Develop Reference

How to implement an ArrayList of Objects as views in a RecyclerView ViewHolder?

I'm trying to populate a RecyclerView with unique views (Buttons, TextViews, Views, etc) via an ArrayList of ArrayLists of Objects. Just know that the first Object element is actually the id of a view.
The problem is I'm not sure how to call the particular view using the ViewHolder object in the onBindViewHolder method since all the views are initialized in the ArrayList. So this is what I've tried, but this line
detailsViewHolder.((TextView) viewTypes.get(i)).setText("A Text"); is not even syntactically correct.
private class DetailsAdapter extends RecyclerView.Adapter<DetailsAdapter.DetailsViewHolder> {
private ArrayList<ArrayList<Object>> viewBundle;
public DetailsAdapter(ArrayList<ArrayList<Object>> viewBundle){
this.viewBundle = viewBundle;
viewTypes = new ArrayList<>();
}
public class DetailsViewHolder extends RecyclerView.ViewHolder{
private ArrayList<View> viewTypes;
public DetailsViewHolder(View itemView){
super(itemView);
viewTypes = new ArrayList<>();
for (int i = 0; i < viewBundle.size(); i++) {
viewTypes.add(itemView.findViewById((Integer) viewBundle.get(i).get(0)));
}
}
}
#Override
public int getItemCount() {
return viewBundle.size();
}
#NonNull
#Override
public DetailsViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int i) {
View resItemView = LayoutInflater.from(parent.getContext()).inflate((Integer) viewBundle.get(i).get(1), parent, false);
DetailsViewHolder viewHolder = new DetailsViewHolder(resItemView);
return viewHolder;
}
#Override
public void onBindViewHolder(#NonNull DetailsViewHolder detailsViewHolder, int i) {
detailsViewHolder.((TextView) viewTypes.get(i)).setText("A Text");
}
}

Well I got it to work with static arrays (not sure about ArrayList).
public DetailsViewHolder(View itemView){
super(itemView);
viewTypes = new View[viewBundle.size()];
for (int i = 0; i < viewBundle.size(); i++) {
viewTypes[i] = (itemView.findViewById((Integer) viewBundle.get(i).get(0)));
}
}
So yeah this solved the problem.
((TextView) detailsViewHolder.viewTypes[i]).setText("A Text");

How to make one view bigger than the other views in RecyclerView?

I have few images in the json API, and I managed to fetch those images using volley Library. I used recyclerview with an image adapter to display image views vertically in two columns, but I want to make one image big and display it as the first image that user can click on. Also that image will be changed each interval of time. Basically, the API will do all the backend task like setting the time and telling which image to be displayed on the top of the recyclerview if not all images must have the same size and be shown in 2 columns vertically.
I have square layout class for recyclerview. I just want to know how I can do this. Even the concept will be fine.

