Howdy, I'm working on a project and I'm running into some issues. Namely, I have two fragments, each with their own adapter as both fragments are meant to be able to swipe horizontally. A photo should be attached of the layout I have for further clarity. I would like to be able to tap the bottom fragment, which when I tap a place on the top fragment, the image I tapped or "Structure" will be placed down. However, what I can't figure out is how to smoothly transfer this data and if I were to do it through the activity, how do I do it as the activity has already run through all its code. Could somebody please help, it would be greatly appreciated.
Main Activity
public class MainMap extends AppCompatActivity
{
MapData data = MapData.get();
StructureData structure = StructureData.get();
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main_map);
FragmentManager frag = getSupportFragmentManager(); //To manage the map fragment
MapCellFragment rv = (MapCellFragment) frag.findFragmentById(R.id.map);
FragmentManager selectionFrag = getSupportFragmentManager(); //To manage the selection fragment
SelectionCellFragment cf = (SelectionCellFragment) selectionFrag.findFragmentById(R.id.bar);
if (rv == null)
{
rv = new MapCellFragment(data);
frag.beginTransaction().add(R.id.map, rv).commit();
}
if (cf == null)
{
cf = new SelectionCellFragment(structure);
selectionFrag.beginTransaction().add(R.id.bar, cf).commit();
}
}
Map Fragment
public MapData data;
public MapCellFragment() {
// Required empty public constructor
}
public MapCellFragment(MapData data)
{
this.data = data;
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #param param1 Parameter 1.
* #param param2 Parameter 2.
* #return A new instance of fragment gridCellFragment.
*/
// TODO: Rename and change types and number of parameters
public static MapCellFragment newInstance(String param1, String param2) {
MapCellFragment fragment = new MapCellFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.map_fragment, container, false);
RecyclerView rv = (RecyclerView) view.findViewById(R.id.recyclerview);
rv.setLayoutManager(new GridLayoutManager(getActivity(), MapData.HEIGHT, GridLayoutManager.HORIZONTAL,false));
MapAdapter myAdapter = new MapAdapter(data);
rv.setAdapter(myAdapter);
return view;
}
Bottom Bar Fragment
This was essentially a copy and paste of the other fragment, just changing the data which goes in and the XML it's attached to.
Map Adapter
package com.example.map;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class MapAdapter extends RecyclerView.Adapter<MapViewHolder>
{
MapData data;
public MapAdapter(MapData data)
{
this.data = data;
}
#NonNull
#Override
public MapViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType)
{
LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
View view = layoutInflater.inflate(R.layout.grid_cells,parent,false);
//Resizes the images within the grid cells xml file
int size = parent.getMeasuredHeight() / MapData.HEIGHT + 1;
ViewGroup.LayoutParams lp = view.getLayoutParams();
lp.width = size;
lp.height = size;
MapViewHolder myViewHolder = new MapViewHolder(view);
return myViewHolder;
}
#Override
public void onBindViewHolder(#NonNull MapViewHolder holder, int position)
{
int row = position % MapData.HEIGHT;
int col = position / MapData.HEIGHT;
MapElement ele = data.get(row, col);
holder.ne.setImageResource(ele.getNorthEast());
holder.nw.setImageResource(ele.getNorthWest());
holder.se.setImageResource(ele.getSouthEast());
holder.sw.setImageResource(ele.getSouthWest());
if(ele.getStructure() != null)
{
holder.mapStruct.setImageResource(ele.getStructure().getDrawableId());
}
}
#Override
public int getItemCount()
{
return 300;
}
}
Map View Holder
package com.example.map;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.Objects;
public class MapViewHolder extends RecyclerView.ViewHolder {
ImageView nw;
ImageView ne;
ImageView sw;
ImageView se;
ImageView mapStruct;
public MapViewHolder(#NonNull View itemView)
{
super(itemView);
nw = itemView.findViewById(R.id.northWest);
ne = itemView.findViewById(R.id.northEast);
sw = itemView.findViewById(R.id.southWest);
se = itemView.findViewById(R.id.southEast);
mapStruct = itemView.findViewById(R.id.structure);
}
}
Bar Adapter
