PwrSwitcher may be freely distributed so long as it includes this documentation. PwrSwitcher may not be sold. The user must assume all risk of loss resulting from use of PwrSwitcher.
Description
PwrSwitcher is a system extension that lets you cycle through the active programs by pressing the power key on your ADB keyboard. This release of PwrSwitcher requires System 7, and a keyboard with a power key.
With the shift key down, PwrSwitcher cycles through active programs in reverse order.
The control key may be held down while invoking PwrSwitcher ╤ it has no effect on operation. Perhaps this will help RadiusWare users avoid triggering PwrSwitcher and Cursor Beacon at the same time.
Similar Programs
PwrSwitcher is most similar to Switch by W. J. Bock. Unfortunately, the only version of Switch that I've ever seen chokes when File Sharing (or any other background╨only application) is active. [Incidentally, AppSwitcher and JustClick also have the same problem, at least for the moment.]
Installation
Drag the PwrSwitcher icon to your System Folder, and allow the Finder to place it in the Extensions folder. PwrSwitcher will be installed the next time you restart your machine. To remove PwrSwitcher, move it somewhere else (not inside the System Folder) and restart your machine. You can prevent PwrSwitcher from installing itself by pressing the mouse button just before its icon appears. (I╒ve always thought that this approach is bogus, but it╒s a ╥standard╙╔)
Compatibility
For now, PwrSwitcher only works under System 7, and with keyboards that have a power key. I may remove these restrictions in a future release.
If you use PwrSwitcher under System 6 or earlier, it will not install itself, and will show a ╥dimmed╙ version of its icon during startup.
If you use PwrSwitcher under System 7 on a keyboard without a power key, it will install normally, but you won╒t be able to access its functionality.
RadiusWare users have found that PwrSwitcher and Cursor Beacon both respond to the power key. As of v1.0a2, I╒ve changed PwrSwitcher so you can also trigger it with the control key down. I hope this will keep Cursor Beacon from doing its thing at the same time.
PwrSwitcher coexists quite nicely with Paul Mercer╒s Programmer╒s Key, which also uses the power key. PwrSwitcher only does its thing when none of the modifier keys (except maybe the Caps Lock key) are pressed, while Programmer╒s Key only does its thing when one or more of the modifier keys are pressed.
Known Problems
One thing that I find annoying is that PwrSwitcher makes ╥hidden╙ layers visible ╤ I╒ll try to fix this, but it depends upon access to the Layer Manager, which Apple hasn╒t documented yet.
Feedback
I would appreciate comments and suggestions regarding PwrSwitcher. I can be reached at the following addresses:
AOL: DBLamkins
Internet: lamkins@cs.umb.edu (not a permanent account)
Caution
I have not yet registered PwrSwitcher╒s creator type, 'PWRS'. You may find that this creator conflicts with an existing application on your disk. If this happens, PwrSwitcher may take on the other application╒s icon, or the other application may take on PwrSwitcher╒s icon.
If this PwrSwitcher╒s creator conflicts with another application, you should remove all copies of PwrSwitcher from your disk and rebuild the desktop by inserting the disk (or restarting from the disk, if it╒s your startup volume) with the Command and Option keys held down until you get the dialog asking for permission to rebuild the desktop. I would also appreciate a note informing me of the conflict.
Future Plans
Ñ Provide an alternate activation key for other keyboards.
Ñ Support operation under System 6 Multifinder.
Ñ Provide a way to ╥mark╙ and switch directly to an application.
Ñ Skip over ╥hidden╙ layers.
Release History
1.0a1 Aug 3, 1991: First release.
1.0a2 Aug 7, 1991: Ignore Control key so RadiusWare users can cycle without triggering Cursor Beacon. Cycle backwards through processes when Shift key is down.
Implementation
PwrSwitcher patches the _KeyTrans trap, looking for a keydown on the power key. When this happens, PwrSwitcher calls the Process Manager to get the next process following the front process, and brings that process to the front. Background╨only processes are skipped.
PwrSwitcher was written entirely in THINK Pascal, using an INIT shell of my own design. The INIT shell allows you to install patches and VBL tasks in a straightforward way without resorting to inline code. The shell also provides a Quickdraw world so the shell can display the init icon, and so the init can (if absolutely necessary, although INITs aren╒t supposed to do this) display windows or dialogs. The shell provides a mechanism for the INIT to easily undo everything and bail out if an error occurs partway into the installation.
