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new item is not getting added in recyclerview?

i am scanning devices from a bluetooth and getting their data from their advertisement,so one of the device gives the data of other devices which is not in ranged from the mobile device,so i specifically filter the data of that device which i wanted to show in recycler view in automatically updating the rssi values.
let's say,
a device A which gives the data of 3 devices B,C,D containing their rssi values continuously,so what i want to show the list of device B,C,D with their rssi values which is changing continuously.
What i have done until now is scan that device "A",and extract the data of B and shown in recyclerview,but when another device i.e C's data comes in the old device i.e B got vanished and so on.
what i want is continuously changing data of B,C,D.
Adapter Class:-
public class ReapeaterDeviceAdapter extends RecyclerView.Adapter<ReapeaterDeviceAdapter.CryptoViewHolder> {
private ArrayList<RepeaterModel> data = new ArrayList<>();;
private Context mCtx;
public class CryptoViewHolder extends RecyclerView.ViewHolder {
private TextView mName, mPrice;
public CryptoViewHolder(View itemView) {
super(itemView);
mName = itemView.findViewById(R.id.txtName);
mPrice = itemView.findViewById(R.id.txtPrice);
}
}
public ReapeaterDeviceAdapter(Context ctx,ArrayList<RepeaterModel> data) {
this.mCtx = ctx;
this.data = data;
}
#Override
public CryptoViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.repeater_dev_data,parent, false);
return new CryptoViewHolder(itemView);
}
#Override
public void onBindViewHolder(CryptoViewHolder holder, int position) {
System.out.println("onBinder");
holder.mName.setText(data.get(position).macdev);
holder.mPrice.setText(String.valueOf(data.get(position).rssi));
}
#Override
public void onBindViewHolder(CryptoViewHolder holder, int position, List<Object> payloads) {
if (payloads.isEmpty()) {
//System.out.println("onbinder");
super.onBindViewHolder(holder, position, payloads);
} else {
Bundle o = (Bundle) payloads.get(0);
//System.out.println("in keyset");
for (String key : o.keySet()) {
if (key.equals("price")) {
holder.mName.setText(data.get(position).macdev);
holder.mPrice.setText(String.valueOf(data.get(position).rssi));
//holder.mPrice.setTextColor(Color.GREEN);
//this.notifyItemChanged(position);
}
}
}
}
#Override
public int getItemCount() {
return data.size();
}
public ArrayList<RepeaterModel> getData() {
return data;
}
public void setData(ArrayList<RepeaterModel> newData) {
MyDiffUtilCallBack diffCallBack = new MyDiffUtilCallBack(newData, this.data);
DiffUtil.DiffResult diffResult = DiffUtil.calculateDiff(diffCallBack);
//this.setData(newData);
// this.data=newData;
this.data.clear();
// this.data = newData;
this.data.addAll(newData);
diffResult.dispatchUpdatesTo(this);
//this.notifyItemRangeChanged(0, this.getItemCount());
//this.notifyDataSetChanged();
//System.out.println("Here");
}
}
Model Class:-
public String macdev;
public int rssi ;
public int imageid;
public RepeaterModel(String macdev, int rssi, int imageid) {
this.macdev = macdev;
this.rssi = rssi;
this.imageid = imageid;
}
public String getMacdev() {
return macdev;
}
public void setMacdev(String macdev) {
this.macdev = macdev;
}
public int getRssi() {
return rssi;
}
public void setRssi(int rssi) {
this.rssi = rssi;
}
public int getImageid() {
return imageid;
}
public void setImageid(int imageid) {
this.imageid = imageid;
}
#Override
public boolean equals(Object o) {
System.out.println("in equals");
