Develop Reference

Android Error: IllegalStateException

I am working on a Bitcoin dashboard for Android. The following fragment uses the entered wallet address to display the balance in BTC. When an address is entered, it will add to the listview. When an item in the listview is selected, it will set the edittext to that address.
It is not yet complete, but for now it is throwing an error with the message, "The content of the adapter has changed but ListView did not receive a notification. Make sure the content of your adapter is not modified from a background thread, but only from the UI thread."
I currently have two example addresses in place for testing. If I select one then the other then the first again etc. it works fine. The error appears when I select one, press the button, then select the other.
public class WalletFragment extends Fragment {
ArrayList<String> savedWallets;
ArrayAdapter<String> listAdapter;
String newWalletAddress, jsonString, address, balance;
JSONObject jsonObj, data;
Double balanceDouble;
DecimalFormat df = new DecimalFormat("#.####");
private WalletListener listener;
public interface WalletListener {
void onCreateWallet(String newWalletAddress);
}
public WalletFragment() {
// Required empty public constructor
}
public static WalletFragment newInstance(ArrayList<String> wallets) {
WalletFragment fragment = new WalletFragment();
Bundle args = new Bundle();
args.putStringArrayList("savedWallets", wallets);
fragment.setArguments(args);
return fragment;
}
public static WalletFragment newInstance(ArrayList<String> wallets, String json) {
WalletFragment fragment = new WalletFragment();
Bundle args = new Bundle();
args.putStringArrayList("savedWallets", wallets);
args.putString("jsonString", json);
fragment.setArguments(args);
return fragment;
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof WalletListener) {
listener = (WalletListener) context;
}
else {
throw new ClassCastException(context.toString()
+ " must implement MyListFragment.OnItemSelectedListener");
}
}
#Override
public void onDetach() {
super.onDetach();
listener = null;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_wallet, container, false);
ListView lv = (ListView) v.findViewById(R.id.walletListView);
df.setRoundingMode(RoundingMode.CEILING);
final EditText walletAddressEditText = (EditText) v.findViewById(R.id.walletAddressEditText);
TextView addressTV = (TextView) v.findViewById(R.id.walletAddresstextView);
TextView balanceTV = (TextView) v.findViewById(R.id.walletBalanceTextView);
savedWallets = getArguments().getStringArrayList("savedWallets");
if (savedWallets == null) {
savedWallets = new ArrayList<>();
}
savedWallets.add("198aMn6ZYAczwrE5NvNTUMyJ5qkfy4g3Hi");
savedWallets.add("1L8meqhMTRpxasdGt8DHSJfscxgHHzvPgk");
// TODO remove test addresses
jsonString = getArguments().getString("jsonString");
if (jsonString != null) {
try {
jsonString = getArguments().getString("jsonString");
jsonObj = new JSONObject(jsonString);
data = new JSONObject(jsonObj.getString("data"));
balance = data.getString("balance");
balanceDouble = Double.parseDouble(balance);
address = data.getString("address");
String walletAddressText = getResources().getString(R.string.wallet_address, address);
addressTV.setText(walletAddressText);
String walletBalanceText = getResources().getString(R.string.wallet_balance, df.format(balanceDouble));
balanceTV.setText(walletBalanceText);
// TODO add viewing for other wallet data at some point
} catch (Exception e) {
Log.d("TickerException", e.toString());
}
}
listAdapter = new ArrayAdapter<>(getActivity(), R.layout.main_list_rows, savedWallets);
lv.setAdapter(listAdapter);
lv.setOnItemClickListener(new AdapterView.OnItemClickListener()
{
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id)
{
String address = savedWallets.get(position);
Log.d("wallet", "Selected: " + address);
walletAddressEditText.setText(address);
}
});
Button button = (Button) v.findViewById(R.id.createWalletButton);
View.OnClickListener ocl = new View.OnClickListener() {
#Override
public void onClick(View view) {
newWalletAddress = walletAddressEditText.getText().toString();
if (walletAddressEntryStructuralValidation(newWalletAddress)) {
if (newWalletAddress != null) {
listener.onCreateWallet(newWalletAddress);
}
else {
Toast.makeText(getActivity(), "newWalletAddress is null", Toast.LENGTH_SHORT).show();
}
}
else {
Toast.makeText(getActivity(), "Please enter a valid wallet address (length is currently " + newWalletAddress.length() + ").", Toast.LENGTH_SHORT).show();
}
}
};
// TODO check if wallet is already on list
button.setOnClickListener(ocl);
return v;
}
public boolean walletAddressEntryStructuralValidation(String address) {
return ((address.length() > 25) &&
(address.length() < 36) && (
(address.substring(0,1).equals("1") ||
(address.substring(0,1).equals("3")))));
}
// Wallet addresses are 26-35 alphanumeric characters and begin with 1 or 3
}
I believe this is all the relevant code but I will be closely watching this thread if anyone needs to request additional source.

