Develop Reference

How can I change text "Default Media Receiver" on Remote Player

I use MediaRouter to connect to remote players.Not using Google Cast. I have problem to customize what users see on e.g. TV. ,mainly text : Default Media Receiver.
HOW CAN I CHANGE IT ?
Here is code I have:
In PlayerActivity (MediaRouter Callback, OnCreate method and DiscoveryFragment class):
public static androidx.mediarouter.media.MediaRouter mMediaRouter;
private final androidx.mediarouter.media.MediaRouter.Callback mMediaRouterCB = new androidx.mediarouter.media.MediaRouter.Callback() {
#Override
public void onRouteSelected(#NonNull androidx.mediarouter.media.MediaRouter router, #NonNull androidx.mediarouter.media.MediaRouter.RouteInfo route, int reason) {
super.onRouteSelected(router, route, reason);
if (route.supportsControlCategory(MediaControlIntent.CATEGORY_REMOTE_PLAYBACK)){
mRoute = route;
isSetRemotePlayer = true;
if (route.isDefault()){
isSetRemotePlayer = false;
}
mMediaRouter.getInstance(PlayerActivity.this);
mMediaRouter.addProvider(new SampleMediaRouteProvider(PlayerActivity.this));
}
}
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Get the media router service.
mMediaRouter = androidx.mediarouter.media.MediaRouter.getInstance(this);
mMediaRouter.setRouterParams(new MediaRouterParams.Builder().setTransferToLocalEnabled(true).build());
// Create a route selector for the type of routes that we care about.
mSelector =
new MediaRouteSelector.Builder().addControlCategory(MediaControlIntent
.CATEGORY_REMOTE_PLAYBACK).addControlCategory(MediaControlIntent
.CATEGORY_LIVE_AUDIO).addControlCategory(SampleMediaRouteProvider.CATEGORY_SAMPLE_ROUTE)
.build();
// Add a fragment to take care of media route discovery.
FragmentManager fm = getSupportFragmentManager();
fs = new ForegroundService();
DiscoveryFragment fragment =
(PlayerActivity.DiscoveryFragment) fm.findFragmentByTag(DISCOVERY_FRAGMENT_TAG);
if (fragment == null) {
fragment = new DiscoveryFragment();
fragment.setCallback(mMediaRouterCB);
fragment.setRouteSelector(mSelector);
fm.beginTransaction().add(fragment, DISCOVERY_FRAGMENT_TAG).commit();
} else {
fragment.setCallback(mMediaRouterCB);
fragment.setRouteSelector(mSelector);
}
}
public static final class DiscoveryFragment extends MediaRouteDiscoveryFragment {
private static final String TAG = "DiscoveryFragment";
private androidx.mediarouter.media.MediaRouter.Callback mCallback;
public DiscoveryFragment() {
mCallback = null;
}
public void setCallback(androidx.mediarouter.media.MediaRouter.Callback cb) {
mCallback = cb;
}
#Override
public androidx.mediarouter.media.MediaRouter.Callback onCreateCallback() {
return mCallback;
}
#Override
public int onPrepareCallbackFlags() {
// Add the CALLBACK_FLAG_UNFILTERED_EVENTS flag to ensure that we will
// observe and log all route events including those that are for routes
// that do not match our selector. This is only for demonstration purposes
// and should not be needed by most applications.
return super.onPrepareCallbackFlags() | androidx.mediarouter.media.MediaRouter.CALLBACK_FLAG_UNFILTERED_EVENTS;
}
}
SampleRouteProvider is class provided by android pages(https://developer.android.com/guide/topics/media/mediarouter) and on bottom is Sample (https://github.com/android/media-samples/tree/main/MediaRouter/):
MANY THANKS

