I'm new to android programming and I have a problem in displaying data from firestore. I want to display the data in fragments in the navigation drawer. I found tutorials that display it on activities but nothing in fragments. Please help me with this.
public class MainActivity extends AppCompatActivity {
Toolbar toolbar;
DrawerLayout drawerLayout;
ActionBarDrawerToggle actionBarDrawerToggle;
NavigationView navigationView;
FragmentTransaction fragmentTransaction;
private boolean shouldLoadProductFragOnBackPress = false;
public static int navItemIndex = 0;
public FirebaseAuth mAuth;
FirebaseFirestore db = FirebaseFirestore.getInstance();
private void Load_Product_fragment() {
navItemIndex = 0;
fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.maincontainer,new ProductFragment());
fragmentTransaction.commit();
getSupportActionBar().setTitle(R.string.Productfragment_Title);
drawerLayout.closeDrawers();
}
private void Load_Service_fragment(){
navItemIndex = 1;
fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.maincontainer,new ServiceFragment());
fragmentTransaction.commit();
getSupportActionBar().setTitle(R.string.Servicefragmnet_Title);
drawerLayout.closeDrawers();
shouldLoadProductFragOnBackPress = true;
}
private void Load_Account_fragment(){
navItemIndex = 2;
fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.maincontainer,new AccountFragment());
fragmentTransaction.commit();
getSupportActionBar().setTitle(R.string.Accountfragment_Title);
drawerLayout.closeDrawers();
shouldLoadProductFragOnBackPress = true;
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar=(Toolbar)findViewById(R.id.Toolbar_Layout);
setSupportActionBar(toolbar);
drawerLayout=(DrawerLayout) findViewById(R.id.Drawer_Layout);
actionBarDrawerToggle = new ActionBarDrawerToggle(this,drawerLayout,toolbar,R.string.drawer_open,R.string.drawer_close);
drawerLayout.addDrawerListener(actionBarDrawerToggle);
drawerLayout.openDrawer(Gravity.LEFT);
Load_Product_fragment();
navigationView= findViewById(R.id.Navigation_View);
navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
switch (item.getItemId())
{
case R.id.Productsfragment_ND:
Load_Product_fragment();
item.setChecked(true);
break;
case R.id.Servicefragment_ND:
Load_Service_fragment();
item.setChecked(true);
break;
case R.id.Accountfragemnt_ND:
Load_Account_fragment();
item.setChecked(true);
break;
}
return false;
}
});
}
#Override
public void onBackPressed() {
if (drawerLayout.isDrawerOpen(GravityCompat.START)) {
drawerLayout.closeDrawers();
return;
}
// This code loads home fragment when back key is pressed
// when user is in other fragment than home
if (shouldLoadProductFragOnBackPress) {
// checking if user is on other navigation menu
// rather than home
if (navItemIndex !=0) {
navItemIndex = 0;
shouldLoadProductFragOnBackPress = false;
Load_Product_fragment();
return;
}
}
super.onBackPressed();
}
#Override
protected void onPostCreate(#Nullable Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
actionBarDrawerToggle.syncState();
}
public void del(View view) {db.collection("products").document("test")
.delete()
.addOnSuccessListener(new OnSuccessListener<Void>() {
#Override
public void onSuccess(Void aVoid) {
}
})
.addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception e) {
}
});
}
}
This is my main-activity.It contains the requirements for a navigation drawer for 3 fragments.I have a Firestore database linked to the app. I need to display the contents of the database in these fragments.
Next i will show one fragment and the recyclerview adapter and view holder i have tried using.
I am not sure if it is the correct way to do it.Please help me with this
public class ProductFragment extends Fragment {
private static final String TAG = ProductFragment.class.getSimpleName();
private RecyclerView recipeRecyclerview;
private LinearLayoutManager linearLayoutManager;
private Product_adapter mAdapter;
private DatabaseReference mDatabaseRef;
private DatabaseReference childRef;
public ProductFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate (R.layout.fragment_product, container, false);
getActivity().setTitle(getString(R.string.Productfrag_title));
linearLayoutManager = new LinearLayoutManager(getActivity());
recipeRecyclerview = view.findViewById(R.id.List_recycleview);
recipeRecyclerview.setHasFixedSize(true);
mDatabaseRef = FirebaseDatabase.getInstance().getReference();
childRef = mDatabaseRef.child("recipes");
mAdapter = new Product_adapter(Product_response.class, R.layout.list_layout, View_holder.class, childRef, getContext());
recipeRecyclerview.setLayoutManager(linearLayoutManager);
recipeRecyclerview.setAdapter(mAdapter);
return view;
}
}
This is my products-fragment. I have tried to add the recycler view.
