NeXT TypedStream Data | 1995-06-12 | 10.5 KB | 113 lines
typedstream
IBObjectData
Object
CustomObject
Thinker
ScrollView
Responder
Button
Control
ButtonCell
ActionCell
Helvetica
NXImage
TextField
TextFieldCell
BackSpace
Helvetica-Bold$
by Samuel G. Streeper
Title
Version 3.00 release 920402
<Copyright 1991,1992 NeXT Computer Inc. All Rights Reserved.
ClipView
ciifffcfffs
[8643c]{\rtf0\ansi{\fonttbl\f0\fswiss Helvetica;}
\margl40
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{\colortbl;\red0\green0\blue0;}
\pard\tx960\tx1920\tx2880\tx3840\tx4800\tx5760\tx6720\tx7680\tx8640\tx9600\f0\b\i0\ulnone\fs28\fc1\cf1 The Extensible Screen Saver\
\b0\fs24 BackSpace is a collection of things to make your screen more interesting and fun. It can give you a flying starfield as a backdrop for your normal work, act as a screen saver, and lock your screen to keep others from tampering with your data if you must leave the computer for a bit.\
I envision BackSpace as a screen saver construction set, a community project that others will extend by writing other neat screen saver modules. My goal is to make our computers look flashy and draw attention, even when they are doing nothing at all. And if I can provide something fun and useful in the process, all the better! If you create an interesting screen saver module and don't mind me distributing it, send it along and I'll include it if it's really cool. Go crazy, huh?\
\b\fs28 Settings
\b0\fs24 \
The window buttons allow you to select what BackSpace does while you actually work on your computer. You can have it put the selected animation in a normal window, or use it as a background screen. Sometimes it's kind of fun to have your computer zoom through space while you work... If you want the program to stay out of your way, just select none.\
\b\fs28 Screen Saver
\b0\fs24 \
If you select the screen saver feature, BackSpace will act as a screen saver; When the computer has been inactive, you will be greeted by the selected screen saver rather than the normal dim screen. You can also force the screen saver/locker into action by selecting "Do Screen Saver" from the menu or the Settings window.\
BackSpace uses the timeout interval set via the Preferences application; however, it might not detect changes to the interval enacted after BackSpace is launched.\
NeXT Computer Inc. makes no warranties of the fitness of BackSpace as a screen saver or as anything else, so be careful.\
\b\fs28 Screen Locker
\b0\fs24 \
BackSpace can be set to lock your screen when the screen saver kicks in. Implicit in this is that the screen won't lock unless you have a screen locking password, enable the screen lock feature, and either have the screen saver enabled or manually initiate the screen saver. This screen locker shouldn't be thought to provide extensive security, but it will keep most casual interlopers out. You should NOT use you account password as your screen locking password, because a bad person could rather easily monitor the passwords given to BackSpace. Nevertheless, both the user's account password and the root password can be used to unlock the screen.\
You can still turn the power off even if the screen is locked. When the
\b Power
\b0 key is pressed, the Workspace application will activate and display a panel asking you to confirm the power-off request, though you won't see this panel because it will be behind the screen saver's display. If you then type return, the computer will turn off. However, you can still unlock the screen after the user has pressed the
\b Power
\b0 button. You must move the mouse to bring up the password panel. You must then click in the panel to activate BackSpace (so it accepts keystrokes) and type your password but
\b do NOT press return
\b0 . After a short period, BackSpace will accept your password and unlock the screen. You can then cancel the power-off request.\
You should be considerate with the use of the screen locker. BackSpace should not be used to lock the screen for an extended period of time on a machine intended for public use; this usage could deprive others who really need to use the public machine. \
\b\fs28 Screen Saver Modules
\b0\fs24 \
The Settings panel includes a browser containing the possible screen saver modules. BackSpace can have any number of screen saver modules, and it will search in ~
\pard\tx960\tx1920\tx2880\tx3840\tx4800\tx5760\tx6720\tx7680\tx8640\tx9600\b0\fc1\cf1 (in that order) for all .BackO and .BackModule files containing compiled View objects to be used as screen saver modules. A .BackModule file is simply a folder containing a .BackO module, and possibly some related files. A .BackO module is a normal object file, but it must obey a certain protocol; see the included file
\b README.rtf
\b0 for more information on writing screen saver modules. A few modules are also built into the BackSpace application.\
\b\fs28 Compatibility with BackSpace 1.0
\b0\fs24 \
BackSpace's .BackO modules implement a superset of the protocol implemented by BackSpace 1.0's modules, so BackSpace can take all those modules. However, the old modules had a .o extention, and BackSpace couldn't readily identify modules. To make the old modules work, you will need to rename them to *View.BackO (where * matches the name of the old module.)\
\b\fs28 \
Module Inspectors
\b0\fs24 \
Some modules provide inspectors that BackSpace installs into its settings panel. These inspectors allow you to tailor the behavior of individual modules. Not all modules supply inspectors, however.\
\b\fs28 Priority
\b0\fs24 \
Most applications run at a Mach priority of 10, but BackSpace is probably more frivolous than anything else you run, so you don't want it to take too much time away from other applications. If you set a lower priority, other applications will get processor time at the expense of BackSpace rather than vice versa, so it shouldn't be too much of a pig. I recommend a priority of 9 or lower. If you run it at priority 0, it won't take much time away from other applications, but it will still run at full speed if no other application is requesting processor time.\
\b\fs28 BackSpace vs Zilla\
\b0\fs24 BackSpace doesn't completely interfere with the use of the Zilla supercomputing application, because Zilla will be able to run anytime BackSpace is running its screensaver display (despite the fact that the screen doesn't appear to dim). However, BackSpace can and will steal much valuable processing time away from Zilla. If your machine is running Zilla and you want to run BackSpace, you should select one of the screen saver modules that spends most of its time sleeping rather than performing animation. A good choice is the
\b Black
\b0 module, which performs no animation and will have negligible impact on Zilla, regardless of BackSpace's priority.\
\b\fs28 \
Features
\b0\fs24 \
I wanted this application to take as little memory as possible under most circumstances, so many of the modules run in an unbuffered window. Modules may also request that they be given buffered windows (which makes it easier to write nice animation); in this case the buffer is discarded any time the window is not on the screen. \
BackSpace remembers most of the things you set in the Settings panel. I figure you probably had a reason for setting things the way you did...\
\b\fs28 Known Bugs\
\b0\fs24 Hmmm, I think I fixed most of them, or they were fixed for me by NeXTstep 3.0...\
You can send bug reports, screen saver modules, suggestions, and chocolate to
\b backspace@NeXT.com
\b0 .\
I'm pretty busy so I won't promise I'll actually do anything with your missives, but you might get lucky.\
\b\fs28 Extra Credit Department
\b0\fs24 \
Lennart Lovstrand beta tested this and sent me a bunch of good code instead of suggestions. He did most of FadingImageView, SlidingImageView, PanelImageView, BackView, functions to find the launch directory and dynamically load the views. Thanx!\
\pard\tx960\tx1920\tx2880\tx3840\tx4800\tx5760\tx6720\tx7680\tx8640\tx9600\fc1\cf1 wrote the SpermView
\pard\tx1340\tx2680\tx4020\tx5360\tx6720\tx8060\tx9400\tx10740\tx12080\tx13440\fc1\cf1 for X windows. It was ported to NeXTstep by Ali Ozer who borrowed user path code from Bruce Blumberg.\
I periodically rummage though Ali Ozer's directory for stuff I don't feel like writing myself, since he writes such good examples... Lines of his code can be found all through the Thinker class.\
The BackWindow class is derived from Scott Hess' code for the Background app.\