Extending classes at runtime

Question

Hi,
Is there a way to extend a class at runtime? What I'd like to do is the following:
I want to have a tabbed pane component that does not stretch its tabs when there are several lines of tabs. The stretching of the tabs is implemented in the UI component of JTabbedPane - and this depends on the look & feel - it can be MetalTabbedPaneUI, WindowsTabbedPaneUI, etc.
I want to extend the currently-used UI class (which is only known at runtime) with my own class that overrides a single method.
I can extend all those that I currently know and use some mapping from the currently used class to the one extending it - but tomorrow someone may install a new look & feel which uses a different UI component, for which I will not have an extending class.
Therefore, I'd like to find the currently used UI component class and extend it at runtime.
Thanks,
Shlomy

Answer 1

Shlomy-Reinstein wrote:
Thanks. It's a good solution, but it requires me to write wrappers for all the public methods of BasicTabbedPaneUI, doesn't it? All I'm interested in is to override a single method. If there is no easier way, that's okay, but since there are scripting languages that interface with Java (e.g. BeanShell), in which I can extend classes, I thought there should be an easy way to extend a class at runtime.You don't write code that is "easy". You write code that is correct.
If there are several different ways to write code which are all correct then you use other criteria to determine the best one. The first criteria is how much maintenance each would require. And how complex each solution would be. Complexity also impacts maintenance.
And nothing I have seen in this thread would suggest that anything but a wrapper is a correct solution. Certainly unless you can demonstrate that it would not work then I doubt anything would be better.
And using beanshell just so you don't have to type is definitely not the correct solution.