title: calling a java method to draw graphics
body: <p>I'm trying out to draw some simple graphics to a frame. I would also like to be able to adjust what I'm drawing from my main method. For example, setting a String variable to be printed, or the coordinates of a rectangle. </p>
  
  <p>The problem I seem to be having is that the <code>paintComponent</code> method is called before I can set class variables. How would I change this code to be able to set up the <code>JPanel</code>/<code>JFrame</code> variables BEFORE it draws to screen?</p>
  
  <p>Thanks</p>
  
  <pre><code>import java.awt.*;
  import javax.swing.*;
  
  public class Test {
  
      public static void main(String[] args) {
          FrameTest test_frame = new FrameTest();
          test_frame.test_string = "I WANT TO DRAW THIS STRING";
      }
  }
  
  class FrameTest extends JFrame{
      private static final long serialVersionUID = 1L;
      String test_string;
  
      public FrameTest(){
          this.test_string = "TEMP STRING FROM FRAME";
          JFrame gui = new JFrame();
          gui.setTitle("Test Title");
          gui.setSize(400,400);
          gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  
          Painting painting = new Painting();
  
          Container pane = gui.getContentPane();
          pane.setLayout(new GridLayout(1,1));
  
          pane.add(painting);
          gui.setVisible(true);
  
      }
  }
  
  class Painting extends JPanel{
      private static final long serialVersionUID = 1L;
      String test_string;
  
      public Painting(){
          setBackground(Color.WHITE);
          this.test_string = "TEMP STRING FROM PANEL";
      }
  
      public void paintComponent(Graphics g) {
          super.paintComponent(g);
  
          g.setColor(Color.RED);
          g.drawString(test_string, 20, 20);
      }
  }
  </code></pre>