That message means that the contents of the adapter (the order of items you see in getItem) changed but notifyDataSetChanged or similar function wasn't called. When changing the items in your adapter contents (which in this case is the savedWallets array list) you must call one of those functions.
Note: If you're adding several objects at once, you only need to call it once after all are added/removed. If you're mutating an object but not adding/removing it, you do not need to call it, but calling it may be the easiest way of doing a redraw.

List size is zero even after adding items

I have a list that I sending to a background asynctask object to do somework on. I am also sending a custom list adapter to be able to populate my list in the background. But the list returns zero and it seems like nothing is added to it as its size remains zero. I know because i debuged it. my custom list adapter works just fine though and creates the list perfectly.
Here's my code.
Fragment_Events.java
public class Fragment_Events extends android.support.v4.app.Fragment implements AdapterView.OnItemClickListener {
FragmentController controller;
ListView eventsListView;
List<Event> events;
EventsListAdapter eventsListAdapter;
public Fragment_Events() {
// Required empty public constructor
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
controller = (FragmentController) getActivity();
}
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
eventsListView = (ListView)getActivity().findViewById(R.id.listView_events);
events = new ArrayList<Event>();//SIZE REMAINS 0 <<<<<<<<<<<<<<<<<<<<<<<<<<<<<
eventsListAdapter = new EventsListAdapter(getActivity(),R.layout.list_events,events);
eventsListView.setAdapter(eventsListAdapter);
DLEvents.init(events,eventsListAdapter);
Bundle sendingBundle = new Bundle();
ArrayList<String> eventNames = new ArrayList<String>();
sendingBundle.putStringArrayList(AppUtils.EVENT_NAMES,eventNames);
controller.sendData(sendingBundle);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_events, container, false);
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
}
}
DLEvents.java
public class DLEvents {
public static final String EVENTS_OBJECT = "Events";
public static final String NAME_COLUMN = "name";
public static final String DESC_COLUMN = "description";
public static final String DATE_COLUMN = "date";
public static final String FOLL_COLUMN = "followers";
public static final String TC_COLUMN = "ticketCount";
public static final String IMAGE_COLUMN = "image";
public static void init(List<Event> list,EventsListAdapter eventsListAdapter){
DownLoadData downLoadData = new DownLoadData(list,eventsListAdapter);
downLoadData.execute();
}
public static class DownLoadData extends AsyncTask<Void,Event,Void>{
public List<Event>events;
public EventsListAdapter eventsListAdapter;
public DownLoadData(List<Event>events, EventsListAdapter eventsListAdapter) {
super();
this.events = events;
this.eventsListAdapter = eventsListAdapter;
}
public Bitmap byteArrayToBitmap(byte[] bytes){
Bitmap temp = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
return temp;
}
#Override
protected Void doInBackground(Void... params) {
ParseQuery<ParseObject> query = ParseQuery.getQuery(EVENTS_OBJECT);
try {
for(ParseObject tempParseObject: query.find()){
String tempName = tempParseObject.getString(NAME_COLUMN);
String tempDesc = tempParseObject.getString(DESC_COLUMN);
String tempID = tempParseObject.getObjectId();
int tempTC = tempParseObject.getInt(TC_COLUMN);
ParseFile tempPF = (ParseFile)tempParseObject.get(IMAGE_COLUMN);
Bitmap tempBM = byteArrayToBitmap(tempPF.getData());
int tempFoll = tempParseObject.getInt(FOLL_COLUMN);
Event event = new Event(tempName,tempDesc,null,tempID,tempTC,tempBM,tempFoll);
publishProgress(event);
}
} catch (ParseException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onProgressUpdate(Event... values) {
super.onProgressUpdate(values);
//events.add(values[0]); //I commented it out because it causes my listview to have duplicates, if you can shed some light on this too , I'd appreciate it. Commenting it back in also doesn't affect the size of my list
eventsListAdapter.add(values[0]);
}
}
}
Asynctask seems to be working fine as the list is populated with no issues. but the list is still at a size 0 event though it's updated in the UI thread via onprogressreport
the adapter populates the list perfectly! that isn't the issue. The event's list that is being passed on to asynctask remains at a zero size. No item is being added. That is the issue.

