mini-cards/app/src/main/java/com/codigoparallevar/minicards/MainActivity.java

package com.codigoparallevar.minicards;

import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;

public class MainActivity extends AppCompatActivity {

    CanvasView canvasView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Hide action bar
        ActionBar actionBar = getSupportActionBar();
        if (actionBar != null) {
            actionBar.hide();
        }

        // Use controled canvas
        setContentView(R.layout.activity_main);

        canvasView = (CanvasView) findViewById(R.id.canvasView);
        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });

    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (canvasView != null){
            return canvasView.onTouchEvent(event);
        }

        Log.e("MainActivity", "CanvasView is null");

        return super.onTouchEvent(event);
    }
}