Java Drag & Drop and Cloneable

Question

I have this problem to solve where you have a JPanel and JLabel and you have to clone JLabel with drag and drop and create a JLabel clone on the JPanel where JLabel was dropped. First thing I'd like to ask is if it's possible to implement Cloneable interface to JLabel in anonymous class like listeners, so I don't have to write my own class that extends JLabel and implements Cloneable. I know how to drag and drop JLabel to JTextField by transfering "text" property, but I have no idea how to clone a JLabel to JPanel.

Answer 1

Implementing the Cloneable interface is unlikely to achieve any beneficial effect in this context. In Effective Java, Second Edition, the author outlines the vagaries of cloning objects in Item 11: Override clone judiciously.

Drag and Drop transfers the data, not the container. Because String is immutable, there's no reason to clone a String at all. For mutable data, a copy constructor or factory method makes more sense.

Because JLabel is not user editable, it may be an unexpected target for DnD, although it is possible. Alternatively, you can add a suitable component at run time using the container's add() method, followed by validate() and repaint().