gitk: Use a text widget for the file list

This lets us do things like highlighting all the entries for which
the corresponding part of the diff is at least partly visible in the
commit/patch display window, and in future it will let us display
the file list in a hierarchical form rather than as a flat file list.

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

gitk

@@ -481,7 +481,7 @@ proc makewindow {} {
     set ctext .ctop.cdet.left.ctext
     text $ctext -bg white -state disabled -font $textfont \
 	-width $geometry(ctextw) -height $geometry(ctexth) \
-	-yscrollcommand ".ctop.cdet.left.sb set" -wrap none
+	-yscrollcommand scrolltext -wrap none
     scrollbar .ctop.cdet.left.sb -command "$ctext yview"
     pack .ctop.cdet.left.sb -side right -fill y
     pack $ctext -side left -fill both -expand 1
@@ -515,11 +515,16 @@ proc makewindow {} {
 
     frame .ctop.cdet.right
     set cflist .ctop.cdet.right.cfiles
-    listbox $cflist -bg white -selectmode extended -width $geometry(cflistw) \
-	-yscrollcommand ".ctop.cdet.right.sb set" -font $mainfont
+    set indent [font measure $mainfont "nn"]
+    text $cflist -width $geometry(cflistw) -background white -font $mainfont \
+	-tabs [list $indent [expr {2 * $indent}]] \
+	-yscrollcommand ".ctop.cdet.right.sb set" \
+	-cursor [. cget -cursor] \
+	-spacing1 1 -spacing3 1
     scrollbar .ctop.cdet.right.sb -command "$cflist yview"
     pack .ctop.cdet.right.sb -side right -fill y
     pack $cflist -side left -fill both -expand 1
+    $cflist tag configure highlight -background yellow
     .ctop.cdet add .ctop.cdet.right
     bind .ctop.cdet <Configure> {resizecdetpanes %W %w}
 
@@ -571,12 +576,13 @@ proc makewindow {} {
     bind . <Control-KP_Add> {incrfont 1}
     bind . <Control-minus> {incrfont -1}
     bind . <Control-KP_Subtract> {incrfont -1}
-    bind $cflist <<ListboxSelect>> listboxsel
     bind . <Destroy> {savestuff %W}
     bind . <Button-1> "click %W"
     bind $fstring <Key-Return> dofind
     bind $sha1entry <Key-Return> gotocommit
     bind $sha1entry <<PasteSelection>> clearsha1
+    bind $cflist <1> {sel_flist %W %x %y; break}
+    bind $cflist <B1-Motion> {sel_flist %W %x %y; break}
 
     set maincursor [. cget -cursor]
     set textcursor [$ctext cget -cursor]
@@ -812,6 +818,101 @@ f		Scroll diff view to next file
     pack $w.ok -side bottom
 }
 
+# Procedures for manipulating the file list window at the
+# bottom right of the overall window.
+proc init_flist {first} {
+    global cflist cflist_top cflist_bot selectedline difffilestart
+
+    $cflist conf -state normal
+    $cflist delete 0.0 end
+    if {$first ne {}} {
+	$cflist insert end $first
+	set cflist_top 1
+	set cflist_bot 1
+	$cflist tag add highlight 1.0 "1.0 lineend"
+    } else {
+	catch {unset cflist_top}
+    }
+    $cflist conf -state disabled
+    set difffilestart {}
+}
+
+proc add_flist {f} {
+    global flistmode cflist
+
+    $cflist conf -state normal
+    if {$flistmode eq "flat"} {
+	$cflist insert end "\n$f"
+    }
+    $cflist conf -state disabled
+}
+
+proc sel_flist {w x y} {
+    global flistmode ctext difffilestart cflist cflist_top
+
+    if {![info exists cflist_top]} return
+    set l [lindex [split [$w index "@$x,$y"] "."] 0]
+    if {$flistmode eq "flat"} {
+	if {$l == 1} {
+	    $ctext yview 1.0
+	} else {
+	    catch {$ctext yview [lindex $difffilestart [expr {$l - 2}]]}
+	}
+	highlight_flist $l
+    }
+}
+
+proc scrolltext {f0 f1} {
+    global cflist_top
+
+    .ctop.cdet.left.sb set $f0 $f1
+    if {[info exists cflist_top]} {
+	highlight_flist $cflist_top
+    }
+}
+
+# Given an index $tl in the $ctext window, this works out which line
+# of the $cflist window displays the filename whose patch is shown
+# at the given point in the $ctext window.  $ll is a hint about which
+# line it might be, and is used as the starting point of the search.
+proc ctext_index {tl ll} {
+    global ctext difffilestart
+
+    while {$ll >= 2 && [$ctext compare $tl < \
+			    [lindex $difffilestart [expr {$ll - 2}]]]} {
+	incr ll -1
+    }
+    set nfiles [llength $difffilestart]
+    while {$ll - 1 < $nfiles && [$ctext compare $tl >= \
+			    [lindex $difffilestart [expr {$ll - 1}]]]} {
+	incr ll
+    }
+    return $ll
+}
+
+proc highlight_flist {ll} {
+    global ctext cflist cflist_top cflist_bot difffilestart
+
+    if {![info exists difffilestart] || [llength $difffilestart] == 0} return
+    set ll [ctext_index [$ctext index @0,1] $ll]
+    set lb $cflist_bot
+    if {$lb < $ll} {
+	set lb $ll
+    }
+    set y [expr {[winfo height $ctext] - 2}]
+    set lb [ctext_index [$ctext index @0,$y] $lb]
+    if {$ll != $cflist_top || $lb != $cflist_bot} {
+	$cflist tag remove highlight $cflist_top.0 "$cflist_bot.0 lineend"
+	for {set l $ll} {$l <= $lb} {incr l} {
+	    $cflist tag add highlight $l.0 "$l.0 lineend"
+	}
+	set cflist_top $ll
+	set cflist_bot $lb
+    }
+}
+
+# Code to implement multiple views
+
 proc newview {} {
     global nextviewnum newviewname newviewperm uifont
 