you will have to create two view one for small item other for the header item and in onBindViewHolder have to bind those accordingly the following code is an example of a news article app and should help.
public class AdapterNewsArticlesListWithHeader extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private List<NewsArticles> items = new ArrayList<>();
private Context ctx;
private NewsArticles header;
private static final int TYPE_HEADER = 0;
private static final int TYPE_ITEM = 1;
private OnItemClickListener mOnItemClickListener;
public interface OnItemClickListener {
void onItemClick(View view, NewsArticles obj, int position);
}
public void setOnItemClickListener(final OnItemClickListener mItemClickListener) {
this.mOnItemClickListener = mItemClickListener;
}
// Provide a suitable constructor (depends on the kind of dataset)
public AdapterNewsArticlesListWithHeader(Context context, NewsArticles header, List<NewsArticles> items) {
this.items = items;
this.header = header;
ctx = context;
}
public class ViewHolder extends RecyclerView.ViewHolder {
// each data item is just a string in this case
public TextView title;
public TextView short_content;
public TextView date;
public ImageView image;
public LinearLayout lyt_parent;
public ViewHolder(View v) {
super(v);
title = (TextView) v.findViewById(R.id.title);
short_content = (TextView) v.findViewById(R.id.short_content);
date = (TextView) v.findViewById(R.id.date);
image = (ImageView) v.findViewById(R.id.image);
lyt_parent = (LinearLayout) v.findViewById(R.id.lyt_parent);
}
}
class ViewHolderHeader extends RecyclerView.ViewHolder {
public TextView title;
public TextView date;
public ImageView image;
public LinearLayout lyt_parent;
public ViewHolderHeader(View v) {
super(v);
title = (TextView) v.findViewById(R.id.title);
date = (TextView) v.findViewById(R.id.date);
image = (ImageView) v.findViewById(R.id.image);
lyt_parent = (LinearLayout) v.findViewById(R.id.lyt_parent);
}
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (viewType == TYPE_HEADER) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_header, parent, false);
return new ViewHolderHeader(v);
} else if (viewType == TYPE_ITEM) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_news, parent, false);
return new ViewHolder(v);
}
return null;
}
// Replace the contents of a view (invoked by the layout manager)
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {
if (holder instanceof ViewHolderHeader) {
ViewHolderHeader vHeader = (ViewHolderHeader) holder;
vHeader.title.setText(header.getTitle());
vHeader.date.setText(header.getDate());
Picasso.with(ctx).load(header.getImage()).into(vHeader.image);
vHeader.lyt_parent.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//TODO: do your thing
}
});
} else if (holder instanceof ViewHolder) {
final NewsArticles c = items.get(position);
ViewHolder vItem = (ViewHolder) holder;
vItem.title.setText(c.getTitle());
vItem.short_content.setText(c.getShort_content());
vItem.date.setText(c.getDate());
Picasso.with(ctx).load(c.getImage()).into(vItem.image);
vItem.lyt_parent.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//TODO: do your thing
}
});
}
}
// need to override this method
#Override
public int getItemViewType(int position) {
if (isPositionHeader(position)) {
return TYPE_HEADER;
}
return TYPE_ITEM;
}
private boolean isPositionHeader(int position) {
return position == 0;
}
public NewsArticles getItem(int position) {
return items.get(position);
}
// Return the size of your dataset (invoked by the layout manager)
#Override
public int getItemCount() {
return items.size();
}
}

Get value of textview in cardview from recycleview

I have a RecycleView that has cards inside of it. Each card has a list of companies and prices.
In my onBindViewHolder I have a click event where I would like to get the price of the TextView in that row inside of the Cardview.
Every time I click I always get the value/price of the top item inside of the individual card and never get the price of the item I am clicking.
The data param of the bindData method is what I am using to create the list of items inside of the Cardview.
Any help would be greatly appreciated. I just need to get the value of the correct TextView where I am clicking.
public class StockCardAdapter extends RecyclerView.Adapter<StockCardAdapter.ViewHolder> {
public static class ViewHolder extends RecyclerView.ViewHolder {
protected RelativeLayout mCardBodyLayout;
protected TextView mTitleTextView;
public ViewHolder(View v) {
super(v);
mCardBodyLayout = (RelativeLayout) v.findViewById(R.id.card_body);
mTitleTextView = (TextView) v.findViewById(R.id.card_title);
}
public void bindData(StockCategoryModel data, Context ctx) {
this.mTitleTextView.setText(data.getCategoryName());
TableLayout tableLayout = new TableLayout(ctx);
int rows = data.getStockList().size();
for (int r = 0; r < rows; r++) {
TableRow row = new TableRow(ctx);
TableLayout.LayoutParams rowParams = new TableLayout.LayoutParams (TableLayout.LayoutParams.MATCH_PARENT,TableLayout.LayoutParams.WRAP_CONTENT);
rowParams.setMargins(0, 0, 0, 16);
row.setLayoutParams(rowParams);
LinearLayout rl = new LinearLayout(ctx);
rl.setOrientation(LinearLayout.VERTICAL);
Integer priceColor = SharedUtilities.getColor(data.getStockList().get(r).priceChange, ctx);
//price row
LinearLayout priceLayout = new LinearLayout(ctx);
priceLayout.setOrientation(LinearLayout.HORIZONTAL);
priceLayout.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));
priceLayout.setWeightSum(4);
LinearLayout.LayoutParams textViewParams = new LinearLayout.LayoutParams(0, LinearLayout.LayoutParams.WRAP_CONTENT, 1f);
final TextView price_text = new TextView(ctx);
price_text.setTag("priceTag");
price_text.setText(data.getStockList().get(r).price);
price_text.setTextSize(TypedValue.COMPLEX_UNIT_SP, 14);
price_text.setTextColor(Color.BLACK);
price_text.setLayoutParams(textViewParams);
priceLayout.addView(price_text);
//company row
final TextView name_text = new TextView(ctx);
name_text.setText(data.getStockList().get(r).company);
name_text.setTextColor(Color.GRAY);
name_text.setLayoutParams( new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.MATCH_PARENT));
name_text.setMaxWidth(700);
name_text.setEllipsize(TextUtils.TruncateAt.END);
name_text.setMaxLines(1);
name_text.setTextSize(TypedValue.COMPLEX_UNIT_SP, 14);
rl.addView(priceLayout);
rl.addView(name_text);
row.addView(rl);
tableLayout.setStretchAllColumns(true);
tableLayout.addView(row);
}
mCardBodyLayout.addView(tableLayout);
}
}
private List<StockCategoryModel> mDataset;
private Context mContext;
// Constructor
public StockCardAdapter(List<StockCategoryModel> dataset, Context ctx) {
this.mDataset = dataset;
this.mContext = ctx;
}
#Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
}
// Create new views (invoked by the layout manager)
#Override
public StockCardAdapter.ViewHolder onCreateViewHolder(ViewGroup viewGroup,
int viewType) {
// create a new view
View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.card_layout, viewGroup, false);
ViewHolder vh = new ViewHolder(v);
return vh;
}
// Replace the contents of a view (invoked by the layout manager)
#Override
public void onBindViewHolder(final ViewHolder holder, int position) {
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override public void onClick(View v2) {
final TextView textViewName = (TextView) v2.findViewWithTag("priceTag"); ;
final String priceTag = textViewName.getText().toString();
}
});
holder.bindData(mDataset.get(position), mContext);
}
// Return the size of your dataset (invoked by the layout manager)
#Override
public int getItemCount() {
return mDataset.size();
}
}

