Coding the LiveDrawingActivity class

Let's get started with coding the Activity-based class. We called this class LiveDrawingActivity, and it was auto-generated for us when we created the project.

Add the first part of the code for the LiveDrawingActivity class:

import android.app.Activity;
import android.graphics.Point;
import android.os.Bundle;
import android.view.Display;

public class LiveDrawingActivity extends Activity {

    private LiveDrawingView mLiveDrawingView;

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

        Display display = getWindowManager().getDefaultDisplay();
        Point size = new Point();
        display.getSize(size);

        mLiveDrawingView = new LiveDrawingView(
        this, size.x, size.y);
        setContentView(mLiveDrawingView);
    }

}

The preceding code shows a number of errors, and we will talk about them shortly.

The code gets the number of pixels (wide and high) for the device...