This package contains a library, SpinningCursor.lib, which allows any program to start an "asynchronous" (i.e. task-independent) spinning cursor. Simply link the library to your program (this varies with the compiler so I won't discuss it).
For your information, I have included a sample program: it simply spins the cursor (it's the Finder's watch, by the way) until you click the mouse.
What you need to know:
1) This library was taken directly and blatantly from the book "Macintosh Programming Secrets, Second Edition" (Addison-Wesley), and is distributed with the author's permission. You should get the book, because a) it's very informative and b) there are _lots_ of source code comments which I obviously didn't type in.
2) The library doesn't work by itself; you need to provide a resource file with two resources:
- a 'CURS' resource, which is a list of all the cursor "frames" that you want to use in your animation. Note that if you want an animation that comes and goes (like the hand in the Apple Installer that first extends the fingers and then folds them back), you need to specify all the frames in order: the animation process goes one-way only.
- an 'acur' resource, which specifies what are the "frames" ID numbers and the order you want them in.
See the sample resource for an example.
3) There are three procedures you want to install in your program:
- InitCursorCtl (acurResourceID: Integer);
Use this routine once to initialize the cursor-animating task. The argument is the resource ID of the 'acur' resource, _not_ the 'CURS' resources: those are contained in the 'acur' resource.
-StartAsyncSpinning (period: Integer);
This starts the spinning cursor asynchronously (i.e. you can do other tasks while the cursor spins; it should not be affected). The argument is the delay (in ticks, or 1/60ths of second) between each cursor "frame". For instance, if you want to change the cursor each .25 second, set this value to 10.
- StopAsyncSpinning;
This stops the spinning cursor.
4) None of these tasks save the current cursor. You should do that yourself, and restore it afterwards.
Other than that, share it and enjoy it!
If you do use that library in anything that goes further than your desk, I would appreciate you telling me (I don't want a mention in your program, 'cause I only typed that code in!). Hey! a postcard would be real nice! But e-mail is fine (though I can't stick e-mail on my fridge and show it to my kids).
Thanks to you all, out there on the 'net, and special thanks to Keith Rollin (and Scott Knaster) for de-mystifying Macintosh programming.
