The System Event Manager APIs allow you to enable the Graffiti® 2 handwriting engine and to control the device's auto-off timer.
The contents of this chapter are organized as follows:
System Event Manager Structures and Types
System Event Manager Constants
System Event Manager Functions and Macros
The header file SysEvtMgr.h
declares the API that this chapter describes.
For other APIs used to work with events, see Chapter 7, "Event." For background information on the Palm OS event system, see Chapter 3, "Events and the Event Loop."
System Event Manager Structures and Types
EvtSetAutoOffCmd Typedef
Purpose
Contains one of the auto-off-timer command values defined by the EvtSetAutoOffTag
enum.
Declared In
SysEvtMgr.h
Prototype
typedef Enum8 EvtSetAutoOffCmd
System Event Manager Constants
EvtSetAutoOffTag Enum
Purpose
Commands used with EvtSetAutoOffTimer()
to control the device's auto-off timer.
Declared In
SysEvtMgr.h
Constants
-
SetAtLeast
- Make sure that the device won't turn off until
timeout
seconds of idle time has passed. (This operation only changes the current value if it's less than the value you specify.) -
SetExactly
- Set the timer to turn off in
timeout
seconds. -
SetAtMost
- Make sure the device will turn before
timeout
seconds has passed. (This operation only changes the current value if it's greater than the value you specify.) -
SetDefault
- Change the default auto-off timeout to
timeout
seconds. -
ResetTimer
- Reset the auto-off timer so that the device does not turn off until at least the default seconds of idle time has passed.
System Event Manager Functions and Macros
EvtEnableGraffiti Function
Purpose
Enable or disable Graffiti 2 handwriting recognition.
Declared In
SysEvtMgr.h
Prototype
void EvtEnableGraffiti (
Boolean enable
)
Parameters
Returns
EvtResetAutoOffTimer Function
Purpose
Declared In
SysEvtMgr.h
Prototype
status_t EvtResetAutoOffTimer ( void )
Parameters
Returns
Comments
EvtResetAutoOffTimer
resets the auto-off timer so that the device does not turn off until at least the default amount of idle time has passed. You can use this function to ensure that the device doesn't automatically power off during a long operation without user input (for example, when there is a lot of serial port activity).
If you need more control over the auto-off timer, consider using EvtSetAutoOffTimer()
instead of this function.
EvtSetAutoOffTimer Function
Purpose
Declared In
SysEvtMgr.h
Prototype
status_t EvtSetAutoOffTimer ( EvtSetAutoOffCmdcmd
, uint16_ttimeout
)
Parameters
-
→ cmd
- One of the commands defined by the
EvtSetAutoOffTag
enum. -
→ timeout
- A new timeout value in seconds. If
cmd
isResetTimer
, this parameter is ignored.
Returns
Comments
Use this function to ensure that the device doesn't automatically power off during a long operation that has no user input (for example, when there is a lot of serial port activity).