Writing a SCOadmin manager

Exiting the application

Managers should preserve user preferences (such as toolbar, refresh options, short help, and so on) before exiting. SaScreenPolicy(TCL_ADM) allows managers to save and retrieve information about user preference configuration in a per-user database ($HOME/.scoadmin.pref).

During shutdown, you may have to interrupt the procedural flow from the caller to present error dialogs to the user. This requires returning to the event-driven user interface loop. The procedure shown in ``Template shutdown procedure: UiStop'' uses ``Template secondary shutdown procedure: UiStop2'' and a callback to return control to the caller,

Template shutdown procedure: UiStop

proc UiStop {cb} {
	global appvals

	# Suspend autorefreshes to reduce our error concerns
	if {$appvals(autorefresh)} {
		SaAutoRefreshPause
	}

	set vtMain $appvals(vtMain)
	set client $appvals(client)

	# Store modified preferences

	# short help
	set cmd [list SaShortHelpStore $client]
	if {[ErrorCatch errorStack 0 $cmd dummy] != 0 } {
		lappend errorStacks $errorStack
	}

	# auto refresh
	if {$appvals(autorefresh)} {
		set cmd [list SaAutoRefreshStore $client]
		if {[ErrorCatch errorStack 0 $cmd dummy] != 0 } {
			lappend errorStacks $errorStack
		}
	}

	# toolbar
	if {$appvals(toolbarcust)} {
		set cmd {UiToolBarStore}
		if {[ErrorCatch errorStack 0 $cmd dummy] != 0 } {
			lappend errorStacks $errorStack
		}
	}

	# any problems?
	if [info exists errorStacks] {
		# present error dialog and enter event-driven Ui loop.
		# Re-gain procedural control via UiStop2 (part 2) and
		# eventually, the caller's cb
		SaDisplayErrorStacks $vtMain.UIStop $errorStacks {} \
			[list UiStop2 $cb]
		UiMainLoop
	} else {
		# stop vtcl
		VtUnLock
		VtClose
		# return control to the caller
		eval $cb
	}
}

Template secondary shutdown procedure: UiStop2

   proc UiStop2 {cb {cbs {}}} {
   	UiUnLock
   	VtClose
   	# return control to the caller
   	eval $cb