JTabbedPane - tab with close button reference

Question

I want to build a tabbed interface in JAVA, with close button on each tab. For that I have used the following class: ButtonTabComponent

I have a button on my GUI which creates a new tab. Let's say I press the New Tab button 4 times, therefore 4 tabs are created:

| tab 0 | tab 1 | tab 2 | tab 3 | (each tab contain a close button)

Now, I decide I want to close tab 1 and the problem appears, when I am closing a middle tab, all indexes are reordered - meaning that:

| tab 0 | tab 2 | tab 3 | (tab 2 will have index 1)

If I try now to create a new tab, the tab is created but new tab:

| tab 0 | tab 2 | tab 3 | tab 1| (tab 1 has no close button)

If I click again New Tab, I get:

| tab 0 | tab 2 | tab 3 | tab 1 | tab 4 | (tab 4 is fine, it has a close button)

Now I decide to close tab 2 and I get:

| tab 0 | tab 3 | tab 1| tab 4| (tab 3 will now have index 1)

If I create a new tab:

| tab 0 | tab 3 | tab 1| tab 4| tab 1 | (the last tab again has no close button).

I believe that this is caused by the index and I read in a similar question, here on stackoverflow : stackoverflow.com/questions/15312252/jtabbedpane-arrayindexoutofboundsexception that a possible solution would be to:

Pass a reference to the tab item, not its index on the tabbed pane, to the listener.

I am not sure how to do that. If anyone has any hint, I would really, really appreciate. I need to keep a solid reference for each tab, as each tab will open a file and it will have the ability to save to a file and obviously the tab index is not reliable.

EDIT: The way I add a new tab in my code is:

...//main class
private final JTabbedPane pane = new JTabbedPane();
//I am using an array to store the tabs created
//I initialize the array with false. the idea was that when a new tab get created, one item in the array
//gets the true value. when the tab is closed, the array item (based on the index) is set back to false
arrTabList = new boolean[10];
        for(int i=0; i<10; i++){
            arrTabList[i] = false;
        }

...


public void newFile()  //this function opens a new tab
{
//parse the array to check the first item with false status
    for(int i=0; i<10; i++){
        if(!arrTabList[i]) {
            System.out.println("false");
            PanelCounter = i;
            break;
            }
    }
    newTab t = new newTab();   //object which contains the tab content (a bunch of graphical components, input fields mostly)
    pane.add("New Entry" + PanelCounter, t.createContentPane());   //adds the new tab to the main window
    pane.setTabComponentAt(PanelCounter, new ButtonTabComponent(pane, this));
    arrTabList[PanelCounter] = true;  //sets the item array to true
}

//when a tab is closed, this function is called in the listener:
public void decreaseCounter(int i)
{
        arrTabList[i] = false;  //sets the item array back to false
}

Answer 1

The error lies in the call

pane.setTabComponentAt(PanelCounter, new ButtonTabComponent(pane, this));

You don't want to add the button to the tab index PanelCounter but to the one just created. Its index can be obtained using getTabCount(), which of course at this point is one too high, hence:

pane.setTabComponentAt(pane.getTabCount()-1, new ButtonTabComponent(pane, this));

Answer 2

I was checking your code and I could accomplish using

pane.remove(pane.getSelectedComponent());

in the actionPerformed method.

Answer 3

Here I am creating JTabbedPane tabs, with a close button for each tab. When the close button is clicked, only the respective tab closes.

//This is where a tab is created in some other function of same class
jtp.addTab("Create",new JPanel());  //jtp is a global JTabbedPane variable
int index = jtp.indexOfTab("Create");
jtp.setTabComponentAt(index,createTabHead("Create"));   

public JPanel createTabHead(String title)
{
    final String st=title;
    JPanel pnlTab = new JPanel();
    pnlTab.setLayout(new BoxLayout(pnlTab,BoxLayout.LINE_AXIS));
    pnlTab.setOpaque(false);
    JButton btnClose = new JButton("x");
    JLabel lblTitle = new JLabel(title+"    ");
    btnClose.setBorderPainted(false);
    btnClose.setOpaque(false);

    btnClose.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent e) {
             int i; 
            for(i=0;i<=jtp.getTabCount()-1;i++)//To find current index of tab
            {
            if(st.equals(jtp.getTitleAt(i)))
                    break;
            }                   
               jtp.removeTabAt(i);
             }
            });

     pnlTab.add(lblTitle);
    pnlTab.add(btnClose);
    return pnlTab;
}