package com.example.map;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class SelectionAdapter extends RecyclerView.Adapter<SelectionViewHolder>
{
StructureData data;
public SelectionAdapter(StructureData data)
{
this.data = data;
}
#NonNull
#Override
public SelectionViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType)
{
LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
View view = layoutInflater.inflate(R.layout.list_selection,parent,false);
SelectionViewHolder myViewHolder = new SelectionViewHolder(view);
return myViewHolder;
}
#Override
public void onBindViewHolder(#NonNull SelectionViewHolder holder, int position)
{
Structure s = data.get(position);
holder.structure.setImageResource(s.getDrawableId());
holder.label.setText(s.getLabel());
holder.bind(s);
}
#Override
public int getItemCount()
{
return data.size();
}
}
Bar ViewHolder
package com.example.map;
import android.annotation.SuppressLint;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.Objects;
public class SelectionViewHolder extends RecyclerView.ViewHolder
{
Structure selectObject;
ImageView structure;
TextView label;
public SelectionViewHolder(#NonNull View itemView)
{
super(itemView);
structure = itemView.findViewById(R.id.image);
label = itemView.findViewById(R.id.label);
structure.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View view)
{
SelectionCellFragment.selectedData = selectObject;
}
});
}
public void bind(Structure s)
{
selectObject = s;
}
//Maybe, I need to place this bind function in MapViewHolder as well
//When I press on the button, I must share the information over to the Map fragment
//Then the new information will form a ImageView on the big one
}
You could use ViewModel to solve your use-case. You could have something like SelectedStructureViewModel that will be set in the SelectionCellFragment when the user taps to select the structure. While the MapCellFragment can observe this SelectedStructureViewModel to be notified whenever the user selects the structure. You can then query it when user taps a place on the Map.
Related
I am absolute beginner for this, I'm sorry if this such a dumb mistakes.
so, I created fragment in which i have got recyclerView, but my recycler view is empty, i saw that my context is empty, and i think, that it can be the reason of this, i try to use getActivity
here is code of my fragment
package com.example.pocketcinema;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.firestore.FirebaseFirestore;
import com.google.firebase.firestore.QueryDocumentSnapshot;
import com.google.firebase.firestore.QuerySnapshot;
import java.util.ArrayList;
import java.util.List;
public class SearchFragment extends Fragment implements RecyclerViewInterface {
private RecyclerView recyclerView;
RecyclerViewInterface rci;
MyAdapter myAdapter;
public List<String> nameOfFilm, youTubeUrl, photoUrl, descriptionToFilm, category;
FirebaseFirestore db = FirebaseFirestore.getInstance();
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
recyclerView = inflater.inflate(R.layout.fragment_search, container,
false).findViewById(R.id.filmsList);
rci = this;
nameOfFilm = new ArrayList<>();
youTubeUrl = new ArrayList<>();
photoUrl = new ArrayList<>();
descriptionToFilm = new ArrayList<>();
category = new ArrayList<>();
loadFilmsFromDB();
return inflater.inflate(R.layout.fragment_search, container, false);
}
private void loadFilmsFromDB() {
Context context = requireContext();
db.collection("films").get().addOnCompleteListener(new
OnCompleteListener<QuerySnapshot>()
{
#Override
public void onComplete(#NonNull Task<QuerySnapshot> task) {
for (QueryDocumentSnapshot document : task.getResult()) {
nameOfFilm.add(document.get("nameOfFilm").toString());
descriptionToFilm.add(document.get("descriptionToFilm").toString());
photoUrl.add(document.get("imageUrl").toString());
youTubeUrl.add(document.get("videoURL").toString());
category.add(document.get("category").toString());
myAdapter = new MyAdapter(context, nameOfFilm, descriptionToFilm,
photoUrl, youTubeUrl,
rci, category);
recyclerView.setAdapter(myAdapter);
recyclerView.setLayoutManager(new LinearLayoutManager(context));
}
}
});
}
here is screenshot with debuger, you can see that context = null
context = null
here you can see that i set layout for recyclerView
with logcat
here is Adapter
package com.example.pocketcinema;
