I want to create nested RecyclerViews and the problem is that only parent is showing.
Parent Adapter
public class SectionsAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
Context mContext;
List<Section> mSections;
public SectionsAdapter(Context context, List<Section> sections) {
mContext = context;
mSections = sections;
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.view_section, parent, false);
return new SectionViewHolder(view);
}
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int pos) {
Section section = mSections.get(pos);
if (holder instanceof SectionViewHolder) {
SectionViewHolder sectionVH = (SectionViewHolder) holder;
sectionVH.mTitle.setText(section.getTitle());
LinearLayoutManager manager = new LinearLayoutManager(mContext);
sectionVH.mPreferences.setLayoutManager(manager);
PreferencesAdapter preferencesAdapter = new PreferencesAdapter(mContext, section.getPreferences());
sectionVH.mPreferences.setAdapter(preferencesAdapter);
sectionVH.mPreferences.getAdapter().notifyDataSetChanged();
}
}
#Override
public int getItemViewType(int pos) {
return 0;
}
#Override
public int getItemCount() {
return mSections.size();
}
}
Child Adapter
public class PreferencesAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
public static final int VIEW_BOOLEAN = 0;
public static final int VIEW_INT = 1;
Context mContext;
List<Preference> mPreferences;
public PreferencesAdapter(Context context, List<Preference> preferences) {
mContext = context;
mPreferences = preferences;
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view;
switch (viewType) {
default:
view = LayoutInflater.from(parent.getContext()).inflate(R.layout.view_preference_boolean, parent, false);
return new BooleanPreferenceViewHolder(view);
}
}
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int pos) {
Preference preference = mPreferences.get(pos);
if (holder instanceof BooleanPreferenceViewHolder) {
BooleanPreferenceViewHolder booleanPreferenceVH = (BooleanPreferenceViewHolder) holder;
booleanPreferenceVH.mPreferenceTitle.setText(preference.getTitle());
booleanPreferenceVH.mPreferenceExplanation.setText(preference.getExplanation());
booleanPreferenceVH.mBooleanSwitch.setChecked((Boolean) preference.getValue());
}
}
#Override
public int getItemViewType(int pos) {
return VIEW_BOOLEAN;
}
#Override
public int getItemCount() {
return mPreferences.size();
}
}
Parent View Holder
public class SectionViewHolder extends RecyclerView.ViewHolder {
public TextView mTitle;
public RecyclerView mPreferences;
public SectionViewHolder(View v) {
super(v);
mTitle = (TextView) v.findViewById(R.id.sectionTitle);
mPreferences = (RecyclerView) v.findViewById(R.id.preferences);
}
}
Child View Holder
public class BooleanPreferenceViewHolder extends RecyclerView.ViewHolder {
public TextView mPreferenceTitle;
public TextView mPreferenceExplanation;
public Switch mBooleanSwitch;
public BooleanPreferenceViewHolder(View v) {
super(v);
mPreferenceTitle = (TextView) v.findViewById(R.id.preferenceTitle);
mBooleanSwitch = (Switch) v.findViewById(R.id.booleanSwitch);
mPreferenceExplanation = (TextView) v.findViewById(R.id.preferenceExplanation);
}
}
So I noticed that is showing only parent title and its recyclerview is empty. Also child onBindViewHolder method is not calling.
You can achieve what you want with only one RecyclerView, overriding the getItemViewType method properly. You can see an example here.
Below is an example using your Section, Preference and BooleanPreferenceViewHolder classes with the library SectionedRecyclerViewAdapter.
