Help with paintComponent!

[joeyea]

Hiya,

I've got a rather large program, a catalogue system. It all works fine, except I have a frame that shows a list of order states. ANyway i want to display graphics on that frame for loading, but I cannot seem to get any of it working. I've used graphics on classes on there own so I understand how the graphics work, but for some reason I cannot get it working in this frame. I have a panel created called paintPanel so far. Anyway pointers on how to draw inside this panel would be greatly appreciated

Here are my class codes
Class DisplayGUI

package Clients;

import java.awt.*;
import java.util.List;
import java.util.Map;
import java.util.Collection;
import javax.swing.*;
import Middle.*;
import java.util.Set;
import java.util.HashMap;




class DisplayGUI extends JFrame
{
  private enum State { process, checked }
  private static final int H = 600;       // Height of window pixels
  private static final int W = 600;       // Width  of window pixels
  private OrderProcessing theOrder     = null;
 
  private JLabel      waiting  = new JLabel();
  private JLabel   beingProcessed  = new JLabel();
  private JLabel     waitingForCollection  = new JLabel();
  private JTextArea   theWaiting  = new JTextArea();
  private JTextArea  theBeingProcessed  = new JTextArea();
  private JTextArea   theWaitingForCollection  = new JTextArea();
  private JPanel    paintPanel = new JPanel();
  

  
  public DisplayGUI(  RootPaneContainer rpc, MiddleFactory mf  )
  {
 try                                           //
    {     
      theOrder = mf.makeOrderProcessing();        // Process order
    } catch ( Exception e )
    {
      System.out.println("Exception: " + e.getMessage() );
    }

    Container cp         = rpc.getContentPane();    // Content Pane
    Container rootWindow = (Container) rpc;         // Root Window
    cp.setLayout(null);                             // No layout manager
    rootWindow.setSize( W, H );                     // Size of Window
 
    Font f = new Font("Monospaced",Font.PLAIN,12);  // Font f is

    waiting.setBounds( 12, 35 , 170, 20 );       // Message area
    waiting.setText( "Waiting" );                      
    cp.add(BorderLayout.EAST, waiting );
    
    theWaiting.setBounds( 10, 65 , 170, 150 );       // Message area
    cp.add(BorderLayout.EAST, theWaiting );                            //  Add to canvas
    
    beingProcessed.setBounds( 202, 35 , 170, 20 );       // Message area
    beingProcessed.setText( "Being Processed" );                      
    cp.add(beingProcessed );
    
    paintPanel.setBounds( 10, 240 , 170, 150 );       // Message area         #
    paintPanel.setBackground(Color.white);
    cp.add(paintPanel );
    
    
    theBeingProcessed.setBounds( 200, 65 , 170, 150 );       // Message area                    
    cp.add( theBeingProcessed );                            //  Add to canvas
    
    waitingForCollection.setBounds( 392, 35 , 170, 20 );       // Message area
    waitingForCollection.setText( "Waiting For Collection" );                      
    cp.add(waitingForCollection );
    
    
    theWaitingForCollection.setBounds( 390, 65 , 170, 150 );       // Message area                      
    cp.add( theWaitingForCollection );                            //  Add to canvas
    
 
    
      rootWindow.setVisible( true );                  // Make visible
      
      backgroundDisplay bd = new backgroundDisplay();
      bd.start();
      
      
    

} 




class backgroundDisplay extends Thread {

 public void run() {
      
      while ( true )
      {
        try
        {
         Processing.Order order = new Processing.Order();
       
          Map res = theOrder.getOrderState();
          System.out.println(res);
          
        {
            StringBuffer sb =   new StringBuffer();
                 
                Object waitingList = res.get("Waiting");
                String waitingListString = waitingList.toString();
                int n = waitingListString.length();
                for(int i=0; i < n; i++)
                {
                    if(!((waitingListString.charAt(i) == '[')||(waitingListString.charAt(i) == ']')))
                    {
                        sb.append(waitingListString.charAt(i));
                    }
                    else
                    {
                        
                    }
                }
                String finalWaiting = sb.toString();
                theWaiting.setText( finalWaiting );  
                
                StringBuffer sc =   new StringBuffer();
                
                Object beingPickedList = res.get("BeingPicked");
                String beingPickedString = beingPickedList.toString();
                   int a = waitingListString.length();
                for(int i=0; i < a; i++)
                {
                    if(!((beingPickedString.charAt(i) == '[')||(beingPickedString.charAt(i) == ']')))
                    {
                        sc.append(beingPickedString.charAt(i));
                    }
                    else
                    {
                        
