The system preference editors
Here's a list of the system preference editors and the system defaults they control. You should know what the system controls provide before writing any controls of your own.
Font
Specification of default screen, system and Workbench fonts. The file format is IFF FORM PREF (FONT chunk). The filenames are screenfont.prefs, sysfont.prefs, and wbfont.prefs, respectively.
IControl
Intuition-specific control items, including verify timeout and command key definitions. The file format is IFF FORM PREF (ICTL chunk). The filename is icontrol.prefs.
Input
Mouse and keyboard control items. The file format is IFF FORM PREF (INPT chunk). The filename is input.prefs.
Overscan
Standard video and text overscan areas for the various modes supported by the system. The file format is IFF FORM PREF (OSCN chunk). The filename is oscan.prefs.
Palette
Colour selections for the Workbench screen. The file format is IFF FORM ILBM (the main chunk is CMAP). The filename is palette.ilbm.
Pointer
Design of the mouse pointer image. The file format is IFF FORM ILBM. The filename is pointer.ilbm.
Printer
Printer text preferences and printer driver selection. The file format is IFF FORM PREF (PTXT chunk). The filename is printer.prefs.
PrinterGfx
Printer graphic preferences. The file format is IFF FORM PREF (PGFX chunk). The filename is printergfx.prefs.
ScreenMode
Display information such as the Workbench display mode and the raster dimensions. The file format is IFF FORM PREF (SCRM chunk). The filename is screenmode.prefs.
Serial
Serial port definitions including baud rate, handshaking and parity. The file format is IFF FORM PREF (SERL chunk). The filename is serial.prefs.
Time
System and real-time clock date and time. No file is used. Data is stored into the system and the battery-backed clock/calendar.
WBPattern
The backdrop patterns used in Workbench and its windows. The file format is custom. Names are wb.pat and win.pat respectively.
Storage of System Settings
Users can change system-wide settings for their current session by clicking the Use gadget in an editor, or they can change the permanent settings by clicking the Save gadget.
Listed at right is how the system stores settings. Your application should follow the steps outlined in the "Accessing Settings Files" section.
The system stores these settings files in four different locations. (Your application should follow these steps only if it installs a system-wide preferences editor in the [SYS:]Prefs drawer. Otherwise, you should follow the conventions outlined in the next section.)
- Defaults are imbedded in the system preferences themselves.
- If the user modifoes a preference item and selects Save on the requester, the settings are stored in the preference archive ENVARC:sys/<filename> and ENV:sys/<filename> (see the list above for the filename).
- If the user selects Use on the requester (instead of Save), the current settings are stored only in ENV:sys/<filename>. The archived settings in ENVARC:sys remain unchanged. ENV: does not survive a reboot.
- Alternate settings called presets are stored in the Workbench:Prefs/Presets drawer or in other user-specified places.
Preference Presets
Preferences presets are alternate versions of the recognized preferences files. Their purpose is to support a variety of user configurations that can be "turned on" at the user's discretion.
For example, the default definition of the Amiga's mouse pointer is archived in ENVARC:sys/pointer.ilbm. However, the user may have an alternate pointer he favours when working with a paint program. An alternate image can be designed in the Pointer editor and saved in Workbench:Prefs/Presets.
Once it's saved as a preset, the user can activate the alternate image at any time by double-clicking on its icon. (The icon's default tool is the Pointer preferences editor.) The preset can also be activated from the Shell or from the editor. The original version will still be available in the ENVARC:sys directory.