First create a section class:
class MySection extends StatelessSection {
String title;
List<Preference> mPreferences;
public MySection(String title, List<Preference> preferences) {
// call constructor with layout resources for this Section header, footer and items
super(R.layout.section_header, R.layout.section_footer, R.layout.section_item);
this.title = title;
this.mPreferences = preferences;
}
#Override
public int getContentItemsTotal() {
return mPreferences.size(); // number of items of this section
}
#Override
public RecyclerView.ViewHolder getItemViewHolder(View view) {
// return a custom instance of ViewHolder for the items of this section
return new BooleanPreferenceViewHolder(view);
}
#Override
public void onBindItemViewHolder(RecyclerView.ViewHolder holder, int position) {
BooleanPreferenceViewHolder itemHolder = (BooleanPreferenceViewHolder) holder;
// bind your view here
itemHolder.mPreferenceExplanation.setText(mPreference.get(position).getExplanation());
}
#Override
public RecyclerView.ViewHolder getHeaderViewHolder(View view) {
return new SimpleHeaderViewHolder(view);
}
#Override
public void onBindHeaderViewHolder(RecyclerView.ViewHolder holder) {
MyHeaderViewHolder headerHolder = (MyHeaderViewHolder) holder;
// bind your header view here
headerHolder.tvItem.setText(title);
}
}
Then you set up the RecyclerView with your Sections:
// Create an instance of SectionedRecyclerViewAdapter
SectionedRecyclerViewAdapter sectionAdapter = new SectionedRecyclerViewAdapter();
MySection section1 = new MySection(mSections.get(0).getTitle(), mSections.get(0).getPreferences());
MySection section2 = new MySection(mSections.get(1).getTitle(), mSections.get(1).getPreferences());
// Add your Sections
sectionAdapter.addSection(section1);
sectionAdapter.addSection(section2);
// Set up your RecyclerView with the SectionedRecyclerViewAdapter
RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerview);
recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
recyclerView.setAdapter(sectionAdapter);
Related
My Title is kind of hard to understand but basically when I add items into my database is should display it in a RecyclerView. Now in my RecyclerView I have two layouts but the problem is the first item of my database goes behind my first item in my other layout. So if I have 3 items in my database, it shows only 2 items from the database and the first item hides behind my first item in the RecyclerView which is a different layout that does not use the database at all.
This is my code:
FirebaseRecyclerOptions<Event> firebaseRecyclerOptions = new FirebaseRecyclerOptions.Builder<Event>()
.setQuery(query1, Event.class).build();
AccAdapter = new FirebaseRecyclerAdapter<Event, RecyclerView.ViewHolder>(firebaseRecyclerOptions){
final static int TYPE_HEADER = 0;
final static int TYPE_ITEM = 1;
#Override
public int getItemViewType(int position) {
if (position == 0) return TYPE_HEADER;
return TYPE_ITEM;
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (viewType == TYPE_HEADER){
View view = LayoutInflater.from(getActivity()).inflate(R.layout.recycler_view_row_add_items,
parent, false);
return new ProdudctHolder3(view);
} else {
View view = LayoutInflater.from(getActivity()).inflate(R.layout.recycler_view_row_acc,
parent, false);
return new ProductHolder2(view);
}
}
#Override
protected void onBindViewHolder(final RecyclerView.ViewHolder holder, int position, final Event model) {
if (holder instanceof ProdudctHolder3){
((ProdudctHolder3) holder).addBackground.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
startActivity(new Intent(getActivity(), AccAddItems.class ));
}
});
} else{
final ProductHolder2 productHolder2 = (ProductHolder2) holder;
productHolder2.mName.setText(model.getName());
productHolder2.view.setBackgroundResource(getBackgroundDrawable(Integer.valueOf(model.getProductAmount())));
productHolder2.mbackground.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
dialog = new Dialog(getActivity());
dialog.setContentView(R.layout.popup_edit_product);
SeekBar amountSeekBar = dialog.findViewById(R.id.amountSeekBar);
amountSeekBar.setMax(100);
amountSeekBar.setProgress(Integer.valueOf(model.getProductAmount()));
amountSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
#Override