What you need to do is to set a click listener to every row separately.
Why do you always get the first row value?
This code,
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override public void onClick(View v2) {
final TextView textViewName = (TextView) v2.findViewWithTag("priceTag"); ;
final String priceTag = textViewName.getText().toString();
}
});
Sets a click listener to every list item - the whole card. This means that every time the user clicks inside the card view bounds - this callback will be fired. BUT, who will be v2? It will always be the view to which we set the listener to - in this case - the whole card.
This means that every time you call v2.findViewWithTag("priceTag"); you are searching the first child of the entire card that has the tag "priceTag" - which is the "top" item in the card.
How to solve this issue?
If you want to identify which child is being clicked - you will have to set a click listener to each child directly.
As an example, try this code (see ADDED comments):
public class StockCardAdapter extends
RecyclerView.Adapter<StockCardAdapter.ViewHolder> {
public static class ViewHolder extends RecyclerView.ViewHolder {
protected RelativeLayout mCardBodyLayout;
protected TextView mTitleTextView;
public ViewHolder(View v) {
super(v);
mCardBodyLayout = (RelativeLayout) v.findViewById(R.id.card_body);
mTitleTextView = (TextView) v.findViewById(R.id.card_title);
}
public void bindData(StockCategoryModel data, Context ctx, View.OnClickListener listener) {
this.mTitleTextView.setText(data.getCategoryName());
TableLayout tableLayout = new TableLayout(ctx);
int rows = data.getStockList().size();
for (int r = 0; r < rows; r++) {
TableRow row = new TableRow(ctx);
TableLayout.LayoutParams rowParams = new TableLayout.LayoutParams (TableLayout.LayoutParams.MATCH_PARENT,TableLayout.LayoutParams.WRAP_CONTENT);
rowParams.setMargins(0, 0, 0, 16);
row.setLayoutParams(rowParams);
LinearLayout rl = new LinearLayout(ctx);
rl.setOrientation(LinearLayout.VERTICAL);
Integer priceColor = SharedUtilities.getColor(data.getStockList().get(r).priceChange, ctx);
//price row
LinearLayout priceLayout = new LinearLayout(ctx);
priceLayout.setOrientation(LinearLayout.HORIZONTAL);
priceLayout.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));
priceLayout.setWeightSum(4);
LinearLayout.LayoutParams textViewParams = new LinearLayout.LayoutParams(0, LinearLayout.LayoutParams.WRAP_CONTENT, 1f);
final TextView price_text = new TextView(ctx);
price_text.setTag("priceTag");
price_text.setText(data.getStockList().get(r).price);
price_text.setTextSize(TypedValue.COMPLEX_UNIT_SP, 14);
price_text.setTextColor(Color.BLACK);
price_text.setLayoutParams(textViewParams);
priceLayout.addView(price_text);
//company row
final TextView name_text = new TextView(ctx);
name_text.setText(data.getStockList().get(r).company);
name_text.setTextColor(Color.GRAY);
name_text.setLayoutParams( new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.MATCH_PARENT));
name_text.setMaxWidth(700);
name_text.setEllipsize(TextUtils.TruncateAt.END);
name_text.setMaxLines(1);
name_text.setTextSize(TypedValue.COMPLEX_UNIT_SP, 14);
rl.addView(priceLayout);
rl.addView(name_text);
row.addView(rl);
tableLayout.setStretchAllColumns(true);
tableLayout.addView(row);
// *ADDED* set the listener directly to each row
row.setOnClickListener(listener);
}
mCardBodyLayout.addView(tableLayout);
}
}
private List<StockCategoryModel> mDataset;
private Context mContext;
// Constructor
public StockCardAdapter(List<StockCategoryModel> dataset, Context ctx) {
this.mDataset = dataset;
this.mContext = ctx;
}
#Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
}
// Create new views (invoked by the layout manager)
#Override
public StockCardAdapter.ViewHolder onCreateViewHolder(ViewGroup viewGroup,
int viewType) {
// create a new view
View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.card_layout, viewGroup, false);
ViewHolder vh = new ViewHolder(v);
return vh;
}
// Replace the contents of a view (invoked by the layout manager)
#Override
public void onBindViewHolder(final ViewHolder holder, int position) {
// *ADDED* Send the callback to the bind method
holder.bindData(mDataset.get(position), mContext, new View.OnClickListener() {
#Override public void onClick(View v2) {
final TextView textViewName = (TextView) v2.findViewWithTag("priceTag"); ;
final String priceTag = textViewName.getText().toString();
}
}));
}
// Return the size of your dataset (invoked by the layout manager)
#Override
public int getItemCount() {
return mDataset.size();
}
}
NOTE:
This is NOT the proper way to handle a RecyclerView - You never want to create a new object (in this case new View.OnClickListener() {}) inside the data binding - that will reduce performance. But this is another issue :)

