Chapter 14, Problem 4FTE

Explanation of Solution

Given code:

public class MyPanel extends JPanel //Line 1

{

public MyPanel() //Line 2

{

//Constructor code...

}

public void paint(Graphics g) //Line 3

{

//paint method code...

}

}

Drawing on panels:

• User can draw on a panel by simply obtain a reference to the panels “Graphics” object and then draw using that object’s method.
  • So, the resulting graphics are drawn only on the panel.
• The “paintComponent” method helps for “JPanel”.
  • This method automatically called once the component requires to be redisplayed.
  • When this method called, this method takes the argument of “Graphics” object.
  • The header for this method’s is shown below:

    public void paintComponent(Graphics g)

• When user override above method, first user should call the superclass “paintComponent” method to confirm that the given component is correctly showed...