public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
progress = i;
}
#Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
#Override
public void onStopTrackingTouch(SeekBar seekBar) {
getRef(holder.getAdapterPosition()).child("productAmount").setValue(String.valueOf(progress));
dialog.dismiss();
}
});
dialog.show();
}
});
productHolder2.mbackground.setOnLongClickListener(new View.OnLongClickListener() {
#Override
public boolean onLongClick(View view) {
final PopupMenu popupMenu = new PopupMenu(getActivity(), productHolder2.mbackground);
popupMenu.inflate(R.menu.menu_acc);
popupMenu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
#Override
public boolean onMenuItemClick(MenuItem menuItem) {
switch (menuItem.getItemId()){
case R.id.deleteProduct:
getRef(productHolder2.getAdapterPosition()).removeValue();
popupMenu.dismiss();
return true;
default:
return false;
}
}
});
popupMenu.show();
return true;
}
});
}
}
};
mAccRecyclerViewRef.setAdapter(AccAdapter);
My two Product Holders
private class ProdudctHolder3 extends RecyclerView.ViewHolder{
private RelativeLayout addBackground;
public ProdudctHolder3(View itemView) {
super(itemView);
addBackground = itemView.findViewById(R.id.mBackground2);
}
}
private class ProductHolder2 extends RecyclerView.ViewHolder{
private TextView mName;
private RelativeLayout mbackground;
private View view;
public ProductHolder2(View itemView) {
super(itemView);
mName = itemView.findViewById(R.id.ItemName);
mbackground = itemView.findViewById(R.id.mBackground1);
view = itemView.findViewById(R.id.amountIndicator);
}
}
The ideal solution would have been to set two adapters on a single RecyclerView but unfortunatelly this is not possible.
However, you can make a single custom Adapter that handles two types of items. I will explain this by getting an example.
Let's assume you need to display objects of two types, humans and aliens. Your objects require completely different layouts and completely different ViewHolders. Please see the below code for the ViewHolders:
public class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private static class HumanViewHolder extends RecyclerView.ViewHolder {
public HumanViewHolder(View itemView) {
super(itemView);
//Prepare your ViewHolder
}
public void bind(Human human) {
//Display your human object
}
}
private static class AlienViewHolder extends RecyclerView.ViewHolder {
public AlienViewHolder(View itemView) {
super(itemView);
//Prepare your ViewHolder
}
public void bind(Alien alien) {
//Display your alien object
}
}
}
First you need to add two different constants to your adapter representing both type of views:
private static final int ITEM_TYPE_HUMAN;
private static final int ITEM_TYPE_ALIEN;
To keep things simple, let's also assume you store your objects in a list:
private List<Object> items = new ArrayList<>();
public MyAdapter(List<Object> items) {
this.items.addAll(items);
//Other stuff if needed
}
Now, the first you need to do, is to implement getItemViewType() method:
#Override
public int getItemViewType(int position) {
if (items.get(position) instanceof Human) {
return ITEM_TYPE_HUMAN;
} else {
return ITEM_TYPE_ALIEN;
}
}
Second, you need to use the item type inside the onCreateViewHolder() method like this:
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
if (viewType == ITEM_TYPE_HUMAN) {
View view = layoutInflater.inflate(R.layout.item_human, parent, false);
return new HumanViewHolder(view);
} else {
View view = layoutInflater.inflate(R.layout.item_alien, parent, false);
return new AlienViewHolder(view);
}
}
In the end, you just need to bind the proper view holder like this:
#Override
public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int position) {
Object item = items.get(position);
if (viewHolder instanceof HumanViewHolder) {
((HumanViewHolder) viewHolder).bind((Human) item);
} else {
((AlienViewHolder) viewHolder).bind((Alien) item);
}
}
Why use the Firebase Recycler Adapter when you could easily make a custom one? If I understood well you want an item to be fixed at position 0 (header) while others will be added below the first one, right? If so, here is a solution I like to use:
public interface ViewType {
public int getViewType();
}
public interface ViewTypeDelegateAdapter {
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent);
