Parsing a variable

[Peter Phung]

Hi guys and girls,
I've written a class which creates an instance of a second class, which in turn creates an instance of a third class i.e.

 
class classA {
ClassB b = new ClassB();
}
class ClassB {
ClassC c = new ClassC();
}
Class ClassC {
Button b = new Button();
int Variable = 1;
}

I need to wait for a button press in class c before returning the value of Variable back to class a.
Can anybody tell me how i can do this.

[Ilja Preuss]

You could do it by writing a constructor for class C which waits for the button to be pressed. But the design as a whole strikes me as a little bit strange. If you would get more concrete on what you want to accomplish, it would be much easier to propose an appropriate solution...

[Peter Phung]

I'm writing an FTP application with a database connection to allow the user to choose which file they want to download.
ClassA is the main GUI which controls the application.
ClassB is a query mask which takes user input and parses that information to classC
ClassC diaplays the results of the query in a table, from which the user can a file to download.
this filename is needed by classA for it to be able to download the file.
I hope that this explains what i'm trying to accomplish
I would appreciate any suggestions for a different approach or any solutions to my current problem.

[Ilja Preuss]

Originally posted by Peter Phung:
I'm writing an FTP application with a database connection to allow the user to choose which file they want to download.
ClassA is the main GUI which controls the application.
ClassB is a query mask which takes user input and parses that information to classC
ClassC diaplays the results of the query in a table, from which the user can a file to download.
this filename is needed by classA for it to be able to download the file.
I hope that this explains what i'm trying to accomplish
I would appreciate any suggestions for a different approach or any solutions to my current problem.

OK, what you seem to want to do is something like

userInfoDialog.show();
FtpFileChooser ffc = new FtpFileChooser(userInfoDialog.getInfo());
ffc.show();
new FtpConnection(ffc.getFileInfo()).download();

This could be pseudocode for your ClassA, whereas UserInfoDialog would resemble ClassB and FtpFileChooser ClassC.
Does that help?

[Peter Phung]

i think i need to explain my appliaction a bit clearer. My application is more than 3 classes. i will explain each class below
class a :
allows the user to select a file for uploading onto the FTP server.
opens a dialog to collect connectiion details and passwords.
Opens the FTP client(class c).
opens the database query tool(class b)
this class only collects data.
class b:
this creates the query for the database. The user inputs the search criteria and the class generates a query for the database and parses the query to class c.
Class c:
this class queries the database and displays all of the results in a table. When the user double clicks on the file name/clicks OK the file name needs to be parsed back to class a. This is so class a has the name of the file which the user wants to download. Class a then calls class d.
class d:
This is the FTP client. Handles both uploading and downloading of files.
I hope that this has explained my problem a bit clearer.
Thanks for the suggestions so far
[ May 22, 2002: Message edited by: Peter Phung ]

[Dirk Schreckmann]

So you want to use class B from class A to get data from class C?

[Peter Phung]

I've found a solution to my problem. Here's the code that i used:

 
class ClassA
{
    int variable;
    ClassB b = new ClassB(this);
    
    public void setVariable(int var)
    {
        variable = var;
    }
}
 
class ClassB
{
    ClassC c;
    
    ClassB(ClassA a)
    {
        c = new ClassC(a);
    }
}
 
class ClassC implements ActionListener
{
    Button b = new Button();
    b.addActionListener(this);
    int Variable = 1;
    ClassA a;
    
    ClassC(ClassA a)
    {
        this.a = a;
    }
    
    actionPerformed(ActionEvent e)
    {
        a.setVariable(Variable);
    }
}

[ May 23, 2002: Message edited by: Dirk Schreckmann ]

[Dirk Schreckmann]

Have you run across the Producer/Consumer example in Sun's Java Tutorial?