if (this == o) return true;
if (!(o instanceof RepeaterModel)) return false;
RepeaterModel that = (RepeaterModel) o;
return getRssi() == that.getRssi() &&
getImageid() == that.getImageid() &&
getMacdev().equals(that.getMacdev());
}
#Override
public int hashCode() {
return Objects.hash(getMacdev(), getRssi(), getImageid());
}
/*#Override
public int hashCode() {
int result = Integer.valueOf(rssi);
// result = result + (imageid != 0 ? imageid.hashCode() : 0);
result = result + rssi.hashCode();
System.out.println("hash");
return result;
}*/
}
Diffutilcallback :-
ArrayList<RepeaterModel> newList;
ArrayList<RepeaterModel> oldList;
public MyDiffUtilCallBack(ArrayList<RepeaterModel> newList, ArrayList<RepeaterModel> oldList) {
this.newList = newList;
this.oldList = oldList;
}
#Override
public int getOldListSize() {
return oldList != null ? oldList.size() : 0;
}
#Override
public int getNewListSize() {
return newList != null ? newList.size() : 0;
}
#Override
public boolean areItemsTheSame(int oldItemPosition, int newItemPosition) {
if(newList.get(newItemPosition).getMacdev().equals(oldList.get(oldItemPosition).getMacdev()))
{
// Log.d("itemsame","in same");
return true;
}
else {
// Log.d("itemsame", "not same");
}
return false;
}
#Override
public boolean areContentsTheSame(int oldItemPosition, int newItemPosition)
{
//System.out.println("in content same");
final RepeaterModel oldRepeater = oldList.get(oldItemPosition);
final RepeaterModel newRepeater = newList.get(newItemPosition);
if(oldRepeater.getRssi()!=(newRepeater.getRssi()))
{
//Log.d("item contenets","content different");
return false;
}
//Log.d("item contenets","content same");
return true;
}
#Nullable
#Override
public Object getChangePayload(int oldItemPosition, int newItemPosition) {
RepeaterModel newModel = newList.get(newItemPosition);
RepeaterModel oldModel = oldList.get(oldItemPosition);
//System.out.println("getchange");
Bundle diff = new Bundle();
//if (newModel.getMacdev().equals(oldModel.getMacdev()))
//{
//System.out.println("getchange");
if (newModel.getRssi()!=(oldModel.getRssi())) {
diff.putInt("price", newModel.getRssi());
}
if (diff.size() == 0) {
return null;
}
// }
return diff;
//return super.getChangePayload(oldItemPosition, newItemPosition);
}
}```
Activity Class:-
public class RepeaterAdvertise extends AppCompatActivity {
private static BluetoothAdapter mBluetoothAdapter;
private static BluetoothLeScanner mLEScanner;
private static final int PERMISSION_REQUEST_COARSE_LOCATION = 1;
private static boolean mScanning;
private static Handler mHandler;
private static final long SCAN_TIMEOUT = 20000;
public DevData data;
public Button cc;
//List<BluetoothDevice> mBluetoothDevice;
RecyclerView recyclerView;
ReapeaterDeviceAdapter reapeaterDeviceAdapter;
ArrayList<RepeaterModel> modelArrayList;// = new ArrayList<>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_repeater_advertise);
modelArrayList = new ArrayList<>();
recyclerView = (RecyclerView) findViewById(R.id.devdata);
//dummyData();
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
reapeaterDeviceAdapter = new ReapeaterDeviceAdapter(RepeaterAdvertise.this, modelArrayList);
recyclerView.setAdapter(reapeaterDeviceAdapter);
mHandler = new Handler();
final Intent intent = getIntent();
data = (DevData) intent.getSerializableExtra(SINGLE_DEV_DATA);
}
#Override
protected void onPause() {
super.onPause();
scanLeDevice(false,data.getMac_address());
}
#Override
protected void onResume() {
super.onResume();
scanLeDevice(true,data.getMac_address());
}
