+ set ret -1
+ if {[info exists children($curview,$id)]} {
+ foreach kid $children($curview,$id) {
+ if {![info exists commitrow($curview,$kid)]} break
+ if {$commitrow($curview,$kid) < $row} {
+ set ret $commitrow($curview,$kid)
+ }
+ }
+ }
+ return $ret
+}
+
+proc make_idlist {row} {
+ global displayorder parentlist uparrowlen downarrowlen mingaplen
+ global commitidx curview ordertok children commitrow
+
+ set r [expr {$row - $mingaplen - $downarrowlen - 1}]
+ if {$r < 0} {
+ set r 0
+ }
+ set ra [expr {$row - $downarrowlen}]
+ if {$ra < 0} {
+ set ra 0
+ }
+ set rb [expr {$row + $uparrowlen}]
+ if {$rb > $commitidx($curview)} {
+ set rb $commitidx($curview)
+ }
+ set ids {}
+ for {} {$r < $ra} {incr r} {
+ set nextid [lindex $displayorder [expr {$r + 1}]]
+ foreach p [lindex $parentlist $r] {
+ if {$p eq $nextid} continue
+ set rn [nextuse $p $r]
+ if {$rn >= $row &&
+ $rn <= $r + $downarrowlen + $mingaplen + $uparrowlen} {
+ lappend ids [list $ordertok($curview,$p) $p]
+ }
+ }
+ }
+ for {} {$r < $row} {incr r} {
+ set nextid [lindex $displayorder [expr {$r + 1}]]
+ foreach p [lindex $parentlist $r] {
+ if {$p eq $nextid} continue
+ set rn [nextuse $p $r]
+ if {$rn < 0 || $rn >= $row} {
+ lappend ids [list $ordertok($curview,$p) $p]
+ }
+ }
+ }
+ set id [lindex $displayorder $row]
+ lappend ids [list $ordertok($curview,$id) $id]
+ while {$r < $rb} {
+ foreach p [lindex $parentlist $r] {
+ set firstkid [lindex $children($curview,$p) 0]
+ if {$commitrow($curview,$firstkid) < $row} {
+ lappend ids [list $ordertok($curview,$p) $p]
+ }
+ }
+ incr r
+ set id [lindex $displayorder $r]
+ if {$id ne {}} {
+ set firstkid [lindex $children($curview,$id) 0]
+ if {$firstkid ne {} && $commitrow($curview,$firstkid) < $row} {
+ lappend ids [list $ordertok($curview,$id) $id]
+ }
+ }
+ }
+ set idlist {}
+ foreach idx [lsort -unique $ids] {
+ lappend idlist [lindex $idx 1]
+ }
+ return $idlist
+}
+
+proc rowsequal {a b} {
+ while {[set i [lsearch -exact $a {}]] >= 0} {
+ set a [lreplace $a $i $i]
+ }
+ while {[set i [lsearch -exact $b {}]] >= 0} {
+ set b [lreplace $b $i $i]
+ }
+ return [expr {$a eq $b}]
+}
+
+proc makeupline {id row rend col} {
+ global rowidlist uparrowlen downarrowlen mingaplen
+
+ for {set r $rend} {1} {set r $rstart} {
+ set rstart [prevuse $id $r]
+ if {$rstart < 0} return
+ if {$rstart < $row} break
+ }
+ if {$rstart + $uparrowlen + $mingaplen + $downarrowlen < $rend} {
+ set rstart [expr {$rend - $uparrowlen - 1}]
+ }
+ for {set r $rstart} {[incr r] <= $row} {} {
+ set idlist [lindex $rowidlist $r]
+ if {$idlist ne {} && [lsearch -exact $idlist $id] < 0} {
+ set col [idcol $idlist $id $col]
+ lset rowidlist $r [linsert $idlist $col $id]
+ changedrow $r
+ }
+ }
+}
+
+proc layoutrows {row endrow} {
+ global rowidlist rowisopt rowfinal displayorder
+ global uparrowlen downarrowlen maxwidth mingaplen
+ global children parentlist
+ global commitidx viewcomplete curview commitrow
+
+ set idlist {}
+ if {$row > 0} {
+ set rm1 [expr {$row - 1}]