public void onBindViewHolder(RecyclerView.ViewHolder holder, ViewType item);
}
public class ViewTypes {
public static int HEADER = 0
public static int ITEM = 1
}
public class ProductDelegateAdapter implements ViewTypeDelegateAdapter {
private int resID;
private Context context;
public ProductDelegateAdapter(int resID, Context context) {
this.resID = resID;
this.context = context;
}
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent) {
return new ProductHolder(LayoutInflater.from(parent.context).inflate(resID, parent, false));
}
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, ViewType item) {
(holder as ProductHolder).bind("test");
}
class ProductHolder extends RecyclerView.ViewHolder {
public ProductHolder(View view) {
super(view);
}
public void bind(String test) {
}
}
}
public class HeaderDelegateAdapter implements ViewTypeDelegateAdapter {
private int resID;
private Context context;
public ProductDelegateAdapter(int resID, Context context) {
this.resID = resID;
this.context = context;
}
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent) {
return new HeaderHolder(LayoutInflater.from(parent.context).inflate(resID, parent, false));
}
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, ViewType item) {
(holder as HeaderHolder).bind("test");
}
class HeaderHolder extends RecyclerView.ViewHolder {
public HeaderHolder(View view) {
super(view);
}
public void bind(String test) {
}
}
}
public class AccAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>() {
private Context context;
private List<ViewType> items;
private SparseArrayCompat<ViewTypeDelegateAdapter> delegateAdapters;
private ViewType headerItem;
public AccAdapter(Context context) {
this.context = context;
this.items = new ArrayList();
this.delegateAdapters = new SparseArrayCompat();
this.headerItem = new ViewType() {
#Override
public int getViewType() {
return ViewTypes.HEADER;
}
};
this.items.add(this.headerItem);
this.delegateAdapters.put(ViewTypes.HEADER, HeaderDelegateAdapter(R.id.test, this.context));
this.delegateAdapters.put(ViewTypes.ITEM, ProductDelegateAdapter(R.id.test, this.context));
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, Int viewType) {
return delegateAdapters.get(viewType).onCreateViewHolder(parent);
}
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, Int position) {
delegateAdapters.get(getItemViewType(position)).onBindViewHolder(holder, items[position])
}
#Override
public Int getItemViewType(Int position) {
return items.get(position).getViewType();
}
#Override
public Int getItemCount() {
return items.getSize();
}
public void add(ViewType viewType) {
val initPosition = this.items.size - 1
this.items.add(item)
notifyItemRangeChanged(initPosition, this.items.size + 1)
}
}
public class Event implements ViewType {
private String id;
#Override
public int getViewType() {
return ViewTypes.ITEM;
}
}
Excuse me for some syntax errors, I've translated to Java from Kotlin to help you. Hope it helps!
In my SectionsListAdapter adapter i have nested Adapter named MonthLessonsList, after get date from web service and set new data and call notifyDataSetChanged method for adapter, main adapter as SectionsListAdapter can be refresh, but nested adapter dont refresh and after calling notifyDataSetChanged for that, doesn't work correctly and don't show new data
call and set new data from Fragment:
monthSectionsItems = SQLite.select().from(MonthSections.class).queryList();
adapter.setData(monthSectionsItems);
and my Adapter with nested adapter:
public class SectionsListAdapter extends RecyclerView.Adapter<SectionsListAdapter.MyViewHolder> {
private final OnItemSelected listener;
private List<MonthSections> list;
private Context context;
private MonthLessonsList lessonsListAdapter;
public SectionsListAdapter(List<MonthSections> followingsList, Context mContext, OnItemSelected listener) {
this.list = followingsList;
this.context = mContext;
this.listener = listener;
}
#Override
public MyViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.sections_list_row, parent, false);
return new MyViewHolder(itemView);
}
#Override
public void onBindViewHolder(#NonNull final MyViewHolder holder, final int position) {
holder.indicatorIcon.setText(list.get(position).getSection_month_name());
...