Call non-static method in Static method JAVA

EDITED:
The real purpose of that is to have one activity and on class who fetch data and render it to the activity.
The problem is I have dropdown menu. When I clicked on an item of the menu it change my url but it does not load or fetch my data to the activity but when i clicked again it works but with the paramaters selected just before and if I clicked again it still works but still with the previous elements selected.
My "teacher" said I have to call build into my callback method.
But it doesen't work at all. And I still didn't find any solution :/.
As you recommended I changed everything for non-static method
I thought why not saving an history of the dropdown, compare the current value with the saved value and if it's diffrent it means it was changed so reload the app to make new fetch and displyed new data.
But I got :
Here my all code
PhotosActivity
public class PhotosActivity extends AppCompatActivity {
// Local variable
private OkHttpClient httpClient;
private ImageButton home_btn;
private ImageButton favorites_btn;
private ImageButton search_btn;
private ImageButton profil_btn;
// Constante variable
private static final String TAG = "PhotoActivity";
private static final String clientId = "bb0c749c6403fd2";
// Private shared variable
private static List<Photo> mPhotos;
private static JSONArray mItems;
private static String mAccessToken;
private static String userID;
static Activity activity;
// Shared variable
private static String selectedItem;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_photos);
this.home_btn = findViewById(R.id.home_button);
this.favorites_btn = findViewById(R.id.favorites_button);
this.search_btn = findViewById(R.id.search_button);
this.profil_btn = findViewById(R.id.profil_button);
final HttpHandler httpHandler = new HttpHandler();
httpHandler.fetchData();
build();
activity = this;
Spinner spinner=(Spinner)findViewById(R.id.spinner);
String[] filters=getResources().getStringArray(R.array.filters);
ArrayAdapter<String> adapter=new ArrayAdapter<String>(this,R.layout.spinner,R.id.text, filters);
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener()
{
#Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id)
{
selectedItem = parent.getItemAtPosition(position).toString();
// httpHandler.fetchData();
// build();
}
public void onNothingSelected(AdapterView<?> parent)
{
Log.d("TAG", "Error");
}
});
home_btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent next_activity = new Intent(getApplicationContext(), PhotosActivity.class);
finish();
startActivity(next_activity);
}
});
favorites_btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent next_activity = new Intent(getApplicationContext(), FavoriteActivity.class);
finish();
startActivity(next_activity);
}
});
search_btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent next_activity = new Intent(getApplicationContext(), SearchActivity.class);
finish();
startActivity(next_activity);
}
});
profil_btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent next_activity = new Intent(getApplicationContext(), ProfileActivity.class);
finish();
startActivity(next_activity);
}
});
}
public void Filters() {
String hSection;
String hSort;
String hShowV;
hSection = HttpHandler.section ;
hSort = HttpHandler.sort;
hShowV = HttpHandler.showV;
Intent next_activity = new Intent(getApplicationContext(), FavoriteActivity.class);
if(selectedItem != null) {
if (selectedItem.equals("Most Viral")) {
HttpHandler.sort = "viral/";
HttpHandler.section = "hot/";
if ( (!HttpHandler.sort.equals(hSort)) || (!HttpHandler.section.equals(hSection))) {
Log.d("TAG", "most: "+HttpHandler.section);
Log.d("TAG", "H most: "+hSection);
// activity.recreate();
// onRestart();
finish();
startActivity(next_activity);
}
} else if (selectedItem.equals("Newest")) {
HttpHandler.section = "top/";
HttpHandler.sort = "time/";
if ( (!HttpHandler.sort.equals(hSort)) || (!HttpHandler.section.equals(hSection))) {
Log.d("TAG", "new: "+HttpHandler.section);
Log.d("TAG", "H new: "+hSection);
finish();
startActivity(next_activity);
// activity.recreate();
// onRestart();
}
} else if (selectedItem.equals("Rising")) {
HttpHandler.section = "user/";
HttpHandler.sort = "rising/";
HttpHandler.showV = "?showViral=false";
if ( (!HttpHandler.sort.equals(hSort)) || (!HttpHandler.section.equals(hSection))) {
Log.d("TAG", "rising: "+HttpHandler.section);
Log.d("TAG", "H rising: "+hSection);
// onRestart();
// activity.recreate();
finish();
startActivity(next_activity);
}
} else {
Log.d(TAG, "Might be a problem");
}
} else {
activity.recreate();
}
}
public void build () {
try {
for(int i = 0; i < mItems.length(); i++) {
JSONObject item = mItems.getJSONObject(i);
Photo photo = new Photo();
if(item.getBoolean("is_album")) {
photo.id = item.getString("cover");
} else {
photo.id = item.getString("id");
}
photo.title = item.getString("title");
mPhotos.add(photo);
runOnUiThread(new Runnable() {
#Override
public void run() {
render(mPhotos);
}
});
}
} catch (Exception e) {
Log.e("JSONerr" , "Something went wrong.");
}
}
private static class PhotoVH extends RecyclerView.ViewHolder {
ImageView photo;
TextView title;
public PhotoVH(View itemView) {
super(itemView);
}
}
private void render(final List<Photo> photos) {
RecyclerView rv = (RecyclerView)findViewById(R.id.rv_of_photos);
rv.setLayoutManager(new LinearLayoutManager(this));
RecyclerView.Adapter<PhotoVH> adapter = new RecyclerView.Adapter<PhotoVH>() {
#NonNull
#Override
public PhotoVH onCreateViewHolder(ViewGroup parent, int viewType) {
PhotoVH vh = new PhotoVH(getLayoutInflater().inflate(R.layout.item, null));
vh.photo = (ImageView) vh.itemView.findViewById(R.id.photo);
vh.title = (TextView) vh.itemView.findViewById(R.id.title);
return vh;
}
#Override
public void onBindViewHolder(PhotoVH holder, int position) {
Picasso.with(PhotosActivity.this).load("https://i.imgur.com/" +
photos.get(position).id + ".jpg").into(holder.photo);
holder.title.setText(photos.get(position).title);
}
#Override
public int getItemCount() {
return photos.size();
}
};
rv.setAdapter(adapter);
}
public static void getUserID(String UserID) {
Log.d("TAG", UserID);
userID = UserID;
}
public void callBackPhoto( List<Photo> photos, JSONArray items)
{
mPhotos = photos;
mItems = items;
// build();
}
}
HttpHandler
public class HttpHandler {
private static final String TAG = "HttpHandler";
private static String clientId = "bb0c749c6403fd2";
private static OkHttpClient httpClient;
private static String mAccessToken;
// URL BUILDER VARIABLES
public static String section = "hot/";
public static String sort = "viral/";
public static String page;
public static String showV;
public static String mUrl;
public void fetchData() {
httpClient = new OkHttpClient.Builder().build();
photosActivity.Filters();
mUrl = "https://api.imgur.com/3/gallery/" + section + sort;
// Log.d("TAG", "Sort: " + sort + ": URl is" + mUrl);
Request request = new Request.Builder()
.url(mUrl + "0.json" + showV)
.addHeader("Authorization", "Client-ID " + clientId)
.header("User-Agent", "epicture")
.build();
httpClient.newCall(request).enqueue(new Callback() {
#Override
public void onFailure(Call call, IOException e) {
Log.e(TAG, "An error has occurred " + e);
}
#Override
public void onResponse(Call call, Response response) throws IOException {
try {
JSONObject data = new JSONObject(response.body().string());
JSONArray items = data.getJSONArray("data");
final List<Photo> photos = new ArrayList<Photo>();
photosActivity.callBackPhoto(photos, items);
} catch (Exception e) {
Log.e("JSONerr", "Something went wrong.");
}
}
});
}
public static void getLoginData(String accessToken) {
mAccessToken = accessToken;
}
}

It doesn't look like making sense to declare callBackPhoto as a static method. If you have put static keyword accidentally in its declaration, simply remove it to solve your problem i.e. replace
public static void callBackPhoto( List<Photo> photos, JSONArray items)
with
public void callBackPhoto( List<Photo> photos, JSONArray items)
Note that there is no way to call a non-static method from a static one directly (i.e. without calling it on an object/instance). Thus, if for any reason, you can't remove static keyword from the declaration of callBackPhoto, you are left with only two options:
Declare build too as static
Call build on an object/instance e.g. new PhotosActivity().build()
Though any of these two options will solve your problem, I don't think this is how you intend to design your class.

In java, a static method belongs to EVERY object of the class that defines it. Therefore, you can call it from the parent class without creating an object like so:
ParentClass.myMethod;
However, this is not the case the case with instance (non-static) methods. To call this type of method, you need to define it in a class, create an object from that class, and then call it from that object, like this:
//inside ParentClass definition
public void myMethod(){bla bla;}
//In some other class
ParentClass obj = new ParentClass;
obj.myMethod;
Suppose you have code calling a static member of a class without creating an instance of that class. If that method contained a non-static method, there would be no object in memory to call it on. This is why it isn't possible.

