Develop Reference

Adding click listener to two buttons in PagerAdpater CardViews

In my project, I have a PagerAdapter to inflate CardViews that hold text objects created by the user.
On each CardView I have edit and delete buttons to access methods to do with the ArrayList holding the text objects.
I have coded an interface in my adapter to handle clicks made within the text object creation activity. However, my instatiateItem method in my adapter is now showing on the #Override annotation "Method does not override method from its superclass". When I remove the #Override annotation I get an error in my Logcat:
java.lang.UnsupportedOperationException: Required method instantiateItem was not overridden
How do I implement a click listener for buttons on a CardView in a PagerAdapter?
Adapter code:
public class CreateAdapter extends PagerAdapter {
private List<PdfPage> pagesList;
private LayoutInflater layoutInflater;
private Context context;
private onItemClickListener mListener;
public interface onItemClickListener{
//click method for edit button
void onEditClick(int position);
//click method for delete button
void onDeleteClick(int position);
}
public void setOnItemClickListener(onItemClickListener listener){
mListener = listener;
}
public CreateAdapter(List<PdfPage> pagesList, Context context) {
this.pagesList = pagesList;
this.context = context;
}
#Override
public int getCount() {
return pagesList.size();
}
#Override
public boolean isViewFromObject(#NonNull View view, #NonNull Object object) {
return view.equals(object);
}
#NonNull
#Override
public Object instantiateItem(#NonNull ViewGroup container, final int position, final onItemClickListener listener) {
layoutInflater = LayoutInflater.from(context);
View view = null;
if(pagesList.get(position).getPageType() == "Text") {
view = layoutInflater.inflate(R.layout.create_text_cardview, container, false);
TextView inputText = view.findViewById(R.id.inputTextView);
ImageButton editButton = view.findViewById(R.id.imageButtonEdit);
ImageButton deleteButton = view.findViewById(R.id.imageButtonDelete);
//if this works, see 12:30 of video for image getter
inputText.setText(pagesList.get(position).getPageText());
//edit click listener
editButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (listener != null){
int position2 = pagesList.indexOf(pagesList.get(position));
listener.onEditClick(position2);
}
}
});
//delete click listener
deleteButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (listener != null){
int position3 = pagesList.indexOf(pagesList.get(position));
listener.onDeleteClick(position3);
}
}
});
container.addView(view, 0);
}
//put else statement here for image cardView
assert view != null;
return view;
}
#Override
public void destroyItem(#NonNull ViewGroup container, int position, #NonNull Object object) {
container.removeView((View)object);
}
Activity code:
public class CreateActivity extends AppCompatActivity {
ViewPager viewPager;
CreateAdapter createAdapter;
List<PdfPage> pdfPageList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_create);
pdfPageList = new ArrayList<>();
createAdapter = new CreateAdapter(pdfPageList, this);
viewPager = findViewById(R.id.viewPager);
viewPager.setAdapter(createAdapter);
viewPager.setPadding(130, 0, 130, 0);
}
#Override
protected void onStart() {
super.onStart();
createAdapter = new CreateAdapter(pdfPageList, this);
viewPager = findViewById(R.id.viewPager);
viewPager.setAdapter(createAdapter);
viewPager.setPadding(130, 0, 130, 0);
createAdapter.setOnItemClickListener(new CreateAdapter.onItemClickListener() {
#Override
public void onEditClick(int position) {
}
#Override
public void onDeleteClick(int position) {
pdfPageList.remove(position);
}
});
}

