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AmigaOS 4.0 - About OS4 - Preferences

GUI Preferences Editor
The GUI Preferences editor enables you to change vitually anything to do with the appearance of the Workbench screen, comprising Colors, Borders, Gadgets, Menus, Styles, Options and Controls, each one with its own editing window accessed from the left-hand menu bar.

Styles

With AmigaOS 4.0, Intuition can use custom-made bitmap images for system gadgets, which can be set for your screen using the Bitmap set gadget. When clicked, it brings up a file requester which allows you to select a bitmap set directory residing on your hard disk.

To remove the currently selected bitmap style, just enter an empty string into the "Bitmap set" gadget.

Bitmap sets are organized in separate directories, named after the style of the set itself, which contain a number of sub-directories. Each of these, in turn, is named after a particular symbol and contains the actual bitmap image files (brushes) for that symbol.

The image files can have any format supported by your picture datatypes.

In addition to the above, the main bitmap set directory can also contain a settings file named "Config". The contents of this file are currently ignored by Intuition (they will become significant in future releases!) but the file itself is very important: if it is missing, Intuition will interpret the images for window border gadgets as if they have just three states (like in VisualPrefs bitmap sets) rather than four states as supported by the new sysiclass. This allows older bitmap sets to be used without modifications; it also means that new bitmap sets designed for Intuition Release 4 MUST have a "Config" file inside their main directory (at least if they contain window border images with four states).

Currently, Intuition uses up to 7 separate image files for each symbol:

  • A file called "Default" containing the images for all possible states of the symbol (inactive, normal, selected, etc.);
  • An optional file called "Default.mask", which is an one-bitplane image used to mask out certain pixels of the symbol image when it is blitted onto its display element (this is not needed if the image file already contains transparency information);
  • An optional file called "Default.outl", which is an one-bitplane image representing a simple outline of the main image: this is used to produce an embossed shape for the image's disabled states;
  • An optional file called "Default.shin", which is an 8-bitplane indexed (CLUT) image whose pixels represent alpha-like intensity levels, useful to produce bright shading effects;
  • An optional file called "Default.shad", which is an 8-bitplane indexed (CLUT) image whose pixels represent alpha-like intensity levels, useful to produce dark shading effects (like drop shadows);
  • An optional file called "Default.amap", which is an 8-bitplane indexed (CLUT) image whose pixels represent alpha intensity levels, useful to perform special effects like alpha blending or antialiasing (this is not needed if the image file already contains alpha channel information, as it can happen for instance with pictures in PNG format);
  • An optional file called "Default.omap", which is an 8-bitplane indexed (CLUT) image whose pixels represent alpha intensity levels, useful to produce a smooth embossed shape/outline for the image's disabled states. This supercedes "Default.outl" on hicolor/truecolor screens.
In the main file all the images for the states must be placed horizontally, next one another, in a specific order (see below). All the state images must have the exact same width. The other image files, if present, must have exactly the same size and image layout as the main one.

A symbol state image is always placed by Intuition in the center of its surrounding display element; if the symbol image is too large for the display element's size, only its center part will be shown.

If the main image file for a particular symbol can't be loaded, the vector symbol from the currently selected vector style will be used in its place. This means you can also "patch" an already-existing vector style, by drawing just a few bitmaps to replace only those symbols you don't like. In the most extreme case, you could use this feature to simply add a logo to your screen titlebar, and keep using a vector style for everything else.

As already mentioned, each symbol image file must contain a number of images corresponding to the various states the symbol can have. The following list shows the names of all currently supported symbols along with the number of states they require, and the exact left-to-right order the states must have.

Note: the MenuCheck and MenuMX images require eight states each, because the first four represent the "checked" version and the last four represent the "unchecked" version.