Static
The static methods are alive all the time. They live from the class is loaded. They don't need objects to live. I think of them as not really belonging to the class, but the class is just a nice way to organize those methods (the same for variables). The methods could be put in any other class definition and it would still work. But organizing them in classes where they will be used make it easy to prevent access from other parts of the program, like other objects or other static methods. They are called class methods or class variables.
Instance
The non-static "stuff" does not live unless there is an object. That's why you cannot call below methodOne or methodTwo from the static methods. You have to create an object first. They are called instance methods or instance variables, because you need an instance of an object to call them.
Error
error: non-static method <methodname> cannot be referenced from a static context basically means "There's no object"
Example
public class StackOverflowTest {
public static void main(String[] args) { // this is just another static method
// methodOne(); // error. There's no object
StackOverflowTest test = new StackOverflowTest();
test.methodOne(); // method called on object.
}
// methods live outside objects
static void staticMethodOne() {
System.out.println("staticMethodOne");
staticMethodTwo(); // no object required.
}
static void staticMethodTwo() {
System.out.println("staticMethodTwo");
// methodTwo(); // error. There's no object
}
// methods that only live inside objects
void methodOne() { // method can only be invoked if there's an object.
System.out.println("methodOne");
methodTwo(); // no problem. Already inside the object.
}
void methodTwo() {
System.out.println("methodTwo");
staticMethodTwo(); // no problem. Objects can access static methods.
}
}
Your case
So you either have to create a PhotosActivity object inside your build(), or you have to make callBackPhoto a static method. I can't see what your render does, but it's the same principle.

unable to set drawable on ImageView in HandlerThread subclass

i am writing a flickr client as part of a project from a book that i am reading. in it i create a subclass of HandlerThread that downloads images from flickr and then sets them in an ImageView. i set a placeholder .png earlier in the program and this binds (but with delay) however when i try to replace it nothing happens. the placeholder stays there and is not replaced. it seems like something is happening between that is preventing my HandlerThread from running properly. i have tried stepping through this with the debugger and also looking through the logcat however the logcat has been particularly unhelpful ever since the last update to android studio. it works partially if at all. so right i am getting no error message. earlier i got one stating that i had a null pointer exception but i wasnt able to see where it had come from and upon running the application again it was gone. i am posting samples of my code including the main Fragment which serves as the UI Thread, and the ThumbnailDownloader class which is my HandlerThread subclass.
public class PhotoGalleryFragment extends Fragment {
private static final String TAG = "PhotoGalleryFragment";
private RecyclerView mRecyclerView;
private List<GalleryItem> mItems = new ArrayList<>();
private ThumbnailDownloader<PhotoHolder> mThumbnailDownloader;
public static PhotoGalleryFragment newInstance(){
return new PhotoGalleryFragment();
}
#Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setRetainInstance(true);
new FetchItemsTask().execute();
Handler responseHandler = new Handler();
mThumbnailDownloader = new ThumbnailDownloader<>(responseHandler);
mThumbnailDownloader.setThumbnailDownloadListener( new ThumbnailDownloader.ThumbnailDownloadListener<PhotoHolder>() {
#Override
public void onThumbnailDownloaded(PhotoHolder target, Bitmap bitmap) {
Log.i(TAG, "setThumbnailDownloadListener() called!");
Drawable drawable = new BitmapDrawable(getResources(), bitmap);
target.bindDrawable(drawable);
}
});
mThumbnailDownloader.start();
mThumbnailDownloader.getLooper();
Log.i(TAG, "background thread started!");
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
View v = inflater.inflate(R.layout.fragment_photo_gallery, container, false);
mRecyclerView = (RecyclerView) v.findViewById(R.id.photo_recycler_view);
mRecyclerView.setLayoutManager(new GridLayoutManager(getActivity(), 3));
setupAdapter();
return v;
}
public void onDestroyView(){
super.onDestroyView();
mThumbnailDownloader.clearQueue();
}
#Override
public void onDestroy(){
super.onDestroy();
mThumbnailDownloader.quit();
Log.i(TAG, "background thread destroyed!");
}
private void setupAdapter(){
if (isAdded()){
mRecyclerView.setAdapter(new PhotoAdapter(mItems));
}
}
private class PhotoHolder extends RecyclerView.ViewHolder{
private ImageView mItemImageView;
public PhotoHolder(View itemView){
super(itemView);
mItemImageView = (ImageView) itemView.findViewById(R.id.item_image_view);
}
public void bindDrawable(Drawable drawable){
mItemImageView.setImageDrawable(drawable);
}
}//end PhotoHolder inner class
private class PhotoAdapter extends RecyclerView.Adapter<PhotoHolder>{
private List<GalleryItem> mGalleryItems;
public PhotoAdapter(List<GalleryItem> items){
mGalleryItems = items;
}
#Override
public PhotoHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
LayoutInflater layoutInflater = LayoutInflater.from(getActivity());
View view = layoutInflater.inflate(R.layout.list_item_gallery, viewGroup, false);
return new PhotoHolder(view);
}
#Override
public void onBindViewHolder(PhotoHolder photoHolder, int position) {
GalleryItem galleryItem = mGalleryItems.get(position);
Drawable placeholder = getResources().getDrawable(R.drawable.wait); <--this is the placeholder image
photoHolder.bindDrawable(placeholder);//this <--this sets the placeholder but seems to wait for the thumbnail download to complete for some reason
mThumbnailDownloader.queueThumbnail(photoHolder, galleryItem.getUrl());
}
#Override
public int getItemCount() {
return mGalleryItems.size();
}
}
private class FetchItemsTask extends AsyncTask<Void, Void, List<GalleryItem>>{
#Override
protected List<GalleryItem> doInBackground(Void... params) {
return new FlickrFetchr().fetchItems();
}
#Override
protected void onPostExecute(List<GalleryItem> items){
mItems = items;
setupAdapter();
}
}//end FetchItemsTask inner class
}//end class
and here is my HandlerThread implementation:
public class ThumbnailDownloader<T> extends HandlerThread {
private static final String TAG = "ThumbnailDownloader";
private static final int MESSAGE_DOWNLOAD = 0;
private boolean mHasQuit = false;
private Handler mRequestHandler = new Handler();
private Handler mResponseHandler = new Handler();
private ThumbnailDownloadListener<T> mThumbnailDownloadListener;
private ConcurrentMap<T, String> mRequestMap = new ConcurrentHashMap<>();
public interface ThumbnailDownloadListener<T>{
void onThumbnailDownloaded(T target, Bitmap bitmap);
}
public void setThumbnailDownloadListener(ThumbnailDownloadListener<T> listener){
mThumbnailDownloadListener = listener;
}
public ThumbnailDownloader(Handler responseHandler){
super(TAG);
mResponseHandler = responseHandler;
Log.i(TAG, "ThumbnailDownloader created!");
}
#Override
protected void onLooperPrepared(){
mRequestHandler = new Handler(){
#Override
public void handleMessage(Message msg){
if (msg.what == MESSAGE_DOWNLOAD){
T target = (T) msg.obj;
Log.i(TAG, "got a request for a url:" + mRequestMap.get(target));
handleRequest(target);
}
}
};
}
#Override
public boolean quit(){
mHasQuit = true;
return super.quit();
}
public void queueThumbnail(T target, String url){
Log.i(TAG, "got a url: " + url);
if(url == null){
mRequestMap.remove(target);
}else {
mRequestMap.put(target, url);
mRequestHandler.obtainMessage(MESSAGE_DOWNLOAD, target).sendToTarget();
}
}
public void clearQueue(){
mRequestHandler.removeMessages(MESSAGE_DOWNLOAD);
mRequestMap.clear();
}
private void handleRequest(final T target){
try{
final String url = mRequestMap.get(target);
if (url == null){
return;
}
byte[] bitmapBytes = new FlickrFetchr().getUrlBytes(url);
final Bitmap bitmap = BitmapFactory.decodeByteArray(bitmapBytes, 0, bitmapBytes.length);
Log.i(TAG, "Bitmap created!"); //<---this is output in the logcat at the terminal but not the android monitor
mResponseHandler.post(new Runnable(){
#Override
public void run() {
if (mRequestMap.get(target) != null || mHasQuit){
return;
}
mRequestMap.remove(target);
mThumbnailDownloadListener.onThumbnailDownloaded(target, bitmap);
}
});
}catch (IOException ioe){
Log.e(TAG, "error downloading image: ", ioe);
}
}
}
honestly at this point i am not even sure where the problem is. it doesn't seem like queueThumbnail ever runs. but just setting the placeholder wait.png takes so long that it almost seems like there is some mix up between the placeholder and the downloaded image when it comes to binding to the ViewHolder. i am just not sure where it could be. i added comments to point this out.