You have to call notifyDataSetChanged() to update the adapter and let it know there is new data.
#Override
protected void onProgressUpdate(Event... values) {
super.onProgressUpdate(values);
//events.add(values[0]); //I commented it out because it causes my listview to have duplicates, if you can shed some light on this too , I'd appreciate it. Commenting it back in also doesn't affect the size of my list
eventsListAdapter.add(values[0]);
eventsListAdapter.notifyDataSetChanged();
}

You need to ask adapter to refresh itself once data is available or its data is modified.
Do this
#Override
protected void onProgressUpdate(Event... values) {
super.onProgressUpdate(values);
events.add(values[0]);
eventsListAdapter.add(values[0]);
eventsListAdapter.notifyDataSetChanged();
}

How to make sure AsyncTask is executed

I'm pretty new to Android development, I feel like I have a relatively simple question here and have managed to tie down the more complex parts but overlook the more simple bits. I've setup an ImageAdapter class which handles displaying images into a GridView in another one of my Fragments. Originally I was following a tutorial that simply displayed a list of items in an Array.
I'm using an AsyncTask to populate an ArrayList, and then converting the ArrayList to a standard array that Picasso can deal with when displaying content.
My problem is that the AsyncTask section of my ImageAdapter is just not getting executed, thus my imageArr[] that Picasso uses is just remaining empty.
How can I make sure that the AsyncTask section of my Adapter is actually executed?
I've tried this, but it just doesn't seem to be working and I think I'm a little bit off...
public void onCreate() {
new GetProjects().execute();
}
I've attached my code bellow, any help would be really appreciated!
Note; ServiceHandler is just retrieving the data at the URL and then turning it into a string which can be parsed.
public class ImageAdapter extends BaseAdapter {
//JSON URL
private static String url = "www.myjsonsourceurl.com";
//JSON NODES
private static final String TAG_LOGO = "logopath";
ArrayList<String> imageUrls = new ArrayList<String>();
String[] imageArr = imageUrls.toArray(new String[imageUrls.size()]);
private Context mContext;
public ImageAdapter(Context c) {
mContext = c;
}
public int getCount() {
return imageArr.length;
}
public Object getItem(int position) {
return null;
}
public long getItemId(int position) {
return 0;
}
public void onCreate() {
new GetProjects().execute();
}
// create a new ImageView for each item referenced by the Adapter
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView;
if (convertView == null) {
// if it's not recycled, initialize some attributes
imageView = new ImageView(mContext);
imageView.setLayoutParams(new GridView.LayoutParams(185, 185));
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setPadding(3, 3, 3, 3);
} else {
imageView = (ImageView) convertView;
}
Picasso.with(mContext).setIndicatorsEnabled(true);
Picasso.with(mContext).setLoggingEnabled(true);
Picasso.with(mContext).load(imageArr[position]).placeholder(R.drawable.ajaxloader).error(R.drawable.imageunavailable).into(imageView);
return imageView;
}
// references to our images
//ASYNC task to get json by making HTTP call
public class GetProjects extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
// Nothing right now
}
#Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONArray json = new JSONArray(jsonStr);
// looping through All Applications
for (int i = 0; i < json.length(); i++) {
JSONObject p = json.getJSONObject(i);
String logopath = p.getString(TAG_LOGO);
imageUrls.add(logopath);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
}
}
}

You need to call in activity or fragment where list is defined not in adapter like this. move asynctask class to your activity and call it from there.
AsyncTask gives methods
onPreExecute() and onPostExecute() where you can toast message that task is started or completed. And you should call setAdapter() in onPostExecute() of class.

