that any current countdown is lost and any time chosen is also lost upon configuration change. I will need to keep the count going (if its started) and any numbers currently displayed....
I know that the Adapter is supposed to handle these things on its own, and I'm setting the SetRetainInstance(true) in both the OnCreate and OnCreateView.
I put in hooks into the Fragment code to let me know whenever the saveInstanceState is NOT null so at least I know what is going on, but it seems like the instance is always NULL, and it creates from scratch...always.
Some other solutions have me overriding the instantiateItem, but it seems that its is only used for getting callbacks reset, others changing a setting in the Manifest(frowned upon).... Other solutions look to me like I have things setup right...but obviously, I'm messing something up along the way. I'm only giving code for the FragmentActivity, FragementPagerAdapter, and a bit of the Fragment code as I don't want to spam the post with code that may not be the issue.
The FragmentActivity
public class Timer_Main extends FragmentActivity {
ViewPager pager;
Timer_Pager mAdapter;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.timer_pager);
mAdapter = new Timer_Pager(this, getSupportFragmentManager());
pager = (ViewPager) findViewById(R.id.timer_pager_display);
pager.setAdapter(mAdapter);
}
public static String getTitle(Context ctxt, int position) {
// TODO Auto-generated method stub
return null;
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("pageItem", pager.getCurrentItem());
}
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
}
}
The FragementPagerAdapter
public class Timer_Pager extends FragmentPagerAdapter{
Context ctxt = null;
public Timer_Pager(Context ctxt, FragmentManager fm) {
super(fm);
this.ctxt = ctxt;
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0: {
return(Countdown_Fragment.newInstance());
}
case 1:
return(Countup_Fragment.newInstance());
}
return null;
}
#Override
public String getPageTitle(int position) {
switch (position) {
case 0:
return(String.format(ctxt.getString(R.string.Countdown_label)));
case 1:
return(String.format(ctxt.getString(R.string.Countup_label)));
}
return null;
}
#Override
public int getCount() {
// doing only three pages, right now...one for countdown, one for countup, and one for Tabata.
return 2;
}
private static String makeFragmentName(int viewId, int position)
{
return "android:switcher:" + viewId + ":" + position;
}
}
The Fragment has a bit more code in it, so I'll push in just what should be the core of the problem....if more is needed, I'll splice it in.
public class Countdown_Fragment extends Fragment implements OnClickListener {
Calendar CountdownTime = Calendar.getInstance();
static AutoResizeTextView tv;
static ImageButton HoursUp;
static ImageButton HoursDown;
static ImageButton MinutesUp;
static ImageButton MinutesDown;
static ImageButton SecondsUp;
static ImageButton SecondsDown;
static ImageButton Reset;
static ImageButton StartPausecount;
static ImageButton Stopcount;
static Boolean Arewecounting = false;
static Boolean Arewecountingdown = false;
static AutoResizeTextView ThreetwooneGO;
static MyCountdownTimer Countdown_Timer_Activity;
ThreetwooneCount Start_countdown;
static Long MillstoPass;
static Countdown_Fragment newInstance() {
Countdown_Fragment frag = new Countdown_Fragment();
return (frag);
}
#Override
public void onSaveInstanceState(Bundle outState) {
outState.putString("CurrentTimer", (String) tv.getText());
Log.v("status", "saved fragment state" + tv.getText());
super.onSaveInstanceState(outState);
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
}
#Override
public void onCreate(Bundle savedInstanceState) {
setRetainInstance(true);
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
setRetainInstance(true);
View result = inflater.inflate(R.layout.countdown_timer_layout,
container, false);
tv = (AutoResizeTextView) result.findViewById(R.id.timer_textview);
tv.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
new TimePickerDialog(getActivity(), t, 0, 0, true).show();
}
});
if (savedInstanceState != null) {
Log.v("status", "fragment is NOT empty");
tv.setText(savedInstanceState.getString("CurrentTimer",
tv.toString()));
} else {
Log.v("status", "fragment is empty");
// tv.setText("00:00:00");
}
tv.resizeText();
ThreetwooneGO = (AutoResizeTextView) result
.findViewById(R.id.timer_countdown_text);
HoursUp = (ImageButton) result.findViewById(R.id.hours_up);
HoursDown = (ImageButton) result.findViewById(R.id.hours_down);
MinutesUp = (ImageButton) result.findViewById(R.id.minutes_up);
MinutesDown = (ImageButton) result.findViewById(R.id.minutes_down);
SecondsUp = (ImageButton) result.findViewById(R.id.seconds_up);
SecondsDown = (ImageButton) result.findViewById(R.id.seconds_down);
Reset = (ImageButton) result.findViewById(R.id.reset);
StartPausecount = (ImageButton) result
.findViewById(R.id.startpausecount);
Stopcount = (ImageButton) result.findViewById(R.id.stopcount);
HoursUp.setOnClickListener(this);
HoursDown.setOnClickListener(this);
SecondsUp.setOnClickListener(this);
SecondsDown.setOnClickListener(this);
MinutesUp.setOnClickListener(this);
MinutesDown.setOnClickListener(this);
Reset.setOnClickListener(this);
StartPausecount.setOnClickListener(this);
Stopcount.setOnClickListener(this);
return (result);
}
public void chooseTime(View v) {
new TimePickerDialog(getActivity(), t, 0, 0, true).show();
}
TimePickerDialog.OnTimeSetListener t = new TimePickerDialog.OnTimeSetListener() {
public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
CountdownTime.set(Calendar.HOUR_OF_DAY, hourOfDay);
CountdownTime.set(Calendar.MINUTE, minute);
CountdownTime.set(Calendar.SECOND, 0);
CountdownTime.set(Calendar.MILLISECOND, 0);
updateLabel();
}
};
private void updateLabel() {
String entiretime;
entiretime = String.format("%tT", CountdownTime);
tv.setText(entiretime);
}
Here is my timer that I'm using for Countdown....
public class MyCountdownTimer {
private long millisInFuture;
private long countDownInterval;
Countdown_Fragment ctxt;
AutoResizeTextView Timer_edit;
private volatile boolean IsStopped = false;
public MyCountdownTimer(long pMillisInFuture, long pCountDownInterval,
AutoResizeTextView Artv) {
this.millisInFuture = pMillisInFuture;
this.countDownInterval = pCountDownInterval;
Timer_edit = Artv;
}
public void Start() {
final Handler handler = new Handler();
final Runnable counter = new Runnable() {
public void run() {
if (IsStopped == false) {
if (millisInFuture <= 0) {
Countdown_Fragment.done_counting();
} else {
long sec = millisInFuture / 1000;
Timer_edit.setText(String.format("%02d:%02d:%02d",
sec / 3600, (sec % 3600) / 60, (sec % 60)));
millisInFuture -= countDownInterval;
handler.postDelayed(this, countDownInterval);
}
}
}
};
handler.postDelayed(counter, countDownInterval);
}
public void Cancel() {
IsStopped = true;
Timer_edit = null;
Log.v("status", "Main Timer cancelled");
// this.ctxt = null;
}
public long whatisourcount(){
return(millisInFuture);
}
}

