By David N. Junod


One of the many improvements made to Workbench for release 2.0 lies in its
ability to supply an application with arguments from Workbench. Prior to
release 2.0, the only Workbench supported way an application could receive
Workbench arguments was through the Workbench startup message.  Now,
Workbench arguments can come from many sources including AppWindows,
AppIcons, and the ASL file requester.  These enhancements have made
processing Workbench arguments more beneficial than ever.

When an application is started via Workbench, the application receives a
startup message (struct WBStartup) from Workbench.  This message contains
a pointer to an array of WBArg structures.  The array of WBArgs
corresponds to all Workbench icons that were selected at the time the
application was launched.  Each WBArg structure contains a file lock on
the file or directory associated with each icon, as well as the name
associated with the icon.  A WBArg supplies the link to the icon, or the
DiskObject, itself, from which necessary information, such as application
or project ToolTypes, can be extracted.

Under release 2.0, Workbench supplies WBArgs using several different
structures.  The structure used depends on the source of the WBArgs. When
it launches an application, Workbench sends the application WBArgs through
the WBStartup structure.  AppWindows and AppIcons use the AppMessage
structure to send WBArgs.  The ASL file requester provides the arguments
in the FileRequester structure.

Also with release 2.0, it is possible that icons passed to an application
do not have an .info file associated with them.  Workbench can now display
all files and directories iconically, not just those with .info files. For
icons without .info files, Workbench supplies a default icon based on the
protection bits and object type (file, dir, etc.) so the user can
manipulate files and directories from Workbench.

The following routine, wbarg.c, uses GetDiskObjectNew() which should be
used only when an application requires an image for every Workbench
argument, whether actual or default.  To only read actual icons and
tooltypes, modify the routine to use GetDiskObject() instead.  For more
information, see the release 2.0 Autodocs.