List<SectionLesson> lessonsList = list.get(position).getLessons();
lessonsListAdapter = new MonthLessonsList(lessonsList);
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(context);
holder.userChildCategories.setLayoutManager(mLayoutManager);
holder.userChildCategories.setAdapter(lessonsListAdapter);
...
}
#Override
public int getItemCount() {
return list.size();
}
public void setData(List<MonthSections> data) {
list.clear();
list.addAll(data);
notifyDataSetChanged();
lessonsListAdapter.notifyDataSetChanged();
}
public List<MonthSections> getData() {
return list;
}
class MyViewHolder extends RecyclerView.ViewHolder {
...
public MyViewHolder(View view) {
super(view);
ButterKnife.bind(this, view);
section_title.setGravity(Gravity.RIGHT);
}
}
public class MonthLessonsList extends RecyclerView.Adapter<MonthLessonsList.LessonsViewHolder> {
private List<SectionLesson> lessonItem;
public class LessonsViewHolder extends RecyclerView.ViewHolder {
public TextView title;
public LessonsViewHolder(View view) {
super(view);
title = view.findViewById(R.id.title);
}
}
public MonthLessonsList(List<SectionLesson> lists) {
this.lessonItem = lists;
}
#Override
public LessonsViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.child_list_row, parent, false);
return new LessonsViewHolder(itemView);
}
#SuppressLint("SetTextI18n")
#Override
public void onBindViewHolder(#NonNull LessonsViewHolder holder, int position) {
SectionLesson lesson = lessonItem.get(position);
holder.title.setText("درس: " + (position + 1) + ") " + lesson.getTitle());
}
#Override
public int getItemCount() {
return lessonItem.size();
}
}
}
Declare child adapter inside onBindViewHolder, and remove from global level.
And no need to notify child adapter. Because that will be automatically filled when parent onBindViewHolder is called.
Like
MonthLessonsList lessonsListAdapter = new MonthLessonsList(lessonsList);
holder.userChildCategories.setAdapter(lessonsListAdapter);
My Title is kind of hard to understand but basically when I add items into my database is should display it in a RecyclerView. Now in my RecyclerView I have two layouts but the problem is the first item of my database goes behind my first item in my other layout. So if I have 3 items in my database, it shows only 2 items from the database and the first item hides behind my first item in the RecyclerView which is a different layout that does not use the database at all.
This is my code:
FirebaseRecyclerOptions<Event> firebaseRecyclerOptions = new FirebaseRecyclerOptions.Builder<Event>()
.setQuery(query1, Event.class).build();
AccAdapter = new FirebaseRecyclerAdapter<Event, RecyclerView.ViewHolder>(firebaseRecyclerOptions){
final static int TYPE_HEADER = 0;
final static int TYPE_ITEM = 1;
#Override
public int getItemViewType(int position) {
if (position == 0) return TYPE_HEADER;
return TYPE_ITEM;
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (viewType == TYPE_HEADER){
View view = LayoutInflater.from(getActivity()).inflate(R.layout.recycler_view_row_add_items,
parent, false);
return new ProdudctHolder3(view);
} else {
View view = LayoutInflater.from(getActivity()).inflate(R.layout.recycler_view_row_acc,
parent, false);
return new ProductHolder2(view);
}
}
#Override
protected void onBindViewHolder(final RecyclerView.ViewHolder holder, int position, final Event model) {
if (holder instanceof ProdudctHolder3){
((ProdudctHolder3) holder).addBackground.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
startActivity(new Intent(getActivity(), AccAddItems.class ));
}
});
} else{
final ProductHolder2 productHolder2 = (ProductHolder2) holder;
productHolder2.mName.setText(model.getName());
productHolder2.view.setBackgroundResource(getBackgroundDrawable(Integer.valueOf(model.getProductAmount())));
productHolder2.mbackground.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
dialog = new Dialog(getActivity());