As it turns out, the RetainInstance was causing a conflict between itself and the ViewPager/Adapter/FragmentManager doing their things . Removing it caused the Pager to properly rebuilt the Fragment, including the TextView I had, where it did not before. I also start to recieve a Bundle in the OnCreateView, where that was always null before with the RetainInstance set to True.
I had to remove the RetainInstance and utilize the OnSaveInstanceState and OnCreateView to pass in the current status of the Fragment before it was destroyed, and then re-create it in OnCreateView to reset the Fragment to its state before it was destroyed.
I was hoping that the Runnable that I was using to do the countdown would survive, or I would be able to reattach it, but I couldn't find a way. I had to save the current count in Milliseconds, and pass back to the Fragment to continue where it left off. Its not that big of a deal, but I am curious to see if you can truely re-attach all those things. The Runnable DOES still continue after the config change, but it doesn't update anything on the UI anymore, so I try to cancel the callbacks and null it when I'm inside OnSaveInstanceState.
I'm also reading items where I only need to use RetainInstance for items that have a AsyncTask attached or another similar item....otherwise, just rebuild it within the code.

Fragments are not being released from memory

I have an activity that contains a View Pager that has an adapter FragmentStatePagerAdapter.
each time enter the activity it will take up 200mb of memory, after going back out of the activity(finish()) and then re entering it it will append and double the memory used on the phone.
After troubleshooting the problem it seems as if the fragment manager is not releasing the fragments although im trying to remove them but its just not working.
I tried emptying the fragment that is being added to make sure its not something internal inside the fragment the the problem remains.
my adapter code is
private class ChildrenPagerAdapter extends FragmentStatePagerAdapter
{
private List<ChildBean> childrenBean;
public ChildrenPagerAdapter(FragmentManager fm, List<ChildBean> bean)
{
super(fm);
this.childrenBean = bean;
}
#Override
public int getItemPosition(Object object)
{
return PagerAdapter.POSITION_NONE;
}
#Override
public Fragment getItem(int position)
{
ReportFragment reportFragment = new ReportFragment();
reportFragment.childBean = childrenBean.get(position);
reportFragment.position = position;
reportFragment.mPager = mPager;
if(position == 0)
{
reportFragment.mostLeft = true;
}
if(position == childrenNumber - 1)
{
reportFragment.mostRight = true;
}
return reportFragment;
}
#Override
public int getCount()
{
return childrenNumber;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object)
{
// TODO Auto-generated method stub
super.destroyItem(container, position, object);
}
}
my activity code is
public class ReportActivity extends CustomActivity
{
public ImageLoader imageLoader;
private ViewPager mPager;
private PagerAdapter mPagerAdapter;
private int childrenNumber;
private int currentChild;
#Override
protected void onDestroy()
{
mPager.removeAllViews();
mPager.removeAllViewsInLayout();
mPager.destroyDrawingCache();
mPagerAdapter = null;
mPager = null;
System.gc();
super.onDestroy();
}
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setCustomTitle(string.title_activity_reports);
this.currentChild = getIntent().getIntExtra("itemselected", -1);
getSupportFragmentManager().
}
#Override
protected void onResume()
{
super.onResume();
mPager = (ViewPager) findViewById(R.id.vpchildren);
mPager.setOffscreenPageLimit(6);
childrenNumber = MainActivity.bean.size();
mPagerAdapter = new ChildrenPagerAdapter(getSupportFragmentManager(), MainActivity.bean);
mPager.setAdapter(mPagerAdapter);
mPager.setCurrentItem(currentChild);
}
}
Fragment code :
public class ReportFragment extends Fragment
{
public ChildBean childBean;
