Develop Reference

Android managing ListViewItem Progressbar update in row

I'm using ListView with custom list rows,where every ListItem has ProgressBar in it.
When the user click the ImageView,the app starts an AsyncTask to download a file from a remote server,and update the progress in progress bar.
I'm using Parallel async tasks,which mean app can launch multiple downloads and update them in the ProgressBar of each row.
This is the code'
static class ViewHolder {
protected TextView title;
protected TextView size;
protected TextView version;
protected ImageView appIcon;
protected ProgressBar progressBar;
}
public class UpdateAdapter extends ArrayAdapter<UpdateItem> {
public UpdateAdapter(Context context, ArrayList<UpdateItem> users) {
super(context, 0, users);
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
// Get the data item for this position
UpdateItem updateItem = getItem(position);
View v = convertView;
ViewHolder viewHolder;
LayoutInflater mInflater = LayoutInflater.from(getContext());
if (convertView == null) { // if convertView is null
convertView = mInflater.inflate(R.layout.row, null);
viewHolder = new ViewHolder();
viewHolder.title = (TextView) convertView.findViewById(R.id.apptitlelabel);
viewHolder.version = (TextView) convertView.findViewById(R.id.versionlabel);
viewHolder.size = (TextView) convertView.findViewById(R.id.sizelabel);
viewHolder.appIcon = (ImageView) convertView.findViewById(R.id.appicon);
viewHolder.progressBar = (ProgressBar) convertView.findViewById(R.id.downloadProgressBar);
convertView.setTag(viewHolder);
} else
viewHolder = (ViewHolder) v.getTag();
viewHolder.progressBar.setProgress(0);
View finalConvertView = convertView;
viewHolder.appIcon.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
DownloadFileFromURL task = new DownloadFileFromURL();
task.position = position;
task.v = finalConvertView;
task.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, updateItem.downloadlink);
}
});
return convertView;
}
class DownloadFileFromURL extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Bar Dialog
**/
int position;
View v;
#Override
protected void onPreExecute() {
super.onPreExecute();
}
/**
* Downloading file in background thread
**/
#Override
protected String doInBackground(String... f_url) {
int count;
try {
URL url = new URL(f_url[0]);
URLConnection conection = url.openConnection();
conection.connect();
// this will be useful so that you can show a tipical 0-100%
// progress bar
int lenghtOfFile = conection.getContentLength();
// download the file
InputStream input = new BufferedInputStream(url.openStream(),
8192);
// Output stream
String fileExtenstion = MimeTypeMap.getFileExtensionFromUrl(url.getPath());
String fname = URLUtil.guessFileName(url.getPath(), null, fileExtenstion);
OutputStream output = new FileOutputStream(Environment
.getExternalStorageDirectory().toString() + "/" + fname);
byte data[] = new byte[1024];
long total = 0;
while ((count = input.read(data)) != -1) {
total += count;
// publishing the progress....
// After this onProgressUpdate will be called
publishProgress("" + (int) ((total * 100) / lenghtOfFile));
// writing data to file
output.write(data, 0, count);
}
// flushing output
output.flush();
// closing streams
output.close();
input.close();
} catch (Exception e) {
Log.e("Error: ", e.getMessage());
}
return null;
}
/**
* Updating progress bar
**/
protected void onProgressUpdate(String... progress) {
// setting progress percentage
// Log.w(TAG, progress[0]);
updateStatus(position, Integer.parseInt(progress[0]));
}
/**
* After completing background task Dismiss the progress dialog
**/
#Override
protected void onPostExecute(String file_url) {
// dismiss the dialog after the file was downloaded
Log.w(TAG, "onPostExecute: ");
removeListItem(v, position);
}
}
public void updateStatus(int index, int Status) {
int in = index - updateLv.getFirstVisiblePosition();
View v = updateLv.getChildAt(in);
ProgressBar progress = (ProgressBar) v.findViewById(R.id.downloadProgressBar);
progress.setProgress(Status);
}
The problem is ,when the user starts two downloads(say hit the first the second imageviews),and the first task has been completed,and the first row getting removed from the list,in onPostExecute,now,the second row turns into the first row,but the task updates the current second row(which was the third before the first item removed...)
I know it happens because I pass into updateStatus,the position of the item to be updated,but in the meantime the ListView Changes and removes items(because their download has been completed),but I have no current solution for this...
I even tried passing the ProgressBar object reference to updateStatus method ,instead of using item position,and I thought it would solve the problem...but no luck :)
I tried also to track the items positions with hashmap..with no success... :)