Directory Explanation # Order of states
SClose Screen close gadget symbol 2 N, S
SDepth Screen depth gadget symbol 2 N, S
Close Window close gadget symbol 4 N, S, I, IS
Zoom Window zoom gadget symbol 4 N, S, I, IS
Depth Window depth gadget symbol 4 N, S, I, IS
Iconify Window iconify gadget symbol 4 N, S, I, IS
Snapshot Window snapshot gadget symbol 4 N, S, I, IS
Settings Window settings gadget symbol 4 N, S, I, IS
PopUp Window popup gadget symbol 4 N, S, I, IS
Screens Window screen-jump gadget symbol 4 N, S, I, IS
Padlock DirOpus "padlock" symbol 4 N, S, I, IS
Size Window sizing gadget symbol 4 N, S, I, IS
ArrowUp Window up arrow symbol 4 N, S, I, IS
ArrowDown Window down arrow symbol 4 N, S, I, IS
ArrowLeft Window left arrow symbol 4 N, S, I, IS
ArrowRight Window right arrow symbol 4 N, S, I, IS
SBarLogo Screen bar logo 1 N
MenuCheck Menu checkmark symbol 8 N, S, D, DS, N, S, D, DS
AmigaKey Menu Amiga key symbol 4 N, S, D, DS
MenuMX Menu mutualexclude symbol 8 N, S, D, DS, N, S, D, DS
MenuSub Menu sub-panel (arrow) symbol 4 N, S, D, DS
Checkmark GT/RA checkmark symbol 4 N, S, D, DS
Cycle GT/RA cycle symbol 4 N, S, D, DS
GArrowUp GT/RA up arrow symbol 4 N, S, D, DS
GArrowDown GT/RA down arrow symbol 4 N, S, D, DS
GArrowLeft GT/RA left arrow symbol 4 N, S, D, DS
GArrowRight GT/RA right arrow symbol 4 N, S, D, DS
N = Normal, S = Selected, I = Inactive, IS = Inactive Selected,
D = Disabled, DS = Disabled Selected

In the future it is planned that Intuition will support different image sizes for each symbol, or even bitmap scaling where appropriate.

Additional notes

  • Bitmap images support four kinds of alpha shading, by way of separate "map" image files. The first two are "bright shading" and "dark shading", which can be used to achieve pseudo-3D effects or just to add realistic shadows to the main image. The third is "alpha blending" which can be used to perform anti-aliasing or transparency effects for the image. The fourth is "alpha disabling" which can be used to automatically draw an anti-aliased embossed shape/outline for the image's disabled states. (Needless to say, all of this only really works on hi/truecolor screens.)

    All shading map files are 8-bit indexed pictures where each pixel's color represents a shade level between 0 and 255. For bright shading maps, 0 means "background unchanged" and 255 means "white". For dark shading maps, 0 means "black" and 255 means "background unchanged". For alpha blending maps, 0 means "100% background color" and 255 means "100% image color" (as you would probably expect ;) For alpha disabling maps, 0 means "background unchanged" and 255 means "maximum contrast".

  • Bitmap images also support an "outline mask" which is used to produce the infamous 3D-embossed disabled look. The format of this file is exactly the same as a normal mask file, although of course the mask shape should be some kind of outline of the main image. On hi/truecolor screens, the outline mask is only used if there isn't an alpha disabling map available.

    Usage of such outlines is of course optional; if you use it, you won't generally need to draw the disabled states in the main image (unless you want to achieve fancy effects with a mixed flat/embossed look.

  • You don't need to have a separate ".mask" file if you save the main image file in a format that specifies a transparent color (and use that color in the picture wherever the background should be transparent). This of course means you need to sacrifice one of the image palette's colors for this purpose. It's likely that this can only work for 8-bit indexed pictures, as truecolor picture formats (as far as I know) don't allow specification of a single transparent color.

  • You don't need to have a separate ".amap" file if you save the main image file in a format that already holds alpha channel information. If you do, however, the ".amap" file contents will override the alpha channel information found in the main image file.
Action Buttons
When you make changes you can choose to 'Save' them permanently, just 'Use' them temporarily until the system is rebooted, or you can 'Cancel' and lose all changes.


Return to Preferences Selection

Disclaimer: Amiga Auckland have prepared the above information for the use of its members based on our experiences and as such is subject to revision at any time. Amiga Auckland cannot guarantee any of the information and cannot be held accountable for any issues that may result from using it.


Copyright 2006 Amiga Auckland Inc. All rights reserved.
Revised: February 9, 2006.