The tag of textView is same in all the cases and that's why it is repeating, only the value of first item. Assign unique tag usually by concatenating "priceTag" with position. Make changes in your code as follows:
public void bindData(StockCategoryModel data, Context ctx, int position) {
//All your code
//..
//...
final TextView price_text = new TextView(ctx);
price_text.setTag("priceTag"+String.valueOf(position));
}
and in your onBindViewHolder:
final TextView textViewName = (TextView) v2.findViewWithTag("priceTag"+String.valueOf(position));
holder.bindData(mDataset.get(position), mContext,position);

Find child view from Tag
please call it.
TextView priceTagTextView =(TextView)getViewsByTag(mCardBodyLayout, "priceTag").get(0);
private ArrayList<View> getViewsByTag(ViewGroup root, String tag){
ArrayList<View> views = new ArrayList<View>();
final int childCount = root.getChildCount();
for (int i = 0; i < childCount; i++) {
final View child = root.getChildAt(i);
if (child instanceof ViewGroup) {
getViewsByTag((ViewGroup) child, tag));
}
final Object tagObj = child.getTag();
if (tagObj != null && tagObj.equals(tag)) {
views.add(child);
}
}
return views;
}

Integrating recyclerview with database

#Override
public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
Collections.swap(queuee, viewHolder.getAdapterPosition(), target.getAdapterPosition());
// and notify the adapter that its dataset has changed
adapterr.notifyItemMoved(viewHolder.getAdapterPosition(), target.getAdapterPosition());
return true;
}
With the above code i m able to swap the items in the recyclerview ,but now the problem is i also want to make the same respective changes to database.
How to go about?
queuee receives the all the data from the database
queuee is a arraylist which is used to set the recyclerview adapter
Regards
Thanks