Problem is also in removeListItem(v, position);, first and third item will be removed in your example. To solve the problem, try providing each item with an unique ID, you can add a field in your UpdateItem class, here I demostrate with a seperate ArrayList.
Change adapter constructor, add an ArrayList and a private method:
public UpdateAdapter(Context context, ArrayList<UpdateItem> users) {
super(context, 0, users);
resetIds(users.size());
}
ArrayList<String> arrayIds = new ArrayList<>();
private void resetIds(int size) {
arrayIds.clear();
for (int i = 0; i < size; i++) arrayIds.add(String.valueOf(i));
}
Inside the OnClickListener, add task.id = arrayIDs.get(position); just before execute AsynTask.
In AsynTask, add a field String id;, change methods onProgressUpdate and onPostExecute.
protected void onProgressUpdate(String... progress) {
// setting progress percentage
// Log.w(TAG, progress[0]);
//updateStatus(position, Integer.parseInt(progress[0]));
updateStatus(id, Integer.parseInt(progress[0]));
}
#Override
protected void onPostExecute(String file_url) {
// dismiss the dialog after the file was downloaded
Log.w(TAG, "onPostExecute: ");
removeListItem(v, position); // Problem, later fix it yourself
arrayIds.remove(id);
}
Change updateStatus
public void updateStatus(String id, int Status) {
int index = arrayIds.indexOf(id);
int in = index - updateLv.getFirstVisiblePosition();
View v = updateLv.getChildAt(in);
ProgressBar progress = (ProgressBar) v.findViewById(R.id.downloadProgressBar);
progress.setProgress(Status);
}
Use ArrayList of Integer for arrayIds may be better but need to be careful when add the code arrayIds.remove(id); in onPostExecute, be sure selected remove(object o), not remove(int index). If this works, then use the same appoach to fix removeListItem.

Android Stop recycler-View adapter binding data for already shown items

I have an app that uses a recyclerView to show results from Google Books API.
In every onBindViewHolder, I ask the client to give me data which leads me eventually to exceeding the rate limit since every scroll calls data.
Let say I got data for position 1-5 and I scroll down to position 6-10 and then go back to 1-5. How can I make sure that it won't call the client again for positions 1-5 since it has already loaded them?
I just want whatever it already called to stay there.
My adapter looks like this ( I deleted some parts like more views so it wont confuse):
public class MyBooksAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private List<DiscoverBooks> discoverBooks;
private FirebaseFirestore db;
private FirebaseAuth auth;
private String UID, BookID2;
private int count, gbsSize, counter;
interface OnDiscoverBookClickListener {
void onClick(DiscoverBooks discoverBooks);
}
private OnDiscoverBookClickListener listener;
public MyBooksAdapter(int counter, List<DiscoverBooks> discoverBooks, int gbsSize, OnDiscoverBookClickListener listener) {
this.counter = counter;
this.discoverBooks = discoverBooks;
this.listener = listener;
this.gbsSize = gbsSize;
}
#Override
public int getItemViewType(int position) {
return AppConstants.IS_NOT_ADS_POSITION;
}
#NonNull
#Override
public RecyclerView.ViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int viewType) {
View view;
view = LayoutInflater.from( viewGroup.getContext() ).inflate( R.layout.item_book_mybook, viewGroup, false );
return new DiscoverBooksViewHolder( view );
}
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
holder.setIsRecyclable( false );
if (holder instanceof DiscoverBooksViewHolder) {
((MyBooksAdapter.DiscoverBooksViewHolder) holder).bind( (discoverBooks.get( position )), holder );
}
}
#Override
public int getItemCount() {
return discoverBooks.size();
}
class DiscoverBooksViewHolder extends RecyclerView.ViewHolder {
private Button tv_Link;
private CardView cardView;
private ImageView Iv_BookCover;
private TextView tv_Author, tv_BorrowedTo, tv_BorrowedTill, tv_DateAdded, tv_Title;
private ImageButton ib_Options;
private ToggleButton tb_Status;
private DiscoverBooks discoverBooks;
private DiscoverBooksViewHolder(View itemView) {
super( itemView );
cardView = itemView.findViewById( R.id.imagecard );
Iv_BookCover = itemView.findViewById( R.id.iv_BookCover );
tv_Title = itemView.findViewById( R.id.tv_Title );
tv_Author = itemView.findViewById( R.id.tv_Author );
tv_DateAdded = itemView.findViewById( R.id.tv_DateAdded );
tv_BorrowedTo = itemView.findViewById( R.id.tv_BorrowedTo );
tv_BorrowedTill = itemView.findViewById( R.id.tv_BorrowedTill );
tv_Link = itemView.findViewById( R.id.tv_Link );
ib_Options = itemView.findViewById( R.id.ib_Options );
tb_Status = itemView.findViewById( R.id.tb_Status );
}
private void bind(DiscoverBooks discoverBooks, RecyclerView.ViewHolder viewHolder) {
this.discoverBooks = discoverBooks;
db = FirebaseFirestore.getInstance();
auth = FirebaseAuth.getInstance();
String BookID = discoverBooks.getBookID();
if (BookID.length() > AppConstants.UPLOADED_BOOK_LENGTH) {
db.collection( "Books" ).document( BookID ).get()
.addOnCompleteListener( task -> {
if (task.isSuccessful()) {
DocumentSnapshot document = task.getResult();
if (document.exists()) {
DO SOMETHING
}
}
} );
} else {
//HERE I CALL GOOGLE BOOKS API
MyBookClient.getInstance().getBooks( BookID, new JsonHttpResponseHandler() {
#Override
public void onSuccess(int statusCode, Header[] headers, JSONObject response) {
if (response != null) {
final MyBook books = MyBook.fromJson( response );
//DO SOMETHING
}
}
} );
}
}
}
}