dialog.setContentView(R.layout.popup_edit_product);
SeekBar amountSeekBar = dialog.findViewById(R.id.amountSeekBar);
amountSeekBar.setMax(100);
amountSeekBar.setProgress(Integer.valueOf(model.getProductAmount()));
amountSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
#Override
public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
progress = i;
}
#Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
#Override
public void onStopTrackingTouch(SeekBar seekBar) {
getRef(holder.getAdapterPosition()).child("productAmount").setValue(String.valueOf(progress));
dialog.dismiss();
}
});
dialog.show();
}
});
productHolder2.mbackground.setOnLongClickListener(new View.OnLongClickListener() {
#Override
public boolean onLongClick(View view) {
final PopupMenu popupMenu = new PopupMenu(getActivity(), productHolder2.mbackground);
popupMenu.inflate(R.menu.menu_acc);
popupMenu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
#Override
public boolean onMenuItemClick(MenuItem menuItem) {
switch (menuItem.getItemId()){
case R.id.deleteProduct:
getRef(productHolder2.getAdapterPosition()).removeValue();
popupMenu.dismiss();
return true;
default:
return false;
}
}
});
popupMenu.show();
return true;
}
});
}
}
};
mAccRecyclerViewRef.setAdapter(AccAdapter);
My two Product Holders
private class ProdudctHolder3 extends RecyclerView.ViewHolder{
private RelativeLayout addBackground;
public ProdudctHolder3(View itemView) {
super(itemView);
addBackground = itemView.findViewById(R.id.mBackground2);
}
}
private class ProductHolder2 extends RecyclerView.ViewHolder{
private TextView mName;
private RelativeLayout mbackground;
private View view;
public ProductHolder2(View itemView) {
super(itemView);
mName = itemView.findViewById(R.id.ItemName);
mbackground = itemView.findViewById(R.id.mBackground1);
view = itemView.findViewById(R.id.amountIndicator);
}
}
The ideal solution would have been to set two adapters on a single RecyclerView but unfortunatelly this is not possible.
However, you can make a single custom Adapter that handles two types of items. I will explain this by getting an example.
Let's assume you need to display objects of two types, humans and aliens. Your objects require completely different layouts and completely different ViewHolders. Please see the below code for the ViewHolders:
public class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private static class HumanViewHolder extends RecyclerView.ViewHolder {
public HumanViewHolder(View itemView) {
super(itemView);
//Prepare your ViewHolder
}
public void bind(Human human) {
//Display your human object
}
}
private static class AlienViewHolder extends RecyclerView.ViewHolder {
public AlienViewHolder(View itemView) {
super(itemView);
//Prepare your ViewHolder
}
public void bind(Alien alien) {
//Display your alien object
}
}
}
First you need to add two different constants to your adapter representing both type of views:
private static final int ITEM_TYPE_HUMAN;
private static final int ITEM_TYPE_ALIEN;
To keep things simple, let's also assume you store your objects in a list:
private List<Object> items = new ArrayList<>();
public MyAdapter(List<Object> items) {
this.items.addAll(items);
//Other stuff if needed
}
Now, the first you need to do, is to implement getItemViewType() method:
#Override
public int getItemViewType(int position) {
if (items.get(position) instanceof Human) {
return ITEM_TYPE_HUMAN;
} else {
return ITEM_TYPE_ALIEN;
}
}
Second, you need to use the item type inside the onCreateViewHolder() method like this:
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
if (viewType == ITEM_TYPE_HUMAN) {
View view = layoutInflater.inflate(R.layout.item_human, parent, false);
return new HumanViewHolder(view);
} else {
View view = layoutInflater.inflate(R.layout.item_alien, parent, false);
return new AlienViewHolder(view);
}
}
In the end, you just need to bind the proper view holder like this:
