On Tue, 6 Apr 1999, Mark Campillo wrote:
> Is it possible to have events from the running application sent your
> application? For example, could keystrokes from the current application
> also be sent to your application? Also, is it possible to display a list,
> or other UI element, on the currently running application from your
> application? I know this kind of functionality is available with
> HackMaster, but can it be done using standard SDK APIs?
The PalmOS only runs one user application at a time, so your app is not
around to get events from another app, or display anything on the screen.
I hear you asking how HackMaster accomplishes the trick. It patches OS
traps so that code can be invoked by certain OS calls (like EvtGetEvent),
and leaves that part of itself in memory after it exits. (The procedure is
quite similar to the old TSR technique under MS-DOS).
Due to the complexity involved with safely maintaing these patched traps,
it is usually recommended that programmers write a Hack that HackMaster
can supervise.
Now, it's conceivable that you could set up a hack that made sub-calls
into your app at specific times, but this would require very careful
attention to details, and very limited memory usage.
--
Kenneth Albanowski ([EMAIL PROTECTED], CIS: 70705,126)