private void scanLeDevice(final boolean enable,String mac) {
if (enable) { // enable set to start scanning
// Stops scanning after a pre-defined scan period.
mHandler.postDelayed(new Runnable() {
#Override
public void run() {
if(mScanning) {
mScanning = false;
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
//noinspection deprecation
mBluetoothAdapter.stopLeScan(mLeScanCallback);
} else {
mLEScanner.stopScan(mScanCallback);
}
invalidateOptionsMenu();
}
}
}, SCAN_TIMEOUT);
mScanning = true;
UUID[] motorServiceArray = {PSoCBleRobotService.getMotorServiceUUID()};
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
//noinspection deprecation
mBluetoothAdapter.startLeScan(motorServiceArray, mLeScanCallback);
} else { // New BLE scanning introduced in LOLLIPOP
ScanSettings settings;
List<ScanFilter> filters;
mLEScanner = mBluetoothAdapter.getBluetoothLeScanner();
settings = new ScanSettings.Builder()
.setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY)
.build();
filters = new ArrayList<>();
//ScanFilter filter = new ScanFilter.Builder().setServiceUuid(PUuid).build();
//ScanFilter filter = new ScanFilter.Builder().setManufacturerData(89,new byte[] {}).build();
ScanFilter filter = new ScanFilter.Builder().setDeviceAddress(mac).build();
filters.add(filter);
if(mLEScanner==null)
{
mLEScanner = mBluetoothAdapter.getBluetoothLeScanner();
}
mLEScanner.startScan(filters, settings, mScanCallback);
}
} else { // enable set to stop scanning
if(mScanning) {
mScanning = false;
if (Build.VERSION.SDK_INT < 21) {
//noinspection deprecation
mBluetoothAdapter.stopLeScan(mLeScanCallback);
} else {
mLEScanner.stopScan(mScanCallback);
}
}
}
invalidateOptionsMenu();
}
private final BluetoothAdapter.LeScanCallback mLeScanCallback = new BluetoothAdapter.LeScanCallback() {
#Override
public void onLeScan(final BluetoothDevice device, int rssi, final byte[] scanRecord) {
runOnUiThread(new Runnable() {
#Override
public void run()
{
byte[] haha = scanRecord;
/* if(!mBluetoothDevice.contains(device))
{
//only add new devices
mBluetoothDevice.add(device);
mBleName.add(device.getName());
mBleArrayAdapter.notifyDataSetChanged(); // Update the list on the screen
}*/
}
});
}
};
public static String SbytesToHex(SparseArray<byte[]> bytes) {
StringBuilder builder = new StringBuilder();
byte[] dd = bytes.valueAt(0);
for (byte b: dd)
{
builder.append(String.format("%02x", b));
}
//System.out.println( dd.length);
return builder.toString();
}
public final ScanCallback mScanCallback = new ScanCallback() {
#Override
public void onScanResult(int callbackType, ScanResult result) {
ScanRecord scanRecord = result.getScanRecord();
// mBluetoothDevice.add(result.getDevice());
SparseArray<byte[]> dataw = scanRecord.getManufacturerSpecificData();
if (dataw.size() > 0) {
//populate_devData(SbytesToHex(dataw));
String data = SbytesToHex(dataw);
ArrayList<RepeaterModel> repeaterModels= new ArrayList<>();
int rssi = Integer.valueOf(data.substring(12, 14), 16) - 256;
repeaterModels.add(new RepeaterModel(data.substring(0, 12), rssi, 1));
insert(repeaterModels);
} else if (false) {
//alertDialog.dismiss();
final Intent intent = new Intent(RepeaterAdvertise.this, ConfigurationView.class);
intent.putExtra(EXTRAS_BLE_ADDRESS, data.getMac_address());
intent.putExtra(EXTRAS_BLE_NAME, data.getName());
intent.putExtra(SINGLE_DEV_DATA, data.getDev_data());
scanLeDevice(false, data.getMac_address());
//mconfig=false;
startActivity(intent);
}
}
};
public void insert(ArrayList<RepeaterModel> rr)
{
modelArrayList.addAll(rr);
reapeaterDeviceAdapter.setData(rr);
}
}

