That is only useful if you want a timer with only 1 second resolution, which
i think i most cases is not acceptable.
The Palm OS was originally totally event driven. The way to do this is do
any processing you need to when you're not processing events. First off
modify your event loop in AppEventLoop (if you're using the standard palm
app stationary) by changing the wait in EvtGetEvent() to 0 or a value close
to the interval you want. (second parameter). more on this later
Then, you can check the number of "ticks" that have elapsed since your last
time through, and compare that with the previous time through and see if
you're at your interval, and do the processing you need.
here's an example:
static void AppEventLoop(void)
{
UInt16 error;
EventType event;
UInt32 curTicks, myTickInterval, lastTicks = 0;
myTickInterval = kMyTickInteralSeconds * SysTicksPerSecond(); // fyi
it's 100 on about all Palm Devices
do {
EvtGetEvent(&event, 0);
if (! SysHandleEvent(&event))
if (! MenuHandleEvent(0, &event, &error))
if (! AppHandleEvent(&event))
FrmDispatchEvent(&event);
curTicks = TimGetTicks();
if (curTicks - lastTicks >= myTickInterval) {
DoSomething();
lastTicks = curTicks;
}
} while (event.eType != appStopEvent);
}
If your interval is high, you might want to change 0 to something that's
like 1/4 of your interval. The reason is, the processor goes to sleep when
it's waiting for the next event. Otherwise, with 0, it never does, and uses
battery power faster.
Nathan
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:bounce-palm-
[EMAIL PROTECTED] Behalf Of Jeffry Loucks
Sent: Tuesday, June 29, 2004 5:17 PM
To: Palm Developer Forum
Subject: RE: Timer and Callback?
Try this (don't forget to clear the alarm before exiting your app):
Err AlarmCallback(UInt16 almProcCmd, SysAlarmTriggeredParamType *paramP)
{
// at this point, app globals are not available, so pass
// what you need as a reference parameter
return 0;
}
void PrvSetCallbackAlarm(UInt32 milliseconds)
{
if (milliseconds)
{
milliseconds = milliseconds / 1000 + 1;
// Not stable if set for less than 2 seconds
if (milliseconds < 2)
milliseconds = 2;
// set alarm
AlmSetProcAlarm(AlarmCallback,0,TimGetSeconds() +
milliseconds);
}
else
{
// clear alarm
AlmSetProcAlarm(0,0,0);
}
}
--------------------
Jeff Loucks
Work 425-284-1128 [EMAIL PROTECTED]
Mobile 253-691-8812 [EMAIL PROTECTED]
Home 253-851-8908 [EMAIL PROTECTED]
-----Original Message-----
From: Marc A. Lepage [mailto:[EMAIL PROTECTED]
Sent: Tuesday, June 29, 2004 4:07 PM
To: Palm Developer Forum
Subject: Timer and Callback?
Is there an API for setting a callback to be called at time intervals
(e.g. every second)?
I looked but I could not find one.
Must I manually count ticks and call the callback myself?
--
For information on using the Palm Developer Forums, or to unsubscribe,
please see http://www.palmos.com/dev/support/forums/
--
For information on using the Palm Developer Forums, or to unsubscribe,
please see http://www.palmos.com/dev/support/forums/
--
For information on using the Palm Developer Forums, or to unsubscribe, please see
http://www.palmos.com/dev/support/forums/