Ok, I understood your problem. For every bookID, you fetch its data from Google Books, and now you want to not hit the api for already loaded items.
Simply, create a global variable for ArrayList as
private ArrayList<MyBook> mybooks = new ArrayList();
Call your onBind() in onBindViewHolder() as
((MyBooksAdapter.DiscoverBooksViewHolder) holder).bind(position, discoverBooks.get( position), holder);
Replace your onBind() with this:
private void bind(int position, UserData discoverBooks, RecyclerView.ViewHolder viewHolder) {
this.discoverBooks = discoverBooks;
db = FirebaseFirestore.getInstance();
auth = FirebaseAuth.getInstance();
String BookID = discoverBooks.getBookID();
if (BookID.length() > AppConstants.UPLOADED_BOOK_LENGTH) {
db.collection("Books").document(BookID).get()
.addOnCompleteListener(task -> {
if (task.isSuccessful()) {
DocumentSnapshot document = task.getResult();
if (document.exists()) {
DO SOMETHING
}
}
});
} else {
if (position >= myBooks.size() || myBooks.get(position) == null) {
//If the value doesn't exist in the ArrayList,
//it will hit the Google Books API
MyBookClient.getInstance().getBooks(BookID, new JsonHttpResponseHandler() {
#Override
public void onSuccess(int statusCode, Header[] headers, JSONObject response) {
if (response != null) {
final MyBook books = MyBook.fromJson(response);
myBooks.add(position, books);
//DO SOMETHING
}
}
});
} else {
//If the value has already been loaded in the list,
//directly use it without hitting the API
final MyBook books = myBooks.get(position);
//DO SOMETHING
}
}
}
This will solve your issue, it will store the already accessed books from the API and will not hit the API again and will use the List to access them.
Apart from this, I'll suggest to go with ViewBinding which will replace your whole DiscoverBooksViewHolder into a single line(in Kotlin) or 2-3 lines(in Java), with viewBinding, you'll not have to declare and initialize views and the views can be accessed directly using Binding, you can then extract your onBind() out of the ViewHolder.

