Earlier sections discussed how Workbench passes filenames as arguments to a program that's about to run. Workbench also allows other types of arguments to be passed in the Tool Types array of an icon. The Tool Types array is found in the do_ToolTypes field of the icon's DiskObject structure. In brief, Tool Types is an array of pointers to strings that contain any information an application wants to store such as the program options that were in effect when the icon was created. These strings can be used to encode information which will be available to all applications that read the icon's .info file. Users can enter and change a selected icon's Tool Types by choosing Information in the Workbench Icons menu. Workbench does not place many restrictions on the Tool Types array, but there are a few conventions you should follow. A string may be no more than 128 bytes long. The alphabet used is 8-bit ANSI (for example, normal ASCII with foreign-language extensions). This means that users may enter Tool Type strings containing international characters. Avoid special or nonprinting characters. The case of the characters is currently significant, so the string "Window" is not equal to "WINDOW". The general format for a Tool Types entry is <name>=<value>[|<value>], where <name> is the field name and <value> is the text to associate with that name. Multiple values for one name may be separated by a vertical bar. The values may be the type of the file, programs that can access the data, parameters to be passed to an application, etc. For example, a paint program might set: FILETYPE = PaintProgram | ILBM This Tool Type indicates that the file is an ILBM, perhaps with some additional chunks of data specific to PaintProgram. Tool Type strings have few restrictions but there are some reserved Tool Types that are parsed by Workbench itself when an application is started from an icon. The reserved Tool Types are TOOLPRI=n (sets the Exec task priority at which Workbench will start the application), STARTPRI=n (sets the starting order for icons in the Wbstartup drawer), and DONOTWAIT (tells Workbench not to wait for the return of a program started via an icon in the Wbstartup drawer). In addition to the reserved Tool Types, which applications should not use, there are standard Tool Types, which applications should use only in the standard way. For a list of standard Tool Types refer to the Amiga User Interface Style Guide. Two routines are provided to help you deal with the Tool Types array. FindToolType() returns the value of a Tool Type element. Using the above example, if you are looking for FILETYPE, the string "PaintProgram|ILBM" will be returned. MatchToolValue() returns nonzero if the specified string is in the reference value string. This routine knows how to parse vertical bars. For example, using the reference value strings of "PaintProgram" or "ILBM", MatchToolValue() will return TRUE for "ILBM" and "PaintProgram" and FALSE for everything else.
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