#Override
public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int position) {
Object item = items.get(position);
if (viewHolder instanceof HumanViewHolder) {
((HumanViewHolder) viewHolder).bind((Human) item);
} else {
((AlienViewHolder) viewHolder).bind((Alien) item);
}
}
Why use the Firebase Recycler Adapter when you could easily make a custom one? If I understood well you want an item to be fixed at position 0 (header) while others will be added below the first one, right? If so, here is a solution I like to use:
public interface ViewType {
public int getViewType();
}
public interface ViewTypeDelegateAdapter {
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent);
public void onBindViewHolder(RecyclerView.ViewHolder holder, ViewType item);
}
public class ViewTypes {
public static int HEADER = 0
public static int ITEM = 1
}
public class ProductDelegateAdapter implements ViewTypeDelegateAdapter {
private int resID;
private Context context;
public ProductDelegateAdapter(int resID, Context context) {
this.resID = resID;
this.context = context;
}
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent) {
return new ProductHolder(LayoutInflater.from(parent.context).inflate(resID, parent, false));
}
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, ViewType item) {
(holder as ProductHolder).bind("test");
}
class ProductHolder extends RecyclerView.ViewHolder {
public ProductHolder(View view) {
super(view);
}
public void bind(String test) {
}
}
}
public class HeaderDelegateAdapter implements ViewTypeDelegateAdapter {
private int resID;
private Context context;
public ProductDelegateAdapter(int resID, Context context) {
this.resID = resID;
this.context = context;
}
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent) {
return new HeaderHolder(LayoutInflater.from(parent.context).inflate(resID, parent, false));
}
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, ViewType item) {
(holder as HeaderHolder).bind("test");
}
class HeaderHolder extends RecyclerView.ViewHolder {
public HeaderHolder(View view) {
super(view);
}
public void bind(String test) {
}
}
}
public class AccAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>() {
private Context context;
private List<ViewType> items;
private SparseArrayCompat<ViewTypeDelegateAdapter> delegateAdapters;
private ViewType headerItem;
public AccAdapter(Context context) {
this.context = context;
this.items = new ArrayList();
this.delegateAdapters = new SparseArrayCompat();
this.headerItem = new ViewType() {
#Override
public int getViewType() {
return ViewTypes.HEADER;
}
};
this.items.add(this.headerItem);
this.delegateAdapters.put(ViewTypes.HEADER, HeaderDelegateAdapter(R.id.test, this.context));
this.delegateAdapters.put(ViewTypes.ITEM, ProductDelegateAdapter(R.id.test, this.context));
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, Int viewType) {
return delegateAdapters.get(viewType).onCreateViewHolder(parent);
}
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, Int position) {
delegateAdapters.get(getItemViewType(position)).onBindViewHolder(holder, items[position])
}
#Override
public Int getItemViewType(Int position) {
return items.get(position).getViewType();
}
#Override
public Int getItemCount() {
return items.getSize();
}
public void add(ViewType viewType) {
val initPosition = this.items.size - 1
this.items.add(item)
notifyItemRangeChanged(initPosition, this.items.size + 1)
}
}
public class Event implements ViewType {
private String id;
#Override
public int getViewType() {
return ViewTypes.ITEM;
}
}
Excuse me for some syntax errors, I've translated to Java from Kotlin to help you. Hope it helps!
I have a recyclerview . I click on a item. It is highlighted ( sets background - color) . And then, I click another item , It doesn't remove old highlighted view. My class is very leak . Also could you give me an advice to make more effective ?