Android studio, recycle view

I have some error in android studio.
When i try to add symbol ('*') to special item, it also add the symbol to the item that placed in +14 from the first.
I will glad if someone have solution for this problem.
For more information you can check this link, where i describe the problem.
https://youtu.be/CJFkt-Cck1A
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.MyViewHolder> {
private static final String TAG = "RecyclerViewAdapter";
private Context context;
private List<WorkDayItem> workDayItemList;
//Complete
public RecyclerViewAdapter(Context context, List<WorkDayItem> workDayItemList) {
this.context = context;
this.workDayItemList = workDayItemList;
}
//Complete
//Here we create view- itemWorkday and inflate it by layout- item_one_work_day
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemWorkDay = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_one_work_day, parent, false);
MyViewHolder myViewHolder = new MyViewHolder(itemWorkDay);
return myViewHolder;
}
#Override
public void onBindViewHolder(final MyViewHolder holder, int position) {
Log.d(TAG, "onBindViewHolder: called." + (position + 1) + "\n" + workDayItemList.get(position).toString());
final WorkDayItem workDayItem = workDayItemList.get(position);
String dateStart = (String) DateFormat.format("dd.MM", workDayItem.getDateStart());
String timeStart = (String) DateFormat.format("HH:mm", workDayItem.getDateStart());
String timeEnd = (String) DateFormat.format("HH:mm", workDayItem.getDateEnd());
//Convert data from firebase String format to int hours and minutes format.
Double convertingDataFromFirebase;
try {
convertingDataFromFirebase = Double.parseDouble(new DecimalFormat("##.##").format(workDayItem.getCount_hours()));
} catch (NumberFormatException e) {
convertingDataFromFirebase = 0.0;
}
int hours = convertingDataFromFirebase.intValue();
convertingDataFromFirebase = (convertingDataFromFirebase - convertingDataFromFirebase.intValue()) * 60;
int minutes = convertingDataFromFirebase.intValue();
//Check if current item have description
if (workDayItemList.get(position).getDesc().length() > 2) {
Log.i(TAG, "TESTER: desc dote added");
holder.doteOfDesc.setVisibility(View.VISIBLE);
}
holder.dayPosition.setText((position + 1) + "");
holder.dateStart.setText(dateStart);
holder.timeStart.setText(timeStart);
holder.timeEnd.setText(timeEnd);
holder.countOfHours.setText(hours + ":" + minutes);
//On click on current hold open alert dialog with some functions
holder.parentLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
initializeAlertDialogForItem(workDayItem, holder);
}
});
}
//initialize data about current work day and have button for changing information
private void initializeAlertDialogForItem(final WorkDayItem workDayItem, final MyViewHolder holder) {
//Initialize alert dialog
final AlertDialog alertDialog = new AlertDialog.Builder(context).create();
View itemWork = LayoutInflater.from(context)
.inflate(R.layout.ad_item_desc, null, false);
alertDialog.setView(itemWork);
alertDialog.show();
//initialize alert dialog buttons and views
final ImageButton change = alertDialog.findViewById(R.id.itemAD_Edit);
final ImageButton delete = alertDialog.findViewById(R.id.itemAD_Delete);
TextView description = alertDialog.findViewById(R.id.itemADDescription);
TextView date = alertDialog.findViewById(R.id.itemADDate);
TextView from = alertDialog.findViewById(R.id.itemADFrom);
TextView to = alertDialog.findViewById(R.id.itemADTO);
String timeStart = (String) (DateFormat.format("HH:mm", workDayItem.getDateStart()));
String timeEnd = (String) (DateFormat.format("HH:mm", workDayItem.getDateEnd()));
String dateStart = (String) (DateFormat.format("dd.MM.yyyy", workDayItem.getDateStart()));
date.setText(dateStart);
from.setText(timeStart);
to.setText(timeEnd);
description.setText(workDayItem.getDesc());
//Change button
change.setOnClickListener(new View.OnClickListener() {
#RequiresApi(api = Build.VERSION_CODES.M)
#Override
public void onClick(View v) {
AlertDialogReport userReport = new AlertDialogReport(context, "replace-remove", workDayItem);
userReport.initializeAlertDialog();
alertDialog.dismiss();
}
});
delete.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//Delete data from firebase
Login.fc.databaseReference.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
String itemTime = "" + workDayItem.getDateStart().getTime();
String firebaseTime = "" + snapshot.child("dateStart").child("time").getValue();
if (itemTime.equals(firebaseTime)) {
Login.fc.databaseReference.child(snapshot.getKey()).removeValue();
}
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});
//Delete data from SqLiteDatabase
MySQLDataBase dataBase = new MySQLDataBase(context);
dataBase.deleteItem(workDayItem);
//Finish with alert dialog and notify user
alertDialog.dismiss();
Toast.makeText(context, R.string.item_deleted, Toast.LENGTH_SHORT).show();
holder.parentLayout.removeAllViews();
}
});
}
//Complete
#Override
public int getItemCount() {
return workDayItemList.size();
}
//Complete
//Here we catch our view and getting reference between view and our objects
public class MyViewHolder extends RecyclerView.ViewHolder {
private LinearLayout parentLayout;
private TextView doteOfDesc, dayPosition, dateStart, timeStart, timeEnd, countOfHours;
public MyViewHolder(View view) {
super(view);
doteOfDesc = view.findViewById(R.id.itemDote);
dayPosition = view.findViewById(R.id.itemDayPosition);
dateStart = view.findViewById(R.id.itemDateStart);
timeStart = view.findViewById(R.id.itemStartHour);
timeEnd = view.findViewById(R.id.itemEndHour);
countOfHours = view.findViewById(R.id.itemCountOfHours);
parentLayout = view.findViewById(R.id.itemWorkDay);
}
}
}

