Android2D move, rotate with Matrix

What should we do to move or rotate shape on canvas?
We have Matrix.

Matrix represents position, rotation of Bitmap or other shapes.

After changing this Matrix, and redraw(invalidate())

This Matrix is 3 x 3.(Android Developers )

Sample

View

public class DrawBitmapView extends View
{
    private Paint paint;
     
    private Bitmap img;
     
    private Matrix matrix;
     
    public DrawBitmapView ( Context context )
    {
        super(context);
        paint = new Paint(Paint.ANTI_ALIAS_FLAG);
        img = BitmapFactory.decodeResource(context.getResources(), R.drawable.mikasa);
        matrix = new Matrix();
    }
 
    @Override
    protected void onDraw ( Canvas canvas )
    {
        canvas.drawColor(Color.BLACK);
        canvas.drawBitmap(img, matrix, paint);
    }
     
    public void translateB( float dx, float dy )
    {
        matrix.postTranslate(dx, dy);
        invalidate();
    }
     
    public void scaleB ( float sx, float sy )
    {
        matrix.postScale(sx, sy);
        invalidate();
    }
     
    public void rotateB ( float degrees )
    {
        matrix.postRotate(degrees);
        invalidate();
    }
     
    public void skewB ( float kx, float ky )
    {
        matrix.postSkew(kx, ky);
        invalidate();
    }
}

Activity

public class MainActivity extends Activity
{
    DrawBitmapView bView;
     
    @Override
    protected void onCreate ( Bundle savedInstanceState )
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
         
         
        bView = new DrawBitmapView(this);
        bView.setClickable(true);
        bView.setOnClickListener(new OnClickListener()
        {
             
            @Override
            public void onClick ( View v )
            {
                bView.translateB(30, 30);
            }
        });
         
        addContentView(bView, new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
    }
}

Add click event. When you click, move view.