Splash Screen using AsyncTask

I have a splash screen using AsyncTask, it will download some data from database and store the data in ArrayList. This ArrayList will be used for RecyclerView in fragments of MainActivity.class.
The problem is when I run the app from Android Studio to my phone, everything works perfectly. But, when I destroy the app and run it manually from my phone it will display blank white screen and then it will crash. And if I run once again after it crashed, the app will work. So, this app will always work only if I run it from Android Studio or after it crashed.
The error says that it is caused by the empty list. If I'm not mistaken, I think the AsyncTask doesn't seem to work properly after the activity is destroyed. But I don't know how to fix it. Please help me to solve this problem.
SplashScreen.java
public class SplashScreenActivity extends AppCompatActivity {
public static Event event;
private static List<Feed> feedList;
private static List<Event> eventList;
private static List<Event> todayList;
private static List<Event> upcomingList;
private static List<Partner> partnerList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splashscreen);
Time today = new Time(Time.getCurrentTimezone());
today.setToNow();
Config.TODAY_DATE = String.valueOf(today.monthDay) + "-" + String.valueOf(today.month) + "-" + String.valueOf(today.year);
new DownloadData().execute("");
}
class DownloadData extends AsyncTask<String, Integer, String>
{
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
startActivity(new Intent(getBaseContext(), WelcomeActivity.class));
finish();
}
#Override
protected String doInBackground(String... params) {
RequestHandler rh = new RequestHandler();
String JSON_STRING = rh.sendGetRequest(Config.URL_GET_ALL_DATA);
JSONObject jsonObject;
eventList = new ArrayList<>();
todayList = new ArrayList<>();
upcomingList = new ArrayList<>();
partnerList = new ArrayList<>();
feedList = new ArrayList<>();
try {
jsonObject = new JSONObject(JSON_STRING);
JSONArray getEvent = jsonObject.getJSONArray(Config.TAG_JSON_EVENT);
for (int i = 0; i < getEvent.length(); i++) {
int id = getEvent.getJSONObject(i).getInt(Config.TAG_ID);
int eoId = getEvent.getJSONObject(i).getInt(Config.TAG_EO_ID);
String eoName = getEvent.getJSONObject(i).getString(Config.TAG_EO_NAME);
String title = getEvent.getJSONObject(i).getString(Config.TAG_TITLE);
String day = getEvent.getJSONObject(i).getString(Config.TAG_DAY);
String date = getEvent.getJSONObject(i).getString(Config.TAG_DATE);
int price = getEvent.getJSONObject(i).getInt(Config.TAG_PRICE);
event = new Event(id, eoId, eoName, title, day, date, price);
eventList.add(event);
if(Config.TODAY_DATE.equals(event.getDate())){
todayList.add(event);
} else {
upcomingList.add(event);
}
}
JSONArray getPartner = jsonObject.getJSONArray(Config.TAG_JSON_PARTNER);
for (int i = 0; i < getPartner.length(); i++) {
int pId = getPartner.getJSONObject(i).getInt(Config.TAG_ID);
String pName = getPartner.getJSONObject(i).getString(Config.TAG_NAME);
String pEmail = getPartner.getJSONObject(i).getString(Config.TAG_EMAIL);
String pPhone = getPartner.getJSONObject(i).getString(Config.TAG_PHONE);
String pPhoto = getPartner.getJSONObject(i).getString(Config.TAG_PHOTO_URL);
Partner partner = new Partner(pId, pName, pEmail, pPhone, pPhoto);
partnerList.add(partner);
}
JSONArray getArticle = jsonObject.getJSONArray(Config.TAG_JSON_ARTICLE);
for (int i = 0; i < getArticle.length(); i++) {
int feedId = getArticle.getJSONObject(i).getInt(Config.TAG_ID);
String feedAuthor = getArticle.getJSONObject(i).getString(Config.TAG_FEED_AUTHOR);
String feedTitle = getArticle.getJSONObject(i).getString(Config.TAG_FEED_TITLE);
String feedContent = getArticle.getJSONObject(i).getString(Config.TAG_FEED_CONTENT);
String feedDate = getArticle.getJSONObject(i).getString(Config.TAG_FEED_DATE);
String feedThumbnail = getArticle.getJSONObject(i).getString(Config.TAG_FEED_THUMBNAIL);
Feed feed = new Feed(feedId, feedAuthor, feedTitle, feedContent, feedDate, feedThumbnail);
feedList.add(feed);
}
} catch (JSONException e) {
e.printStackTrace();
}
return JSON_STRING;
}
}
public static List<Feed> getFeedList(){ return feedList;}
public static List<Event> getEventList() {return eventList;}
public static List<Event> getTodayList() { return todayList;}
public static List<Event> getUpcomingList() { return upcomingList;}
public static List<Partner> getPartnerList() {return partnerList;}
}
DiscoverFragment.java
public class DiscoverFragment extends Fragment implements ViewPager.OnPageChangeListener, View.OnClickListener {
protected View view;
private LinearLayout pager_indicator;
private int dotsCount;
private ImageView[] dots;
private List<Feed> feedList;
private List<Event> eventList;
private List<Partner> partnerList;
public DiscoverFragment() {}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_discover, container, false);
RecyclerView recyclerViewEvent = (RecyclerView) view.findViewById(R.id.discover_event_recycler_view);
RecyclerView recyclerViewPartner = (RecyclerView) view.findViewById(R.id.discover_partner_recycler_view);
ClickableViewPager intro_images = (ClickableViewPager) view.findViewById(R.id.pager_introduction);
pager_indicator = (LinearLayout) view.findViewById(R.id.viewPagerCountDots);
eventList = SplashScreenActivity.getEventList();
partnerList = SplashScreenActivity.getPartnerList();
feedList = SplashScreenActivity.getFeedList();
EventAdapter eventAdapter = new EventAdapter(getContext(), eventList);
DiscoverPartnerAdapter discoverPartnerAdapter = new DiscoverPartnerAdapter(getContext(), partnerList);
DiscoverFeedAdapter mAdapter = new DiscoverFeedAdapter(getContext(), feedList);
final LinearLayoutManager layoutManagerEvent = new LinearLayoutManager(getContext());
final LinearLayoutManager layoutManagerPartner = new LinearLayoutManager(getContext());
layoutManagerEvent.setOrientation(LinearLayoutManager.HORIZONTAL);
layoutManagerPartner.setOrientation(LinearLayoutManager.HORIZONTAL);
addBottomDots(0);
intro_images.setAdapter(mAdapter);
intro_images.setCurrentItem(0);
intro_images.addOnPageChangeListener(this);
intro_images.setOnItemClickListener(new ClickableViewPager.OnItemClickListener() {
#Override
public void onItemClick(int position) {
Config.FEED_ID = position;
startActivity(new Intent(getContext(), ArticleActivity.class));
}
});
return view;
}
private void addBottomDots(int currentPage) {
dots = new ImageView[feedList.size()]; //the problem
pager_indicator.removeAllViews();
for (int i = 0; i < dots.length; i++) {
dots[i] = new ImageView(getContext());
dots[i].setImageDrawable(getResources().getDrawable(R.drawable.nonselecteditem_dot));
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT
);
params.setMargins(4, 0, 4, 0);
pager_indicator.addView(dots[i], params);
}
if (dots.length > 0)
dots[currentPage].setImageDrawable(getResources().getDrawable(R.drawable.selecteditem_dot));
}
#Override
public void onClick(View v) {
switch (v.getId()) {
}
}
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
addBottomDots(position);
for (int i = 0; i < dotsCount; i++) {
dots[i].setImageDrawable(getResources().getDrawable(R.drawable.nonselecteditem_dot));
}
dots[position].setImageDrawable(getResources().getDrawable(R.drawable.selecteditem_dot));
}
}
LogCat
01-29 00:40:57.565 32535-32535/com.irmaelita.esodiaapp E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.irmaelita.esodiaapp, PID: 32535
java.lang.NullPointerException: Attempt to invoke interface method 'int java.util.List.size()' on a null object reference
at com.irmaelita.esodiaapp.fragment.DiscoverFragment.addBottomDots(DiscoverFragment.java:181)
at com.irmaelita.esodiaapp.fragment.DiscoverFragment.onCreateView(DiscoverFragment.java:158)

feedList is null. You create feedList instance when DownloadData task is executed. But you call feedList.size() in addBottomDots when fragment view should be created. So, most probably addBottomDots is called before DownloadData task is executed. You need to fix it.

The feedlist in your discover fragment is going empty while initializing. Please set a null check before doing so.It not about running from android studio.If I have understood it correctly you are trying to access a list from splasScreen activity after finishing it. ie in post execute you finish the current activity and the fragment is in main activity,so the list is going null.So if this is the case (and please correct me if not) then either download the data somewhere centrally or best way send it to main activity with intent and use it there. Also when running from android studio kill the app manually and run it again,while the phone is connected and see if it crashes in current scenario.

