AddActivity.java

package com.example.kathrinegibson.watercare;

import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.app.Activity;
import android.support.design.widget.FloatingActionButton;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.AdapterView.OnItemSelectedListener;

import com.google.gson.Gson;

import static android.content.ContentValues.TAG;
import static com.example.kathrinegibson.watercare.MainActivity.editor_string;
import static com.example.kathrinegibson.watercare.MainActivity.userAddedPlants;


public class AddActivity extends Activity implements OnItemSelectedListener {
    PlantType newPlantType = PlantType.Default;
    String plantName = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_add);

        FloatingActionButton fab2 = findViewById(R.id.fab2);
        fab2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent returnIntent = new Intent();
                setResult(RESULT_CANCELED, returnIntent);
                finish();
            }
        });

        Button addButton = findViewById(R.id.add_plant_button);
      
        
        addButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                EditText userInput = findViewById(R.id.editText1);
                plantName = userInput.getText().toString();
                if(!plantName.isEmpty() && (newPlantType != PlantType.Default)){
                    Plant newPlant = new Plant(newPlantType);
                    newPlant.changePlantName(plantName);
                    userAddedPlants.add(newPlant);
                    IOUtility.SaveData(AddActivity.this, userAddedPlants);
                }
                setResult(RESULT_OK);
                finish();
            }
        });

        Spinner spinner = findViewById(R.id.spinner1);
        spinner.setOnItemSelectedListener(this);

        // Creating adapter for spinner
        ArrayAdapter<PlantType> dataAdapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, PlantType.values());

        // Drop down layout style - list view with radio button
        dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

        // attaching data adapter to spinner
        spinner.setAdapter(dataAdapter);
    }

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        newPlantType = PlantType.values()[position];
    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {

    }
}

IOUtility.java

package com.example.kathrinegibson.watercare;

import android.app.Activity;
import android.content.SharedPreferences;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;

import java.lang.reflect.Type;
import java.util.ArrayList;

import static android.content.Context.MODE_PRIVATE;
import static com.example.kathrinegibson.watercare.MainActivity.editor_string;
import static com.example.kathrinegibson.watercare.MainActivity.userAddedPlants;

public class IOUtility {

   static String KEY = "plant list";

    //load up list of plants when starting the app
   public static ArrayList<Plant> LoadData(Activity activity){
        ArrayList<Plant> plants = new ArrayList<Plant>();
        SharedPreferences sharedPreferences = activity.getSharedPreferences("shared preferences", MODE_PRIVATE);
        Gson gson = new Gson();
        String json = sharedPreferences.getString(KEY, null);
        Type type = new TypeToken<ArrayList<Plant>>() {}.getType();
        plants = gson.fromJson(json, type);

        if (plants == null){
            plants = new ArrayList<>();
        }
        
        return plants;
    }

    //update the list of plants when adding a plant
    public static void SaveData(Activity activity, ArrayList<Plant> plantList){
        SharedPreferences sharedPreferences = activity.getSharedPreferences("shared preferences", MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPreferences.edit();
        Gson gson = new Gson();
        String json = gson.toJson(plants);

        editor.putString(KEY, json);
        editor.apply();
    }
}

MainActivity.java

package com.example.kathrinegibson.watercare;

import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.design.widget.TabLayout;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.SimpleAdapter;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;

import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.List;

import static android.content.ContentValues.TAG;

public class MainActivity extends AppCompatActivity {
    static ArrayList<Plant> userAddedPlants;
    private LinearLayoutManager lLayout;
    private RecyclerViewAdapter rcAdapter;
    private RecyclerView rView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        userAddedPlants = loadData(this);
        
        setContentView(R.layout.activity_main);

        Toolbar toolbar = findViewById(R.id.toolbar);
        toolbar.setSubtitle("WaterCare");
        toolbar.inflateMenu(R.menu.menu_main);


        lLayout = new GridLayoutManager(MainActivity.this,2);

        rView= findViewById(R.id.recycler_view);
        rView.setLayoutManager(lLayout);
        rcAdapter = new RecyclerViewAdapter(MainActivity.this, userAddedPlants);
        rView.setAdapter(rcAdapter);

        FloatingActionButton fab = findViewById(R.id.fab);
        final Intent addPlantIntent = new Intent(this, AddActivity.class);
        
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
               startActivity(addPlantIntent);
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_help) {
            return true;
        }

        if (id == R.id.action_about) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

RecyclerViewAdapter.java

package com.example.kathrinegibson.watercare;

import android.app.Activity;
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.PopupMenu;
import android.widget.Toast;

import java.sql.SQLException;
import java.util.List;

public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewHolders> {

    private List<Plant> itemList;
    private Context context;

    public RecyclerViewAdapter(Context context, List<Plant> itemList) {
        this.itemList = itemList;
        this.context = context;
    }

    @Override
    public RecyclerViewHolders onCreateViewHolder(ViewGroup parent, int viewType) {

        View layoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.card_view, null);
        RecyclerViewHolders rcv = new RecyclerViewHolders(layoutView);
        return rcv;
    }

    @Override
    public void onBindViewHolder(final RecyclerViewHolders holder, final int position) {
        Activity myActivity = this;
        holder.plantName.setText(itemList.get(position).getName());
        holder.plantType.setText(itemList.get(position).getPlantType());
        holder.plantPhoto.setImageResource(itemList.get(position).getImagePath());
        holder.buttonViewOption.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                PopupMenu popup = new PopupMenu(context, holder.buttonViewOption);
                //inflating menu from xml resource
                popup.inflate(R.menu.plant_menu);
                //adding click listener
                popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
                    @Override
                    public boolean onMenuItemClick(MenuItem item) {
                        switch (item.getItemId()) {
                            case R.id.menu1:
                                Toast.makeText(context, "menu 1 clicked", Toast.LENGTH_SHORT).show();
                                break;
                            case R.id.menu2:
                                Toast.makeText(context, "menu 2 clicked", Toast.LENGTH_SHORT).show();
                                break;
                            case R.id.menu3:
                                Toast.makeText(context, "menu 3 clicked", Toast.LENGTH_SHORT).show();
                                break;
                            case R.id.menu4:
                                itemList.remove(position);
                                IOUtility.UpdateData((Activity) context, itemList);
                                //make a save function ->write to shared preferences, use the same key
                                notifyItemRemoved(position);
                                notifyItemRangeChanged(position,itemList.size());
                                Toast.makeText(context,"Removed : " + position, Toast.LENGTH_SHORT).show();
                                break;
                        }
                        return false;
                    }
                });
                //displaying the popup
                popup.show();
            }
        });
    }

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