gitk: Make it possible to lay out all the rows we have received so far

This arranges things so that we can do the layout all the way up to
the last commit that we have received from git log.  If we get more
commits we re-lay and redisplay (if necessary) the visible rows.

Signed-off-by: Paul Mackerras <paulus@samba.org>

gitk

@@ -82,11 +82,12 @@ proc dorunq {} {
 proc start_rev_list {view} {
     global startmsecs
     global commfd leftover tclencoding datemode
-    global viewargs viewfiles commitidx vnextroot
+    global viewargs viewfiles commitidx viewcomplete vnextroot
     global lookingforhead showlocalchanges
 
     set startmsecs [clock clicks -milliseconds]
     set commitidx($view) 0
+    set viewcomplete($view) 0
     set vnextroot($view) 0
     set order "--topo-order"
     if {$datemode} {
@@ -148,7 +149,7 @@ proc strrep {n} {
 proc getcommitlines {fd view}  {
     global commitlisted
     global leftover commfd
-    global displayorder commitidx commitrow commitdata
+    global displayorder commitidx viewcomplete commitrow commitdata
     global parentlist children curview hlview
     global vparentlist vdisporder vcmitlisted
     global ordertok vnextroot idpending
@@ -179,6 +180,7 @@ proc getcommitlines {fd view}  {
 		lappend vcmitlisted($view) 0
 	    }
 	}
+	set viewcomplete($view) 1
 	global viewname
 	unset commfd($view)
 	notbusy $view
@@ -310,15 +312,12 @@ proc getcommitlines {fd view}  {
 }
 
 proc chewcommits {view} {
-    global curview hlview commfd
+    global curview hlview viewcomplete
     global selectedline pending_select
 
-    set more 0
     if {$view == $curview} {
-	set allread [expr {![info exists commfd($view)]}]
-	set tlimit [expr {[clock clicks -milliseconds] + 50}]
-	set more [layoutmore $tlimit $allread]
-	if {$allread && !$more} {
+	layoutmore
+	if {$viewcomplete($view)} {
 	    global displayorder commitidx phase
 	    global numcommits startmsecs
 
@@ -339,7 +338,7 @@ proc chewcommits {view} {
     if {[info exists hlview] && $view == $hlview} {
 	vhighlightmore
     }
-    return $more
+    return 0
 }
 
 proc readcommit {id} {
@@ -1949,7 +1948,7 @@ proc unflatten {var l} {
 
 proc showview {n} {
     global curview viewdata viewfiles
-    global displayorder parentlist rowidlist rowisopt
+    global displayorder parentlist rowidlist rowisopt rowfinal
     global colormap rowtextx commitrow nextcolor canvxmax
     global numcommits commitlisted
     global selectedline currentid canv canvy0
@@ -1985,13 +1984,11 @@ proc showview {n} {
 	set vparentlist($curview) $parentlist
 	set vdisporder($curview) $displayorder
 	set vcmitlisted($curview) $commitlisted
-	if {$phase ne {}} {
-	    set viewdata($curview) \
-		[list $phase $rowidlist $rowisopt $numcommits]
-	} elseif {![info exists viewdata($curview)]
-		  || [lindex $viewdata($curview) 0] ne {}} {
+	if {$phase ne {} ||
+	    ![info exists viewdata($curview)] ||
+	    [lindex $viewdata($curview) 0] ne {}} {
 	    set viewdata($curview) \
-		[list {} $rowidlist $rowisopt]
+		[list $phase $rowidlist $rowisopt $rowfinal]
 	}
     }
     catch {unset treediffs}
@@ -2023,11 +2020,8 @@ proc showview {n} {
     set commitlisted $vcmitlisted($n)
     set rowidlist [lindex $v 1]
     set rowisopt [lindex $v 2]
-    if {$phase eq {}} {
-	set numcommits [llength $displayorder]
-    } else {
-	set numcommits [lindex $v 3]
-    }
+    set rowfinal [lindex $v 3]
+    set numcommits $commitidx($n)
 
