help needed @ Listener to combo-box

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vikas talwar - 27 May 2006 14:28 GMT

Hi Everyone,

below is my code. Please find my question between '?'ed lines.

//------------------------------------------------------------
// CREATE COMBO BOX
//------------------------------------------------------------
if(obj[i].equals(CSV_COMBO_BOX))
{
    _combobox[_combobox_count] = new JComboBox();

    //get possible value for combo box
    String [] possible_values = get_possible_values(val[i]);
    for(int i=0; i < possible_values.length; ++i)
    _combobox[_combobox_count].addItem(possible_values[i]);

    //set the default value to usr_val[i]
    _combobox[_combobox_count].setSelectedItem(usr_val[i]);

    // add to panel
    panel.add("tab",_combobox[_combobox_count]);

    // listner
    _combobox[_combobox_count].addItemListener(new ItemListener(){
        public void itemStateChanged(ItemEvent e)
        {
// ?????????????????????????????????????

// ? I WANT TO UPDATE usr_val[i] here ?
// ? how could i get the value of "i" or

// _combo_box_counter in this block?????????
// ???????????????????????????????<?????
        }
    });
    _combobox_count++;
}

--
need your help
Vikas Talwar

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Duane Evenson - 27 May 2006 15:34 GMT

> Hi Everyone,
>
[quoted text clipped - 33 lines]
> _combobox_count++;
> }

You can reference the selected value with
(JComboBox)e.getSource()).getSelectedItem() or 'i' with
(JComboBox)e.getSource()).getSelectedIndex()

and reference the _combo_box_counter with
(JComboBox)e.getSource()).getItemCount()

The key is to use e.getSource() and cast it to the event object's class -- in
this case, JComboBox.
Then you can use whatever methods available to that class you want.

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vikas talwar - 27 May 2006 16:52 GMT

going to implement, i guess it'll work.

Thanks a lot.

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vikas talwar - 27 May 2006 17:04 GMT

hi Duane,

I think you didnt' get what I wanted to ask ( maybe I was not clear)

(JComboBox)e.getSource()).getSelectedItem() returns new selected
value in combo box
(JComboBox)e.getSource()).getSelectedIndex() returns index of new
selected value in combo box
(JComboBox)e.getSource()).getItemCount() don't what its
returning.

Please read my code again.

Reply to this Message

Piet71 - 28 May 2006 08:54 GMT

> hi Duane,
>
> I think you didnt' get what I wanted to ask ( maybe I was not clear)

The "maybe I was not clear" is a good start....

> (JComboBox)e.getSource()).getSelectedItem() returns new selected
> value in combo box
[quoted text clipped - 4 lines]
>
> Please read my code again.

...but thats no a really good continuation. Do you think the question
is much clearer now?
Anyways, you have shown us a big "if" block where lots of things are
happening. If I understand your scenario correctly, you have two
arrays: one called "val" which is an array of string arrays that you
use to populate a JComboBox, and the other one is called "usr_val" that
holds strings and is used to set the JComboBox default values. You want
to change the default value when the selected item in the corresponding
JComboBox has changed. To manage your arrays and JComboBoxes, you have
one counter "i" which seems to count the arrays of string arrays and
the array with the default strings and one counter "_combobox_count"
which counts the JComboBoxes that have been genererated with the help
of these arrays. Obviously, the arrays could be used to generate a
different JComponent as well, in which case "i" and "_combobox_count"
will have different values.
Both "i" and "_combobox_count" are clearly available within the
if-block, so you don´t need any extra tricks to access them. What
happens if you directly access "i" or "_combobox_count" from within the
"itemStateChanged"-method?
HTH, PIet

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vikas talwar - 28 May 2006 09:58 GMT

Hello Piet,

you hava understood my code( ur perfectly clear).

but value of 'i' and '_combobox_counter' is always chaning while
generating GUI interface.
and at the time of event genreration the value of 'i' will be last
element of JComponentArray, and '_combobox_counter' will be last
element comboBoxArray.

Reply to this Message

vikas talwar - 28 May 2006 10:00 GMT

.Hello Piet,

you understood my code well (gr8).

but value of 'i' and '_combobox_counter' is always chaning while
generating GUI interface.
and at the time of event genreration the value of 'i' will be last
element of JComponentArray, and '_combobox_counter' will be last
element comboBoxArray

Reply to this Message

Duane Evenson - 28 May 2006 12:39 GMT

> hi Duane,
>
[quoted text clipped - 8 lines]
>
> Please read my code again.

Oh, you just want to refer to variable in the outer class from within the
inner class, right?
Declare these variables as class variables, then they will be visible to
inner classes. You can refer to them inside the inner class as just "i"
and "_combobox_count".

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help needed @ Listener to combo-box

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