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;
}