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How to move items from one JList to other

843806Jun 28 2007 — edited Jun 29 2007
Can u pls help me out to implement this(I m using Netbeans 5.5):
I want to move items from one JList to other thru a ADD button placed between JLists, I am able to add element on Right side JList but as soon as compiler encounter removeElementAt() it throws Array Index Out of Bound Exception
and if I use
removeElement() it removes all items from left side JList and returns value false.
Pls have a look at this code:
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
Object selItem = jList1.getSelectedValue();
int selIndex = jList1.getSelectedIndex();
DefaultListModel model = new DefaultListModel();
jList2.setModel(model);
model.addElement(selItem);

DefaultListModel modelr = new DefaultListModel();
jList1.setModel(modelr);
flag = modelr.removeElement(selItem);
//modelr.removeElementAt(selIndex);
System.out.println(flag);


}

Comments

holod
I have some troubles wth JList too.

jListleft={leftFirst,leftSecond,leftThird};
jListRight{rightFirst,rightSecond,rightThird};
Also you have a JButton, that "moves" elements from left list to the right list

So if you want to move element "leftSecond" to right JList
you will get:

jListleft={leftSecond,leftThird};
jListRight{rightFirst,rightSecond,rightThird,leftFirst};

Did I understand your idea?
800774
Use code formatting when posting code:
http://forum.java.sun.com/help.jspa?sec=formatting

Why are you setting a new model for both lists?
Just add the new item to the second list and remove it from the first one:

Read in the tutorial Adding Items to and Removing Items from a List
http://java.sun.com/docs/books/tutorial/uiswing/components/list.html#mutable

Set the model for both list to be DefaultListModel when you create the lists. 
jList1 = new JList(new DefaultListModel());
jList2 = new JList(new DefaultListModel());
Then you can just do this: 
Object selItem = jList1.getSelectedValue();
((DefaultListModel) jList1.getModel()).removeElement(selItem);
((DefaultListModel) jList2.getModel()).addElement(selItem);
843806
Ya, u have understand the problem exactly, now do u have any clue to implement it in Netbeans 5.5
Thanks for ur time.
843806
Ya, u have understand the problem exactly, now do u
have any clue to implement it in Netbeans 5.5
I don't use NetBeans, but I'll bet it allows you to edit source code. Do so, as Rodney_McKay outlines above.
843806
hi Rodney_McKay,
Thanks for valuable time but my problem is as it is, pls have a look what I have done and what more can b done in this direction.
Here is the code:
import javax.swing.DefaultListModel;
import javax.swing.JList;

public class twoList extends javax.swing.JFrame {

/** Creates new form twoList */
public twoList() {
initComponents();
}
//The code shown below is automatically generated and we can�t edit this code
// <editor-fold defaultstate="collapsed" desc=" Generated Code ">
private void initComponents() {
jScrollPane1 = new javax.swing.JScrollPane();
jList1 = new javax.swing.JList();
jButton1 = new javax.swing.JButton();
jScrollPane2 = new javax.swing.JScrollPane();
jList2 = new javax.swing.JList();

setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jList1.setModel(new javax.swing.AbstractListModel() {
String[] strings = { "Item 1", "Item 2", "Item 3", "Item 4", "Item 5" };
public int getSize() { return strings.length; }
public Object getElementAt(int i) { return strings[i]; }
});
jList1.addListSelectionListener(new javax.swing.event.ListSelectionListener() {
public void valueChanged(javax.swing.event.ListSelectionEvent evt) {
jList1ValueChanged(evt);
}
});

jScrollPane1.setViewportView(jList1);

jButton1.setText("ADD>>");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});

jScrollPane2.setViewportView(jList2);

javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(31, 31, 31)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 44, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jButton1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, 63, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(78, Short.MAX_VALUE))
);

layout.linkSize(javax.swing.SwingConstants.HORIZONTAL, new java.awt.Component[] {jScrollPane1, jScrollPane2});

layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(62, 62, 62)
.addComponent(jButton1))
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))))
.addContainerGap(159, Short.MAX_VALUE))
);

layout.linkSize(javax.swing.SwingConstants.VERTICAL, new java.awt.Component[] {jScrollPane1, jScrollPane2});

pack();
}// </editor-fold>
//automatic code ends here 
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
// TODO add your handling code here:
        
        jList1 = new JList(new DefaultListModel());
        jList2 = new JList(new DefaultListModel());
        
         Object selItem = jList1.getSelectedValue();
         System.out.println(selItem);
        ((DefaultListModel) jList1.getModel()).removeElement(selItem);
        ((DefaultListModel) jList2.getModel()).addElement(selItem);
}
//Now trying with this code it is neither adding or removing and the value �null� is coming in �selItem� .It may be bcoz JList and Jlist are already instantiated in automatic code. So, I tried this:
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
// TODO add your handling code here:
        