add this line in insert function reapeaterDeviceAdapter.notifyDataSetChanged();
public void insert(ArrayList<RepeaterModel> rr){
modelArrayList.addAll(rr);
reapeaterDeviceAdapter.setData(rr);
reapeaterDeviceAdapter.notifyDataSetChanged();
}

How to update total no of child from firebase child node everytime onDataChange from AddSingleValueEventListner?

Below image shows my Firebase database structure:
All data retrieved successfully. Here is my model class.
public class Post
{
public String lastname;
public String postid;
public long timestamp;
public HashMap<String,Boolean> count;
public Post()
{
}
public Post(String lastname, long timestamp, String postid,HashMap count)
{
this.lastname=lastname;
this.timestamp=timestamp;
this.postid=postid;
this.count=count;
}
public HashMap<String, Boolean> getCounts() {
return count;
}
public void setCounts(HashMap<String, Boolean> count) {
this.count = count;
}
In Main Activity i used to get data
mAdapter = new PostAdapter(MainActivity.this);
getAllPost(null);
postList.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
if (!recyclerView.canScrollVertically(1))
{
loaded=loaded+10;
if (totalPost== mAdapter.getItemCount())
{
Toast.makeText(MainActivity.this, "no more post", Toast.LENGTH_SHORT).show();
}
else
{
getAllPost(mAdapter.getLastItemId());
}
}
}
});
postList.setAdapter(mAdapter);
private void getAllPost(final String nodeId)
{
final Query query;
final int left= (int) (totalPost-mAdapter.getItemCount());
Toast.makeText(this, String .valueOf(left), Toast.LENGTH_SHORT).show();
if (nodeId == null)
{
query = PostRef
.orderByChild("timestamp")
.limitToLast(mPostsPerPage);
}
else
{
if (left<10)
{
query = PostRef
.orderByChild("timestamp")
.limitToFirst(left);
}
else
{
Long time=Long.parseLong(nodeId);
query = PostRef
.orderByChild("timestamp").endAt(time)
.limitToLast(10);
}
}
query.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
List<Post> userModels = new ArrayList<>();
for (DataSnapshot userSnapshot : dataSnapshot.getChildren())
{
userModels.add(userSnapshot.getValue(Post.class));
}
if (!(nodeId ==null))
{
if (left>10)
{
userModels.remove(9);
}
}
Collections.reverse(userModels);
mAdapter.addAll(userModels);
}
#Override
public void onCancelled(DatabaseError databaseError) {
throw databaseError.toException();
}
});
}
And in adapter:
public class PostAdapter extends RecyclerView.Adapter<PostHolder>
{
List<Post> mPost;
Context mContext;
public PostAdapter(Context c) {
this.mPost = new ArrayList<>();
mContext=c;
}
#NonNull
#Override
public PostHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
return new PostHolder(LayoutInflater.from(viewGroup.getContext())
.inflate(R.layout.all_post_layout, viewGroup, false));
}
#Override
public void onBindViewHolder(#NonNull final PostHolder postHolder, final int i) {
final String PostKey=mPost.get(i).getPostid();
FirebaseAuth mAuth=FirebaseAuth.getInstance();
final String currentUserID=mAuth.getCurrentUser().getUid();
final DatabaseReference post=FirebaseDatabase.getInstance().getReference().child("Posts");
showCounts(postHolder,i);
setCountsButton(postHolder,i,currentUserID);
tapOnCounts(postHolder,i,currentUserID,post,PostKey);
}
private void tapOncounts(final PostHolder postHolder, final int i, final String currentUserID, final DatabaseReference post, final String postKey)
{
postHolder.countsButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v)
{
if (mPost.get(i).getCounts() !=null)
{
if(mPost.get(i).getCounts().containsKey(currentUserID))
{
post.child(postKey).child("counts").child(currentUserID).removeValue();
postHolder.countsButton.setImageResource(R.drawable.discounts);
}
else
{
postHolder.countsButton.setImageResource(R.drawable.counts);
post.child(postKey).child("counts").child(currentUserID).setValue(true);
}
}
else
{
postHolder.countsButton.setImageResource(R.drawable.counts);
post.child(postKey).child("counts").child(currentUserID).setValue(true);
}
}
});
}
private void setcountsButton(final PostHolder postHolder, int i, String currentUserID)
{
if (mPost.get(i).getCounts() !=null)
{
if(mPost.get(i).getCounts().containsKey(currentUserID))
{
postHolder.countsButton.setImageResource(R.drawable.counts);
}
else
{
postHolder.countsButton.setImageResource(R.drawable.discounts);
}
}
}
private void showCounts(PostHolder postHolder, int i)
{
if((mPost.get(i).getCounts() !=null))
{
postHolder.noOfcounts.setText(String.valueOf(mPost.get(i).getCounts().size()));
}
else
{
postHolder.noOfcounts.setText("0");
}
}
#Override
public int getItemCount() {
return mPost.size();
}
public void addAll(List<Post> newPost) {
int initialSize = mPost.size();
mPost.addAll(newPost);
notifyItemRangeInserted(initialSize, newPost.size());
}
public String getLastItemId() {
return String.valueOf(mPost.get(mPost.size() - 1).getTimestamp());
}
}
All is successfully but whenever total no. of child change(new child added OR old child removed) in count node recylerview is not update. It will only update when i tried to go another activity and come to rerun in MainActivity.