Adapter
public class Product_adapter extends RecyclerView.Adapter {
FirebaseFirestore db = FirebaseFirestore.getInstance();
private Context context;
Query query = db.collection("products");
FirestoreRecyclerOptions<Product_response> response = new FirestoreRecyclerOptions.Builder<Product_response>()
.setQuery(query, Product_response.class)
.build();
FirestoreRecyclerAdapter adapter = new FirestoreRecyclerAdapter<Product_response, View_holder>(response) {
#Override
protected void onBindViewHolder(View_holder holder, int position, Product_response model) {
}
#Override
public View_holder onCreateViewHolder(ViewGroup group, int i) {
// Create a new instance of the ViewHolder, in this case we are using a custom
// layout called R.layout.message for each item
View view = LayoutInflater.from(group.getContext())
.inflate(R.layout.list_layout, group, false);
return new View_holder(view);
}
};
public Product_adapter(Class<Product_response> product_responseClass, int list_layout, Class<View_holder> view_holderClass, DatabaseReference childRef, Context context) {
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
return null;
}
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
}
#Override
public int getItemCount() {
return 0;
}
}
View holder
public class View_holder extends RecyclerView.ViewHolder{
private static final String TAG = View_holder.class.getSimpleName();
public TextView main_text, subtext ;
public ImageView image;
public View_holder(View itemView) {
super(itemView);
main_text = (TextView)itemView.findViewById(R.id.List_maintext);
subtext = (TextView)itemView.findViewById(R.id.List_subtext);
image = (ImageView)itemView.findViewById(R.id.List_imageview);
}
}
Next i will show the response page where i used the getter and setter for the firebase
import com.google.firebase.firestore.IgnoreExtraProperties;
#IgnoreExtraProperties
public class Product_response {
private String Product;
private String Cost;
public Product_response() {
}
public Product_response(String Product, String Cost){
this.Product= Product;
this.Cost= Cost;
}
public String getProduct() {
return Product;
}
public void setProduct(String Product) {
this.Product = Product;
}
public String getCost(){
return Cost;
}
public void setCost(String Cost)
{
this.Cost = Cost;
}
}
This is how my database looks like. I need to display this products in my fragment
This is the github link of the app. Please help me complete this
Related
my code in android studio and JAVA language has a problem with its database. I have a edittext in a fragment and I use it for update database. the database is initialized using Room library in activity and the DAO file is defined public and static in mainActivity, and use method DAO.update(photo) in a fragment, but sometimes when type in edittext it updates the field in database but sometimes not, I do not know why? can you please help me on it and do you have same experience?
related code in activity:
public class MainActivity extends AppCompatActivity {
public AppDB appDB;
public static AlbumDAO albumDAO;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
appDB= Room.databaseBuilder(this, AppDB.class, "db_App")
.allowMainThreadQueries()
.build();
albumDAO= appDB.getAlbumDAO();
and then I used the database initialized in main activity in this fragment:
public class PhotoFragment extends Fragment {
private Album album;
EditText title;
String inputTitle;
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.album=getArguments().getParcelable("key");
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
return LayoutInflater.from(getContext()).inflate(R.layout.fragment_photo,container,false);
}
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
title=view.findViewById(R.id.txt_postTitle);
title.setText(album.getTitle());
title.addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
#Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
inputTitle=charSequence.toString();
}
#Override
public void afterTextChanged(Editable editable) {
album.setTitle(inputTitle);
albumDAO.updateAlbum(album);
}
});
}
and the albumDAO is:
#Dao
public interface AlbumDAO {
#Insert
long addAlbum(Album album);
#Query("SELECT * FROM tbl_album")
List<Album> getAllAlbums();
#Update
void updateAlbum(Album album);
#Delete
void deleteAlbum(Album album);
#Query("DELETE FROM tbl_album")
void deleteAllAlbum();
}
and the Album class is:
#Entity(tableName = "tbl_album")
public class Album implements Parcelable {
#PrimaryKey (autoGenerate = true)
private int id;
private String title;
public Album() {
}
protected Album(Parcel in) {
title = in.readString();
}
public static final Creator<Album> CREATOR = new Creator<Album>() {
#Override
public Album createFromParcel(Parcel in) {
return new Album(in);
}
#Override
public Album[] newArray(int size) {
return new Album[size];
}
};
#Override
public int describeContents() {
return 0;
}
#Override
public void writeToParcel(Parcel parcel, int i) {
parcel.writeString(title);
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
}
In the overidden afterTextChanged method. You are updating the database and then changing the title in the album, so the database will not reflect the changed title.