                    }
                }
                String finalProcessed = sc.toString();
                theBeingProcessed.setText( finalProcessed );  
                
                Object toBeCollectedList = res.get("ToBeCollected");
                String beingCollectedString = toBeCollectedList.toString();
                theWaitingForCollection.setText( beingCollectedString );   
           
            }
          sleep(5000);                             // delay
        } catch ( Exception err )
        {
        }
      }
    }
   

        
    }
        }

Class DisplayCLient

package Clients;

import javax.swing.*;
import java.awt.*;
import Middle.*;

/**
 * The Display Client.
 * @author  Michael Alexander Smith
 * @version 2.0
 */


public class DisplayClient
{
   public static void main (String args[])
   {
     String stockURL = args.length < 1     // URL of stock RW
                     ? Names.STOCK_RW      //  default  location
                     : args[0];            //  supplied location
     String orderURL = args.length < 2     // URL of order
                     ? Names.ORDER         //  default  location
                     : args[1];            //  supplied location
     
    RemoteMiddleFactory mrf = new RemoteMiddleFactory();
    mrf.setStockRWInfo( stockURL );
    mrf.setOrderInfo  ( orderURL );        //
    displayGUI(mrf);                       // Create GUI
  }
  
  public static void displayGUI(MiddleFactory mf)
  {     
    JFrame  window = new JFrame();
     
    window.setTitle( "Display Client (RMI)");
    window.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
    new DisplayGUI( window, mf );
  }

}

Thanks

[Fubarable]

You state you need help with paintComponent, yet you're not showing your paintComponent code, and that confuses me. Shouldn't your paintPanel override this method?

[joeyea]

I have this :

public void paintComponent(Graphics paintFrame) {
int width = getWidth();
int height = getHeight();
paintFrame.setColor(Color.black);
paintFrame.drawOval(0, 0, width, height);
}

which I have placed :

package Clients;

import java.awt.*;
import java.util.List;
import java.util.Map;
import java.util.Collection;
import javax.swing.*;
import Middle.*;
import java.util.Set;
import java.util.HashMap;




class DisplayGUI extends JFrame
{
  private enum State { process, checked }
  private static final int H = 600;       // Height of window pixels
  private static final int W = 600;       // Width  of window pixels
  private OrderProcessing theOrder     = null;
 
  private JLabel      waiting  = new JLabel();
  private JLabel   beingProcessed  = new JLabel();
  private JLabel     waitingForCollection  = new JLabel();
  private JTextArea   theWaiting  = new JTextArea();
  private JTextArea  theBeingProcessed  = new JTextArea();
  private JTextArea   theWaitingForCollection  = new JTextArea();
  private JPanel    paintFrame = new JPanel();
  
[B][COLOR="Red"]//HERE//[/COLOR][/B]
  
 public void paintComponent(Graphics paintFrame) {
    int width = getWidth();
    int height = getHeight();
    paintFrame.setColor(Color.black);
    paintFrame.drawOval(0, 0, width, height);
  }
  
  public DisplayGUI(  RootPaneContainer rpc, MiddleFactory mf  )
  {
 try                                           //
    {     
      theOrder = mf.makeOrderProcessing();        // Process order
    } catch ( Exception e )
    {
      System.out.println("Exception: " + e.getMessage() );
    }

    Container cp         = rpc.getContentPane();    // Content Pane
    Container rootWindow = (Container) rpc;         // Root Window
    cp.setLayout(null);                             // No layout manager
    rootWindow.setSize( W, H );                     // Size of Window
 
    Font f = new Font("Monospaced",Font.PLAIN,12);  // Font f is

    waiting.setBounds( 12, 35 , 170, 20 );       // Message area
    waiting.setText( "Waiting" );                      
    cp.add(BorderLayout.EAST, waiting );
    
    theWaiting.setBounds( 10, 65 , 170, 150 );       // Message area
    cp.add(BorderLayout.EAST, theWaiting );                            //  Add to canvas
    
    beingProcessed.setBounds( 202, 35 , 170, 20 );       // Message area
    beingProcessed.setText( "Being Processed" );                      
    cp.add(beingProcessed );
    
    paintFrame.setBounds( 10, 240 , 170, 150 );       // Message area         #
    paintFrame.setBackground(Color.white);
    cp.add(paintFrame );
    
    
    theBeingProcessed.setBounds( 200, 65 , 170, 150 );       // Message area                    
    cp.add( theBeingProcessed );                            //  Add to canvas
    
    waitingForCollection.setBounds( 392, 35 , 170, 20 );       // Message area
    waitingForCollection.setText( "Waiting For Collection" );                      
    cp.add(waitingForCollection );
    
    
    theWaitingForCollection.setBounds( 390, 65 , 170, 150 );       // Message area                      
    cp.add( theWaitingForCollection );                            //  Add to canvas
    