Try adding this:
//Check if current item have description
if (workDayItemList.get(position).getDesc().length() > 2) {
Log.i(TAG, "TESTER: desc dote added");
holder.doteOfDesc.setVisibility(View.VISIBLE);
}
else if( workDayItemList.get(position).getDesc().length() < 2
&& holder.doteOfDesc.getVisibility()== View.VISIBLE ){
holder.doteOfDesc.setVisibility(View.GONE);
}
The reason why this is happening is that RecyclerView creates as many ViewHolders as its needed to cover a whole screen plus few extra ( 12 in your case) then reuses them via rebinding values to views. And you set doteOfDescto View.VISIBLE in 2. ViewHolder, but never set it back to View.GONE, thats why every time that ViewHolder is reused it will have doteOfDesc visible.
The Prettier version:
Boolean hasDescription = workDayItemList.get(position).getDesc().length() > 2;
holder.doteOfDesc.setVisibility( hasDescription ? View.VISIBLE : View.GONE);

Clear ListView if response is a empty array?

I have two spinners the first one for month and the second for years.I am trying to call a method send_date() if on Item Selected is called for any of the 2 spinners.
So I have two problems:- 1)send_date() gets called twice the first
time it gets the correct data as expected but the 2nd time it returns
a empty array. 2)When I select another month or year the old data does
not get removed that is the list does not refresh.
The following is my code for on Item Selected :-
public void onItemSelected(AdapterView<?> parent, View view, int position, long id)
{
int i = spinYear.getSelectedItemPosition();
selected_year = years.get(i);
Log.d("Selection Year",selected_year);
tv_year.setText(selected_year);
try {
send_date();
} catch (JSONException e) {
e.printStackTrace();
}
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
And for the month spinner:-
public void onItemSelected(AdapterView<?> parent, View view, int position, long id)
{
int j = spinMonths.getSelectedItemPosition();
selected_month = Months[j];
Date date = null;
try {
date = new SimpleDateFormat("MMMM").parse(selected_month);
} catch (ParseException e) {
e.printStackTrace();
}
Calendar cal = Calendar.getInstance();
cal.setTime(date);
tv_month.setText(String.valueOf(cal.get(Calendar.MONTH)+1));
Log.d("Selection Month",selected_month);
try {
send_date();
} catch (JSONException e) {
e.printStackTrace();
}
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
On response I call the following method for populating the list view with data:-
public void showBS(String response)
{
ParseBS_all pb = new ParseBS_all(response);
pb.parseBS();
bl = new BS_allList(getActivity(),ParseBS_all.doc_no,ParseBS_all.balance,ParseBS_all.total,ParseBS_all.vat,ParseBS_all.profit);
lv_bsall.setAdapter(bl);
}
This is the code for the send_date method:-
//This method is used to send month and year
private void send_date() throws JSONException {
final String year = tv_year.getText().toString();
final String month = tv_month.getText().toString();
StringRequest stringRequest = new StringRequest(Request.Method.POST, SEND_DATE,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
//display.setText("This is the Response : " + response);
String resp = response.toString().trim();
if (resp.equals("Nothing to display"))
{
Toast.makeText(getContext(), "Nothing to Display", Toast.LENGTH_SHORT).show();
// bl.clear();
lv_bsall.setAdapter(bl);
bl.notifyDataSetChanged();
}else
{
Toast.makeText(getContext(), "Response" + response, Toast.LENGTH_LONG).show();
Log.d("RESPONSE for date", response.toString().trim());
showBS(response);
}
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
}
}) {
#Override
protected Map<String, String> getParams() throws AuthFailureError {
GlobalClass gvar = (GlobalClass) getActivity().getApplicationContext();
String dbname = gvar.getDbname();
Map<String, String> params = new HashMap<>();
params.put(KEY_DBNAME, dbname);
params.put(KEY_MONTH, month);
params.put(KEY_YEAR,year);
return params;
}
};
RequestQueue requestQ = Volley.newRequestQueue(getContext());
requestQ.add(stringRequest);
}
Adapter code for list view.
public class BS_allList extends ArrayAdapter<String>
{
private String[] doc_no;
private String[] balance;
private String[] total;
private String[] vat;
private String[] profit;
private Activity context;
public BS_allList(Activity context, String[] doc_no, String[]balance, String[] total, String[] vat, String[] profit)
{
super(context, R.layout.bs_list_all, doc_no);
this.context =context;
this.doc_no= doc_no;
this.balance = balance;
this.total = total;
this.vat=vat;
this.profit = profit;
}
#Override
public View getView(int position, View listViewItem, ViewGroup parent)
{
if (null == listViewItem)
{
LayoutInflater inflater = context.getLayoutInflater();
listViewItem = inflater.inflate(R.layout.bs_list_all, null, true);
}
TextView tv_docNo = (TextView) listViewItem.findViewById(R.id.tvdoc_no);
TextView tv_balance = (TextView) listViewItem.findViewById(R.id.tv_balance);
TextView tv_tot = (TextView) listViewItem.findViewById(R.id.tv_total);
TextView tv_vat = (TextView) listViewItem.findViewById(R.id.tv_vat);
TextView tv_pf = (TextView) listViewItem.findViewById(R.id.tv_profit);
tv_docNo.setText(doc_no[position]);
tv_balance.setText(balance[position]);
tv_tot.setText(total[position]);
tv_vat.setText(vat[position]);
tv_pf.setText(profit[position]);
return listViewItem;
}
}
Also note that I have set the spinner to point to the current month and year so the first time it works properly.
I am new to programming so any help or suggestion is appreciated.Thank you.

