Cardlayout problem

[Samuel Woodhams]

wow its a long time since i wrote a message here (or worked on my project at all) but i decided enough was enough i need to set aside some time to work on it. so i have done and i have run into a brick all after about an hour

my problem is to do with the show() class in the cardlayout. Im hoping i've cut my code down enough for you guys (it still shows the same error)

    
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Dimension;
import java.awt.GraphicsEnvironment;
import java.awt.LayoutManager;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class Main {
	public static JPanel passwordPanel(){
		JPanel passwordPanel = new JPanel();
		JLabel test = new JLabel("hoping this works");
		passwordPanel.add(test);
		
		return passwordPanel;		
	}
	public static JPanel encryptionPanel(){
		JPanel encryptionPanel = new JPanel();
		JLabel test = new JLabel("test");
		encryptionPanel.add(test);
		
		return encryptionPanel;
	}
	
	public static JPanel selectToolPanel() {
		final JPanel selectToolPanel = new JPanel();
		LayoutManager lay = new BoxLayout(selectToolPanel, BoxLayout.PAGE_AXIS);
		selectToolPanel.setLayout(lay);
		
		class pageSwitch implements ActionListener {  
			public void actionPerformed(ActionEvent select) {
				CardLayout cl = (CardLayout)(masterToolPanel().getLayout());
				cl.show(masterToolPanel(), select.getActionCommand());
		    }  
		}		
		
		JButton test = new JButton("TEST");
		JButton test2 = new JButton("TEST2 has a different size");
		test.addActionListener(new pageSwitch());
		test2.addActionListener(new pageSwitch());
		
		selectToolPanel.add(test);
		selectToolPanel.add(Box.createRigidArea(new Dimension(0,10)));
		selectToolPanel.add(test2);
		
		return selectToolPanel;
	}
	
	public static JPanel masterToolPanel(){
		final JPanel switchPanel = new JPanel();
		switchPanel.setLayout(new CardLayout());
		JPanel card1 = passwordPanel();
		JPanel card2 = encryptionPanel();
		switchPanel.add(card1, "TEST");
		switchPanel.add(card2, "TEST2 has a different size");
		
		return switchPanel;
	}
	
	public static JPanel masterLayout() {
		JPanel masterPanel = new JPanel();
		LayoutManager lay = new BorderLayout();
		masterPanel.setLayout(lay);
		masterPanel.add(masterToolPanel(), BorderLayout.CENTER);
		masterPanel.add(selectToolPanel(), BorderLayout.WEST);
		
		return masterPanel;
	}

	public static void centerScreen(JFrame frame){
		GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
		int x = ge.getMaximumWindowBounds().width;
		int y = ge.getMaximumWindowBounds().height;
		frame.setSize(Math.min(x, 800), Math.min(y, 500));
		frame.setLocation((x - frame.getWidth()) / 2,(y - frame.getHeight()) / 2);
    }
	
	public static void createAndShowGUI(){
		JFrame frame = new JFrame("Hacking Utility");
		frame.add(masterLayout());
		frame.setResizable(false);
		centerScreen(frame);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.setVisible(true);
	}

	public static void main(String[] args) {
		SwingUtilities.invokeLater(new Runnable() {
            public void run() {
            	createAndShowGUI();
            }
        });
	}
}

The code compiles propolly but during run time i get the following error when trying to use one of the buttons to switch to another card

    
Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: wrong parent for CardLayout
	at java.awt.CardLayout.checkLayout(Unknown Source)
	at java.awt.CardLayout.show(Unknown Source)
	at Main$1pageSwitch.actionPerformed(Main.java:40)
	at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
	at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
	at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
	at java.awt.Component.processMouseEvent(Unknown Source)
	at javax.swing.JComponent.processMouseEvent(Unknown Source)
	at java.awt.Component.processEvent(Unknown Source)
	at java.awt.Container.processEvent(Unknown Source)
	at java.awt.Component.dispatchEventImpl(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(Unknown Source)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
	at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
	at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Window.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(Unknown Source)
	at java.awt.EventQueue.dispatchEvent(Unknown Source)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
	at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.run(Unknown Source)

the only thing that springs to mind when i read this is that it doesn't like having to refferrence another method from inside an anonymous inner class, but im a little out of my depth. any surrgestions are most welcome.

