SettingsActivity.java

package com.Go.GoCart;

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;

import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.View;


public class SettingsActivity extends AppCompatActivity {

    private Toolbar toolbar;

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

        toolbar = findViewById(R.id.toolbar_settings);
        setSupportActionBar(toolbar);

        if (findViewById(R.id.fragment_container) != null) {
            if (savedInstanceState != null) {
                return;
            }
            getFragmentManager().beginTransaction().add(R.id.fragment_container, new SettingsFragment()).commit();
        }
        toolbar.setNavigationOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Log.d("pressed", "pressed");
                Intent intent = new Intent(SettingsActivity.this, MainActivity.class);
                startActivity(intent);
            }
        });
    }

    @Override
    public void onBackPressed() {
        startActivity(new Intent(SettingsActivity.this, MainActivity.class));
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        super.onCreateOptionsMenu(menu);
        getMenuInflater().inflate(R.menu.settings_menu, menu);
        return true;
    }

    public void savePrefs() {
        SharedPreferences sharedPreferences = getSharedPreferences("Shared_Preferences", MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPreferences.edit();
    }
}