To get realtime updates, you should use Query's addValueEventListener(ValueEventListener listener) method:
Add a listener for changes in the data at this location.
When using addListenerForSingleValueEvent(ValueEventListener listener):
Add a listener for a single change in the data at this location.
Edit:
To get the size of your list, please change the following line of code:
holder.count.setText(String.valueOf(mPost.get(i).getCount().size));
to
holder.count.setText(String.valueOf(getItemCount());

Whenever total number of child changes then your list of Post modal also changes i.e. userModels in your case. Hence whenever your list of model changes your adapter needs to be notified. Hence my guess is to add notifyDataSetChanged to adapter.
Try this:
query.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
List<Post> userModels = new ArrayList<>();
for (DataSnapshot userSnapshot : dataSnapshot.getChildren()) {
userModels.add(userSnapshot.getValue(Post.class));
}
mAdapter.notifyDataSetChanged(); //<<changes made HERE
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
})
For this to work I hope userModels is instance variable to your MainActivity and is set to mAdapter during initialization.

How to implement search filter properly on a Recycleview in Android

I have successfully populated my recycleview from mysql database and I want to implement search filter on it. I have seen some examples and tried to implement it. I know i'm close but cant get it properly to work.
My current progress is when I try to search something the whole recycle view goes blank and nothing happens after that.
Here are my java code:
MainActivity.java
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getHotelDetails();
mylearningAdapters1 = new ArrayList<>();
recyclerView = (RecyclerView) findViewById(R.id.reviews_list);
recyclerView.setHasFixedSize(true);
recyclerViewlayoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);
recyclerView.setLayoutManager(recyclerViewlayoutManager);
inputSearch = (EditText)findViewById(R.id.searchBar);
inputSearch.addTextChangedListener(new TextWatcher() {
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
// TODO Auto-generated method stub
}
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
// TODO Auto-generated method stub
}
#Override
public void afterTextChanged(Editable s) {
// filter your list from your input
filter(s.toString());
//you can use runnable postDelayed like 500 ms to delay search text
}
});
}
void filter(String text){
List<MyHotelReviewAdapter> temp = new ArrayList();
for(MyHotelReviewAdapter d: mylearningAdapters){
//or use .equal(text) with you want equal match
//use .toLowerCase() for better matches
if(d.getHotel_user().contains(text)){
temp.add(d);
}
}
//update recyclerview
RecyclerViewMyHotelReviewAdapter rc = new RecyclerViewMyHotelReviewAdapter(mylearningAdapters);
rc.updateList(temp);
}
Here is my Recycleview adapter class code:
RecyclerViewMyHotelReviewAdapter.java
public class RecyclerViewMyHotelReviewAdapter extends RecyclerView.Adapter<RecyclerViewMyHotelReviewAdapter.LearningHolder> {
static Context context;
public static List<MyHotelReviewAdapter> mylearningAdapters;
public RecyclerViewMyHotelReviewAdapter(List<MyHotelReviewAdapter> mylearningAdapters, Context context){
super();
this.mylearningAdapters = mylearningAdapters;