Hi #AndroidNewBee,
As per our discussion made following changes in your code and you will get proper output and it will resolve your issues.
if (resp.equals("Nothing to display"))
{
Toast.makeText(getContext(), "Nothing to Display", Toast.LENGTH_SHORT).show();
bl = new BS_allList(getActivity(),{""},{""},{""},{""},{""});
lv_bsall.setAdapter(bl);
}
And second is check validation as below,
try {
if((selected_year != null & selected_year.length > 0 ) & (tv_month.getText().toString() != null & tv_month.getText().toString().length > 0))
{
send_date();
}
} catch (JSONException e) {
e.printStackTrace();
}

First you shouldn't be using so many String[], instead wrap them in a class
Class BSDataModel{
private String doc_no;
private String balance;
private String total;
private String vat;
private String profit;
//getters and setters
}
Now the reponse result should be added as in ,it returns List<BSDataModel>
List<BSDataModel> reponseList = new ArrayList<>();
//for example adding single response
for(int i=0;i<jsonArrayResponse.length();i++){
BSDataModel singleResponse = new BSDataModel();
singleResponse.setDocNo(jsonArrayResponse.get(i).getString("doc_no"));
singleResponse.setBalace(jsonArrayResponse.get(i).getString("balance"));
//etc..finall add that single response to responseList
reponseList.add(singleResponse);
}
BS_allList.java
public class BS_allList extends ArrayAdapter<BSDataModel>
{
private List<BSDataModel> bsList;
private Activity context;
public BS_allList(Activity context,List<BSDataModel> bsList)
{
super(context, R.layout.bs_list_all, bsList);
this.context =context;
this.bsList = bsList;
}
#Override
public View getView(int position, View listViewItem, ViewGroup parent)
{
if (null == listViewItem)
{
LayoutInflater inflater = context.getLayoutInflater();
listViewItem = inflater.inflate(R.layout.bs_list_all, null, true);
}
TextView tv_docNo = (TextView) listViewItem.findViewById(R.id.tvdoc_no);
TextView tv_balance = (TextView) listViewItem.findViewById(R.id.tv_balance);
TextView tv_tot = (TextView) listViewItem.findViewById(R.id.tv_total);
TextView tv_vat = (TextView) listViewItem.findViewById(R.id.tv_vat);
TextView tv_pf = (TextView) listViewItem.findViewById(R.id.tv_profit);
BSDataModel bsData = bsList.get(position);
tv_docNo.setText(bsData.getDoc());
tv_balance.setText(bsData.getBalance());
tv_tot.setText(bsData.getTot());
tv_vat.setText(bsData.getVat());
tv_pf.setText(bsData.getPF());
return listViewItem;
}
}
Now in your class
BS_allList bl = new BS_allList(getActivity(),responseList);//which you got above
After receiving new Response
// remove old data
responseList.clear(); // list items in the sense list of array used to populate listview
if(newresponseArray.size() > 0){
for(int i=0;i<newjsonArrayResponse.length();i++){
BSDataModel singleResponse = new BSDataModel();
singleResponse.setDocNo(newjsonArrayResponse.get(i).getString("doc_no"));
singleResponse.setBalace(newjsonArrayResponse.get(i).getString("balance"));
//etc..finall add that single response to responseList
reponseList.add(singleResponse);
}
}
//refresh listview
bl.notifyDataSetChanged();