Try using :-
#Override
public void afterTextChanged(Editable editable) {
album.setTitle(inputTitle); //<<<<< MOVED UP
albumDAO.updateAlbum(album);
}
You can also utilise the value (int) returned by the #Update annotated function, to see if anything has been updated by changing it to:-
#Update
int updateAlbum(Album album)
Then you could use something along the lines of:-
#Override
public void afterTextChanged(Editable editable) {
album.setTitle(inputTitle);
if (album.setTitle(inputTitle)> 0) {
.... do whatever here to indicate update was OK
} else {
.... do whatever here to indicate not updated
}
}
I'm new to android and this is the first time I'm using room in my application. Either insert operation is not performed or the database is not created or any other error.
I don't know what I'm doing wrong so I need your help.
This program is running but No result is displayed. Nothing is showing on the screen.
Here is my code-
please let me know what is wrong in this code and what I should do to correct it.
Car_details.java
#PrimaryKey
#NonNull
#SerializedName("id")
#Expose
private String id;
#SerializedName("name")
#Expose
private String name;
#SerializedName("desc")
#Expose
private String desc;
#SerializedName("image")
#Expose
private String image;
CarDao.java-
#Insert(onConflict = OnConflictStrategy.REPLACE)
void insert(Car_Details car_details);
#Query("Select * from car_table")
LiveData<List<Car_Details>> selectAll();
CarListDatabase.java
private static CarListDatabase instance;
public abstract CarDao carDao();
public static synchronized CarListDatabase getInstance(Context context){
if(instance==null)
{
instance= Room.databaseBuilder(context.getApplicationContext(),
CarListDatabase.class,"Car_database").fallbackToDestructiveMigration()
.build();
}
return instance;
}
CarRepository.java
public void getCarList(){
CarlistInterface carlistInterface= retrofit.create(CarlistInterface.class);
Call<List<Car_Details>> carList= carlistInterface.carList();
carList.enqueue(new Callback<List<Car_Details>>() {
#Override
public void onResponse(Call<List<Car_Details>> call, final Response<List<Car_Details>> response) {
if(response.body() != null){
List<Car_Details> car_details = response.body();
for (int i = 0; i < car_details.size(); i++) {
String id=car_details.get(i).getId();
String names = car_details.get(i).getName();
String desc=car_details.get(i).getDesc();
String image= car_details.get(i).getImage();
Car_Details car = new Car_Details();
car .setId(id);
car .setName(names);
car .setDesc(desc);
car .setImage(image);
new InsertNoteAsyncTask(carDao).execute(car);
}
}
}
});
}
public LiveData<List<Car_Details>> getCarLists(){
return allCarList;
}
private static class InsertNoteAsyncTask extends AsyncTask<Car_Details,Void,Void> {
private CarDao carDao;
private InsertNoteAsyncTask(CarDao carDao){
this.carDao= carDao;
}
#Override
protected Void doInBackground(Car_Details... car_details) {
carDao.insert(car_details[0]);
return null;
}
CarViewModel.java
public CarViewModel(#NonNull Application application) {
super(application);
repository= new CarRepository(application);
carList= repository.getCarLists();
}
public LiveData<List<Car_Details>> getListLiveData() {
return carList;
MainActivity.java
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
repository = new CarRepository(this);
carViewModel = ViewModelProviders.of(this).get(CarViewModel.class);
recyclerView= findViewById(R.id.cars_recyclerView);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
List = new ArrayList<>();
recyclerAdapter = new RecyclerAdapter(List);
recyclerView.setAdapter(recyclerAdapter);
recyclerAdapter = new RecyclerAdapter(List);
recyclerView.setAdapter(recyclerAdapter);
carViewModel.getListLiveData().observe(this, new
Observer<java.util.List<Car_Details>>() {
#Override
public void onChanged(java.util.List<Car_Details> car_details) {
recyclerAdapter.setUserList(List);
}
});
repository.getCarList();
}
RecyclerAdapter.java
public class RecyclerAdapter extends RecyclerView.Adapter {
List<Car_Details> carList= new ArrayList<>();
public RecyclerAdapter(List<Car_Details> carList) {
this.carList = carList;
