Question

Whenever I Call my add corePanel or add electivePanel methods They simply replace the last button that was added instead off adding a new one along side in the 4 columns I have set in the Jpanel.

I am aware that I have named the variables Panel when they are really buttons but that is irrelevant.

I really need some help.

Thanks

EDIT:
NOW when I mouse over the buttons all the information (Jpanels) inside of them disappears?

package Assignment2.view;

import java.awt.Color;
import java.awt.GridLayout;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.border.Border;

import ams.model.Course;

public class CoursePanel extends JPanel 
{
private JButton corePanel = new JButton();
private JButton electivePanel = new JButton();
private JLabel ccLabel = new JLabel("Code: ");
private JLabel titleLabel = new JLabel("Title: ");
private JLabel cpLabel = new JLabel("Credit Points: ");
private JLabel prLabel = new JLabel("Prereqs: ");
private Border blackline;


public CoursePanel()
{   
    setLayout(new GridLayout(0,4));
}



public void addcorePanel(Course createcourse)
{
    // core panel properties
    blackline = BorderFactory.createLineBorder(Color.black,10);

    corePanel.setLayout(new GridLayout(4,1));
    corePanel.setBackground(Color.GRAY);
    corePanel.setBorder(blackline);
    corePanel.add(ccLabel);
    corePanel.add(titleLabel);
    corePanel.add(cpLabel);
    corePanel.add(prLabel);
    corePanel.setAlignmentX(LEFT_ALIGNMENT);
    corePanel.setAlignmentY(TOP_ALIGNMENT);

    //Needed to rebuild the prerequisites for display.
    String[] prereqs = null;
    String result = null;
    prereqs = createcourse.getPreReqs();

    if (prereqs != null)
    {
    StringBuilder builder = new StringBuilder();
    for(String s : prereqs) 
    {
        builder.append(s);
        builder.append("\n");
    }
    result = builder.toString();
    }
    ccLabel.setText("Code: " + createcourse.getCode());
    titleLabel.setText("Title: " + createcourse.getTitle());
    cpLabel.setText("Credit points: " + Integer.toString(createcourse.getCreditPoints()));
    prLabel.setText("Prereqs: " + result);

    add(corePanel);

}


public void addelectivePanel(Course createcourseE)
{


    //elective panel properties
    electivePanel.setLayout(new GridLayout(4,1));
    electivePanel.setBackground(Color.GRAY);
    electivePanel.add(ccLabel);
    electivePanel.add(titleLabel);
    electivePanel.add(cpLabel);
    electivePanel.add(prLabel);
    electivePanel.setAlignmentX(LEFT_ALIGNMENT);
    electivePanel.setAlignmentY(TOP_ALIGNMENT);

    //Needed to rebuild the prerequisites for display.
    String[] prereqs = null;
    String result = null;
    prereqs = createcourseE.getPreReqs();

    if (prereqs != null)
    {
    StringBuilder builder = new StringBuilder();
    for(String s : prereqs) 
    {
        builder.append(s);
        builder.append("\n");
    }
    result = builder.toString();
    }

    ccLabel.setText("Code: " + createcourseE.getCode());
    titleLabel.setText("Title: " + createcourseE.getTitle());
    cpLabel.setText("Credit points: " + Integer.toString(createcourseE.getCreditPoints()));
    prLabel.setText("Prereqs: " + result);


    add(electivePanel);


}

}

Answer 1

This happens because your labels and buttons (corePanel, electivePanel) are class variables, so when you call for example addcorePanel, instead of creating a new JButton you’re manipulating the same corePanel button. You should move your variables inside the method body, like this:

public void addcorePanel(Course createcourse)
{
    JButton corePanel = new JButton();
    JLabel ccLabel = new JLabel("Code: ");
    JLabel titleLabel = new JLabel("Title: ");
    JLabel cpLabel = new JLabel("Credit Points: ");
    JLabel prLabel = new JLabel("Prereqs: ");

// ....

// ....
}

JLabels and JButtons cannot be shared so you must create new instances each time you call your methods.