WhiteboardView in Android

WhiteboardView in Android

public class WhiteboardView extends View {
    private Paint mPaint;
    private Path mPath;

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

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

    public WhiteboardView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    private void init() {
        mPaint = new Paint();
        mPaint.setColor(Color.WHITE);
        mPaint.setStrokeWidth(10);
        mPaint.setStyle(Paint.Style.STROKE);
        mPaint.setStrokeJoin(Paint.Join.ROUND);
        mPath = new Path();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        canvas.drawColor(Color.BLACK); // set the background color of the view
        canvas.drawPath(mPath, mPaint); // draw the path using the paint object
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        float x = event.getX();
        float y = event.getY();

        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                mPath.moveTo(x, y);
                return true;
            case MotionEvent.ACTION_MOVE:
                mPath.lineTo(x, y);
                break;
            case MotionEvent.ACTION_UP:
                // do nothing
                break;
            default:
                return false;
        }

        // invalidate the view to trigger a redraw
        invalidate();

        return true;
    }
}