MainActivity for initial setup

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

  //one lonely little button will do the job!
    <Button
        android:id="@+id/start_cam"
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:layout_margin="16dp"
        android:text="Start Camera"
        />

</RelativeLayout>

MainActivity.java

// change this to your own package:
package com.example.android.myapplication;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

    Button startCam;
    
    // Load library initially
    static {
        System.loadLibrary("native");
    }

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

        startCam = (Button) findViewById(R.id.start_cam);

        startCam.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // do stuff here
            }
        });
    }
}