Adapter:
public class QueueAdapter extends RecyclerView.Adapter<QueueAdapter.MyViewHolder> {
private Context mContext;
public ArrayList<Music> queue;
MediaPlayer mPlayer = new MediaPlayer();
public class MyViewHolder extends RecyclerView.ViewHolder {
public TextView title,tt,artist;
public Button play,stop;
public ImageButton option;
public MyViewHolder(View view) {
super(view);
title = (TextView) view.findViewById(R.id.songtitle1);
artist = (TextView)view.findViewById(R.id.artist1);
// play = (Button) view.findViewById(R.id.play);
// stop = (Button) view.findViewById(R.id.stop);
// tt = (TextView) view.findViewById(R.id.song_name);
option = (ImageButton) view.findViewById(R.id.option1);
}
}
public QueueAdapter(Context mContext, ArrayList<Music> queue) {
this.mContext = mContext;
this.queue = queue;
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.queue_card, parent, false);
return new MyViewHolder(itemView);
}
#Override
public void onBindViewHolder(final MyViewHolder holder, final int position) {
Music mu1 = queue.get(position);
holder.title.setText(mu1.getTitle());
holder.artist.setText(mu1.getArtist());
final String link =mu1.getUrl();
final String SongName = mu1.getTitle();
}
#Override
public int getItemCount() {
return queue.size();
}
public void removeItem(int position) {
queue.remove(position);
notifyItemRemoved(position);
notifyItemRangeChanged(position, queue.size());
}
}
activity:
recyclerView = (RecyclerView) findViewById(R.id.recyclerqueue);
recyclerView.setHasFixedSize(true);
layoutManager = new LinearLayoutManager(this);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setItemAnimator(new DefaultItemAnimator());
adapterr = new QueueAdapter(this,queuee);
recyclerView.addItemDecoration(new DividerItemDecoration(this, LinearLayoutManager.VERTICAL));
// adapterr.
recyclerView.setAdapter(adapterr);
initSwipe();

In my opinion, you can do it on OnDestroy method in your Activity. Specifically speaking, firstly, you can get all your data from your adapter, and then delete datas in your database, at last, you can save your data obtained from your adapter again. In this moment, the sequence of your datas is what you want, and this way is easy to code. I'd rather you don't
update your database during onMove, because it's too frequently during your drag, and operates all data is easier than two datas in database.

Android Recycler View select only one image and show tick mark on selected image

I need a solution of how to do the following thing using Android Recycler View.
I have Multiple Images and i need to select only one image like how the radio button works. Now i can select all the images that i have, but i need to restrict the current working behavior to work like the radio button (E.g.) If one is selected the other images that i have should not be selected.
I have tried with the below code but no luck for me. Can anyone rectify the mistake and make the code workable as per my need.
public class StarCountAdapter extends RecyclerView.Adapter<StarCountAdapter.StarCountHolder> {
Context context;
LayoutInflater inflater;
List<StarCount> starCounts = new ArrayList<>();
public StarCountAdapter(Context context, List<StarCount> starCounts) {
this.context = context;
this.inflater = LayoutInflater.from(context);
this.starCounts = starCounts;
}
#Override
public StarCountHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = inflater.inflate(R.layout.star_count_row,parent,false);
return new StarCountHolder(view);
}
#Override
public void onBindViewHolder(StarCountHolder holder, int position) {
StarCount model = starCounts.get(position);
Picasso.with(context)
.load("http://"+model.getImagePath())
.into(holder.starImage);
holder.actorName.setText(model.getName());
holder.counts.setText(""+model.getCount());
}
#Override
public int getItemCount() {
return starCounts.size();
}
public class StarCountHolder extends RecyclerView.ViewHolder {
ImageView starImage;
TextView actorName,counts;
StarCount modelCount;
public StarCountHolder(View itemView) {
super(itemView);
starImage = (ImageView) itemView.findViewById(R.id.starCountIv);
actorName = (TextView) itemView.findViewById(R.id.acterName);
counts = (TextView) itemView.findViewById(R.id.counts);
}
}
}
help needed to solve this issue since i am struck up for more than a Day. Share thoughts to rectify my Error in the code and rectify my error.

public int selectedPosition = -1
public class StarCountHolder extends RecyclerView.ViewHolder {
ImageView starImage;
TextView actorName,counts;
StarCount modelCount;
public StarCountHolder(View itemView) {
super(itemView);
starImage = (ImageView) itemView.findViewById(R.id.starCountIv);
actorName = (TextView) itemView.findViewById(R.id.acterName);
counts = (TextView) itemView.findViewById(R.id.counts);
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
selectedPosition = getLayoutPosition());
notifyDatasetChanged();
}
});
}
}
Now you are done with the selected item position, change it in your binder
#Override
public void onBindViewHolder(StarCountHolder holder, int position) {
StarCount model = starCounts.get(position);
Picasso.with(context)
.load("http://"+model.getImagePath())
.into(holder.starImage);
holder.actorName.setText(model.getName());
holder.counts.setText(""+model.getCount());
if(selectedPosition == position){
// do whatever you want to do to make it selected.
}
}
Now to get the selected item in your activity, you can do something like this...
inside activity
StartCount startC = starCounts.get(adapter.selectedPosition);
hope it helps