Passing object between dialogs. please help
I have a panel which displays student's info.
There is a button called "Create New Student"
When the button is clicked, a new Dialog will shows up, where users can enter basic info for new student.
My question is, after a user finish entering data for new student, a new Student Object will be created.
How do I pass this Student Object back to original frame?
The basic question would be how do I pass object from a Dialog to its' caller Panel.
Thanks
[497 byte] By [
tsongweia] at [2007-11-26 12:30:56]
# 1
You should use interfaces to communicate between components.
Something like this..
public class A implements B.StudentUpdaterInterface{
...
public void addStudent(Student student){
...
}
private void showDialog(){
new B(this);
}
}
public class B{
static interface StudentUpdaterInterface{
public void addStudent();
}
public B(StudentUpdaterInterface sui)
...
}
...
}
# 2
sorry I don't really understand the code...Where should the Student Object be?Thanks.
# 3
Put your Student object in global scope or in such a scope that both the dialog boxes can access it!
# 4
> Put your Student object in global scope or in such a> scope that both the dialog boxes can access it!That is not a good idea.
# 5
> sorry I don't really understand the code...> > Where should the Student Object be?> > Thanks.Class B is your dialog. It calls the method on the interface that A implements to add the student.
# 6
I am sorry but can you (Zadok) pleae tell me why taht is a bad idea?That is just what I do...so maybe I am doing something wrong...
# 7
> I am sorry but can you (Zadok) pleae tell me why taht> is a bad idea?> That is just what I do...so maybe I am doing> something wrong... http://en.wikipedia.org/wiki/Information_hiding
# 8
Student class can be anywhere (just about). It can be within a package containing A and B or in some package imported by A and B, or even a static inner-class of A or B.
just import it properly:
(some external package)
some.package.Student student = new some.package.Student();
and reference it properly:
(e.g. static inner class)
A.Student student = new A.Student();
or Direct reference from within package:
(if Studen is defined in its own file, within same package as A and B)
Student student = new Student();
it doesn't matter, as long as Student is accesible(properly declared public or protected) and it's package is on your classpath
# 9
> Put your Student object in global scope or in such a
> scope that both the dialog boxes can access it!
>That is not a good idea.
I think there is some misunderstanding here.
Putting Student object at global scope has nothing to do with encapsulation. Furthermore, it is a requirement! In OP's main panel he/she needs reference to Student object. In Student creation dialog, we need to create a new Student. These two requirements necessitate the accesibility of Student class.
# 10
> > Put your Student object in global scope or in such
> a
> > scope that both the dialog boxes can access it!
>
> >That is not a good idea.
>
> I think there is some misunderstanding here.
> Putting Student object at global scope has nothing to
> do with encapsulation. Furthermore, it is a
> requirement! In OP's main panel he/she needs
> reference to Student object. In Student
> creation dialog, we need to create a new
> Student. These two requirements necessitate the
> accesibility of Student class.
Yes, they both need to see the class. But it would be a bad idea to make the object that is in the main panel a global variable for the dialog to update.
# 11
I got it now!!This is a new way of thinking for me...I use interface for Buttons and other widgets, never thought I can use it for Dialogs.This really makes sense!!Thank you all!!!
# 12
thanx for clarification Zadok ;)
