This level provides the user with a way to run CDTV applications without rebooting the system. A Level Two compliant title will also return cleanly to the Workbench or the CLI when it is finished. This stage requires that a title: 1) Supports input from the keyboard and the mouse. 2) Runs under both Release 1.3 and Release 2.0 of the operating system. 3) Launches from either the Workbench (via an icon) or the CLI. 4) Manages any resources it allocates. 5) Safely and Cleanly aborts in case any resource allocation fails. 6) Cleans up properly upon exit, closing all libraries and devices, and returning all memory. 7) Remembers the environment from which the user launched the title. If the user started the title from a CLI or Workbench, the title must be able to restore that environment cleanly. If the title was booted directly from the CD-ROM, before exiting, the title should take precautions against leaving the system in an unusable environment. For example, if a title makes all of the Workbench colors black using the devs:system-configuration file, the user should not be allowed to return to the CLI or Workbench, as the user will only see a black screen. In level two compatible titles, temporary assigns are acceptable. The application may assign system directories (such as fonts:, sys:, etc.) to the CD during startup. If it does so the title must restore any of the assigns it reassigned. A simple way to launch a title from a Workbench icon is using the IconX utility. This allows you to create a script that the system executes when the user clicks on the program icon. This script may contain any assigns that a title requires. An easy way a title can tell if the user booted directly from the CD-ROM is checking for special command line arguments. Imagine your title is called ``MyApp''. When the user boots the system from the CD-ROM, the startup-sequence launches the application by using a special command line, for example: ``MyApp ss''. The ``ss'' tells the title that the system was booted from the CD-ROM. If the user starts the application from the CLI, he would simply type ``MyApp''. A title might even utilize another special command line option to tell if it was launched from an IconX script (i.e. ``MyApp iconx''). Using this method a title can detect how the user started it and can choose an appropriate exit plan.
[Back to Amiga Developer Docs]