JFrame help

Below is the code to generate the random color,size and position of rectangles in a JFrame. my question is how can i make sure that the rectangle drawn is entirely
inside the JFrame? Asume the frame is 500x500


class DrawPanel extends JPanel {

public void paintComponent(Graphics g){

Graphics2D g2 = (Graphics2D) g;

int r = (int) (Math.random() * 250);
int gr = (int) (Math.random() * 250);
int b = (int) (Math.random() * 250);

g.setColor(new Color(r,gr,b));

int ht = (int) ((Math.random() * 120) + 10);
int width = (int) ((Math.random() * 120) + 10);
int x = (int) ((Math.random() * 40) + 10);
int y = (int) ((Math.random() * 40) + 10);

g.fillRect(x,y,ht,width);

There are a few ways of tackling this, a simple way is to generate the x and y points first and then generate the width and height with maximum values of the frame size minus the location ie max rect width = frame width - x and max rect height = frame height - y