java - How to implement RecyclerView with section header depending on category?

Question

I want to implement sections in my list. I have a list of tasks. List has a custom adapter which extends recyclerview swipe adapter as I have implemented swipe gesture to the recyclerview.

So now tasks list is shown together with completed and pending tasks. Each list item has a check box which shows task is completed or pending.

If check box is checked then task is completed and vise versa. Now I want to make two sections in this with header. One For completed tasks and another for pending tasks.

So completed tasks should be shown inside completed section and vise versa. Also if the task is unchecked i.e pending and if user checks the check box then the item should get removed from the pending section and should get added to the completed section and vise versa.

I checked with one library for sections.

https://github.com/afollestad/sectioned-recyclerview

But when I tried to implement the library I got the error that adapter can not extend two classes as I have extended recyclerview swipe library before.

Adapter :

    public class IAdapter extends RecyclerSwipeAdapter<IAdapter.ItemViewHolder> {

    public ArrayList<Task> items;
    Context conext;
    public int _mId;

    List<Task> itemsPendingRemoval = new ArrayList<>();

    public IAdapter(Context context, ArrayList<Task> item) {
        this.conext=context;
       this.items=item;
    }


    @Override
    public int getItemCount() {
        return items.size();

    }

    public static class ItemViewHolder extends RecyclerView.ViewHolder {
        Task task;
        CheckBox cb;
        SwipeLayout swipeLayout;
        TaskTableHelper taskTableHelper;
        ItemViewHolder(final View itemView) {
            super(itemView);

            taskTableHelper= new TaskTableHelper(itemView.getContext());
            swipeLayout = (SwipeLayout) itemView.findViewById(R.id.swipe);
            cb = (CheckBox) itemView.findViewById(R.id.checkbox);

        }
    }

    @Override
    public void onBindViewHolder(final ItemViewHolder itemViewHolder,final int i) {

        itemViewHolder.cb.setText(items.get(i).getTitle());

        itemViewHolder.task = items.get(i);

        int taskId = itemViewHolder.task.getId();

        itemViewHolder.task = itemViewHolder.taskTableHelper.getTask(taskId);

        int status = itemViewHolder.task.getStatus();

        if(status == 0)
        {
            itemViewHolder.cb.setTextColor(Color.WHITE);
        }

        else {

            itemViewHolder.cb.setChecked(true);

            itemViewHolder.cb.setTextColor(Color.parseColor("#B0BEC5"));

        }


       itemViewHolder.cb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {

                if (isChecked) {

                    itemViewHolder.cb.setTextColor(Color.parseColor("#B0BEC5"));

                    itemViewHolder.task.setStatus(1);

                    itemViewHolder.taskTableHelper.updateStatus(itemViewHolder.task);

                }
                else

                {

                    itemViewHolder.cb.setTextColor(Color.WHITE);

                    itemViewHolder.task.setStatus(0);

                    itemViewHolder.taskTableHelper.updateStatus(itemViewHolder.task);

                }

            }

        });



        final Task item = items.get(i);
        itemViewHolder.swipeLayout.addDrag(SwipeLayout.DragEdge.Right,itemViewHolder.swipeLayout.findViewById(R.id.bottom_wrapper_2));
        itemViewHolder.swipeLayout.setShowMode(SwipeLayout.ShowMode.LayDown);

        itemViewHolder.swipeLayout.setOnDoubleClickListener(new SwipeLayout.DoubleClickListener() {
            @Override
            public void onDoubleClick(SwipeLayout layout, boolean surface) {
                Toast.makeText(conext, "DoubleClick", Toast.LENGTH_SHORT).show();
            }
        });
        itemViewHolder.swipeLayout.findViewById(R.id.trash2).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                mItemManger.removeShownLayouts(itemViewHolder.swipeLayout);
                items.remove(i);
                notifyItemRemoved(i);
                notifyItemRangeChanged(i, items.size());
                mItemManger.closeAllItems();

                itemViewHolder.taskTableHelper.deleteTask(item);

                _mId = item.getAlertId();

                cancelNotification();