import android.content.Context;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.cardview.widget.CardView;
import androidx.recyclerview.widget.RecyclerView;
import com.squareup.picasso.Picasso;
import java.util.List;
public class MyAdapter extends
RecyclerView.Adapter<MyAdapter.MyViewHolder> {
Context ct;
List<String> name, description, image, video, category;
private final RecyclerViewInterface recyclerViewInterface;
public MyAdapter(Context ct, List<String> nameOfFilm, List<String>
descriptionOfFilm, List<String> imageUrl, List<String> videoUrl,
RecyclerViewInterface rci,List<String> category) {
name = nameOfFilm;
description = descriptionOfFilm;
image = imageUrl;
video = videoUrl;
this.ct = ct;
recyclerViewInterface = rci;
this.category = category;
}
#NonNull
#Override
public MyViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int
viewType) {
LayoutInflater inflater = LayoutInflater.from(ct);
View view = inflater.inflate(R.layout.my_row, parent, false);
return new MyViewHolder(view, recyclerViewInterface);
}
#Override
public void onBindViewHolder(#NonNull MyViewHolder holder, int
position) {
holder.nameFilm.setText(name.get(position));
holder.cardView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(ct, PlayerActivity.class);
}
});
Picasso.get().load(image.get(position)).into(holder.image2);
}
#Override
public int getItemCount() {
return image.size();
}
public static class MyViewHolder extends RecyclerView.ViewHolder {
TextView nameFilm;
ImageView image2;
CardView cardView;
public MyViewHolder(#NonNull View itemView, RecyclerViewInterface
recyclerViewInterface) {
super(itemView);
nameFilm = itemView.findViewById(R.id.nameTV);
image2 = itemView.findViewById(R.id.imageView2);
cardView = itemView.findViewById(R.id.cardView);
itemView.findViewById(R.id.sectionOFRecyclerView).setOnClickListener
(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (recyclerViewInterface != null) {
int pos = getAdapterPosition();
if (pos != RecyclerView.NO_POSITION) {
recyclerViewInterface.onItemClick(pos);
}
}
}
});
}
}
}
myAdapter isn't null
You are trying to create an instance of activity as global variable. That means the context has not been generated yet.
Basically you can just use requireContext() method of Fragment class. This will provide you the context.
As I have mentioned in comment, you need to update your onCreateView method as below:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_search, container, false);
}
Then, you need to initialize your view and other stuff on onViewCreated method. You can update that method like this:
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
recyclerView = view.findViewById(R.id.filmsList);
textView = view.findViewById(R.id.test);
rci = this;
nameOfFilm = new ArrayList<>();
youTubeUrl = new ArrayList<>();
photoUrl = new ArrayList<>();
descriptionToFilm = new ArrayList<>();
category = new ArrayList<>();
loadFilmsFromDB();
}
Notes
You don't have to send many string parameters to your adapter. It is better to create a Model class for that item, and send the list of that item. So, model classes will have all the data you need, and you can use them from that model. This will give you better coding style and will let you manage your data easier.
To communicate with your XML layout, you can use ViewBinding or DataBinding for that. This will also help you to use your view elements without creating variables for each of them.
I am using Firebase RecyclerAdapter rather than using the normal RecyclerAdapter. I wanted to store the position of the list Item which is clicked.
The code for the HomeFragment is below
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import com.firebase.ui.database.FirebaseRecyclerOptions;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.FirebaseDatabase;
/**
* A simple {#link Fragment} subclass.
* Use the {#link HomeFragment#newInstance} factory method to
* create an instance of this fragment.
*/
public class HomeFragment extends Fragment {
private static final String TAG = "HomeFragment";
private RecyclerView recyclerView;
private ProductAdapter adapter;
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
public HomeFragment() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #param param1 Parameter 1.
* #param param2 Parameter 2.