Your instantiateItem method does not override from it's superclass because you added an extra argument final onItemClickListener listener.
As you are using the same clickListener for all entries and passing the item position as an argument, I suggest that you pass the onItemClickListener in the adapter constructor, or just set it via
public void setOnItemClickListener(onItemClickListener listener){
mListener = listener;
}
Adapter code:
public class CreateAdapter extends PagerAdapter {
private List<PdfPage> pagesList;
private LayoutInflater layoutInflater;
private Context context;
private onItemClickListener mListener;
public interface onItemClickListener{
//click method for edit button
void onEditClick(int position);
//click method for delete button
void onDeleteClick(int position);
}
public void setOnItemClickListener(onItemClickListener listener){
mListener = listener;
}
public CreateAdapter(List<PdfPage> pagesList, Context context) {
this.pagesList = pagesList;
this.context = context;
}
#Override
public int getCount() {
return pagesList.size();
}
#Override
public boolean isViewFromObject(#NonNull View view, #NonNull Object object) {
return view.equals(object);
}
#NonNull
#Override
public Object instantiateItem(#NonNull ViewGroup container, final int position) {
layoutInflater = LayoutInflater.from(context);
View view = null;
if(pagesList.get(position).getPageType() == "Text") {
view = layoutInflater.inflate(R.layout.create_text_cardview, container, false);
TextView inputText = view.findViewById(R.id.inputTextView);
ImageButton editButton = view.findViewById(R.id.imageButtonEdit);
ImageButton deleteButton = view.findViewById(R.id.imageButtonDelete);
//if this works, see 12:30 of video for image getter
inputText.setText(pagesList.get(position).getPageText());
//edit click listener
editButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (mlistener != null){
int position2 = pagesList.indexOf(pagesList.get(position));
mlistener.onEditClick(position2);
}
}
});
//delete click listener
deleteButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (mlistener != null){
int position3 = pagesList.indexOf(pagesList.get(position));
mlistener.onDeleteClick(position3);
}
}
});
container.addView(view, 0);
}
//put else statement here for image cardView
assert view != null;
return view;
}
#Override
public void destroyItem(#NonNull ViewGroup container, int position, #NonNull Object object) {
container.removeView((View)object);
}
And your Activity code could stay as it is.

How to make 2 buttons for multiple listview elements

I'm creating an app for ordering food, and I created a Dish class and a Dish array adapter.
Currently you can add quantity for a specific dish by clicking on the view.
However, I wish to have 2 buttons to add or sub the quantity.
How can I make the 2 buttons for each dish, without the need to write for each element its ows button code? is there a way to make an "add" and "sub" methods and that the listview will know on which view it was clicked and by that update its quantity?
public Dish(String dishName, int dishPrice, int Image, int quantity) {
mdishName = dishName;
mdishPrice = dishPrice;
mdishPic = Image;
mquantity = quantity;
}
public class DishAdapter extends ArrayAdapter<Dish> {
public DishAdapter(Activity context, ArrayList<Dish> dishes){
super(context, 0, dishes);
}
#NonNull
#Override
public View getView(int position, #Nullable View convertView, #NonNull ViewGroup parent) {
View listItemView = convertView;
if(listItemView == null){
listItemView = LayoutInflater.from(getContext()).inflate(R.layout.list_layout, parent, false);
}
final Dish currenDish = getItem(position);
TextView dishName = (TextView) listItemView.findViewById(R.id.dishName);
dishName.setText(currenDish.getDishName());
TextView dishPrice = (TextView) listItemView.findViewById(R.id.dishPrice);
dishPrice.setText(String.valueOf(currenDish.getDishPrice()));
ImageView image = (ImageView) listItemView.findViewById(R.id.dishPic);
image.setImageResource(currenDish.getDishPic());
image.setVisibility(View.VISIBLE);
TextView quantity = (TextView) listItemView.findViewById(R.id.quantity);
quantity.setText(String.valueOf(currenDish.getQuantity()));
return listItemView;
}
public class DesertsActivity extends AppCompatActivity {
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.deserts_activity);
final ArrayList<Dish> dishes = new ArrayList<Dish>();
dishes.add(new Dish("Number Cake",180, R.drawable.cake_number, 0));
dishes.add(new Dish("Ear of Haman", 40, R.drawable.ozen_haman, 0));
dishes.add(new Dish("Alphachores", 35, R.drawable.alphachores, 0));
dishes.add(new Dish("Snow Cookies", 35, R.drawable.snow_cookies, 0));
DishAdapter adapter = new DishAdapter(this, dishes);
final ListView listView = (ListView) findViewById(R.id.deserts_list);
listView.setAdapter(adapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
dishes.set(position, new Dish(dishes.get(position).getDishName(),
dishes.get(position).getDishPrice(), dishes.get(position).getDishPic(),
dishes.get(position).getQuantity()+1));
TextView quantity = (TextView) view.findViewById(R.id.quantity);
quantity.setText(String.valueOf(dishes.get(position).getQuantity()));
}
});
}
}