                Toast.makeText(view.getContext(), "Deleted " + itemViewHolder.cb.getText().toString() + "!", Toast.LENGTH_SHORT).show();
            }
        });

        itemViewHolder.swipeLayout.findViewById(R.id.done).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                itemViewHolder.task.setStatus(1);
                itemViewHolder.taskTableHelper.updateStatus(itemViewHolder.task);
                itemViewHolder.cb.setChecked(true);
                Toast.makeText(conext, "Task Completed.", Toast.LENGTH_SHORT).show();
            }
        });

        itemViewHolder.swipeLayout.getSurfaceView().setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                boolean mEditMode;

                int id = item.getId();
                int priority = item.getTaskPriority();
                String title = item.getTitle();
                String alertDate = item.getAlertDate();
                String alertTime = item.getAlertTime();
                String dueDate = item.getDueDate();
                String dueTime = item.getDueTime();
                _mId = item.getAlertId();

                int listId = item.getList();

                mEditMode = true;

                Intent i = new Intent(conext, AddTaskActivity.class);

                i.putExtra("taskId", id);
                i.putExtra("taskTitle", title);
                i.putExtra("taskPriority", priority);
                i.putExtra("taskAlertTime", alertTime);
                i.putExtra("taskAlertDate", alertDate);
                i.putExtra("taskDueDate", dueDate);
                i.putExtra("taskDueTime", dueTime);
                i.putExtra("taskListId", listId);
                i.putExtra("EditMode", mEditMode);
                i.putExtra("AlertId",_mId);

                conext.startActivity(i);

            }
        });


        mItemManger.bindView(itemViewHolder.itemView, i);

    }

    @Override
    public ItemViewHolder onCreateViewHolder(ViewGroup viewGroup,int position) {

            View itemView = LayoutInflater.
                    from(viewGroup.getContext()).
                    inflate(R.layout.card_layout, viewGroup, false);
            return new ItemViewHolder(itemView);

    }



        @Override
    public void onAttachedToRecyclerView(RecyclerView recyclerView) {
        super.onAttachedToRecyclerView(recyclerView);
    }


    public void remove(int position) {
       Task item = items.get(position);
        if (itemsPendingRemoval.contains(item)) {
            itemsPendingRemoval.remove(item);
        }
        if (items.contains(item)) {
            items.remove(position);
            notifyItemRemoved(position);
        }
    }

    public void cancelNotification()
    {
        AlarmManager alarmManager = (AlarmManager)conext.getSystemService(Context.ALARM_SERVICE);
        Intent intent = new Intent(conext, NotificationReceiver.class);
        PendingIntent pendingIntent = PendingIntent.getBroadcast(conext,_mId, intent, 0);
        alarmManager.cancel(pendingIntent);
    }
    @Override
    public int getSwipeLayoutResourceId(int position) {
        return R.id.swipe;
    }
}

EDIT:

onBindViewHolder method after extending sectionedRecyclerview adapter:

 @Override
public void onBindViewHolder(ItemViewHolder itemViewHolder, int section, int i, int absolutePosition) {

    itemViewHolder.cb.setText(items.get(i).getTitle());

    itemViewHolder.task = items.get(i);

    int taskId = itemViewHolder.task.getId();

    itemViewHolder.task = itemViewHolder.taskTableHelper.getTask(taskId);

    int status = itemViewHolder.task.getStatus();

    if(status == 0)
    {
        itemViewHolder.cb.setTextColor(Color.WHITE);
    }

    else {

        itemViewHolder.cb.setChecked(true);

        itemViewHolder.cb.setTextColor(Color.parseColor("#B0BEC5"));

    }


   itemViewHolder.cb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {

            if (isChecked) {

                itemViewHolder.cb.setTextColor(Color.parseColor("#B0BEC5"));

                itemViewHolder.task.setStatus(1);

                itemViewHolder.taskTableHelper.updateStatus(itemViewHolder.task);

            }
            else

            {

                itemViewHolder.cb.setTextColor(Color.WHITE);

                itemViewHolder.task.setStatus(0);

                itemViewHolder.taskTableHelper.updateStatus(itemViewHolder.task);

            }

        }

    });



    final Task item = items.get(i);
    itemViewHolder.swipeLayout.addDrag(SwipeLayout.DragEdge.Right,itemViewHolder.swipeLayout.findViewById(R.id.bottom_wrapper_2));
    itemViewHolder.swipeLayout.setShowMode(SwipeLayout.ShowMode.LayDown);

    itemViewHolder.swipeLayout.setOnDoubleClickListener(new SwipeLayout.DoubleClickListener() {
        @Override
        public void onDoubleClick(SwipeLayout layout, boolean surface) {
            Toast.makeText(conext, "DoubleClick", Toast.LENGTH_SHORT).show();
        }
    });
    itemViewHolder.swipeLayout.findViewById(R.id.trash2).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            mItemManger.removeShownLayouts(itemViewHolder.swipeLayout);
            items.remove(i);
            notifyItemRemoved(i);
            notifyItemRangeChanged(i, items.size());
            mItemManger.closeAllItems();

            itemViewHolder.taskTableHelper.deleteTask(item);