@@ -2718,7 +2819,7 @@ proc selectline {l isnew} {
     global canv canv2 canv3 ctext commitinfo selectedline
     global displayorder linehtag linentag linedtag
     global canvy0 linespc parentlist childlist
-    global cflist currentid sha1entry
+    global currentid sha1entry
     global commentend idtags linknum
     global mergemax numcommits pending_select
 
@@ -2841,8 +2942,7 @@ proc selectline {l isnew} {
     $ctext conf -state disabled
     set commentend [$ctext index "end - 1c"]
 
-    $cflist delete 0 end
-    $cflist insert end "Comments"
+    init_flist "Comments"
     if {[llength $olds] <= 1} {
 	startdiff $id
     } else {
@@ -2960,12 +3060,11 @@ proc goforw {} {
 
 proc mergediff {id l} {
     global diffmergeid diffopts mdifffd
-    global difffilestart diffids
+    global diffids
     global parentlist
 
     set diffmergeid $id
     set diffids $id
-    catch {unset difffilestart}
     # this doesn't seem to actually affect anything...
     set env(GIT_DIFF_OPTS) $diffopts
     set cmd [concat | git-diff-tree --no-commit-id --cc $id]
@@ -3000,11 +3099,10 @@ proc getmergediffline {mdf id np} {
 	# start of a new file
 	$ctext insert end "\n"
 	set here [$ctext index "end - 1c"]
-	set i [$cflist index end]
-	$ctext mark set fmark.$i $here
-	$ctext mark gravity fmark.$i left
-	set difffilestart([expr {$i-1}]) $here
-	$cflist insert end $fname
+	$ctext mark set f:$fname $here
+	$ctext mark gravity f:$fname left
+	lappend difffilestart $here
+	add_flist $fname
 	set l [expr {(78 - [string length $fname]) / 2}]
 	set pad [string range "----------------------------------------" 1 $l]
 	$ctext insert end "$pad $fname $pad\n" filesep
@@ -3075,7 +3173,7 @@ proc startdiff {ids} {
 proc addtocflist {ids} {
     global treediffs cflist
     foreach f $treediffs($ids) {
-	$cflist insert end $f
+	add_flist $f
     }
     getblobdiffs $ids
 }
@@ -3115,7 +3213,7 @@ proc gettreediffline {gdtf ids} {
 
 proc getblobdiffs {ids} {
     global diffopts blobdifffd diffids env curdifftag curtagstart
-    global difffilestart nextupdate diffinhdr treediffs
+    global nextupdate diffinhdr treediffs
 