You have to create a separate Adaptor Class and then apply button click listeners on the buttons. I am attaching the image for the reference.
and My product Adaptor Is
public class ProductAdaptor extends RecyclerView.Adapter<ProductAdaptor.ViewHolder> {
List<ProductsItem> productsItems;
Context context;
public ProductAdaptor(Context context, List<ProductsItem> productsItems)
{
this.context = context;
this.productsItems = productsItems;
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(context).inflate(R.layout.single_product_design,viewGroup, false);
return new ProductAdaptor.ViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull ViewHolder viewHolder, int i) {
final ProductsItem productsItem = productsItems.get(i);
viewHolder.productname.setText(productsItem.getProductName());
Glide.with(context).load(productsItem.getProductImageUrl()).into(viewHolder.productImage);
viewHolder.stock.setText(productsItem.getStock());
viewHolder.farmername.setText(productsItem.getFarmerName());
// add listener on single Item
viewHolder.btnAdd.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(context, "Clicked", Toast.LENGTH_LONG).show();
}
});
viewHolder.btnPlus.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// apply code to increment the number
// first of all get the value form text counter and increment after that bind on the UI
}
});
viewHolder.btnMinus.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// first of all get the value form text counter and decrement after that bind on the UI
}
});
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public int getItemViewType(int position) {
return position;
}
#Override
public int getItemCount() {
return productsItems.size();
}
public class ViewHolder extends RecyclerView.ViewHolder
{
TextView productname;
ImageView productImage;
TextView stock, farmername, specility,qty;
Button btnPlus, btnMinus;
LinearLayout btnAdd;
public ViewHolder(#NonNull View itemView)
{
super(itemView);
productname = itemView.findViewById(R.id.productname);
productImage = itemView.findViewById(R.id.productimage);
stock = itemView.findViewById(R.id.stcokValue);
farmername = itemView.findViewById(R.id.farmerName);
qty = itemView.findViewById(R.id.qty);
specility = itemView.findViewById(R.id.specility);
btnPlus = itemView.findViewById(R.id.plusbutton);
btnMinus = itemView.findViewById(R.id.minusbtn);
btnAdd = itemView.findViewById(R.id.add_button);
}
}
}

How to pass data to getView method

I'm getting a variable data sent from activity to my adapter by using
sendData method, but every time when I try to access it in my getView method it resets to 0, please help. I've tried to debug code to check if the data from an activity is passing and it looks ok. I also created a getNumb method but still, the variable resets to 0. Here is my adapter code:
public class WorkoutListAdapterTwo extends BaseAdapter {
private int y;
public WorkoutListAdapterTwo() {
}
public int sendData(int x){
this.y = x;
return y;
}
public int getNumb(){
return this.y;
}
private static LayoutInflater mLayoutInflater = null;
public WorkoutListAdapterTwo(Activity ctx) {
this.mLayoutInflater = ctx.getLayoutInflater();
}
#Override
public int getCount() {
return WorkoutContentTwo.WORKOUTSTWO.size();
}
#Override
public Object getItem(int position) {
return WorkoutContentTwo.WORKOUTSTWO.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
int j = getNumb();
WorkoutTwo workout = (WorkoutTwo) getItem(j);
String [] arrOfStrings = workout.name.split(",");
if (convertView == null) {
convertView = mLayoutInflater.inflate(R.layout.adapter_workout_row, parent, false);
holder = new ViewHolder();
holder.id = (TextView) convertView.findViewById(R.id.workout_id);
holder.name = (TextView) convertView.findViewById(R.id.workout_name);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
// Set the content for the ListView row
//holder.id.setText(workout.id);
//holder.name.setText(arrOfStrings[i]);
holder.id.setText(Integer.toString(position+1));
holder.name.setText(workout.ArrList[position]);
// Set the color for the ListView row
holder.id.setBackgroundColor(workout.dark);
holder.name.setBackgroundColor(workout.light);
return convertView;
}
Here I'm adding the code where I'm calling my method:
public void onItemSelected(int position) {
// Start the detail activity for the selected workout ID.
Intent detailIntent = new Intent(this, WorkoutDetailActivityTwo.class);
detailIntent.putExtra(WorkoutDetailFragmentTwo.ARG_WORKOUT_POS, position);
WorkoutListAdapterTwo newAdd = new WorkoutListAdapterTwo();
newAdd.sendData(position);
newAdd.notifyDataSetChanged();
startActivity(detailIntent);
}

