The main LookAndFeel class instantiates and queries ComponentPluginManager to get the details of third-party UI components. The constructor of PluginManager gets the XML descriptor name. The plugin class LafComponentPlugin contains a number of functions:

* initialize and uninitalize - should be called by the main LookAndFeel class on initialization and unitialization.
* getDefaults - returns collection of all settings for custom components. Can also return settings for core Swing components, effectively overriding the settings of the LAF