this.context = context;
}
public RecyclerViewMyHotelReviewAdapter(List<MyHotelReviewAdapter> mylearningAdapters) {
}
#Override
public RecyclerViewMyHotelReviewAdapter.LearningHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.show_hotel_details, parent, false);
LearningHolder learningHolder = new LearningHolder(view);
//RecyclerViewModuleAdapter.ModuleHolder moduleHolder = new RecyclerViewModuleAdapter.ModuleHolder(view);
return learningHolder;
}
#SuppressLint("NewApi")
#Override
public void onBindViewHolder(RecyclerViewMyHotelReviewAdapter.LearningHolder holder, int position) {
final MyHotelReviewAdapter mylearningAdapter1 = mylearningAdapters.get(position);
int t = 4;
String a = mylearningAdapter1.getHotel_People();
int c = t + Integer.parseInt(a);
//Toast.makeText(context, ""+c, Toast.LENGTH_SHORT).show();
holder.hotel_user.setText(mylearningAdapter1.getHotel_user());
holder.hotel_dateIn.setText(mylearningAdapter1.getHotel_CheckIn());
holder.hotel_dateOut.setText(mylearningAdapter1.getHotel_CheckOut());
holder.total.setText(String.valueOf("Guests: "+c));
holder.htlName.setText(mylearningAdapter1.getHotel_name());
holder.id.setText(mylearningAdapter1.getHotel_id());
//holder.english_d.setText(mylearningAdapter1.getEnglish());
}
public void updateList(List<MyHotelReviewAdapter> list){
mylearningAdapters = list;
notifyDataSetChanged();
}
#Override
public int getItemCount() {
return mylearningAdapters.size();
}
public class LearningHolder extends RecyclerView.ViewHolder {
String deleteBooking = "http://site2test.in/OxygenClub/mobileapp/delete_booking_careTaker.php";
AppCompatTextView hotel_user, hotel_dateIn, hotel_dateOut, htlName, total, id;
Button checkIn, checkOut;
public LearningHolder(View itemView) {
super(itemView);
hotel_user = (AppCompatTextView)itemView.findViewById(R.id.name);
hotel_dateIn = (AppCompatTextView)itemView.findViewById(R.id.checkin);
hotel_dateOut = (AppCompatTextView)itemView.findViewById(R.id.checkout);
htlName = (AppCompatTextView)itemView.findViewById(R.id.hotelName);
total = (AppCompatTextView)itemView.findViewById(R.id.totalPeople);
id = (AppCompatTextView)itemView.findViewById(R.id.hotelId);
}
}
}...
My DataHolder class.
public class MyHotelReviewAdapter {
public String Hotel_People;
public String Hotel_CheckIn;
public String Hotel_CheckOut;
public String Hotel_User;
public String Hotel_Name;
public String Hotel_Id;
public String getHotel_CheckIn() {
return this.Hotel_CheckIn;
}
public void setHotel_CheckIn(String hotel_checkIn) {
this.Hotel_CheckIn = hotel_checkIn;
}
public String getHotel_CheckOut() {
return this.Hotel_CheckOut;
}
public void setHotel_CheckOut(String hotel_checkOut) {
this.Hotel_CheckOut = hotel_checkOut;
}
public String getHotel_People() {
return this.Hotel_People;
}
public void setHotel_People(String hotel_people) {
this.Hotel_People = hotel_people;
}
public String getHotel_user() {
return this.Hotel_User;
}
public void setHotel_user(String hotel_user) {
this.Hotel_User = hotel_user;
}
public String getHotel_name(){
return this.Hotel_Name;
}
public void setHotel_name(String hotel_name){
this.Hotel_Name = hotel_name;
}
public String getHotel_id(){
return this.Hotel_Id;
}
public void setHotel_id(String hotel_id){
this.Hotel_Id = hotel_id;
}
}
I want to search my data by Hotel_user. I have coded the value of getHotel_user in filter function.