     set env(GIT_DIFF_OPTS) $diffopts
     set cmd [concat | git-diff-tree --no-commit-id -r -p -C $ids]
@@ -3128,7 +3226,6 @@ proc getblobdiffs {ids} {
     set blobdifffd($ids) $bdf
     set curdifftag Comments
     set curtagstart 0.0
-    catch {unset difffilestart}
     fileevent $bdf readable [list getblobdiffline $bdf $diffids]
     set nextupdate [expr {[clock clicks -milliseconds] + 100}]
 }
@@ -3156,24 +3253,15 @@ proc getblobdiffline {bdf ids} {
 	# start of a new file
 	$ctext insert end "\n"
 	$ctext tag add $curdifftag $curtagstart end
-	set curtagstart [$ctext index "end - 1c"]
-	set header $newname
 	set here [$ctext index "end - 1c"]
-	set i [lsearch -exact $treediffs($diffids) $fname]
-	if {$i >= 0} {
-	    set difffilestart($i) $here
-	    incr i
-	    $ctext mark set fmark.$i $here
-	    $ctext mark gravity fmark.$i left
-	}
+	set curtagstart $here
+	set header $newname
+	lappend difffilestart $here
+	$ctext mark set f:$fname $here
+	$ctext mark gravity f:$fname left
 	if {$newname != $fname} {
-	    set i [lsearch -exact $treediffs($diffids) $newname]
-	    if {$i >= 0} {
-		set difffilestart($i) $here
-		incr i
-		$ctext mark set fmark.$i $here
-		$ctext mark gravity fmark.$i left
-	    }
+	    $ctext mark set f:$newfname $here
+	    $ctext mark gravity f:$newfname left
 	}
 	set curdifftag "f:$fname"
 	$ctext tag delete $curdifftag
@@ -3222,26 +3310,11 @@ proc getblobdiffline {bdf ids} {
 proc nextfile {} {
     global difffilestart ctext
     set here [$ctext index @0,0]
-    for {set i 0} {[info exists difffilestart($i)]} {incr i} {
-	if {[$ctext compare $difffilestart($i) > $here]} {
-	    if {![info exists pos]
-		|| [$ctext compare $difffilestart($i) < $pos]} {
-		set pos $difffilestart($i)
-	    }
+    foreach loc $difffilestart {
+	if {[$ctext compare $loc > $here]} {
+	    $ctext yview $loc
 	}
     }
-    if {[info exists pos]} {
-	$ctext yview $pos
-    }
-}
-
-proc listboxsel {} {
-    global ctext cflist currentid
-    if {![info exists currentid]} return
-    set sel [lsort [$cflist curselection]]
-    if {$sel eq {}} return
-    set first [lindex $sel 0]
-    catch {$ctext yview fmark.$first}
 }
 
 proc setcoords {} {
@@ -3452,7 +3525,7 @@ proc arrowjump {id n y} {
 }
 
 proc lineclick {x y id isnew} {
-    global ctext commitinfo childlist commitrow cflist canv thickerline
+    global ctext commitinfo childlist commitrow canv thickerline
 
     if {![info exists commitinfo($id)] && ![getcommit $id]} return
     unmarkmatches
@@ -3509,8 +3582,7 @@ proc lineclick {x y id isnew} {
 	}
     }
     $ctext conf -state disabled
-
-    $cflist delete 0 end
+    init_flist {}
 }
 
 proc normalline {} {
@@ -3568,15 +3640,14 @@ proc diffvssel {dirn} {
 }
 
 proc doseldiff {oldid newid} {
-    global ctext cflist
+    global ctext
     global commitinfo
 
     $ctext conf -state normal
     $ctext delete 0.0 end
     $ctext mark set fmark.0 0.0
     $ctext mark gravity fmark.0 left
-    $cflist delete 0 end
-    $cflist insert end "Top"
+    init_flist "Top"
     $ctext insert end "From "
     $ctext tag conf link -foreground blue -underline 1
     $ctext tag bind link <Enter> { %W configure -cursor hand2 }
@@ -3862,7 +3933,7 @@ proc rereadrefs {} {
 }
 
 proc showtag {tag isnew} {
-    global ctext cflist tagcontents tagids linknum
+    global ctext tagcontents tagids linknum
 
     if {$isnew} {
 	addtohistory [list showtag $tag 0]
@@ -3877,7 +3948,7 @@ proc showtag {tag isnew} {
     }
     appendwithlinks $text
     $ctext conf -state disabled
-    $cflist delete 0 end
+    init_flist {}
 }
 
 proc doquit {} {
@@ -4259,6 +4330,7 @@ set fastdate 0
 set uparrowlen 7
 set downarrowlen 7
 set mingaplen 30
+set flistmode "flat"
 
 set colors {green red blue magenta darkgrey brown orange}