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
LayoutInflater layoutInflater= LayoutInflater.from(parent.getContext());
View view= layoutInflater.inflate(R.layout.row_item,parent,false);
return new RecyclerAdapter.ViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull ViewHolder holder, int position) {
holder.car_name.setText(carList.get(position).getName());
holder.car_desc.setText(carList.get(position).getDesc());
}
public void setUserList(List<Car_Details> userList) {
this.carList = userList;
notifyDataSetChanged();
}
#Override
public int getItemCount() {
return carList.size();
}
class ViewHolder extends RecyclerView.ViewHolder {
private TextView car_name,car_desc;
public ViewHolder(#NonNull View itemView) {
super(itemView);
car_name= itemView.findViewById(R.id.car_name);
car_desc= itemView.findViewById(R.id.car_desc);
}
}
}
#Override
public int getItemCount() {
return carList.size();
}
class ViewHolder extends RecyclerView.ViewHolder {
private TextView car_name,car_desc;
public ViewHolder(#NonNull View itemView) {
super(itemView);
car_name= itemView.findViewById(R.id.car_name);
car_desc= itemView.findViewById(R.id.car_desc);
}
}
}
There is nothing wrong with your insert operation with room.
The way you have used live date in your application seems wrong that's why your program is running but no result is coming.
You have to check the part where you are using live data.
Hope this help you out.
I want to access JSON array . so I created 2 Object !!Have a look at my code , Url
Url-cricapi.com/api/matches/?apikey=JimJAfsmRGOnDpCrRrqO6htlilg1
My MatchesArrayClass
package com.piyushjaiswal.jsonpractis;
public class MatchesArray {
private Matches matches;
private provider provider2;
public MatchesArray(Matches matches, provider provider2) {
this.matches = matches;
this.provider2 = provider2;
}
public Matches getMatches() {
return matches;
}
public void setMatches(Matches matches) {
this.matches = matches;
}
public provider getProvider2() {
return provider2;
}
public void setProvider2(provider provider2) {
this.provider2 = provider2;
}
}
Matches Class
package com.piyushjaiswal.jsonpractis;
import com.google.gson.annotations.SerializedName;
public class Matches {
private int unique_id;
private String date;
private String dateTimeGMT;
#SerializedName("team-1")
private String team1;
#SerializedName("team-2")
private String team2;
private String type;
private String toss_winner_team;
private boolean squad;
private boolean matchStarted;
public int getUnique_id() {
return unique_id;
}
public void setUnique_id(int unique_id) {
this.unique_id = unique_id;
}
public String getDate() {
return date;
}
public void setDate(String date) {
this.date = date;
}
public String getDateTimeGMT() {
return dateTimeGMT;
}
public void setDateTimeGMT(String dateTimeGMT) {
this.dateTimeGMT = dateTimeGMT;
}
public String getTeam1() {
return team1;
}
public void setTeam1(String team1) {
this.team1 = team1;
}
public String getTeam2() {
return team2;
}
public void setTeam2(String team2) {
this.team2 = team2;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public String getToss_winner_team() {
return toss_winner_team;
}
public void setToss_winner_team(String toss_winner_team) {
this.toss_winner_team = toss_winner_team;
}
public boolean isSquad() {
return squad;
}
public void setSquad(boolean squad) {
this.squad = squad;
}
public boolean isMatchStarted() {
return matchStarted;
}
public void setMatchStarted(boolean matchStarted) {
this.matchStarted = matchStarted;
}
}
My Provider class
package com.piyushjaiswal.jsonpractis;
public class provider {
private String source;
private String url;
private String pubDate;
public String getSource() {
return source;
}
public void setSource(String source) {
this.source = source;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public String getPubDate() {
return pubDate;
}
public void setPubDate(String pubDate) {
this.pubDate = pubDate;
}
}
MainActivity Class
package com.piyushjaiswal.jsonpractis;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.List;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;
public class MainActivity extends AppCompatActivity {