public int position;
public ImageView img;
public ImageLoader imageLoader;
public DisplayImageOptions options;
private int pee = 0;
private int poop = 0;
private double sleep = 0.0;
public ViewPager mPager;
public boolean mostLeft = false;
public boolean mostRight = false;
public ReportFragment()
{
}
#Override
public void onDestroyView()
{
super.onDestroyView();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
ViewGroup rootView = (ViewGroup) inflater.inflate(R.layout.report_fragment, container, false);
if(mostLeft)
{
rootView.findViewById(id.btnleft).setVisibility(View.GONE);
}
if(mostRight)
{
rootView.findViewById(id.btnright).setVisibility(View.GONE);
}
rootView.findViewById(id.btnleft).setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
mPager.setCurrentItem(mPager.getCurrentItem() - 1);
}
});
rootView.findViewById(id.btnright).setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
mPager.setCurrentItem(mPager.getCurrentItem() + 1);
}
});
SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy", Locale.ENGLISH);
Date dobchild = new Date();
((TextView) rootView.findViewById(id.tvday)).setText(sdf.format(dobchild));
ImageView childimg = (ImageView) rootView.findViewById(id.img_child);
((TextView) rootView.findViewById(id.tvchildname)).setText(childBean.childname);
((TextView) rootView.findViewById(id.tvclassname)).setText(((CustomApplication) getActivity().getApplication()).preferenceAccess.getCurrentClassName());
Date dob = null;
String age = "";
try
{
dob = sdf.parse(childBean.childdob);
age = GeneralUtils.getAge(dob.getTime(), getString(string.tv_day), getString(string.tv_month), getString(string.tv_year));
}
catch(ParseException e)
{
// TODO:
}
((CustomTextView) rootView.findViewById(id.tvchildage)).setText(age);
DisplayImageOptions options =
new DisplayImageOptions.Builder().showImageForEmptyUri(drawable.noimage).showImageOnFail(drawable.noimage).showStubImage(drawable.noimage).cacheInMemory()
.imageScaleType(ImageScaleType.NONE).build();
imageLoader = ImageLoader.getInstance();
imageLoader.displayImage(childBean.childphoto, childimg, options);
final TextView tvpee = (TextView) rootView.findViewById(id.tvpeetime);
final TextView tvpoop = (TextView) rootView.findViewById(id.tvpootimes);
final TextView tvsleep = (TextView) rootView.findViewById(id.tvsleeptime);
rootView.findViewById(id.btnaddpee).setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
pee = pee + 1;
if(pee > 9)
{
Toast.makeText(getActivity(), getString(string.tvareyousurepee), Toast.LENGTH_LONG).show();
}
tvpee.setText(String.format(getString(string.tvtimes), pee));
}
});
rootView.findViewById(id.btnminuspee).setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
if(pee > 0)
{
pee = pee - 1;
tvpee.setText(String.format(getString(string.tvtimes), pee));
}
}
});
rootView.findViewById(id.btnpluspoo).setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
poop = poop + 1;
if(poop > 9)
{
Toast.makeText(getActivity(), getString(string.tvareyousurepoop), Toast.LENGTH_LONG).show();
}
tvpoop.setText(String.format(getString(string.tvtimes), poop));
}
});
rootView.findViewById(id.btnminuspoo).setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
if(poop > 0)
{
poop = poop - 1;
tvpoop.setText(String.format(getString(string.tvtimes), poop));
}
}
});
rootView.findViewById(id.btnaddsleep).setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
sleep = sleep + 0.25;
tvsleep.setText(String.format(getString(string.tvhours), sleep));
}
});
rootView.findViewById(id.btnminussleep).setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
if(sleep > 0)
{
sleep = sleep - 0.25;
tvsleep.setText(String.format(getString(string.tvhours), sleep));
}
}
});
rootView.findViewById(id.btnsave).setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
Toast.makeText(getActivity(), "Report Saved.", Toast.LENGTH_LONG).show();
getActivity().finish();
}
});
return rootView;
}
}
Please advise... Thanks

