+proc unselectline {} {
+ global selectedline
+
+ catch {unset selectedline}
+ allcanvs delete secsel
+}
+
+proc addtohistory {cmd} {
+ global history historyindex
+
+ if {$historyindex > 0
+ && [lindex $history [expr {$historyindex - 1}]] == $cmd} {
+ return
+ }
+
+ if {$historyindex < [llength $history]} {
+ set history [lreplace $history $historyindex end $cmd]
+ } else {
+ lappend history $cmd
+ }
+ incr historyindex
+ if {$historyindex > 1} {
+ .ctop.top.bar.leftbut conf -state normal
+ } else {
+ .ctop.top.bar.leftbut conf -state disabled
+ }
+ .ctop.top.bar.rightbut conf -state disabled
+}
+