Sort List by Integer

I get the Latitude and Longtitude from my Database and I calculate the distance between two persons in the RecyclerView Adapter.
I want to sort these items by distance, but I have no clue how I can do this.
My Adapter:
public class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.ViewHolder>{
Context context;
List<HomeGetter> homeGetters;
HomeCallback homeCallback;
public HomeAdapter(Context context, List<HomeGetter> homeGetters, HomeCallback homeCallback) {
this.context = context;
this.homeGetters = homeGetters;
this.homeCallback = homeCallback;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(context).inflate(R.layout.custom_home_profil,parent,false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
calculate_age calculate_age = new calculate_age();
final HomeGetter homeGetter = homeGetters.get(position);
String[] splittedAge = homeGetter.getBirthday().split("\\.");
try {
String age = calculate_age.getAge(context,Integer.valueOf(splittedAge[0]),Integer.valueOf(splittedAge[1]),Integer.valueOf(splittedAge[2]));
String username = homeGetter.getUsername().substring(0,1).toUpperCase() + homeGetter.getUsername().substring(1);
holder.textViewUsername.setText(username + "," + age);
} catch (ParseException e) {
e.printStackTrace();
}
Picasso.with(context).load(homeGetter.getImageURL()).resize(600,700).centerCrop().into(holder.imageView);
holder.cardView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
homeCallback.getPosition(position);
}
});
holder.textViewLocation.setText(homeGetter.getLocation());
if(homeGetter.getStatus().equals("0")){
holder.status.setImageDrawable(context.getResources().getDrawable(R.drawable.offline));
}else {
holder.status.setImageDrawable(context.getResources().getDrawable(R.drawable.online));
}
}
#Override
public int getItemCount() {
return homeGetters.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
ImageView imageView;
TextView textViewUsername;
CardView cardView;
TextView textViewLocation;
ImageView status;
public ViewHolder(View itemView) {
super(itemView);
imageView = itemView.findViewById(R.id.imageViewThumb);
textViewUsername = itemView.findViewById(R.id.textViewProfilUsername);
cardView = itemView.findViewById(R.id.cardViewProfil);
textViewLocation = itemView.findViewById(R.id.textViewLocation);
status = itemView.findViewById(R.id.imageViewOnlinestatus);
}
}
}
On this line I get the distance in km:
holder.textViewLocation.setText(homeGetter.getLocation());
e.g 544
Is it possible to sort the list in the adapter?
Or how can I sort this?
So, how can I achive this?
The Activity
pullData.getData(USERNAME, "1", new Pullcallback() {
#Override
public void getSingleData(String data) {
}
#Override
public void getMultipleData(String[] multipledatas) {
GENDER = multipledatas[5];
GENDERSEARCH = multipledatas[6];
GetStrangers getStrangers = new GetStrangers(Home.this);
Map<String,String> map = new HashMap<>();
map.put("USERNAME",USERNAME);
map.put("GENDER",GENDER);
map.put("SEARCH",GENDERSEARCH);
getStrangers.strangers(map, "7", new Pullcallback() {
#Override
public void getSingleData(String data) {
}
#Override
public void getMultipleData(final String[] multipledatas) {
// username,imagelink,position,birthday
// imageURL,username,birthday,location
pullData.getData(USERNAME, "2", new Pullcallback() {
#Override
public void getSingleData(String data) {
}
#Override
public void getMultipleData(String[] multipledatas2) {
String[] split1 = multipledatas2[1].split(",");
String[] split2 = multipledatas[2].split(",");
float lat1 = Float.valueOf(split1[0]);
float lng1 = Float.valueOf(split1[1]);
float lat2 = Float.valueOf(split2[0]);
float lng2 = Float.valueOf(split2[1]);
Collections.sort(getterList, new Comparator<HomeGetter>() {
public int compare(HomeGetter s1, HomeGetter s2) {
return Integer.compare(Integer.parseInt(s1.getLocation()), Integer.parseInt(s2.getLocation()));
}
});
homeGetter = new HomeGetter(multipledatas[1],multipledatas[0],multipledatas[3],String.valueOf(Math.round(Calculator.calculateDistance(lat1,lng1,lat2,lng2))),multipledatas[4]);
getterList.add(homeGetter);
homeAdapter.notifyDataSetChanged();
loading.setVisibility(View.GONE);
content.setVisibility(View.VISIBLE);
}
#Override
public void onError(String errormessage) {
}
});
}
#Override
public void onError(String errormessage) {
}
});
}
#Override
public void onError(String errormessage) {
}
});
pullData.getData(USERNAME, "2", new Pullcallback() {
#Override
public void getSingleData(String data) {
}
#Override
public void getMultipleData(String[] multipledatas) {
if(multipledatas[7].equals("0")){
Intent intentFirststep = new Intent(Home.this,Firststep.class);
startActivity(intentFirststep);
finish();
}else {
}
}
#Override
public void onError(String errormessage) {
}
});
recyclerViewHome = findViewById(R.id.recyclerViewHome);
homeAdapter = new HomeAdapter(Home.this, getterList, new HomeCallback() {
#Override
public void getPosition(int position) {
Intent stranger = new Intent(Home.this,Stranger.class);
stranger.putExtra("USERNAME",getterList.get(position).getUsername());
startActivity(stranger);
finish();
}
});
recyclerViewHome.setHasFixedSize(true);
recyclerViewHome.setLayoutManager(new GridLayoutManager(Home.this,3));
recyclerViewHome.setItemAnimator(new DefaultItemAnimator());
recyclerViewHome.setAdapter(homeAdapter);
}
But it is not working correctly it shows me 4,14,507 and 12
but it shoild sort 4,12,14,507