private TextView textView;
private JsonPlaceHolderApi jsonPlaceHolderApi;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView = findViewById(R.id.textview);
Retrofit retrofit = new Retrofit.Builder()
.baseUrl("http://cricapi.com/api/")
.addConverterFactory(GsonConverterFactory.create())
.build();
jsonPlaceHolderApi = retrofit.create(JsonPlaceHolderApi.class);
getMatchList();
}
private void getMatchList() {
Call<List<MatchesArray>> call = jsonPlaceHolderApi.getPosts("JimJAfsmRGOnDpCrRrqO6htlilg1");
call.enqueue(new Callback<List<MatchesArray>>() {
#Override
public void onResponse(Call<List<MatchesArray>> call, Response<List<MatchesArray>> response) {
if(!response.isSuccessful()){
textView.setText(response.message() + "123");
return;
}
List<MatchesArray> list = response.body();
textView.setText(list.get(0).getMatches().getDate());
}
#Override
public void onFailure(Call<List<MatchesArray>> call, Throwable t) {
textView.setText(t.getMessage() +"22");
}
});
}
}
But output on screenshot is
"Expected BEGIB_ARRAY but was BEGIN_OBJECT at line 1 column 2 patg $2"
Your JSON syntax is wrong. The response starts with {"matches":[, this means it is an object, with the parameter matches that is of type match[].
So, you need a new class along the lines of:
public class MatchesWrapper {
private List<Matches> matches;
}
And change all your Call<List<MatchesArray>> to Call<MatchesWrapper>.
The error you received tells you this. You expected an array of Matches (Expected BEGIN_ARRAY), but instead received an object (was BEGIN_OBJECT).
I have a RecyclerView list of CardViews. Each CardView has a CheckBox that the user can select/de-select. The initial selection launches a Contextual Action Bar. An ArrayList of Integers is used to hold the checkbox state (selected or un-selected). Scrolling and the checkbox views appear to be working correctly. However, when I click a checkbox to de-select it, it remains checked and another checkbox on a different CardView is de-selected? What am I missing here?
Please note that I do not want to set up a ClickListener in onBindViewHolder.
MainActivity.java
public class MainActivity extends AppCompatActivity implements
RecyclerItemClickListener {
private ArrayList<ListItem> allList;
boolean isMultiSelect = false; // for the Contextual Action Bar status
private ActionMode mActionMode;
ArrayList<ListItem> multiselect_list = new ArrayList<>();
private ArrayList<Integer> checkedListItems = new ArrayList<>();
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
...
// method from the Adapter, the ItemHolder's onClick()
public void onCheckBoxClick(View view, int position) {
if (!isMultiSelect) {
multiselect_list = new ArrayList<>();
isMultiSelect = true;
if (mActionMode == null) {
mActionMode = startSupportActionMode(actionModeCallback);
}
}
multi_select(position);
}
public void multi_select(int position) {
if (mActionMode != null) {
// If a CardView with a CheckBox already selected is clicked on, then the
// Checkbox is unselected, the position is removed from the multiselect_list
// and the size of the list is decremented by +1.
if (multiselect_list.contains(allList.get(position))) {
multiselect_list.remove(allList.get(position));
}
else {
// If an empty CheckBox on a CardView is clicked on, then the position is added to the
// multiselect_list and the size of the list is incremented by +1.
multiselect_list.add(allList.get(position));
}
if (multiselect_list.size() == 1) {
mActionMode.setTitle("1 selected");
}
else if (multiselect_list.size() >= 2) {
mActionMode.setTitle(multiselect_list.size() + " selected");
}
else if (multiselect_list.size() == 0) {
mActionMode.finish();
}
refreshAdapter();
}
}
public void refreshAdapter() {
adapter.selectedItemsList = multiselect_list;
adapter.mListItems = allList;
adapter.notifyDataSetChanged();
}
private ActionMode.Callback actionModeCallback = new ActionMode.Callback() {
Menu context_menu;
#Override
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
MenuInflater inflater = mode.getMenuInflater();
inflater.inflate(R.menu.menu_action_mode, menu);
context_menu = menu;
return true;
}
...