public class DrawerMenuShelfListAdapter extends RecyclerView.Adapter<DrawerMenuShelfListAdapter.ViewHolder> implements View.OnClickListener {
private int selectedRow = 0;
public Fragment fragment;
public ViewHolder holder;
public RecyclerView recyclerView;
private ArrayList<ShelfModel> shelfList;
public DrawerMenuShelfListAdapter(Fragment fragment, ArrayList<ShelfModel> shelfList, RecyclerView recyclerView) {
this.shelfList = shelfList;
this.fragment = fragment;
this.recyclerView = recyclerView;
}
public void setItemSelected(int position){
recyclerView.getChildAt(selectedRow).setBackgroundColor(fragment.getActivity().getResources().getColor(android.R.color.transparent));
notifyItemChanged(selectedRow);
selectedRow = position;
recyclerView.getChildAt(selectedRow).setBackgroundColor(fragment.getActivity().getResources().getColor(android.R.color.black));
notifyItemChanged(selectedRow);
}
public void updateList(ArrayList<ShelfModel> list){
shelfList.clear();
shelfList.addAll(list);
notifyDataSetChanged();
notifyItemChanged(selectedRow);
}
#Override
public DrawerMenuShelfListAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v= LayoutInflater.from(parent.getContext())
.inflate(R.layout.navigation_drawer_list_row, parent, false);
holder = new ViewHolder(v);
holder.text = (TextView) v.findViewById(R.id.definitionText);
holder.total = (TextView) v.findViewById(R.id.countText);
holder.editButton = (ImageButton)v.findViewById(R.id.editButton);
holder.text.setTypeface(App.MUSEO_100);
holder.total.setTypeface(App.MUSEO_300);
return holder;
}
#Override
public void onBindViewHolder(ViewHolder holder, final int position) {
final ShelfModel shelfModel = shelfList.get(position);
holder.text.setText(shelfModel.getName());
holder.total.setText(String.valueOf(shelfModel.getTotal()));
holder.shelfId = shelfModel.getShelfId();
holder.itemView.setOnClickListener(this);
}
#Override
public int getItemCount() {
return shelfList.size();
}
#Override
public void onClick(View v) {
int position = recyclerView.getChildLayoutPosition(v);
((DrawerMenuShelfListListener)fragment).onShelfItemClick(shelfList.get(position));
setItemSelected(position);
}
public interface DrawerMenuShelfListListener extends BaseRecyclerViewListener {
void onShelfItemClick(ShelfModel shelfModel);
}
public static class ViewHolder extends RecyclerView.ViewHolder {
public TextView text;
public TextView total;
public ImageView editButton;
public int shelfId;
public ViewHolder(View view) {
super(view);
}
}
}
Ok. I found the solution.If I don't call notifyItemChanged , it works
I have some items in my adapter but nothing is shown in the RecyclerView.
Adapter
public class WorkOrderAdapter extends RecyclerView.Adapter<WorkOrderViewHolder> {
private List<WorkOrder> orders = new LinkedList<>();
public void setData(List<WorkOrder> orders) {
this.orders = orders;
}
#Override
public WorkOrderViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_workorder, parent, false);
return new WorkOrderViewHolder(view);
}
#Override
public void onBindViewHolder(WorkOrderViewHolder holder, int position) {
WorkOrder order = orders.get(position);
holder.bind(order);
}
#Override
public int getItemCount() {
return orders.size();
}
}
ViewHolder
public class WorkOrderViewHolder extends RecyclerView.ViewHolder {
private TextView title;
private TextView description;
private TextView date;
public WorkOrderViewHolder(View view) {
super(view);
title = (TextView) view.findViewById(R.id.title_textview);
description = (TextView) view.findViewById(R.id.description_textview);
date = (TextView) view.findViewById(R.id.date_textview);
}
public void bind(WorkOrder order) {
title.setText("Test");
description.setText("Test");
date.setText("Test");
}
}
Activity (Using AndroidAnnotations)
#EActivity(R.layout.activity_workorders)
#OptionsMenu(R.menu.activity_workorders)
public class WorkOrdersActivity extends ToolbarActivity {
#ViewById(R.id.orders_recyclerview)
RecyclerView ordersList;
List<WorkOrder> orders = new LinkedList<>();
private WorkOrderAdapter adapter;
{
adapter = new WorkOrderAdapter();
orders.add(new WorkOrder());
orders.add(new WorkOrder());
orders.add(new WorkOrder());
adapter.setData(orders);
}
#AfterViews
public void initViews() {
ordersList.setAdapter(adapter);
}
}
Please add the LayoutManager to the RecyclerView and try again
ordersList.setLayoutManager(new LinearLayoutManager(this));
ordersList.setAdapter(adapter);