+ foreach id [lindex $rowidlist $rm1] {
+ if {$id ne {}} {
+ lappend idlist $id
+ }
+ }
+ set final [lindex $rowfinal $rm1]
+ }
+ for {} {$row < $endrow} {incr row} {
+ set rm1 [expr {$row - 1}]
+ if {$rm1 < 0 || $idlist eq {}} {
+ set idlist [make_idlist $row]
+ set final 1
+ } else {
+ set id [lindex $displayorder $rm1]
+ set col [lsearch -exact $idlist $id]
+ set idlist [lreplace $idlist $col $col]
+ foreach p [lindex $parentlist $rm1] {
+ if {[lsearch -exact $idlist $p] < 0} {
+ set col [idcol $idlist $p $col]
+ set idlist [linsert $idlist $col $p]
+ # if not the first child, we have to insert a line going up
+ if {$id ne [lindex $children($curview,$p) 0]} {
+ makeupline $p $rm1 $row $col
+ }
+ }
+ }
+ set id [lindex $displayorder $row]
+ if {$row > $downarrowlen} {
+ set termrow [expr {$row - $downarrowlen - 1}]
+ foreach p [lindex $parentlist $termrow] {
+ set i [lsearch -exact $idlist $p]
+ if {$i < 0} continue
+ set nr [nextuse $p $termrow]
+ if {$nr < 0 || $nr >= $row + $mingaplen + $uparrowlen} {
+ set idlist [lreplace $idlist $i $i]
+ }
+ }
+ }
+ set col [lsearch -exact $idlist $id]
+ if {$col < 0} {
+ set col [idcol $idlist $id]
+ set idlist [linsert $idlist $col $id]
+ if {$children($curview,$id) ne {}} {
+ makeupline $id $rm1 $row $col
+ }
+ }
+ set r [expr {$row + $uparrowlen - 1}]
+ if {$r < $commitidx($curview)} {
+ set x $col
+ foreach p [lindex $parentlist $r] {
+ if {[lsearch -exact $idlist $p] >= 0} continue
+ set fk [lindex $children($curview,$p) 0]
+ if {$commitrow($curview,$fk) < $row} {
+ set x [idcol $idlist $p $x]
+ set idlist [linsert $idlist $x $p]
+ }
+ }
+ if {[incr r] < $commitidx($curview)} {
+ set p [lindex $displayorder $r]
+ if {[lsearch -exact $idlist $p] < 0} {
+ set fk [lindex $children($curview,$p) 0]
+ if {$fk ne {} && $commitrow($curview,$fk) < $row} {
+ set x [idcol $idlist $p $x]
+ set idlist [linsert $idlist $x $p]
+ }
+ }
+ }
+ }
+ }
+ if {$final && !$viewcomplete($curview) &&
+ $row + $uparrowlen + $mingaplen + $downarrowlen
+ >= $commitidx($curview)} {
+ set final 0
+ }
+ set l [llength $rowidlist]
+ if {$row == $l} {
+ lappend rowidlist $idlist
+ lappend rowisopt 0
+ lappend rowfinal $final
+ } elseif {$row < $l} {
+ if {![rowsequal $idlist [lindex $rowidlist $row]]} {
+ lset rowidlist $row $idlist
+ changedrow $row
+ }
+ lset rowfinal $row $final
+ } else {
+ set pad [ntimes [expr {$row - $l}] {}]
+ set rowidlist [concat $rowidlist $pad]
+ lappend rowidlist $idlist
+ set rowfinal [concat $rowfinal $pad]
+ lappend rowfinal $final
+ set rowisopt [concat $rowisopt [ntimes [expr {$row - $l + 1}] 0]]
+ }
+ }
+ return $row
+}
+
+proc changedrow {row} {
+ global displayorder iddrawn rowisopt need_redisplay
+
+ set l [llength $rowisopt]
+ if {$row < $l} {
+ lset rowisopt $row 0
+ if {$row + 1 < $l} {
+ lset rowisopt [expr {$row + 1}] 0
+ if {$row + 2 < $l} {
+ lset rowisopt [expr {$row + 2}] 0
+ }
+ }
+ }
+ set id [lindex $displayorder $row]
+ if {[info exists iddrawn($id)]} {
+ set need_redisplay 1