 
    
      rootWindow.setVisible( true );                  // Make visible
      
      backgroundDisplay bd = new backgroundDisplay();
      bd.start();
      
      
    

} 




class backgroundDisplay extends Thread {

 public void run() {
      
      while ( true )
      {
        try
        {
         Processing.Order order = new Processing.Order();
       
          Map res = theOrder.getOrderState();
          System.out.println(res);
          
        {
            StringBuffer sb =   new StringBuffer();
                 
                Object waitingList = res.get("Waiting");
                String waitingListString = waitingList.toString();
                int n = waitingListString.length();
                for(int i=0; i < n; i++)
                {
                    if(!((waitingListString.charAt(i) == '[')||(waitingListString.charAt(i) == ']')))
                    {
                        sb.append(waitingListString.charAt(i));
                    }
                    else
                    {
                        
                    }
                }
                String finalWaiting = sb.toString();
                theWaiting.setText( finalWaiting );  
                
                StringBuffer sc =   new StringBuffer();
                
                Object beingPickedList = res.get("BeingPicked");
                String beingPickedString = beingPickedList.toString();
                   int a = waitingListString.length();
                for(int i=0; i < a; i++)
                {
                    if(!((beingPickedString.charAt(i) == '[')||(beingPickedString.charAt(i) == ']')))
                    {
                        sc.append(beingPickedString.charAt(i));
                    }
                    else
                    {
                        
                    }
                }
                String finalProcessed = sc.toString();
                theBeingProcessed.setText( finalProcessed );  
                
                Object toBeCollectedList = res.get("ToBeCollected");
                String beingCollectedString = toBeCollectedList.toString();
                theWaitingForCollection.setText( beingCollectedString );   
           
            }
          sleep(5000);                             // delay
        } catch ( Exception err )
        {
        }
      }
    }
   

        
    }
        }

But obviously I'm not doing it properly as it's not drawing anything in the JPanel, I'd take a guess at I havn't pointed it to paint that specific panel?

[JosAH]

A JFrame isn't a JComponent so it can never override a paintComponent( ... ) method and it will never be called. A JFrame has a content pane that is painted in the area of the JFrame. The content pane is a JComponent (a JPanel perhaps?). Read the API documentation of the JFrame class.

kind regards,

Jos

[joeyea]

Thnaks for the reply, I have declared and added a JPanel called paintFrame (sorry for the confusing name!) to my content pane.
taken from my code :

private JPanel    paintFrame = new JPanel();

 paintFrame.setBounds( 10, 240 , 170, 150 );       
 paintFrame.setBackground(Color.white);
 cp.add(paintFrame );

and my code to paint on this so far is :

 public void paintComponent(Graphics paintFrame) {
    int width = getWidth();
    int height = getHeight();
    paintFrame.setColor(Color.black);
    paintFrame.drawOval(0, 0, width, height);
  }

[Fubarable]

Please read the tutorials on painting in Swing as need to unlearn some assumptions. You must extend JPanel or other JComponent to be able to override and use its paintComponent method. Again, I strongly urge you to study the tutorials.

Edit: an example of extending a JPanel and overriding its paintComponent is as Jos is showing below.

[JosAH]

Thnaks for the reply, I have declared and added a JPanel called paintFrame (sorry for the confusing name!) to my content pane.
taken from my code :

private JPanel    paintFrame = new JPanel();

 paintFrame.setBounds( 10, 240 , 170, 150 );       
 paintFrame.setBackground(Color.white);
 cp.add(paintFrame );

and my code to paint on this so far is :

 public void paintComponent(Graphics paintFrame) {
    int width = getWidth();
    int height = getHeight();
    paintFrame.setColor(Color.black);
    paintFrame.drawOval(0, 0, width, height);
  }

You can't just define a paintComponent( ... ) method anywhere and expect it to be called when an unrelated JPanel needs to be repainted. You have to extend the JPanel class and override that method in that class so it'll be called whenever the object needs to be repainted, so your paintPanel has to be of this class:

public class PaintPanel extends JPanel {
   ...
   public void paintComponent(Graphics g) {
      // do your graphics here
   }
}

and, of course your have to define your paintPanel variable like this:

PaintPanel paintPanel= new PaintPanel();

kind regards,

Jos