            _mId = item.getAlertId();

            cancelNotification();

            Toast.makeText(view.getContext(), "Deleted " + itemViewHolder.cb.getText().toString() + "!", Toast.LENGTH_SHORT).show();
        }
    });

    itemViewHolder.swipeLayout.findViewById(R.id.done).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            itemViewHolder.task.setStatus(1);
            itemViewHolder.taskTableHelper.updateStatus(itemViewHolder.task);
            itemViewHolder.cb.setChecked(true);
            Toast.makeText(conext, "Task Completed.", Toast.LENGTH_SHORT).show();
        }
    });

    itemViewHolder.swipeLayout.getSurfaceView().setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            boolean mEditMode;

            int id = item.getId();
            int priority = item.getTaskPriority();
            String title = item.getTitle();
            String alertDate = item.getAlertDate();
            String alertTime = item.getAlertTime();
            String dueDate = item.getDueDate();
            String dueTime = item.getDueTime();
            _mId = item.getAlertId();

            i

Answer 1

The most simple way to split your recycler view into sections is by using a layout with the header and the item already in place and then changing the visibility if the header is the same.

Layout:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/tvHeader"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="start"
        android:padding="16dp"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:textColor="@color/primary"
        android:textStyle="bold"
        tools:text="A" />

    <TextView
        android:id="@+id/tvName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/tvHeader"
        android:background="?android:attr/selectableItemBackground"
        android:padding="16dp"
        android:textAppearance="?android:attr/textAppearanceMedium"
        tools:text="Adam" />

</RelativeLayout>

Adapter (2018 Kotlin Edition):

class ContactAdapter @Inject constructor() : RecyclerView.Adapter<ContactAdapter.ViewHolder>() {

    var onItemClick: ((Contact) -> Unit)? = null
    var contacts = emptyList<Contact>()

    override fun getItemCount(): Int {
        return contacts.size
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        return ViewHolder(LayoutInflater.from(parent.context).inflate(R.layout.item_contact, parent, false))
    }

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        val name = contacts[position].name
        holder.header.text = name.substring(0, 1)
        holder.name.text = name

        // if not first item, check if item above has the same header
        if (position > 0 && contacts[position - 1].name.substring(0, 1) == name.substring(0, 1)) {
            holder.headerTextView.visibility = View.GONE
        } else {
            holder.headerTextView.visibility = View.VISIBLE
        }
    }

    inner class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        val headerTextView: TextView = itemView.tvHeader
        val nameTextView: TextView = itemView.tvName

        init {
            itemView.setOnClickListener {
                onItemClick?.invoke(contacts[adapterPosition])
            }
        }
    }
}

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Might be helpful as well: RecyclerView itemClickListener in Kotlin

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Old Java Adapter Version:

public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.DataViewHolder> {

    private List<Contact> mData;

    @Inject
    public RecyclerAdapter() {
        mData = new ArrayList<>();
    }

    public void setData(List<Contact> data) {
        mData = data;
    }

    public Contact getItem(int position){
        return mData.get(position);
    }

    @Override
    public DataViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_contact, parent, false);
        return new DataViewHolder(itemView);
    }

    @Override
    public void onBindViewHolder(final DataViewHolder holder, int position) {
        Contact contact = mData.get(position);
        holder.headerTextView.setText(contact.getName().substring(0, 1));
        holder.nameTextView.setText(contact.getName());

        // if not first item check if item above has the same header
        if (position > 0 && mData.get(position - 1).getName().substring(0, 1).equals(contact.getName().substring(0, 1))) {
            holder.headerTextView.setVisibility(View.GONE);
        } else {
            holder.headerTextView.setVisibility(View.VISIBLE);
        }
    }

    @Override
    public int getItemCount() {
        return mData.size();
    }

    public class DataViewHolder extends RecyclerView.ViewHolder {

        @BindView(R.id.text_header)
        TextView headerTextView;
        @BindView(R.id.text_name)
        TextView nameTextView;

        public DataViewHolder(View itemView) {
            super(itemView);
            ButterKnife.bind(this, itemView);
        }
    }
}