     catch {unset colormap}
     catch {unset rowtextx}
@@ -2660,7 +2654,7 @@ proc idcol {idlist id {i 0}} {
 }
 
 proc initlayout {} {
-    global rowidlist rowisopt displayorder commitlisted
+    global rowidlist rowisopt rowfinal displayorder commitlisted
     global numcommits canvxmax canv
     global nextcolor
     global parentlist
@@ -2674,6 +2668,7 @@ proc initlayout {} {
     set nextcolor 0
     set rowidlist {}
     set rowisopt {}
+    set rowfinal {}
     set canvxmax [$canv cget -width]
     catch {unset colormap}
     catch {unset rowtextx}
@@ -2708,19 +2703,14 @@ proc visiblerows {} {
     return [list $r0 $r1]
 }
 
-proc layoutmore {tmax allread} {
-    global commitidx numcommits
+proc layoutmore {} {
+    global commitidx viewcomplete numcommits
     global uparrowlen downarrowlen mingaplen curview
 
     set show $commitidx($curview)
-    if {!$allread} {
-	set delay [expr {$uparrowlen + $mingaplen + $downarrowlen + 3}]
-	set show [expr {$show - $delay}]
-    }
     if {$show > $numcommits} {
-	showstuff $show $allread
+	showstuff $show $viewcomplete($curview)
     }
-    return 0
 }
 
 proc showstuff {canshow last} {
@@ -2901,6 +2891,21 @@ proc nextuse {id row} {
     return -1
 }
 
+proc prevuse {id row} {
+    global commitrow curview children
+
+    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
@@ -2964,11 +2969,42 @@ proc make_idlist {row} {
     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 displayorder
+    global rowidlist rowisopt rowfinal displayorder
     global uparrowlen downarrowlen maxwidth mingaplen
     global children parentlist
-    global commitidx curview commitrow
+    global commitidx viewcomplete curview commitrow
 
     set idlist {}
     if {$row > 0} {
@@ -2982,14 +3018,20 @@ proc layoutrows {row endrow} {
 	set rm1 [expr {$row - 1}]
 	if {$rm1 < 0 || [lindex $rowidlist $rm1] eq {}} {
 	    set idlist [make_idlist $row]
+	    set final 1
 	} else {
 	    set id [lindex $displayorder $rm1]
+	    set final [lindex $rowfinal $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 $row]
@@ -3008,6 +3050,9 @@ proc layoutrows {row endrow} {
 	    if {$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)} {
@@ -3032,18 +3077,28 @@ proc layoutrows {row endrow} {
 		}
 	    }
 	}
+	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 < $l} {
-	    if {$idlist ne [lindex $rowidlist $row]} {
+	    if {![rowsequal $idlist [lindex $rowidlist $row]]} {
 		lset rowidlist $row $idlist
+		lset rowfinal $row $final
 		changedrow $row
 	    }
 	} else {
-	    set rowidlist [concat $rowidlist [ntimes [expr {$row - $l}] {}]]
+	    set pad [ntimes [expr {$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]]
 	}
     }
@@ -3659,7 +3714,7 @@ proc drawcmitrow {row} {
 
 proc drawcommits {row {endrow {}}} {
     global numcommits iddrawn displayorder curview need_redisplay
-    global parentlist rowidlist uparrowlen downarrowlen nrows_drawn
+    global parentlist rowidlist rowfinal uparrowlen downarrowlen nrows_drawn
 
     if {$row < 0} {
 	set row 0
@@ -3684,7 +3739,7 @@ proc drawcommits {row {endrow {}}} {
 	set r2 $numcommits
     }
     for {set r $rl1} {$r < $r2} {incr r} {
-	if {[lindex $rowidlist $r] ne {}} {
+	if {[lindex $rowidlist $r] ne {} && [lindex $rowfinal $r]} {
 	    if {$rl1 < $r} {
 		layoutrows $rl1 $r
 	    }