        
         Object selItem = jList1.getSelectedValue();
         System.out.println(selItem);
        ((DefaultListModel) jList1.getModel()).removeElement(selItem);
        ((DefaultListModel) jList2.getModel()).addElement(selItem);

}
//Now with this as soon as I click on �jButton1�, it is throwing this error: 
Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: twoList$1 cannot be cast to javax.swing.DefaultListModel
        at twoList.jButton1ActionPerformed(twoList.java:105)
        at twoList.access$100(twoList.java:13)
        at twoList$3.actionPerformed(twoList.java:50)
        at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
        at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
        at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
        at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
        at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
        at java.awt.Component.processMouseEvent(Component.java:6038)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3260)
        at java.awt.Component.processEvent(Component.java:5803)
        at java.awt.Container.processEvent(Container.java:2058)
        at java.awt.Component.dispatchEventImpl(Component.java:4410)
        at java.awt.Container.dispatchEventImpl(Container.java:2116)
        at java.awt.Component.dispatchEvent(Component.java:4240)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4322)
        at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3986)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3916)
        at java.awt.Container.dispatchEventImpl(Container.java:2102)
        at java.awt.Window.dispatchEventImpl(Window.java:2429)
        at java.awt.Component.dispatchEvent(Component.java:4240)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)
holod 
private void jButtonMoveItemsActionPerformed(java.awt.event.ActionEvent evt) {                                                 
        //get access through interface ListModel to left and Right JLists's models
        ListModel leftLM = jListLeft.getModel();        
        ListModel rightLM = jListRight.getModel();
        
        int leftSelected = jListLeft.getSelectedIndex();    //index of selected Left JList item
        Object selectedItem = jListLeft.getSelectedValue(); //value of selected Left JList item
        
        DefaultListModel leftDLM = new DefaultListModel();  //Create new instance of DefaultListModel for left JList
        DefaultListModel rightDLM = new DefaultListModel(); //Create new instance of DefaultListModel for right JList
        
        //copy existing items to DefaultListModel
        for(int i=0;i<leftLM.getSize();i++){
            if(i == leftSelected){  //but we have to skip selected item
                    continue;
            }//if
            else{
                leftDLM.addElement(leftLM.getElementAt(i)); //element added
            }//else
        }//for
        jListLeft.setModel(leftDLM);//set new model for left JList without "deleted" item
        System.out.println(leftDLM);//let's print it and see the new model
        
        //copy items from right ListModel to new DefaultListModel
        for(int i=0;i<rightLM.getSize();i++){   
           rightDLM.addElement(rightLM.getElementAt(i));
        }
        rightDLM.addElement(selectedItem);  //Item from left List added
        
        jListRight.setModel(rightDLM);  //set new model with added item
        System.out.println(rightDLM);   //let's print and see the new model
        
       //accomplished!!!! Yah!!!
    }
This Is my solution.
It works 100%
I've used NetBeans 5.5 + GUI Builder
I've made JFrame Form
I've put there 2JLists: jListLeft and jListRight
I've put there JButton: jButtonMoveItems

So You can see ActionPerformed event to this Button.


P.S

Do not forget to add something to JList models while you are designing (do it through "Properties")

P.P.S.
Code it pretty long, but you can easilly make it shorter.
I've tried to explain you each action I did
843806
Hi Holod.............Thanks a lot
Its working perfectly now, thanks for your yseful time devoted
holod
It's my pleasure!
Sometimes Rodney and camickr help me very much, so I try to help other starters like I am too!
800774
Hi Holod,

Although this solution will work, it's not a good one.
You create 2 new models every time you want to move one element from one list to the other.
And then you copy all the elements to the new models.
This is completely unnecessary.

As I tried to explain, if you create the jlist from the beginning using DefaultListModel, you can just take the model from both lists and remove the selected element from the first list and add it to the second list.
holod
jList1 = new JList(new DefaultListModel());
That does not work....

The same... I do a project with JTable.
JTable is created with help of GUI Builder.
I try to do pretty the same:
1.Create my own model and reCreate JTable
2.put it in container instead of previous one

The idea of discussed task is the same.

modelWord = new DefaultTableModel(vectorWord,columnNamesUserVector);
        modelWord.addTableModelListener(this);
        jTableWord = new JTable(modelWord)
        {
            
            public Class getColumnClass(int column){
                if(column  == 0) 
                    return Integer.class;
                else 
                    return getValueAt(0, column).getClass();
            }//Class getColumnClass
            
         //bla-bla-bla
//...
//..
        };//table model
jScrollPane1.removeAll();
jScrollPane1.add(jTableWord);
Nothing happens:
No errors, no exceptions,
I see table which was built with help of GUI Buider.
newly created table doesn't appear

The same situation with your example....
No error, but nothing happens.

I don't know why...(((((
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Locked on Jul 27 2007
Added on Jun 28 2007
#swing
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