* #return A new instance of fragment HomeFragment.
*/
// TODO: Rename and change types and number of parameters
public static HomeFragment newInstance(String param1, String param2) {
HomeFragment fragment = new HomeFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View v= inflater.inflate(R.layout.fragment_home, container, false);
recyclerView = v.findViewById(R.id.recyclerView);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
String u = FirebaseAuth.getInstance().getCurrentUser().getUid();
FirebaseRecyclerOptions<Product> options = new FirebaseRecyclerOptions.Builder<Product>()
.setLifecycleOwner(this)
.setQuery(FirebaseDatabase.getInstance().getReference().child(u).child("Products"), Product.class)
.build();
adapter = new ProductAdapter(options);
recyclerView.setAdapter(adapter);
return v;
}
#Override
public void onStart() {
super.onStart();
}
#Override
public void onStop() {
super.onStop();
}
}
The code for the ProductAdapter class is given below
package com.example.prj;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.firebase.ui.database.FirebaseRecyclerOptions;
import com.squareup.picasso.Picasso;
public class ProductAdapter extends FirebaseRecyclerAdapter<Product, ProductAdapter.ProductViewHolder> {
private static final String TAG = "ProductAdapter";
ImageView btn_stock;
public ProductAdapter(#NonNull FirebaseRecyclerOptions<Product> options) {
super(options);
}
#Override
protected void onBindViewHolder(#NonNull ProductViewHolder holder, int position, #NonNull Product model) {
holder.pname.setText(model.getPname());
holder.price.setText(model.getPrice());
holder.description.setText(model.getDescription());
Picasso.get().load(model.getImage()).into(holder.image);
}
#NonNull
#Override
public ProductViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view= LayoutInflater.from(parent.getContext())
.inflate(R.layout.item_row, parent, false);
return new ProductViewHolder(view);
}
class ProductViewHolder extends RecyclerView.ViewHolder{
TextView pname, price, description;
ImageView image ;
public ProductViewHolder(#NonNull final View itemView) {
super(itemView);
pname = itemView.findViewById(R.id.product_list_name);
price = itemView.findViewById(R.id.product_list_price);
description = itemView.findViewById(R.id.product_list_description);
image = itemView.findViewById(R.id.product_list_image);
}
}
Using the position of the list item which is clicked I want to make the list item expandable.Like the users clicks on the list item and the list item expands and shows some more details about that item..If someone has the solution for that please help me in that also..
In onBindViewHolder() set the item click listener:
#Override
protected void onBindViewHolder(#NonNull ProductViewHolder holder, int position, #NonNull Product model) {
.....
.....
....
//here set the click of the item
holder.view.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View view){
//here do something with position that is passed in the onBindViewHolder
//if you clicked item 1 the position is 0
//if you clicked item 2 the position is 1
..............
Log.d("POSITION" , String.valueOf(position));
}
});
In your Viewholder add the view parameter
class ProductViewHolder extends RecyclerView.ViewHolder{
TextView pname, price, description;
ImageView image ;
//here
View view;
public ProductViewHolder(#NonNull final View itemView) {
super(itemView);
//set it here
view = itemView;
......
......
We have been working on implementing a RecyclerView in our project for a while now, and although the backend seems to work just fine, as soon as I call the recyclerView.setAdapter it causes the program to crash. I have spent several hours poring over this program, and nothing yet, although I have suspicions that the answer lies in the adapter. Can anyone shed some light on this?
