Using two classes, you can create a graphical window and draw shapes and/or text in it.

The two classes are:

• JFrame
• JComponent

The JFrame class creates a window that 'frames' other items.

You can't draw or place text directly on a JFrame instance.

A JComponent is an item that can be added to a JFrame; i.e., inside the 'frame'.

A simple graphical program

• creates a JFrame specifying its size (width and height in pixels) and its location on the screen.
• make sure the program will terminate if the user closes the window.
• Create an element that is of a JComponent type and add it to the JFrame.
• make the JFrame visible.

But, there are some additional things going on.

• When the JFrame is first made visible it will automatically draw all its components (if any)
• If the JFrame is minimized and then restored or if part becomes obscured and then uncovered again, or if the user resizes the window, the JFrame will redraw its components.
• But... the JFrame redraws its components by having each component do the redrawing.
• The element of JComponent type should have a method

   public void paintComponent(Graphics g)   
         
  

  that draws the element in the JComponent using the graphics resource g.