Send your data from doInBackground to MainActivity with sendBroadcast
Add broadcast method in DownloadData class
private void broadcast(SplashParcel parcel) {
Intent i = new Intent("splash_parcel");
i.putExtra("values", parcel);
sendBroadcast(i);
}
#Override
protected String doInBackground(String... params) {
// your code
// ..
try {
// your code
// ..
// send splashParcel to MainActivity
SplashParcel splashParcel = new SplashParcel(feedList, eventList, todayList, upcomingList, partnerList);
broadcast (splashParcel);
} catch (JSONException e) {
e.printStackTrace();
}
return JSON_STRING;
}
Add new class SplashParcel.java
public class SplashParcel implements Parcelable {
public static final Creator<SplashParcel> CREATOR = new Creator<SplashParcel>() {
#Override
public SplashParcel createFromParcel(Parcel in) {
return new SplashParcel(in);
}
#Override
public SplashParcel[] newArray(int size) {
return new SplashParcel[size];
}
};
private static List<Feed> _feedList;
private static List<Event> _eventList;
private static List<Event> _todayList;
private static List<Event> _upcomingList;
private static List<Partner> _partnerList;
protected SplashParcel(Parcel in) {
_feedList = new ArrayList<Feed>();
in.readList(_feedList, null);
_eventList = new ArrayList<Event>();
in.readList(_eventList, null);
_todayList = new ArrayList<Event>();
in.readList(_todayList, null);
_upcomingList = new ArrayList<Event>();
in.readList(_upcomingList, null);
_partnerList = new ArrayList<Partner>();
in.readList(_partnerList, null);
}
public SplashParcel(List<Feed> feedList, List<Event> eventList, List<Event> todayList, List<Event> upcomingList, List<Partner> partnerList) {
_feedList = feedList;
_eventList = eventList;
_todayList = todayList;
_upcomingList = upcomingList;
_partnerList = partnerList;
}
public SplashParcel() {
}
public List<Feed> getFeedList() {
return _feedList;
}
public void setFeedList(List<Feed> feedList) {
_feedList = feedList;
}
public List<Event> getEventList() {
return _eventList;
}
public void setEventList(List<Event> eventList) {
_eventList = eventList;
}
public List<Event> getTodayList() {
return _todayList;
}
public void setTodayList(List<Event> todayList) {
_todayList = todayList;
}
public List<Event> getUpcomingList() {
return _upcomingList;
}
public void setUpcomingList(List<Event> upcomingList) {
_upcomingList = upcomingList;
}
public List<Partner> getPartnerList() {
return _partnerList;
}
public void setPartnerList(List<Partner> partnerList) {
_partnerList = partnerList;
}
#Override
public int describeContents() {
return 0;
}
#Override
public void writeToParcel(Parcel parcel, int i) {
parcel.writeList(_feedList);
parcel.writeList(_eventList);
parcel.writeList(_todayList);
parcel.writeList(_upcomingList);
parcel.writeList(_partnerList);
}
}
MainActivity.java
// member variable
private BroadcastReceiver _splashReceiver;
private Bundle _bundle = new Bundle();
#Override
protected void onResume() {
super.onResume();
splashReceiver();
}
// receive splashParcel from SplashScreenActivity
private void splashReceiver() {
if (_splashReceiver == null) {
_splashReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
SplashParcel splashParcel = intent.getParcelableExtra("values");
if (splashParcel != null) {
// save splashParcel into _budle
_bundle.putParcelable("splash_parcel", splashParcel);
}
}
};
registerReceiver(_splashReceiver, new IntentFilter("splash_parcel"));
}
}
//Send _bundle to DiscoverFragment
private void showDiscoverFragment(){
if(_bundle != null) {
// create instance of discoverFragment with passing _bundle as arguments
DiscoverFragment discoverFragment = new DiscoverFragment();
discoverFragment.setArguments(_bundle);
// replace activity_main.xml with discoverFragment
getSupportFragmentManager().beginTransaction().replace(R.id.main_container, discoverFragment).addBackStack(null).commit();
}
}
In onCreateView of DiscoverFragment:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
SplashParcel splashParcel = getArguments().getParcelable("splash_parcel");
if(splashParcel != null) {
// your splashParcel ready in here
List<Feed> feedList = splashParcel.getFeedList()
List<Event> eventList = splashParcel.getEventList()
List<Event> todayList = splashParcel.getTodayList();
List<Event> upcommingList = splashParcel.getUpcomingList();
List<Partner> partnerList = splashParcel.getPartnerList();
}
}

