Thread: A program with a GUI

I have an (a subclass to) AbstractTableModel which contains an ArrayList of type Item (a home-made class) and some basic methods such as add, remove,getColumnCount, getRowCount and getValueAt. This extension of AbstractTableModel has been put in a JTable, which has been put in a JScrollPane and in a JFrame for viewing.

What I am trying to create now in the GUI is a function for the user to add Items to the ArrayList so that they will appear shortly after in the JTable.

In overly simplified pseudocode, this function would look something like:

1.User presses button1 which is labeled "create new.."
2.Dialog box with text fields pops up
3.the input is used to create a new instance
4.the add-method is called with that instance.

How do I make this happened?
I have created a class for handling events.(in param: ActionEvent event). So far that class does nothing. I guess I need some kind of conditional statement like: if(button1 == event.getSource()) and then something that makes a dialog pop up.

I've read tons of info on Jdialog and JOptionPane, the classes suggested to use for the dialog. However, I am unable to make anything happened. Please dont just post links to some page at sun microsystems (it feels like I've read them all.)

For example, how would a dialog box even be able to appear in the first place? Shouldn't the method that makes it pop up be in the main method that actually starts the program?

What I would like as a response to this is some code that easily just could be put in after my if statement and makes a simple dialog box appear. Some clarifying advice would also be nice.

PHP Code:

public class EventHandler implements ActionListener{
        
        public void actionPerformed(ActionEvent event){
            
            
            if (event.getSource()== button1){
                


            }
            
            
        }
    } 


You just need to create a JOptionPane and retrieve the output...the JOptionPane handles all the intricacies. Grab the returning string, then create a new item object based upon that input, and add the item to your list

String s = (String)JOptionPane.showInputDialog("Please enter new item a value:");//create an option pane
if ( s != null ){//s will be null if cancel is pressed, otherwise use it to create a new item
//validate the user input if necessary
//create your new item based upon s
//add your new item
tableModel.fireTableDataChanged();//assuming tableModel is the name of your model - necessary to let the table know its data has changed
}

Is it possible for me to create my own JOptionPane? I need more than one string to pass on to the constructor.(The constructor takes like 6 parameters of 3 different types). Of course I could have the program read it like one string and extract different substrings and parse them, but I would really prefer to have it customized like "enter title:___, enter year:____" etc.
Also, the code you posted did not compile, I got the error message "Cannot make a static reference to the non-static method fireTableDataChanged() from the type
AbstractTableModel" How do I get rid of that?

Originally Posted by joachim89

Also, the code you posted did not compile, I got the error message "Cannot make a static reference to the non-static method fireTableDataChanged() from the type
AbstractTableModel" How do I get rid of that?

This is because you need to call fireTableDataChanged on a reference to your abstract table model...I'm guessing you are calling it in a static context (eg AbstractTableModel. fireTableDataChanged() is a static context and won't compile).

Originally Posted by joachim89

Is it possible for me to create my own JOptionPane? I need more than one string to pass on to the constructor.(The constructor takes like 6 parameters of 3 different types). Of course I could have the program read it like one string and extract different substrings and parse them, but I would really prefer to have it customized like "enter title:___, enter year:____" etc.

It sounds like you need a much more comprehensive interface than JOptionPane supplies. You can create a new JFrame to do so, sending it a reference to the JFrame with the table in it so you can update the table from that reference. Another way which may be easier is - when the add item button is fired - add an empty item to your list, and prompt the user to enter the information directly into the new row in the table. You can do so by:

Item item = new Item();//empty item
//add the item to the list
//call fireTableDataChanged on your TableModel
//call editCellAt specifying the new entry where you wish users to enter info

Of course your table needs to be editable for this to be an option

Originally Posted by joachim89

This code gives me the error message that the method setVisible is undefined for the type PopupWindow.

Make sure your PopupWindow extends JFrame. If it does you will probably have to post the code to that object because its tough to debug without knowing that info

I decided to create a JFrame with data fields.

Here's an EventHandler class that reads input from the JFrame dialog box.
(createNew is a JButton)

PHP Code:

public class EventHandler implements ActionListener{
        public String title, producer, pubYear, genre;
        public int length, ageLimit;
        Film addFilm;
        public void actionPerformed(ActionEvent event){
            
            if(event.getSource() == createNew)
              addFilm = new Film(field1.getText(),field2.getText(),false,field3.getText(),Integer.parseInt(field4.getText()),Integer.parseInt(field6.getText()),field5.getText());
                
                    }
    } 


So this is supposed to take enough info to create a Film object. Now i want to add this to my Items ArrayList (Film is a subclass to Item). The arraylist is inside a subclass(called LendingModel) to AbstractTableModel, which is in a JTable in a JFrame.
But as I try to add the new object to my LendingModel object (lm) in the EventHandler class posted above, it does not recognize lm. (Error message: lm cannot be resolved to a type).
So where do I add it? Or is it the right place to add it?

I really need some help with this, thanks in advance.

The compiler needs a reference to your ArrayList object. I don't know how your project is organized, but however you do it your EventHandler class must know of your list through a reference. You can pass it the list via the constructor, have your previous JFrame window act as the actionListener, or any number of other designs

You do not define what 'lm' is anywhere else in the object, which is why you are getting the error. As mentioned earlier you need to let the class know what is what...As an example of how to accomplish this, you can pass your LendingModel reference to the constructor of the new frame:

 
private LendingModel lm = null;//define the reference
//update your constructor
public NewFilmDialog(LendingModel lm){
    //construct
    this.lm = lm;
    ///etc...
}
//etc...