MainActivity.java

package com.androidcookbook.fragmentsdemos;

import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;

/**
 * A simple Activity that contains a Fragment, created in its XML layout,
 * and has a MenuItem to start the Tasks List-Detail demo.
 */
public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
    }

    @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) {
        switch(item.getItemId()) {
            case R.id.action_tasks:
                startActivity(new Intent(this, TaskListActivity.class));
                return true;
            case R.id.action_settings:
                startActivity(new Intent(this, SettingsActivity.class));
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }
}