thanks in advance

sam

[Michael Dunn]

masterToolPanel() returns a JPanel, so each time you call it, you get another JPanel(CardLayout)

setting one initially should work

JPanel cardLayoutPanel = masterToolPanel();

and then refer to 'cardLayoutPanel'

[Samuel Woodhams]

ok, first thankyou for your quick reply

I think i get why that makes sence so thats a step in the right direction :P but im not sure how who want me to impliment that change! i tried like this

    
public static JPanel selectToolPanel() {
	final JPanel selectToolPanel = new JPanel();
	LayoutManager lay = new BoxLayout(selectToolPanel, BoxLayout.PAGE_AXIS);
	selectToolPanel.setLayout(lay);
	final JPanel cardLayoutPanel = masterToolPanel(); //add cardLayoutPanel here
	
	class pageSwitch implements ActionListener {  
		public void actionPerformed(ActionEvent select) {
			CardLayout cl = (CardLayout)(cardLayoutPanel.getLayout()); //implimented the change respectivly
			cl.show(cardLayoutPanel, select.getActionCommand()); //implimented the change respectivly
	       }  
        }		

and your quite right i don't get an error now, but im still not getting the card to switch so if i've missinterpritted what you were saying can you please correct me.

i've also tried defining it inside the inner class - again no error but the card doesn't switch.

    
public static JPanel selectToolPanel() {
	final JPanel selectToolPanel = new JPanel();
	LayoutManager lay = new BoxLayout(selectToolPanel, BoxLayout.PAGE_AXIS);
	selectToolPanel.setLayout(lay);
	
	class pageSwitch implements ActionListener {  
		public void actionPerformed(ActionEvent select) {
			JPanel cardLayoutPanel = masterToolPanel(); //add cardLayoutPanel here
			CardLayout cl = (CardLayout)(cardLayoutPanel.getLayout()); //implimented the change respectivly
			cl.show(cardLayoutPanel, select.getActionCommand()); //implimented the change respectivly
	    }  
	}		

thanks in advance

sam

[Michael Dunn]

but you still have another masterToolPanel() here:
masterPanel.add(masterToolPanel(), BorderLayout.CENTER);

this is the one seen on the screen, not the 'cardLayoutPanel' you've created, and accessed via the actionListeners

move cardLayoutPanel to a class field, then
masterPanel.add(cardLayoutPanel, BorderLayout.CENTER);
and it works OK

also, all those 'statics' will bite you later on

[Samuel Woodhams]

hey thanks for the reply

Michael Dunn wrote:move cardLayoutPanel to a class field

could you explain what you mean by a class field because im a little lost.

also, all those 'statics' will bite you later on

the only statics i have are (according to eclipse) needed so im a little there!

[Michael Dunn]

here's your code modified to include the class field, and the statics removed
the statics were needed because of your code structure, now changed

run the program, click the second button and the text message changes
click the first button, it changes back - hopefully this is what you are trying to do.