FragmentPagerAdapter dynamic tabs and page count

My application pulls data from a web service that generates different sections for each user. Then I am going to use these sections to create tabs using FragmentPagerAdapter.
I have used an Async task to pull data from the web service. However the overridden methods such as getCount() and getPageTitle() in the FragmentPagerAdapter executed prior to my asynctask and completes its job. How can I prevent this and generate dynamic number of tabs and their title name based on the data fetched from the web service?
In other words how can I create dynamic number of tabs and titles based on the data fetch from the web service
My Code for FragmentPagerAdapter as below. As you can see I have hard coded the amount of tabs as well as their title names.
public class SectionsPagerAdapter extends FragmentPagerAdapter{
private boolean proceedStatus = false;
private String requestURL = "xxxxxxxxxxxxxxxxxxxxxxxx";
//list of fragments need to be added dynamically
public final ArrayList<Fragment> screens = new ArrayList<Fragment>();
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a DummySectionFragment (defined as a static inner class
// below) with the page number as its lone argument.
Fragment fragment = new SectionFragment();
Bundle args = new Bundle();
args.putInt(SectionFragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
return fragment;
}
#Override
public int getCount() {
return 2;
}
#Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return "Camera".toUpperCase(l);
case 1:
return getString(R.string.title_section2).toUpperCase(l);
case 2:
return getString(R.string.title_section3).toUpperCase(l);
case 3:
return "SECTION 4";
}
return null;
}
//setting the section title
private void setSectionTitle(){
}
//count the number of sections
private int countNumberofSections(){
int numberOfSection = 0;
return numberOfSection;
}
}
Then I have my Fragment code as below which has the the caller to the Async Task
public static class SectionFragment extends Fragment implements OnTaskCompleted {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private Slider adapter;
private ViewPager viewPager;
public static final String ARG_SECTION_NUMBER = "section_number";
Button thumbUpBut;
Button thumbDownBut;
Button captureButton;
ImageView genImage;
TextView genCaption;
private Camera mCamera;
private CameraPreview mPreview;
private static File mediaFile;
private ProgressDialog progress;
private static String imageSaveLocation;
private static String file_name_without_extension;
private ImageView imageView;
private Button uploadButton;
private Button cancelButton;
private Collection<Place> places = null;
private Collection<Happenings> events = null;
private Collection<General> general = null;
private ArrayList<String> sections;
public int getNumberOfPages(){
return sections.size();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main_dummy,container, false);
TextView dummyTextView = (TextView) rootView.findViewById(R.id.section_label);
dummyTextView.setText(Integer.toString(getArguments().getInt(ARG_SECTION_NUMBER)));
FeedRequest task = new FeedRequest(this);
task.execute("xxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
captureButton = (Button) rootView.findViewById(R.id.button_capture);
captureButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
takePhoto();
}
});
thumbUpBut = (Button) rootView.findViewById(R.id.thumbUp);
thumbUpBut.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Log.v("thumbPress", "thumbPressUp");
thumb("up");
}
});
thumbDownBut = (Button) rootView.findViewById(R.id.thumbDown);
thumbDownBut.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Log.v("thumbPress", "thumbPressDown");
thumb("down");
}
});
//allocating the activity one to the camera
if(getArguments().getInt(ARG_SECTION_NUMBER) == 1){
mCamera = getCameraInstance();
mPreview = new CameraPreview(this.getActivity(), mCamera);
FrameLayout preview = (FrameLayout)rootView.findViewById(R.id.camera_preview);
preview.addView(mPreview);
//hide buttons
thumbDownBut.setVisibility(rootView.INVISIBLE);
thumbUpBut.setVisibility(rootView.INVISIBLE);
}else{
thumbDownBut.setVisibility(rootView.VISIBLE);
thumbUpBut.setVisibility(rootView.VISIBLE);
captureButton.setVisibility(rootView.INVISIBLE);
}
viewPager = (ViewPager) rootView.findViewById(R.id.pager);
return rootView;
}
//take photo function
private void takePhoto() {
//get coordinates of the location
UserLocation userLocation = new UserLocation();
userLocation.getUserLocation(getActivity());
coordinates[0] = userLocation.longitude;
coordinates[1] = userLocation.latitude;
PictureCallback pictureCB = new PictureCallback() {
public void onPictureTaken(byte[] data, Camera cam) {
new SavePhotoAndMetadata().execute(data);
cam.startPreview();
}
};
mCamera.takePicture(null, null, pictureCB);
}
//get camera instance
private Camera getCameraInstance() {
Camera camera = null;
try {
camera = Camera.open();
} catch (Exception e) {
// cannot get camera or does not exist
}
return camera;
}
//get the media out
private static File getOutputMediaFile() {
File mediaStorageDir = new File(Environment.getExternalStorageDirectory() + "/Android/data/asia.ceynet.realsnap/temp_img");
if (!mediaStorageDir.exists()) {
if (!mediaStorageDir.mkdirs()) {
Log.d("MyCameraApp", "failed to create directory");
return null;
}
}
// Create a media file name
String timeStamp = (DateFormat.format("dd-MM-yyyy hh:mm:ss", new java.util.Date()).toString());
mediaFile = new File(mediaStorageDir.getPath() + File.separator + "IMG_" + timeStamp + ".jpg");
file_name_without_extension = "IMG_" + timeStamp;
imageSaveLocation = mediaFile.toString();
return mediaFile;
}
//saving the image and metadata together
class SavePhotoAndMetadata extends AsyncTask<byte[], String, String> {
#Override
protected String doInBackground(byte[]... data) {
File picFile = getOutputMediaFile();
if (picFile == null) {
return null;
}
byte[] photoData = data[0];
try {
//save the image
FileOutputStream fos = new FileOutputStream(picFile);
fos.write(photoData);
fos.close();
} catch (FileNotFoundException e) {
e.getStackTrace();
} catch (IOException e) {
e.getStackTrace();
}
return null;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
progress = new ProgressDialog(getActivity());
progress.setMessage("Saving Picture..Please wait...");
progress.show();
}
#Override
protected void onPostExecute(String s) {
progress.dismiss();
imagePreviewDialog();
