How does the declarative XML API for the window system work?
The API is not hard, just a bit baroque. On startup, the window system needs to know some things to construct the main window, and possibly restore the state it was in before shutdown: • The window system needs know what components it will be displaying • It needs to know where to display individual components • And it has a way to define places where components can be displayed, and needs to know what places have been defined It would be a disaster for performance if all possible components in the system had to be instantiated/deserialized during startup just to figure out if they actually need to be on screen. The XML definitions for window system components allow a module to completely declaratively provide all the information described above. There are three main file types to be concerned with – these are put in the System Filesystem by declaring them in your module’s layer file: • .settings files – representing TopComponents that will be on screen – these go in Windows2/Component
