UkolListAdapter.java

package cz.grejtCZ.ukolnicek.android.headeredList;

import android.arch.paging.PagedListAdapter;
import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v4.content.ContextCompat;
import android.support.v7.util.DiffUtil;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CheckBox;
import android.widget.TextView;

import org.joda.time.LocalDate;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;

import cz.grejtCZ.ukolnicek.android.R;
import cz.grejtCZ.ukolnicek.android.activity.MainActivity;
import cz.grejtCZ.ukolnicek.android.sql.SQLUkol; //I had old system without database, so most database-based object are colled SQL-something


public class UkolListAdapter extends PagedListAdapter<UkolOrHeader, UkolListAdapter.Holder> {
    public static final int TYPE_HEADER = 1;
    public static final int TYPE_ITEM = 0;


    Context context;
    MainActivity.ClickCallback callback;

    public UkolListAdapter(Context context, MainActivity.ClickCallback callback) {
        super(DIFF_CALLBACK);
        this.context = context;
        this.callback = callback;
    }

    /**
     * Reutrns {@link #TYPE_HEADER} or {@link #TYPE_ITEM} whether item on given position  is {@link Header} or {@link UkolInList}
     * @param position position of the item in list
     * @return {@link #TYPE_HEADER} or {@link #TYPE_ITEM} whether item on given position  is {@link Header} or {@link UkolInList}
     */
    @Override
    public int getItemViewType(int position) {
        if (getItem(position) instanceof UkolInList)
            return TYPE_ITEM;
        return TYPE_HEADER;
    }

    @Override
    public Holder onCreateViewHolder(ViewGroup parent, int viewType) {
        LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        if (viewType == TYPE_ITEM)
        return new UkolHolder(layoutInflater.inflate(R.layout.ukol_list_item, parent, false), callback);
        else
            return new HeaderHolder(layoutInflater.inflate(R.layout.ukol_list_header,parent,false));
    }

    @Override
    public void onBindViewHolder(Holder holder, int position) {
        UkolOrHeader ukol = getItem(position);
        if (ukol != null) {
            holder.bindTo(ukol);
        } else {
            holder.clear();
        }
    }

    /**
     * Base Holder class
     */
    public static abstract class Holder extends RecyclerView.ViewHolder {
        public Holder(View itemView) {
            super(itemView);
        }

        /**
         * Binds the holder to the give {@link UkolOrHeader}
         * @param item item to bind to
         */
        public abstract void bindTo(UkolOrHeader item);

        /**
         * Unbinds the holder
         */
        public abstract void clear();
    }

    /**
     * Holder for Ukols
     */
    public static class UkolHolder extends Holder {
        public TextView textView;
        public CheckBox checkBox;
        public View view;
        public MainActivity.ClickCallback callBack;

        public UkolHolder(View itemView, MainActivity.ClickCallback callBack) {
            super(itemView);
            view = itemView;
            textView = itemView.findViewById(R.id.textView);
            checkBox = itemView.findViewById(R.id.checkBox);
            this.callBack = callBack;
        }

        public void bindTo(UkolOrHeader ukolInList) {
            if (!(ukolInList instanceof UkolInList))
                throw new IllegalArgumentException("This is holder for UkolInList a given argument is not UkolInList");

            final SQLUkol ukol = ((UkolInList) ukolInList).getUkol();
            checkBox.setChecked(ukol.isCompleted());
            checkBox.setVisibility(View.VISIBLE);
            textView.setText(ukol.getTitle());
            final long fid = ukol.getId();
            view.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    callBack.edit(fid);
                }
            });
            checkBox.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    //here is the "checked" state of Ukol updated and written to the Room database
                    ukol.setCompleted(checkBox.isChecked());
                    ukol.save();
                }
            });

        }

        public void clear() {
            textView.setText("");
            checkBox.setChecked(false);
            checkBox.setVisibility(View.INVISIBLE);
            view.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                }
            });
            //id se nemeni
        }
    }

    public static class HeaderHolder extends Holder {
        TextView textView;
        LocalDate date;

        private final DateTimeFormatter DTF = DateTimeFormat.forPattern("EEE dd. MMMM YYYY");


        public HeaderHolder(View itemView) {
            super(itemView);
            textView = itemView.findViewById(R.id.textView);
        }

        @Override
        public void bindTo(UkolOrHeader item) {
            if (!(item instanceof Header))
                throw new IllegalArgumentException("This is holder for Header a given argument is not Header");
            date = ((Header) item).getDate();

            Context context = textView.getContext();

            if (date == null) {
                textView.setText(R.string.no_date);
                textView.setTextColor(ContextCompat.getColor(context, R.color.colorAccent));
            } else {
                if (date.isBefore(LocalDate.now())) {
                    textView.setTextColor(ContextCompat.getColor(context, R.color.colorMinimal));
                } else {
                    textView.setTextColor(ContextCompat.getColor(context, R.color.colorAccent));
                }

                LocalDate now = LocalDate.now();

                if (date.isEqual(now.minusDays(1)))
                    textView.setText(R.string.yesterday);
                else if (date.isEqual(now))
                    textView.setText(R.string.today);
                else if (date.isEqual(now.plusDays(1)))
                    textView.setText(R.string.tommorow);
                else {
                    textView.setText(DTF.print(date));
                }
            }
        }

        @Override
        public void clear() {
            textView.setText("");
        }
    }

    /**
     * Calculates Differences between old and new items
     */
    public static final DiffUtil.ItemCallback<UkolOrHeader> DIFF_CALLBACK = new DiffUtil.ItemCallback<UkolOrHeader>() {
        @Override
        public boolean areItemsTheSame(@NonNull UkolOrHeader old, @NonNull UkolOrHeader young) {
            boolean oldUkol = old instanceof UkolInList;
            boolean youngUkol = young instanceof UkolInList;
            if (oldUkol != youngUkol)
                return false;
            if (!youngUkol) {
                return old.equals(young);
            }
            return ((UkolInList) old).getUkol().getId() == ((UkolInList) young).getUkol().getId();
        }

        @Override
        public boolean areContentsTheSame(@NonNull UkolOrHeader old, @NonNull UkolOrHeader young) {
            boolean oldUkol = old instanceof UkolInList;
            boolean youngUkol = young instanceof UkolInList;
            if (oldUkol != youngUkol)
                return false;
            if (!youngUkol) {
                return old.equals(young);
            }
            return ((UkolInList) old).getUkol().getTitle().equals(((UkolInList) young).getUkol().getTitle());
        }
    };

}