CrimeListFragment.java

package ru.orlovph.criminalintent2020;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import java.util.List;

public class CrimeListFragment extends Fragment {
    private static final String SAVED_SUBTITLE_VISIBLE = "subtitle";
    private RecyclerView crimeRecyclerView;
    private CrimeAdapter crimeAdapter;
    private boolean mSubtitleVisible;

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setHasOptionsMenu(true);
    }

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container
            , @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_crime_list, container, false);

        crimeRecyclerView = view.findViewById(R.id.crime_recycler_view);
        crimeRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));

        if (savedInstanceState !=null){
            mSubtitleVisible = savedInstanceState.getBoolean(SAVED_SUBTITLE_VISIBLE);
        }

        updateUI();
        return view;
    }

    @Override
    public void onResume() {
        super.onResume();
        updateUI();
    }

    @Override
    public void onSaveInstanceState(@NonNull Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putBoolean(SAVED_SUBTITLE_VISIBLE, mSubtitleVisible);
    }

    @Override
    public void onCreateOptionsMenu(@NonNull Menu menu, @NonNull MenuInflater inflater) {
        super.onCreateOptionsMenu(menu, inflater);
        inflater.inflate(R.menu.fragment_crime_list, menu);

        MenuItem subtitleItem = menu.findItem(R.id.show_subtitle);
        if (mSubtitleVisible){
            subtitleItem.setTitle(R.string.hide_subtitle);
        }else{
            subtitleItem.setTitle(R.string.show_subtitle);
        }
    }

    @Override
    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
        switch (item.getItemId()) {
            case R.id.new_crime:
                Crime crime = new Crime();
                CrimeLab.get(getActivity()).addCrime(crime);
                Intent intent = CrimePagerActivity
                        .newIntent(getActivity(), crime.getId());
                startActivity(intent);
                return true;
            case R.id.show_subtitle:
                mSubtitleVisible = !mSubtitleVisible;
                getActivity().invalidateOptionsMenu();
                updateSubtitle();
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }

    private void updateSubtitle() {
        CrimeLab crimeLab = CrimeLab.get(getActivity());
        int crimeCount = crimeLab.getCrimes().size();
        String subtitle = getString(R.string.subtitle_format, crimeCount);

        if (!mSubtitleVisible){
            subtitle=null;
        }

        AppCompatActivity activity = (AppCompatActivity) getActivity();
        activity.getSupportActionBar().setSubtitle(subtitle);
    }

    private void updateUI() {
        CrimeLab crimeLab = CrimeLab.get(getActivity());
        List<Crime> crimes = crimeLab.getCrimes();

        if (crimeAdapter == null) {
            crimeAdapter = new CrimeAdapter(crimes);
            crimeRecyclerView.setAdapter(crimeAdapter);
        } else {
            crimeAdapter.notifyDataSetChanged();
        }

        updateSubtitle();
    }

    // CRIME HOLDER
    private class CrimeHolder extends RecyclerView.ViewHolder
            implements View.OnClickListener {

        private TextView titleTextView;
        private TextView dateTextView;
        private ImageView solvedImage;

        private Crime mCrime;

        public CrimeHolder(LayoutInflater inflater, ViewGroup parent) {
            super(inflater.inflate(R.layout.list_item_crime, parent, false));
            itemView.setOnClickListener(this);

            titleTextView = itemView.findViewById(R.id.crime_title);
            dateTextView = itemView.findViewById(R.id.crime_date);
            solvedImage = itemView.findViewById(R.id.crime_solved);
        }

        public void bind(Crime bCrime) {

            mCrime = bCrime;
            titleTextView.setText(mCrime.getTitle());
            dateTextView.setText(mCrime.getDate().toString());
            solvedImage.setVisibility(bCrime.isSolved() ? View.VISIBLE : View.GONE);
        }

        @Override
        public void onClick(View v) {
            Intent intent = CrimePagerActivity.newIntent(getActivity(), mCrime.getId());
            startActivity(intent);
        }
    }

    // CRIME ADAPTER
    private class CrimeAdapter extends RecyclerView.Adapter<CrimeHolder> {
        private List<Crime> mCrimes;

        public CrimeAdapter(List<Crime> crimes) {
            mCrimes = crimes;
        }

        @NonNull
        @Override
        public CrimeHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
            LayoutInflater layoutInflater = LayoutInflater.from(getActivity());
            return new CrimeHolder(layoutInflater, parent);
        }

        @Override
        public void onBindViewHolder(@NonNull CrimeHolder holder, int position) {
            Crime crime = mCrimes.get(position);
            holder.bind(crime);
        }

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