Create and set adapter:
mLayoutManager = new LinearLayoutManager(this);
mRecyclerView = findViewById(R.id.navRV);
mRecyclerView.setHasFixedSize(false);
mRecyclerView.setLayoutManager(mLayoutManager);
Date todaysDate = new Date(System.currentTimeMillis());
AnnouncementList.add("Test Announcement 1", "This is some random text in the body" +
". It really needs to show up correctly!!", todaysDate);
mAdapter = new TwitterAdapter(mContext);
mRecyclerView.setAdapter(mAdapter);
And this is the adapter:
package com.company.application;
import android.content.Context;
import android.graphics.drawable.Drawable;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.TextView;
/**
* Twitter Adapter:
* This adapter is the interface between the data and the view
*/
public class TwitterAdapter extends RecyclerView.Adapter<TwitterAdapter.ViewHolder> {
//Use this as the tag for logging in this activity
final private String LOGTAG = "TWITTER_ADAPTER";
private Context mContext;
public TwitterAdapter(Context mContext) {
this.mContext = mContext;
}
#NonNull
#Override
public TwitterAdapter.ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(mContext);
View view = inflater.inflate(R.layout.list_layout, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull TwitterAdapter.ViewHolder holder, int position) {
//Set the text and the title
holder.textViewBody.setText((String)AnnouncementList.getList().get(position).getBody());
holder.textViewTitle.setText((String)AnnouncementList.getList().get(position).getTitle());
//If we have an image, insert it so we can draw it
if(AnnouncementList.getList().get(position).getImage() != null)
holder.imageView.setImageDrawable((Drawable)AnnouncementList.getList().get(position).getImage());
else
holder.imageView.setImageDrawable(null);
}
#Override
public int getItemCount() {
Log.d(LOGTAG, "getItemCount returns " + AnnouncementList.size());
return AnnouncementList.size();
}
/**
* Holds the view so that the RecyclerView can process it
*/
public static class ViewHolder extends RecyclerView.ViewHolder {
public TextView mTextView;
public RelativeLayout mRelativeLayout;
ImageView imageView;
TextView textViewTitle, textViewBody, textViewDate;
public ViewHolder(View itemView) {
super(itemView);
imageView = itemView.findViewById(R.id.imageView);
textViewTitle = itemView.findViewById(R.id.textViewTitle);
textViewBody = itemView.findViewById(R.id.textViewBody);
// textViewDate = itemView.findViewById(R.id.textViewDate);
}
}
}
You need to pass the the arraylist to adapter like this
mAdapter = new TwitterAdapter(mContext, AnnouncementList);
Then in the adapter change the constructor like this
private Context mContext;
private ArrayList<ModelClass> mAnnouncementList = new ArrayList();
public TwitterAdapter(Context mContext,ArrayList<ModelClass> mAnnouncementList) {
this.mContext = mContext;
this.mAnnouncementList= mAnnouncementList;
}
and then access variables like this
holder.textViewBody.setText(mAnnouncementList.getList().get(position).getBody());
holder.textViewTitle.setText(mAnnouncementList.getList().get(position).getTitle());
dont forget to return the size like below
#Override
public int getItemCount() {
Log.d(LOGTAG, "getItemCount returns " + mAnnouncementList.size());
return mAnnouncementList.size();
}
Please am having issue with this null error message java.lang.NullPointerException (no error message). I really need assistance on how and where to add the appropriate code so that the application would not crash. Here is the JAVA file that i am having issues with. I am trying to create a recycler view and jpg images from my drawable folder
HorizontalListAdapter.java
import android.app.Activity;
import android.graphics.Picture;
import android.os.Bundle;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;
public class HorizontalListAdapter extends RecyclerView.Adapter<HorizontalListAdapter.ViewHolder>
{
private Activity activity;
int[] images= {R.drawable.vb1,R.drawable.pota,R.drawable.vb1,
R.drawable.pota,R.drawable.vb1,R.drawable.download1,R.drawable.pota};
String[] food_items={"prawan","awadhi_lucknow_biryani","eggwraps","chips","mayonnaise","companin","mixvegwrap"};
public HorizontalListAdapter(Activity activity)
{
this.activity = activity;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
LayoutInflater inflater = activity.getLayoutInflater();
View view = inflater.inflate(R.layout.item_horizontal_list, viewGroup, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(HorizontalListAdapter.ViewHolder viewHolder, final int position) {
