Swing component not load in GUI

Related with #14.

Problem

When a Swing component has a parent, it cannot have a new parent.

For example, if you create a new JPanel with the new keyword and then insert the original component into it, the component will not be visible on the screen.

void addListIntoJPanel(JPanel jPanel){
    for(JTextPane elem : list){
        jPanel.add(elem);
    }
}

void showTab(){
    JPanel jPanel = new JPanel();
    addListIntoJPanel(jPanel);

    openJPanel(); // show this jPanel into new window
}

public static void main(String[] args) {
    showTab(); // in first tab, every components in list are shown
    showTab(); // in second tab, any components in list are **not** shown. 
}

This is problem 1 what I suffered.

Solution

Therefore, when reusing swing components, you must check if the parent exists and, if so, delete it.

void addListIntoJPanel(JPanel jPanel){
    for(JTextPane elem : list){
        if(elem.getParent() != null){
            elem.getParent().remove(elem);
        }
        jPanel.add(elem);
    }
}