In your activity where you are passing your ArrayList just do this before passing it.
Collections.sort(homeGetter, new Comparator<HomeGetter>() {
public int compare(HomeGetter s1, HomeGetter s2) {
return Integer.compare(Integer.parseInt(s1.getLocation()), Integer.parseInt(s2.getLocation()));
}
});
P.S. Don't use parse if you are already storing as integers.
Happy to help.
EDIT:
Put it here-
getterList.add(homeGetter);
Collections.sort(homeGetter, new Comparator<HomeGetter>() {
public int compare(HomeGetter s1, HomeGetter s2) {
return Integer.compare(Integer.parseInt(s1.getLocation()), Integer.parseInt(s2.getLocation()));
}
});
homeAdapter.notifyDataSetChanged();

You can also sort the List<HomeGetter> homegetters using a Comparator & then initialize HomeAdapter with sorted homegetters list.
An Example:
homegetters.sort((hG1, hG2) -> hG1.getLocation().compareTo(hG2.getLocation()));
Above line will sort homegetters list based on getLocation().
Edit:
In your activity, you are sorting the List first and then adding an item into it.
You should instead add all the items first & then sort the List.

Android: detecting removed item in ObservableList

I am using ObservableList in my model for binding. When the item is removed from ObservableList, I want to know about what item has been removed. So I am using ObservableList.OnListChangedCallback.
When the item is removed, it will called onItemRangeRemoved(). But the problem is the item has been removed from the ObservableList in onItemRangeRemoved().
catDatas.addOnListChangedCallback(new ObservableList.OnListChangedCallback<ObservableList<CatData>>()
{
#Override
public void onChanged(ObservableList<CatData> sender)
{
}
#Override
public void onItemRangeChanged(ObservableList<CatData> sender, int positionStart, int itemCount)
{
}
#Override
public void onItemRangeInserted(ObservableList<CatData> sender, int positionStart, int itemCount)
{
}
#Override
public void onItemRangeMoved(ObservableList<XROrderItemData> sender, int fromPosition, int toPosition, int itemCount)
{
}
#Override
public void onItemRangeRemoved(ObservableList<CatData> sender, int positionStart, int itemCount)
{
for (int idx = itemCount - 1; idx >= 0; idx--)
{
CatData data = sender.get(idx + positionStart); //this line will throw index out of bounds exception
...
...
...
uninitData(data);
}
}
});
Any idea how to capture the items that are removed?
Thanks...

The folks at Google overlooked the removeAll() method, so it does not notify observers. To fix this, use this custom class:
class MyObservableArrayList<T>: ObservableArrayList<T>() {
override fun removeAll(elements: Collection<T>): Boolean {
var success = false
elements.forEach { if (super.remove(it)) success = true }
return success
}
}