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(3tlib) 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]
		VtUnLock
		VtMainLoop
	} else {
		# stop vtcl
		VtUnLock
		VtClose
		# return control to the caller
		eval $cb
	}
}

Template secondary shutdown procedure: UiStop2

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