JCombo + override toString

Question

Alright, I am working on a rather large program.

I will try to put in only what you need.

So right now, the comboBox is filling (with the override toString), and the first item is selected.

When I choose different parameters and force the contents of the comboBox to change, the new list is put into the comboBox and the first item is selected again.

I can see the update, so I know it is filling properly.

The problem is that when I select anything in the comboBox, nothing happens.

The first item remains selected, none of my System.out.println lines are printing, so nothing is being executed.

When I remove my override toString, everything works as intended.

The strange part, past that, is when having this override toString removed, it falls back on the parent class who has an override toString.

What is going on?

To my understanding the toString literally changes what is displayed, it does not change the data.

I am adding the objects to the comboBox, but displaying a bit of the information.

public class Belt extends Part{
    //variable initialization and methods
    @override
    public String toString(){
    String display = this.getCode() + " - " + this.color;
    return display;
}

public final class Something implements ActionListener{
    //variable initialization and methods
    //there are several methods that call the fillBeltCombo()

    GridBagConstraints c = new GridBagConstraints();
    private void pad(GridBagConstraints c){
        c.anchor = GridBagConstraints.NORTHWEST;
        c.weightx = 1;
        c.insets.left = 10;
        c.insets.right = 10;
        c.insets.top = 5;
        c.insets.bottom = 5;
    }

    beltCombo = new JComboBox();
    beltCombo.setVisible(true);
    c.gridwidth = 2;
    c.gridx = 4;
    c.gridy = 9;
    beltCombo.addActionListener((ActionEvent eventBelt) -> {
        JComboBox beltCodeCombo1 = (JComboBox) eventBelt.getSource();
        if(beltCombo.getItemCount()>0){
            currentProduct.setBelt((Belt)beltCodeCombo1.getSelectedItem());
        }else{/*do nothing*/}
    });
    pane.add(beltCombo, c);

    public static void fillBeltCombo(ArrayList<Belt> list){
        beltCombo.removeAllItems();
        int size = list.size();
        for(int x=0; x<size; x++){
            beltCombo.addItem(list.get(x));
        }
    }
}

Answer 1

Aright, so based on yesterdays successful creation (which I was frustrated by) I continued to fill in the skeleton until it broke again. - Adjusted classes to reflect the actual types of data that I was dealing with. - Added my override equals method <-------problem

What happened was that when I originally created the equals override, all of the toStrings were the same, and that was displayed in the comboBox. So the equals override looked like

@Override public boolean equals(Object other){
    if (other == null) return false;
    return (String.valueOf(other)).equals(this.description);
}

The problem with this, was that when I was asked to change what was displayed in the comboBox, I did not realize that the comboBox seems to use that equals check. The new other Object was

this.getCode() + " - " + this.color;

and it was being compared to num, which returned false.

Now correct me if I am wrong, but the moral of the story seems to be: JComboBox will not let you select something from the list that does not equal something on the list. So because my equals override changed how the objects were compared: string value of object, compared to string variable of the object- the same object was not equaling itself. The adjusted code:

@Override public boolean equals(Object other){
    if (other == null) return false;
    return ((Parent)other).description.equals(this.description);
}