}
}
//save image metadata in async task
class SaveMetadataTask extends AsyncTask<Void, String, Void> {
#Override
protected Void doInBackground(Void... params) {
serializeDeserialize.serializeData("This is for testing", file_name_without_extension, Double.toString(coordinates[0]), Double.toString(coordinates[1]), deviceId, deviceEmail);
return null;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected void onPostExecute(Void v) {
}
}
//image preview dialog and its functionality
private void imagePreviewDialog(){
//setting the bitmap
Bitmap bmp = BitmapFactory.decodeFile(mediaFile.toString());
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setTitle("Image Preview");
builder.setCancelable(false);
LayoutInflater inflater = getActivity().getLayoutInflater();
ViewGroup vg = (ViewGroup)inflater.inflate(R.layout.sanp_preview_layout, null);
ImageView image = (ImageView) vg.findViewById(R.id.imageView);
image.setImageBitmap(rotateBitmap(bmp));
builder.setView(vg);
//buttons
builder.setPositiveButton("Upload",new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
if(checkInternetConnection.haveNetworkConnection(sContext)){
//upload the image
uploadImage();
//save image metadata
new SaveMetadataTask().execute();
}else{
Toast.makeText(sContext, "Error! No internet connection detected. Image will be uploaded on an active internet connection", Toast.LENGTH_LONG).show();
new SaveMetadataTask().execute();
}
}
});
builder.setNegativeButton("Discard",new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
discardImage(mediaFile.toString());
dialog.dismiss();
}
});
builder.show();
}
private Bitmap rotateBitmap(Bitmap image){
int width=image.getHeight();
int height=image.getWidth();
Bitmap srcBitmap=Bitmap.createBitmap(width, height, image.getConfig());
for (int y=width-1;y>=0;y--)
for(int x=0;x<height;x++)
srcBitmap.setPixel(width-y-1, x,image.getPixel(x, y));
return srcBitmap;
}
//device email
private String getDeviceEmail(){
AccountManager accountManager = AccountManager.get(sContext);
Account[] account = accountManager.getAccountsByType("com.google");
//device email
for(Account accLoop : account){
deviceEmail = accLoop.name;
}
return deviceEmail;
}
//upload image to the server
private void uploadImage(){
//save metadata
//call upload service
Intent intent = new Intent(sContext, HttpUploader.class);
Bundle loc = new Bundle();
loc.putDoubleArray("ss", coordinates);
intent.putExtra("url", PHOTO_UPLOAD);
intent.putExtra("paths", mediaFile.toString());
intent.putExtra("deviceid", deviceId);
intent.putExtra("deviceemail", getDeviceEmail());
intent.putExtra("posttext", "This is for testing");
intent.putExtra("filename", file_name_without_extension);
intent.putExtra("geo", loc);
sContext.startService(intent);
Toast.makeText(getActivity(), "Your image is being uploaded", Toast.LENGTH_LONG).show();
}
//discard image when the discard button is pressed
private void discardImage(String imagePath){
File file = new File(imagePath);
try{
file.delete();
}catch(Exception e){
Log.e("IMAGE_DELETION_ERROR", e.toString());
}
}
#Override
public void onTaskCompleted(boolean status, String message) {
// TODO Auto-generated method stub
Log.e("onTaskCompleted", "success" + status);
if (message == "tumb UP success") {
thumbUpBut.setSelected(true);
thumbDownBut.setSelected(false);
Log.e("tumb", "tumb");
} else if (message == "tumb DOWN success") {
thumbDownBut.setSelected(true);
thumbUpBut.setSelected(false);
Log.e("tumb", "tumb");
}
}
//listener for fetching main objects
#Override
public void onFeedCompleted(ArrayList<Posts> postArray, Multimap<String, Object> multiMap) {
// TODO Auto-generated method stub
numberOfPages = postArray.size();
adapter = new Slider(getActivity(), postArray, getContext());
viewPager.setAdapter(adapter);
// displaying selected image first
viewPager.setCurrentItem(postArray.size());
//saving the keyset
Set<String> keys = multiMap.keySet();
sections = new ArrayList<String>();
//sorting the categories and creating the category list
for(String key:keys){
//getting category list
if(!sections.contains(keys)){
sections.add(key);
}
//sorting categories
if(key.equals("Place")){
places.add((Place) multiMap.get(key));
}else if(key.equals("Events")){
events.add((Happenings) multiMap.get(key));
}else if(key.equals("General")){
general.add((General) multiMap.get(key));
}
}
}
//adding the pages to the adaptor dynamically
public void addPagesDynamically(){
}
}
//create the parent directory
private void createParentDiectory(){
File dir = new File(Environment.getExternalStorageDirectory() + "/Android/data/asia.ceynet.realsnap");
if(!(dir.exists() && dir.isDirectory())) {
dir.mkdirs();
}
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle presses on the action bar items
switch (item.getItemId()) {
case R.id.action_post:
openPost();
return true;
case R.id.action_settings:
// openSettings();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
public void openPost() {
/*
Intent i = new Intent(getApplicationContext(), PhotoActivity.class);
startActivity(i);
*/
}
public static void thumb(String type) {
SectionFragment d = new SectionFragment();
PostThumb task = new PostThumb(type, d);
task.execute("xxxxxxxxxxxxxxxxxxxxxxxxxxxx");
}
//broadcast receiver for picture upload
public class MyWebRequestReceiver extends BroadcastReceiver {
public static final String PROCESS_RESPONSE = "asia.ceynet.intent.action.PROCESS_RESPONSE";
#Override
public void onReceive(Context context, Intent intent) {
//String responseString = intent.getStringExtra(HttpUploader.RESPONSE_STRING);
String reponseMessage = intent.getStringExtra(HttpUploader.RESPONSE_MESSAGE);
String responseStatus = intent.getStringExtra(HttpUploader.RESPONSE_STATUS);
String file_to_be_deleted = intent.getStringExtra(HttpUploader.FILE_NAME_WITHOUT_EXTENSION);
Toast.makeText(getApplicationContext(), reponseMessage + " - " + file_to_be_deleted + ".jpg", Toast.LENGTH_LONG).show();
//if uploaded successfully delete or image and metadata
if(responseStatus.equals("true")){
File temp_image_dir = new File(Environment.getExternalStorageDirectory() + "/Android/data/asia.ceynet.realsnap/temp_img/" + file_to_be_deleted + ".jpg");
File metadata_file = new File(Environment.getExternalStorageDirectory() + "/Android/data/asia.ceynet.realsnap/temp_img/" + file_to_be_deleted + ".ser");
try{
temp_image_dir.delete();
metadata_file.delete();
}catch(Exception e){
Log.e("IMAGE_DELETION_ERROR", e.toString());
}
}
}
}

