Viewing the Information of a Selected Category
Obviously, you want to do much more than just expand and collapse tree nodes representing the different categories. You may want to display the information about a category when the user double-clicks a particular node. You can enhance the application to detect user events such as double-clicking a node and display information about the specified category.
Detecting Mouse Double-Clicks
You can detect mouse double-clicks a particular component by listening to the java.awt.event.MouseEvent generated by it. You can do this by implementing the java.awt.event.MouseListener interface and the methods defined in it. When a particular mouse event occurs, a particular method of the interface is invoked. ...