Workbench (AmigaOS)
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Workbench is the name given to both the core AmigaOS software that is not stored in the Kickstart ROM (the "Workbench disk"), and also the native graphical shell for the Amiga computer. The Workbench environment does not have to be loaded for software to run. In fact, to take over the Amiga hardware and keep all memory and resources to themselves, many games boot directly from Kickstart (using a custom bootblock on the floppy disk).
As the name suggests, the metaphor of a workbench is used, rather than a desktop; directories are depicted as drawers, executable files are tools, data files are projects and GUI widgets are gadgets. In many other aspects the interface resembles Mac OS, with the main desktop showing icons of inserted disks and hard drive partitions, and a single menu bar at the top of every screen. Unlike the Macintosh, the standard Amiga mouse has two buttons – the right mouse button operates the pull-down menus, with a Macintosh-style "release to select" mechanism.
A unique feature of Workbench is multiple screens. These are conceptually similar to X Window System virtual desktops or workspaces, but are generated dynamically by application programs as necessary. Each screen can have a different resolution and colour depth. A gadget in the top-right corner of the screen allows screens to be cycled - as the OS stores all screens in memory simultaneously, redrawing is instantaneous. Screens can also be dragged up and down by their title bars. On older Amigas this functionality was provided by the custom chipsets specially designed for the platform, but since AmigaOS4 a new technique is adopted and the screens are draggable in any direction. Drag and drop between different screens is possible too.
Underlying the Workbench is the Intuition windowing system. This controls and draws screens, windows and gadgets, and handles input from the keyboard and mouse, passing messages to programs.
[edit] Workbench 2.0 user interface improvements
Until Workbench 2.0, there was no unified look and feel design standard - application developers had to write their own widgets (both buttons and menus), with Intuition providing minimal support. With Workbench 2.0 came gadtools.library, which provided standard widget sets, and the Amiga User Interface Style Guide, which explained how applications should be laid out for consistency.
Workbench 2.0 also added support for public screens. Instead of the Workbench screen being the only shareable screen, applications could create their own named screens to share with other applications.
Workbench 2.0 introduced AmigaGuide, a simple text-only hypertext markup scheme and browser, for providing online help inside applications. It also introduced Installer, a standard software installation program, driven by a LISP-like scripting language.
Finally, Workbench 2.0 rectified the problem of developers hooking directly into the input-events stream to capture keyboard and mouse movements, often locking up the whole system. Workbench 2.0 provided Commodities, a standard interface for modifying or scanning input events. This included a standard method for specifying global "hotkey" key-sequences, and a Commodities Exchange registry for the user to see what commodities were running.
[edit] Workbench icons
The icons that Workbench uses to represent the files in a volume or a drawer are stored in special .info files, with the name of the .info file matching the name of the file it represents. For example, the icon for NotePad, a text editor, is found in the file NotePad.info.
The .info file includes the graphical representation of the icon and its position in the volume or drawer window. The icon also specifies the type of the file, as used by Workbench. Workbench recognises five different file types:
- Tool: An executable program.
- Project: A data file of an executable program. The program which created the file is named in the icon file, double-clicking on the icon loads the program that created it.
- Drawer: A directory containing files, and other drawers.
- Volume: A physical disk or a RAM disk.
- Garbage: The Trashcan - a deleted file backup, which works in a similar way to the 'Recycle bin' in Microsoft Windows.
An additional three file types are available and are intended for future expansion:
- Device: designed for displaying information about attached devices
- Kick: The icon of a bootable disk
- App Icon: An icon which will be used as (part of) the GUI for an application
Of these three only App Icons currently are used by any part of Workbench/AmigaOS.
Tool files can include "tool types" in the .info file. These are used as configuration options for the program. Each tool type is a single line of text, which can optionally include parameters, written after an = sign. Tool types can be commented out by writing them in parentheses. For example, the tooltype "CX_POPKEY=ctrl alt f1" says that the application (a Commodity) will pop up the user interface in response to the key sequence Ctrl-Alt-F1.
The colours used in the icon are normally only stored as indices to the Amiga Workbench screen's current palette. Because of this, the icons' colour scheme is inherently tied to the chosen hues in the screen's palette, and choosing non-standard colours can give the icons an ugly appearance. This problem was party solved by a third-party system called NewIcons, which adds additional features to the standard .info files. Unlike normal Workbench icons, NewIcons include actual RGB colour information, and the system tries its best to match the icons' colour hues to those in the screen palette.
Since AmigaOS 3.5, Workbench supports icons with up to 256 colors, still based on the screen palette. This release of AmigaOS features the Glowicons icon set by Matt Chaput. With AmigaOS 4.0, a screen-palette-independent system is used. The 4.0 icons, designed by Martin Merz, can use a palette of 256 colors each.
[edit] External Links
| AmigaOS (category) | |
|---|---|
| Companies: | Commodore International | Hyperion Entertainment |
| Computers: | Amiga |
| Technology: | Workbench | Intuition | AmigaDOS | ARexx | AmigaBASIC | Amigaguide | Software | Games | Demos |
| Operating systems: | AmigaOS (versions) | AROS | MorphOS |