Try this way,
1. adapter.clear();
2. Add/Remove your list Items.
3. listview.setAdapter(adapter);
4. adapter.notifyDatasetChanged();
this procedure should work.

Android loading images to listview asynchronously?

I have a listview in which I'm loading all the images (as previews) from the user's SD card. I have a custom SimpleCursorAdapter and when I override the getView() method, I try to start background threads for the image loading.
What I'm trying to do is basically "lazy loading" the image previews into the listview using background threads or something. I'm open for new solutions. The main problem is that scrolling is ungodly slow since loading images is so expensive an operation.
Here's the relevant code I'm trying:
public class listOfImages extends SimpleCursorAdapter {
private Cursor c;
private Context context;
public listOfImages(Context context, int layout, Cursor c,
String[] from, int[] to) {
super(context, layout, c, from, to);
this.c = c;
this.context = context;
}
public View getView(int pos, View inView, ViewGroup parent) {
View v = inView;
if (v == null) {
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = inflater.inflate(R.layout.image_item, null);
}
this.c.moveToPosition(pos);
int columnIndex = this.c.getColumnIndexOrThrow(MediaStore.Images.Media.DISPLAY_NAME);
String name = this.c.getString(columnIndex);
columnIndex = this.c.getColumnIndexOrThrow(MediaStore.Images.Media.SIZE);
String size = this.c.getString(columnIndex);
columnIndex = this.c.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
String data = this.c.getString(columnIndex); //gives the filename
TextView sTitle = (TextView) v.findViewById(R.id.image_title);
sTitle.setText(name);
imagePreviewLoader ipl = new imagePreviewLoader(v, data);
ipl.mainProcessing();
v.setTag(data);
v.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(context, "Image: " + v.getTag(), Toast.LENGTH_SHORT).show();
String filename = (String) v.getTag();
Intent intent = new Intent(context, ViewImage.class);
intent.putExtra("filename", filename);
context.startActivity(intent);
}
});
return v;
}
}
And now the background threading that I'm trying:
public class imagePreviewLoader {
private Handler handler = new Handler();
private View v;
private String data;
public imagePreviewLoader(View v, String data) {
this.v = v;
this.data = data;
}
protected void mainProcessing() {
Thread thread = new Thread(null, doBackground, "Background");
thread.start();
}
private Runnable doBackground = new Runnable() {
public void run() {
backgroundThreadProcessing();
}
};
private void backgroundThreadProcessing() {
handler.post(doUpdateGUI);
}
private Runnable doUpdateGUI = new Runnable() {
public void run() {
updateGUI();
}
};
private void updateGUI() {
ImageView img = (ImageView) v.findViewById(R.id.image_view);
BitmapFactory.Options bfo = new BitmapFactory.Options();
bfo.inSampleSize = 30;
bfo.inTargetDensity = 50;
Bitmap bm = BitmapFactory.decodeFile(data, bfo);
img.setImageBitmap(bm);
}
}
The issue is that everything tries to load at once when you scroll, so scrolling is really slow. I thought what would happen is the imageview would just stay blank (or a placeholder) until the thread has loaded the appropriate image. I guess not though.
Thanks for any help.

Have a look at my answer to this question, it has a sample project which shows how to do it but downloading images from the net. You should be able to modify it quite easily to work for you getting images from the SD card.

I have an easy to use library under a basically public domain license that you can check out... It will cancel loading for rows that aren't displaying and uses two threads to do image loading.
You can check it out on my GitHub: https://github.com/tbiehn/Android-Adapter-Image-Loader