}
Adapter.java
public class MyRecylerAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
public ArrayList<ListItem> mListItems;
private Context mContext;
private RecyclerItemClickListener recyclerItemClickListener;
public ArrayList<ListItem> selectedItemsList = new ArrayList<>();
public MyRecylerAdapter(Context context, ArrayList<ListItem> listItems, ArrayList<ListItem> selectedList) {
this.mContext = context;
this.mListItems = listItems;
this.selectedItemsList = selectedList;
}
private class ItemHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
private CheckBox chkSelected;
private ItemHolder(final View itemView) {
super(itemView);
chkSelected = (CheckBox) itemView.findViewById(R.id.chkSelected);
chkSelected.setOnClickListener(this);
}
public void onClick(View v) {
int adapterPos = getAdapterPosition();
// send data to MainActivity() for starting CAB.
if (recyclerItemClickListener !=null) {
recyclerItemClickListener.onCheckBoxClick(v, adapterPos);
}
if (((CheckBox)v).isChecked()) {
checkedListItems.add(adapterPos);
}
else {
checkedListItems.remove(adapterPos);
}
}
void bind(int position) {
if (checkedListItems.contains(position)) {
chkSelected.setChecked(true);
}
else {
chkSelected.setChecked(false);
}
}
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_contact_item, parent, false);
final ItemHolder itemHolder = new ItemHolder(view);
...
return itemHolder;
}
public void onBindViewHolder(final RecyclerView.ViewHolder holder, int position) {
final ListItem listItem = mListItems.get(position);
final ItemHolder itemHolder = (ItemHolder) holder;
itemHolder.bind(position);
...
}
In Adpater declare an ArrayList of integers
ArrayList<Integer> checkedItems = new ArrayList();
And in bind function
void bind(int position) {
if (checkedItems.contains(position)) {
chkSelected.setChecked(true);
}
else {
chkSelected.setChecked(false);
}
}
In OnBindviewholder add below code
CompoundButton.OnCheckedChangeListener onCheckedChangeListener = new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
int adapterPos = getAdapterPosition();
if(isChecked) {
checkedItems.add(Integer.valueOf(adapterPos));
}else {
checkedItems.remove(Integer.valueOf(adapterPos));
}
}
}
My question is very similar to this thread, however it was never properly answered.
I have an ImageAdapter setup as so;
public class ImageAdapter extends BaseAdapter {
private Context mContext;
int[] mImages;
public ImageAdapter(Context c, int[] images) {
mContext = c;
mImages = images;
}
#Override
public int getCount() {
return 0;
}
#Override
public Object getItem(int position) {
return null;
}
#Override
public long getItemId(int position) {
return 0;
}
#Override
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(200, 200));
} else {
imageView = (ImageView) convertView;
}
imageView.setImageResource(mImages[position]);
return imageView;
}
}
And I want the images to be from an XML;
<integer-array name="images">
<item>#drawable/image1</item>
<item>#drawable/image2</item>
<item>#drawable/image3</item>
</integer-array>
In my MainActivity class I have tried to get the image array and pass it into the ImageAdapter but I can't;
public class MainActivity extends AppCompatActivity {
private int images[] = getResources().getIntArray(R.array.images);
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
GridView gridview = (GridView) findViewById(R.id.gridView);
gridview.setAdapter(new ImageAdapter(MainActivity.this, images));
}
}
I am currently getting an error message:
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources android.content.Context.getResources()' on a null object reference
with my app crashing on load up. I want to make my ImageAdapter display images from an XML in my GridView.
try to use
private int images[] = {R.drawable.image1, R.drawable.image3, R.drawable.image3};
instead of
private int images[] = getResources().getIntArray(R.array.images);