There`s no onCreate method for BaseAdapter which you can override. Execute your code
new GetProjects().execute();
either in contructor or call your onCreate function (I suggest changing its name) manualy from outside of the adapter.

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.

looping android method

I am making an android game. I am using RelativeLayout, which hosts a FrameLayout, which hosts a SurfaceView. However, i have added a textview onto the RelativeLayout to show how many health points the player has left. I have a method which sets the int value of how many health points he has left into the text view. The int value is located in the SurfaceView, which is another class. But the textview and the method which updates the textview, is inside the other class. I want the method in the other class to be constantly updated, so that the textview will always display the health value. How can i do this? The method is called updateHealthPointsTextView(). Please help me and thanks so much! My code:
package com.mysoftwaremobileapps.alien.attack;
import java.util.ArrayList;
public class GameScreenActivity extends Activity {
/** Called when the activity is first created. */
List<String> myList = new ArrayList<String>();
RadioButton radioEasy, radioMedium, radioHard;
private ExampleView eView;
public int ParachuterIndex;
TextView healthPoints;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
dropParachuters();
}
private void dropParachuters() {
// TODO Auto-generated method stub
}
#Override
protected void onStart()
{
FrameLayout fl = new FrameLayout(this);
eView = new ExampleView(this);
fl.addView(eView);
healthPoints = new TextView(this);
healthPoints.setText("Health Points: " + eView.getThread().healthPoints);
RelativeLayout relativeLayout= new RelativeLayout(this);
relativeLayout.addView(fl);
relativeLayout.addView(healthPoints);
setContentView(relativeLayout);
eView.getThread().drawAlien();
eView.getThread().drawAlien();
eView.getThread().drawAlien();
eView.getThread().drawAlien();
eView.getThread().drawAlien();
eView.getThread().drawAlien();
eView.getThread().drawAlien();
eView.getThread().drawAlien();
eView.getThread().drawAlien();
eView.getThread().drawAlien();
eView.getThread().publicFloatX = 750;
eView.getThread().gettingAttacked();
updateHealthPointsTextView();
super.onStart();
try {
Bundle extras = getIntent().getExtras();
if (extras != null) {
String value = extras.getString("KEY");
}
} catch (Exception e) {
// TODO: handle exception
}
}
private void updateHealthPointsTextView() {
// TODO Auto-generated method stub
//Updating textview with health points value
healthPoints.setText(Integer.toString(eView.getThread().healthPoints));
}
}
#Override
public boolean onKeyDown(int KeyCode, KeyEvent Event) {
if ((KeyCode == KeyEvent.KEYCODE_MENU)) {
//Call performSpecialAttack()
Log.d("Parachute Hunter", "calling performSpecialAttack()");
eView.getThread().performSpecialAttack();
return true;
}
return super.onKeyDown(KeyCode, Event);
}
#Override
protected void onStop()
{
try {
eView.getThread().setRunning(false);
eView = null;
}
catch (NullPointerException e) {}
super.onStop();
}
}

How about having a method like this:
public void setHealthPoints(int points) {
eView.getThread().healthPoints = points;
//Updating textview with health points value
healthPoints.setText("Health Points: " + Integer.toString(points));
}
}
call it from everywhere, it should not block the GUI-Thread

just pass the reference of textview in constructor of that class and use handler to update it frequently.
public final class MethodUtil {
TextView mTextView;
public MethodUtil(TextView mTextView) {
//this.mTextView =(TextView)mTextView.findViewById(R.id.textview);
this.mTextView=mTextView;
}
public void updateHealthPointsTextView(){
mTextView.post(new Runnable() {
#Override
public void run() {
mTextView.setText("Health Points: " + eView.getThread().healthPoints);
}
});
}
}

I fixed it by simply making a countdown timer counting down from 1 second and then restarting itself and updating the textview when it's fininished. It works
public void updateHealthPointsTextView() {
//The aliens are firing and throwing rocks, make the defender lose health
new CountDownTimer(1000, 1000) {
public void onTick(long millisUntilFinished) {
}
public void onFinish() {
//Updating textview
healthPoints.setText("Health points: " + Integer.toString(eView.getThread().healthPoints));
updateHealthPointsTextView();
}
}.start();
}