// BirdsArrayList Example
// Source Code File: MainActivity.java

package it372.sjost.testserialization;
import android.content.Intent;
import android.os.Bundle;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.Spinner;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.view.ViewCompat;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {

    // Declare instance variables.
    ArrayList<String> birds;
    Spinner spn1;
    Button btn1, btn2;

    // onCreate fires when app is first created, or
    // recreated after being destroyed when app is rotated.
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // Set activity_main.xml as startup activity.
        setContentView(R.layout.activity_main);

        // Create objects for Spinner and button widgets.
        spn1 = findViewById(R.id.spinner);
        btn1 = findViewById(R.id.button);
        btn2 = findViewById(R.id.button2);

        // If bundle is not null, restore arraylist from
        // bundle. Otherwise instantiate empty arraylist.
        if (savedInstanceState != null) {
            birds = (ArrayList<String>)
                savedInstanceState.getSerializable("arrlist");
        }
        else {
            birds = new ArrayList<String>( );
        }

        // OnClickListener for button1 adds selected item
        // in spinner to arraylist.
        btn1.setOnClickListener( v -> {
            birds.add(spn1.getSelectedItem( ).toString( ));
        });

        // OnClickListener for button2
        // (a) creates a new intent,
        // (b) places the birds arraylist in a bundle,
        // (c) places the bundle in the intent,
        // (c) starts the new activity passing it the intent.
        btn2.setOnClickListener( v -> {
            Intent intent = new Intent(this,
                    ShowBirdsActivity.class);
            Bundle bundle = new Bundle( );
            bundle.putSerializable("arrlist", birds);
            intent.putExtras(bundle);
            startActivity(intent);
        });
    }

    // Immediately before app is destroyed because emulator
    // is rotated, save the arraylist in a bundle.
    public void onSaveInstanceState(Bundle savedInstanceState) {
        super.onSaveInstanceState(savedInstanceState);
        savedInstanceState.putSerializable("arrlist", birds);
    }
}