Are you notifying your adapter to update views after updating the value? If your sendData() is not called until after the adapter has done it's first draw, you will need to call notifyDataSetChanged() so that the adapter knows there are new values that should be used to update your views.

You have to make a interface or you can a use notifyDataSetChanged depends on the use if you are doing search operation then use the notifyDataSetChanged method but if you want to send some data then
Fragment or activity
public class ExampleFragment extends Fragment implements MyAdapter.SuccessResponse{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View contentView = inflater.inflate(R.layout.my_layout, container, false);
MyAdapter myAdapter = new MyAdapter(getActivity(), 0);
myAdapter.successResponse = this;
return contentView;
}
#Override
public void onSuccess() {
}
}
The adapter code
class MyAdapter extends ArrayAdapter{
SuccessResponse successResponse;
public MyAdapter(Context context, int resource) {
super(context, resource);
}
public interface SuccessResponse{
void onSuccess();
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
//ur views
linearLayout.setOnClickListener(new View.OnClickListener{
#Override
public void onClick (View view){
if(successResponse!=null)
successResponse.onSuccess();
}
})
}
}
You can use any type of adapter i am use arrayadaper here.

Intent putExtra from PagerAdapter to Fragment

I need to get the vales passed from ThePagerAdapter.java inside SliderHome.java. How can I implement this? I have tried a lot, but no success.
This is my code:
ThePagerAdapter.java
public class ThePagerAdapter extends PagerAdapter {
Context context;
#Override
public int getCount() {
return list.size();
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view == ((RelativeLayout) object);
}
public ThePagerAdapter(Context context,List<Slider> list) {
this.list = list;
this.context = context;
}
#Override
public Object instantiateItem(final ViewGroup container, int position) {
// Declare Variables
ImageView imgflag;
inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View itemView = inflater.inflate(R.layout.image_item, container, false);
// Capture position and set to the TextViews
final String id = list.get(position).getId();
imgflag = (ImageView) itemView.findViewById(R.id.imageView);
imgflag.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
Intent i = new Intent(context, SliderMore.class);
i.putExtra("slider_id", id);
context.startActivity(i);
}
});
((ViewPager) container).addView(itemView);
return itemView;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
// Remove viewpager_item.xml from ViewPager
((ViewPager) container).removeView((RelativeLayout) object);
}
}
From the above PagerAdapter I am send values to another Fragment described below using Intent.putExtra
SliderHome.java
public class SliderHome extends Fragment {
ViewPager viewPager;
ImageView iv2,iv3;
String slider_id;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.slider_more, container, false);
viewPager = (ViewPager) rootView.findViewById(R.id.viewPager);
iv2 = (ImageView) rootView.findViewById(R.id.imageView2);
iv3 = (ImageView) rootView.findViewById(R.id.imageView3);
return rootView;
}
Is there a solution? Thanks in advance.