viewHolder.imageView.setImageResource(images[position]);
viewHolder.txtview.setText(food_items[position].toUpperCase());
viewHolder.linearLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(activity, "Position clicked: " + position, Toast.LENGTH_SHORT).show();
}
});
}
#Override
public int getItemCount() {
return images.length;
}
/**
* View holder to display each RecylerView item
*/
protected class ViewHolder extends RecyclerView.ViewHolder {
private LinearLayout linearLayout;
private ImageView imageView;
private TextView txtview;
public ViewHolder(View view) {
super(view);
imageView = (ImageView) view.findViewById(R.id.imageview);
txtview = (TextView) view.findViewById(R.id.txtview);
linearLayout = (LinearLayout) view.findViewById(R.id.layout);
}
}
}
The second java class VerticalListAdapter.java
import android.app.Activity;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;
public class VerticalListAdapter extends RecyclerView.Adapter<VerticalListAdapter.ViewHolder> {
private Activity activity;
public VerticalListAdapter(Activity activity) {
this.activity = activity;
}
int[] images= {R.drawable.images,R.drawable.images,R.drawable.images,
R.drawable.images,R.drawable.images,R.drawable.images,R.drawable.images};
String[] food_items={"prawan","awadhi_lucknow_biryani","eggwraps","chips","mayonnaise","companin","mixvegwrap"};
String[] cost={"Rs 200","Rs 300","Rs 150","R 320","Rs 450","Rs 120","Rs 380"};
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = activity.getLayoutInflater();
View view = inflater.inflate(R.layout.item_recycler_view, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(ViewHolder viewHolder, final int position) {
// if ((position + 1) % 2 == 0) {
viewHolder.imageView.setImageResource(images[position]);
viewHolder.txtview.setText(food_items[position].toUpperCase());
viewHolder.txtCost.setText("Cost Per Person "+cost[position]);
// } else {
// viewHolder.imageView.setImageResource(R.drawable.awadhi_lucknow_biryani);
//}
viewHolder.container.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(activity, "Position: " + position, Toast.LENGTH_SHORT).show();
}
});
}
#Override
public int getItemCount() {
return images.length;
}
/**
* View holder to display each RecylerView item
*/
protected class ViewHolder extends RecyclerView.ViewHolder {
private ImageView imageView;
private TextView txtview;
private TextView txtCost;
private RelativeLayout container;
public ViewHolder(View view) {
super(view);
imageView = (ImageView) view.findViewById(R.id.image);
txtview = (TextView) view.findViewById(R.id.text);
txtCost= (TextView) view.findViewById(R.id.textView);
container = (RelativeLayout) view.findViewById(R.id.container);
}
}
}
Please i need assistance with this i guess it is the int[]images causing the error i may be wrong please correct me with the right code i would use to replace and make the code work.
changeimageview accessibility form private to any other modifier & try again
This question already has answers here:
What does the "Assigned value is never used" warning mean?
(5 answers)
Closed 7 years ago.
After creating my activity, I get this warning:
Variable 'station' is never used
I not certain as to what that warning means nor how to fix it. I'm guessing the 'station' variable hasn't been declared however I don't know the correct way to declare it. All help would be appreciated.
FragmentWCLine.java
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;
public class FragmentWCLine extends android.support.v4.app.Fragment {
public final static String EXTRA_MESSAGE = "Station_key";
private class WC {
private CharSequence station;
private CharSequence zone;
private Class<? extends Activity> activityClass;
private Class<? extends android.support.v4.app.Fragment> fragmentClass;
public WC(int stationResId, int zoneResId, Class<? extends Activity> activityClass, Class<? extends android.support.v4.app.Fragment> fragmentClass) {
this.fragmentClass = fragmentClass;
this.activityClass = activityClass;
this.station = getResources().getString(stationResId);
this.zone = getResources().getString(zoneResId);
}
#Override
public String toString() { return station.toString(); }
public String getzone(){ return zone.toString(); }
}
private static WC[] mWC;
private boolean mTwoPane;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
View v = inflater.inflate(R.layout.fragment_wc_line, container, false);
// Instantiate the list of stations.