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

class Main {
  JPanel cardLayoutPanel = masterToolPanel(); //<---------class field
  public JPanel passwordPanel(){
    JPanel passwordPanel = new JPanel();
    JLabel test = new JLabel("hoping this works");
    passwordPanel.add(test);
    return passwordPanel;
  }
  public JPanel encryptionPanel(){
    JPanel encryptionPanel = new JPanel();
    JLabel test = new JLabel("test");
    encryptionPanel.add(test);
    return encryptionPanel;
  }
  public JPanel selectToolPanel() {
  final JPanel selectToolPanel = new JPanel();
  LayoutManager lay = new BoxLayout(selectToolPanel, BoxLayout.PAGE_AXIS);
  selectToolPanel.setLayout(lay);
  class pageSwitch implements ActionListener {
    public void actionPerformed(ActionEvent select) {
      CardLayout cl = (CardLayout)(cardLayoutPanel.getLayout()); //implimented the change respectivly
      cl.show(cardLayoutPanel, select.getActionCommand()); //implimented the change respectivly
         }
        }
    JButton test = new JButton("TEST");
    JButton test2 = new JButton("TEST2 has a different size");
    test.addActionListener(new pageSwitch());
    test2.addActionListener(new pageSwitch());
    selectToolPanel.add(test);
    selectToolPanel.add(Box.createRigidArea(new Dimension(0,10)));
    selectToolPanel.add(test2);
    return selectToolPanel;
  }
  public JPanel masterToolPanel(){
    final JPanel switchPanel = new JPanel();
    switchPanel.setLayout(new CardLayout());
    JPanel card1 = passwordPanel();
    JPanel card2 = encryptionPanel();
    switchPanel.add(card1, "TEST");
    switchPanel.add(card2, "TEST2 has a different size");
    return switchPanel;
  }
  public JPanel masterLayout() {
    JPanel masterPanel = new JPanel();
    LayoutManager lay = new BorderLayout();
    masterPanel.setLayout(lay);
    //masterPanel.add(masterToolPanel(), BorderLayout.CENTER);
    masterPanel.add(cardLayoutPanel);
    masterPanel.add(selectToolPanel(), BorderLayout.WEST);
    return masterPanel;
  }
  public void centerScreen(JFrame frame){
    GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
    int x = ge.getMaximumWindowBounds().width;
    int y = ge.getMaximumWindowBounds().height;
    frame.setSize(Math.min(x, 800), Math.min(y, 500));
    frame.setLocation((x - frame.getWidth()) / 2,(y - frame.getHeight()) / 2);
    }
  public Main(){
    JFrame frame = new JFrame("Hacking Utility");
    frame.add(masterLayout());
    frame.setResizable(false);
    centerScreen(frame);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
  }
  public static void createAndShowGUI(){
    new Main();
  }
  public static void main(String[] args) {
    SwingUtilities.invokeLater(new Runnable() {
            public void run() {
              createAndShowGUI();
            }
        });
  }
}
 

[Samuel Woodhams]

Thats brilliant it works perfectly

as an aside why is using "static" in a method not avisable?

thanks again

sam

[Michael Dunn]

> as an aside why is using "static" in a method not avisable?

specific usage of static is good
Math.random()
System.out...()
etc

but overuse can lead to problems.
I've seen numerous posts of "is this a Swing bug" turn out to be
just a changed program (now to be reused) where a static field was the culprit

simple demo, QuizPanel.
run as is, see all the radioButtons/labels when you click 'next'
now change the comments around so they're static, rerun and see

and if someone was using this, the forum post would be "why don't my radioButtons appear"

   
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
class QuizPanel extends JPanel
{
  //static JRadioButton rb1 = new JRadioButton();
  //static JRadioButton rb2 = new JRadioButton();
  //static JRadioButton rb3 = new JRadioButton();
  JRadioButton rb1 = new JRadioButton();
  JRadioButton rb2 = new JRadioButton();
  JRadioButton rb3 = new JRadioButton();
  public QuizPanel(String[] arr)
  {
    setLayout(new GridLayout(3,2));
    rb1.setText(arr[0]);
    add(rb1); add(new JLabel(arr[0]));
    rb2.setText(arr[1]);
    add(rb2); add(new JLabel(arr[1]));
    rb3.setText(arr[2]);
    add(rb3); add(new JLabel(arr[2]));
  }
}
class Testing
{
  CardLayout cl = new CardLayout();
  JPanel cardLayoutPanel = new JPanel(cl);
  public void buildGUI()
  {
    JButton btn = new JButton("Next");
    cardLayoutPanel.add("0", new QuizPanel(new String[]{"a","b","c"}));
    cardLayoutPanel.add("1", new QuizPanel(new String[]{"1","2","3"}));
    cardLayoutPanel.add("2", new QuizPanel(new String[]{"x","y","z"}));
    JFrame f = new JFrame();
    f.getContentPane().add(cardLayoutPanel);
    f.getContentPane().add(btn,BorderLayout.SOUTH);
    f.setSize(300,200);
    f.setLocationRelativeTo(null);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setVisible(true);
    btn.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent ae){
        cl.next(cardLayoutPanel);
      }
    });
  }
  public static void main(String[] args)
  {
    SwingUtilities.invokeLater(new Runnable(){
      public void run(){
        new Testing().buildGUI();
      }
    });
  }
}

[Samuel Woodhams]

Thankyou very much this has cleared quite a few misconseption i had and hopfully i'll avoid being one of the people who thinks he has found a bug

cheers