In this cases I like to use a Factory Method Pattern.
Example:
public static MatchDetailSummaryFragment newInstance(String matchIdString, int position) {
MyFragment fragment = new MyFragment();
Bundle args = new Bundle();
args.putString(ARGS_MY_ID, matchIdString);
args.putInt(ARG_POSITION,position);
fragment.setArguments(args);
return fragment;
}
public MyFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.mPosition = getArguments().getInt(ARG_POSITION);
this.id = getArguments().getString(ARGS_MY_ID) != null)
}
You can invoke this:
public void fillMyPagerAdapter()
{
mChildFragments = new Hashtable<Integer,GxuBaseFragment>();
int count = 0;
MyFragment a = MyFragment.newInstance(Integer.toString(my.getId()),count);
mChildFragments.put(count,a);
count += 1;
mViewPagerAdapter.setTabHolderScrollingContent(this);
mPager.setAdapter(mViewPagerAdapter);
mPagerSlidingTabStrip.setViewPager(mPager);
mPagerSlidingTabStrip.setOnPageChangeListener(this);
}
This code may not work because is a couple of extracts of my production code but it will explain the main ideas.

non static variable cannot be referenced from a static context in Adapter

I am using Base Adapter for displaying image in grid view. The working fine when images are fixed IMAGE_URLS directly but am try with geting url from list and assign into IMAGE_URLS that shows non static variable cannot be referenced from a static context. I don't know how to solve this issue. please help to solve this issue
public class ImageGridFragment extends AbsListViewBaseFragment {
public static final int INDEX = 1;
String description="";
ArrayList<String> img = new ArrayList<String>();
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fr_image_grid, container, false);
listView = (GridView) rootView.findViewById(R.id.grid);
img.clear();
Bundle bundle = this.getArguments();
description = bundle.getString("description");
String[] separated= description.split(",");
for(int i=0;i<separated.length;i++)
{
img.add(separated[i]);
}
ImageGalleryFragment.imageLoader.init(ImageLoaderConfiguration.createDefault(getActivity()));
((GridView) listView).setAdapter(new ImageAdapter(getActivity()));
listView.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
startImagePagerActivity(position);
}
});
return rootView;
}
private static class ImageAdapter extends BaseAdapter {
String[] IMAGE_URLS = img.toArray(new String[img.size()]);
private LayoutInflater inflater;
private DisplayImageOptions options;
ImageAdapter(Context context) {
inflater = LayoutInflater.from(context);
options = new DisplayImageOptions.Builder()
.showImageOnLoading(R.drawable.ic_stub)
.showImageForEmptyUri(R.drawable.ic_empty)
.showImageOnFail(R.drawable.ic_error)
.cacheInMemory(true)
.cacheOnDisk(true)
.considerExifParams(true)
.bitmapConfig(Bitmap.Config.RGB_565)
.build();
}
#Override
public int getCount() {
return IMAGE_URLS.length;
}
#Override
public Object getItem(int position) {
return null;
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
final ViewHolder holder;
View view = convertView;
if (view == null) {
view = inflater.inflate(R.layout.item_grid_image, parent, false);
holder = new ViewHolder();
assert view != null;
holder.imageView = (ImageView) view.findViewById(R.id.image);
holder.progressBar = (ProgressBar) view.findViewById(R.id.progress);
view.setTag(holder);
} else {
holder = (ViewHolder) view.getTag();
}
ImageLoader.getInstance()
.displayImage(IMAGE_URLS[position], holder.imageView, options, new SimpleImageLoadingListener() {
#Override
public void onLoadingStarted(String imageUri, View view) {
holder.progressBar.setProgress(0);
holder.progressBar.setVisibility(View.VISIBLE);
}
#Override
public void onLoadingFailed(String imageUri, View view, FailReason failReason) {
holder.progressBar.setVisibility(View.GONE);
}
#Override
public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
holder.progressBar.setVisibility(View.GONE);
}
}, new ImageLoadingProgressListener() {
#Override
public void onProgressUpdate(String imageUri, View view, int current, int total) {
holder.progressBar.setProgress(Math.round(100.0f * current / total));
}
});
return view;
}
}
static class ViewHolder {
ImageView imageView;
ProgressBar progressBar;
}
}

Change the class from private static to "private class ImageAdapter".