When you finnish pulling the async data, provide the adapter with the new data and call .notifyDataSetChanged() on that adapter instance and the framework will update the pages and count by itself.
If you wish a more detailed explanation post your FragmentPagerAdapter implementation.

First of all, let me apologize if I'm not making myself clear enough because this is one of my first participation(s) here. But I'll be always here to answer queries related to this answer and clear any confusions arose by my statements.
Since you're using fragments, so I'm assuming you must have included your fragments inside an activity (lets say MainActivity.java).
What you need, can be done inside that activity containing fragment.
Here is the example code of onCreate method inside the MainActivity
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FragmentManager fragmentManager = getSupportFragmentManager();
//Instance of viewpager included inside activity_main.xml
viewPager = (ViewPager) findViewById(R.id.vpMain);
SectionsPagerAdapter adapter = new SectionsPagerAdapter (fragmentManager);
//Adding some fragments right from the beginning, you could ignore it if not needed.
addFragments();
//This `OnPageChangeListener` will do the trick for you.
viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
//Show the title of fragment
Toast.makeText(MainActivity.this, adapter.screens.get(position), Toast.LENGTH_SHORT).show();
//If fragment being loaded is later than the first one,
// then add one more fragment after the last fragment to the adapter.
// integer currentPosition is declared as a field, outside onCreate method and initially set to 0.
if(position>currentPosition){
currentPosition+=1;
adapter.addFragment(new SectionFragment(), "Fragment"+String.valueOf(position+3));
adapter.notifyDataSetChanged();
}else{
currentPosition--;
}
}
#Override
public void onPageScrollStateChanged(int state) {
}
});
} // onCreate ends here.
Create this method inside your MainActivity (just to add 3 fragments to give your application a head-start.
private void addFragments(){
adapter.addFragment(new SectionFragment());
adapter.addFragment(new SectionFragment());
adapter.addFragment(new SectionFragment());
}
Then modify your SectionsPagerAdapter's getItem and getCount methods as below:
public class SectionsPagerAdapter extends FragmentPagerAdapter{
private boolean proceedStatus = false;
private String requestURL = "xxxxxxxxxxxxxxxxxxxxxxxx";
//list of fragments need to be added dynamically
public final ArrayList<Fragment> screens = new ArrayList<Fragment>();
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
return screens.get(position);
}
#Override
public int getCount() {
return screens.size();
}
//This method will dynamically add a fragment each time it is called.
public void addFragment(Fragment fragment) {
screens.add(fragment);
}
Now, no work related to "adding new fragment to the list" needs to be done inside your SectionFragment class.