mWC = new WC[]{
new WC(R.string.bank, R.string.zone_1, WCBankActivity.class, FragmentWCBank.class),
new WC(R.string.wat, R.string.zone_1, WCWATActivity.class, FragmentWCWAT.class)
};
final ListView listView = (ListView)v.findViewById(R.id.list_wc);
listView.setAdapter(new MyAdapter(getActivity(), mWC));
listView.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
if(mTwoPane){
setItemNormal();
View rowView = view;
setItemSelected(rowView);
}
else{
Intent intent = new Intent(getActivity(), mWC[position].activityClass);
String station = mWC[position].station.toString();
intent.putExtra(EXTRA_MESSAGE, station);
startActivity(intent);
}
}
public void setItemSelected(View view){
View rowView = view;
view.setBackgroundColor(Color.parseColor("#66CCCC"));
TextView tv0 = (TextView)rowView.findViewById(R.id.list_item_station);
tv0.setTextColor(Color.parseColor("#000099"));
TextView tv1 = (TextView)rowView.findViewById(R.id.list_item_zone);
tv1.setTextColor(Color.parseColor("#000099"));
}
public void setItemNormal()
{
for (int i=0; i< listView.getChildCount(); i++) {
View v = listView.getChildAt(i);
v.setBackgroundColor(Color.TRANSPARENT);
TextView tv0 = ((TextView) v.findViewById(R.id.list_item_station));
tv0.setTextColor(Color.WHITE);
TextView tv1 = ((TextView) v.findViewById(R.id.list_item_zone));
tv1.setTextColor(Color.parseColor("#B5B5B5"));
}
}
});
return v;
}
static class MyAdapter extends BaseAdapter {
static class ViewHolder {
TextView station;
TextView zone;
}
LayoutInflater inflater;
WC[] mWC;
public MyAdapter(Context contexts, WC[] samples) {
this.mWC = samples;
inflater = LayoutInflater.from(contexts);
}
#Override
public int getCount() {
return mWC.length;
}
#Override
public Object getItem(int position) {
return mWC[position];
}
#Override
public long getItemId(int position) {
return 0;
}
/**set selected position**/
private int selectPosition = -1;
public void setSelectPosition(int position){
if(position!=selectPosition){
selectPosition = position;
}
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
if (convertView == null) {
convertView = inflater.inflate(R.layout.list_item_dualline, null);
viewHolder = new ViewHolder();
viewHolder.station = (TextView) convertView.findViewById(R.id.list_item_station);
viewHolder.zone = (TextView) convertView.findViewById(R.id.list_item_zone);
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
viewHolder.station.setText(mWC[position].station);
viewHolder.zone.setText(mWC[position].getzone());
//change item color
if(position==selectPosition){
convertView.setBackgroundColor(Color.parseColor("#000099"));
viewHolder.station.setTextColor(Color.parseColor("#000099"));
}else {
}
return convertView;
}
}
}
WCBankActivity.java
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.ActionBarActivity;
public class WCBankActivity extends ActionBarActivity {
public final static String EXTRA_MESSAGE = "Station_key";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_wc_bank);
if (savedInstanceState == null) {
// Get the message from the intent
Intent intent = getIntent();
// Notice to specify the sender Activity for the message
String station = intent.getStringExtra(WCBankActivity.EXTRA_MESSAGE);
FragmentWCBank newFragment = new FragmentWCBank();
FragmentTransaction transaction = this.getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.detail_container, newFragment);
transaction.commit();
}
}
}
FragmentWCBank.java
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class FragmentWCBank extends android.support.v4.app.Fragment {
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_wc_bank, container, false);
return v;
}
}
What you are seeing is a Warning rather than an Error. The difference being a Warning will not prevent your program from running, but an Error would.
The warning you are seeing is due to the fact that you are declaring a variable station but then never using it. Your IDE is smart enough to notice this and is trying to warn you as a reminder that you aren't using the variable that you created.
In this case it's this line:
String station = intent.getStringExtra(WCBankActivity.EXTRA_MESSAGE);
You declare a variable station and give it a value but then you never read that value or do anything else with it. Therefore you could theoretically remove the variable with no other impact to your app.