ViewPager itself has a method setOffscreenPageLimit which allows you to specify number of pages kept by the adapter. So your fragments that are far away will be destroyed.
First of all looking at your code I don't see you doing any memory releasing measures in your fragments onDestroy(). The fact that fragment itself is destroyed and gc'ed does not mean all resources you allocated were removed too.
For example, my big concern is:
imageLoader = ImageLoader.getInstance();
imageLoader.displayImage(childBean.childphoto, childimg, options);
From what I see here it seems that there is a static instance of ImageLoader that gets poked every time a new fragment appears, but I can't see where a dying fragment would ask ImageLoader to unload its stuff. That looks suspicious to me.
If I were you I would dump an HPROF file of my application the moment it took extra 200mb (as you claim) after activity restart and analyze references via MAT (memory analyzer tool). You are clearly having memory leaks issue and I highly doubt the problem is in Fragments themselves not being destroyed.
In case you don't know how to analyze memory heap, here is a good video. I can't count how many times it helped me identifying and getting rid of memory leaks in my apps.

Don't store 'strong' references to ViewPager or ImageView in your Fragment. You're creating a cyclical reference that will keep everything in memory. Instead, if you must keep a reference to ViewPager or any other element that references its context outside of your Activity, try using a WeakReference, e.g:
private WeakReference<ViewPager> mPagerRef;
...
mPagerRef = new WeakReference<ViewPager>(mPager);
...
final ViewPager pager = mPagerRef.get();
if (pager != null) {
pager.setCurrentItem(...);
}
Following this pattern with Objects that store a reference to the Activity or Application context (hint: any ViewGroup, ImageView, Activity, etc.) should prevent "memory leaks" in the form of "retain cycles" from occurring.

it seems that your code is not destroying the view, check this Destroy item from the ViewPager's adapter might solve this issue.

After using the memory analyzer tool in eclipse i found out that what is sticking in my memory is the actual layout of my fragments.
Relative layout in specific.
The reason for this is a CustomTextView that i created that has a custom font set as a typeface.
Typeface face=Typeface.createFromAsset(context.getAssets(), "Helvetica_Neue.ttf");
this.setTypeface(face);
To solve the memory leak i simply did the following answer found here:
public class FontCache {
private static Hashtable<String, Typeface> fontCache = new Hashtable<String, Typeface>();
public static Typeface get(String name, Context context) {
Typeface tf = fontCache.get(name);
if(tf == null) {
try {
tf = Typeface.createFromAsset(context.getAssets(), name);
}
catch (Exception e) {
return null;
}
fontCache.put(name, tf);
}
return tf;
}
}