HoleSurfaceView for make vignette effect

HoleSurfaceView.java

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.util.AttributeSet;
import android.view.SurfaceView;

public class HoleSurfaceView extends SurfaceView {
    private Paint backgroundPaint;
    private Paint holePaint;
    private Paint borderPaint;
    private int padding;

    public HoleView(Context context) {
        super(context);
        init();
    }

    public HoleView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public void init() {
        setWillNotDraw(false);
        Resources resources = getContext().getResources();
        padding = (int)resources.getDimension(R.dimen.photo_shadow_padding);

        backgroundPaint = new Paint();
        backgroundPaint.setColor(resources.getColor(R.color.photo_shadow_background));
        borderPaint = new Paint();
        borderPaint.setColor(resources.getColor(R.color.black));
        holePaint = new Paint();
        holePaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        int height = getHeight();
        int width = getWidth();

        int borderHeight = (height - width) / 2;

        canvas.drawPaint(backgroundPaint);
        canvas.drawCircle(width / 2, height / 2, (width - padding * 2) / 2, holePaint);
        canvas.drawRect(0, 0, width, borderHeight, borderPaint);
        canvas.drawRect(0, height - borderHeight, width, height, borderPaint);
    }

}