[PATCH 0/3] gitk: improve dark background

@@ -6270,7 +6270,7 @@ proc drawtags {id x xt y1} {
 	set xt [expr {$xt + $delta + $wid + $lthickness + $linespc}]
     }
     set t [$canv create line $x $y1 [lindex $xvals end] $y1 \
-	       -width $lthickness -fill black -tags tag.$id]
+	       -width $lthickness -fill $fgcolor -tags [list tag.$id line]]
     $canv lower $t
     foreach tag $marks x $xvals wid $wvals {
 	set xl [expr {$x + $delta}]

@@ -6280,7 +6280,7 @@ proc drawtags {id x xt y1} {
 	    # draw a tag
 	    set t [$canv create polygon $x [expr {$yt + $delta}] $xl $yt \
 		       $xr $yt $xr $yb $xl $yb $x [expr {$yb - $delta}] \
-		       -width 1 -outline black -fill yellow -tags tag.$id]
+		       -width 1 -outline $fgcolor -fill yellow -tags tag.$id]
 	    $canv bind $t <1> [list showtag $tag 1]
 	    set rowtextx([rowofcommit $id]) [expr {$xr + $linespc}]
 	} else {

@@ -6295,7 +6295,7 @@ proc drawtags {id x xt y1} {
 	    }
 	    set xl [expr {$xl - $delta/2}]
 	    $canv create polygon $x $yt $xr $yt $xr $yb $x $yb \
-		-width 1 -outline black -fill $col -tags tag.$id
+		-width 1 -outline $fgcolor -fill $col -tags tag.$id
 	    if {[regexp {^(remotes/.*/|remotes/)} $tag match remoteprefix]} {
 	        set rwid [font measure mainfont $remoteprefix]
 		set xi [expr {$x + 1}]

@@ -8215,6 +8215,7 @@ proc linehover {} {
     global hoverx hovery hoverid hovertimer
     global canv linespc lthickness
     global commitinfo
+    global fgcolor
 
     set text [lindex $commitinfo($hoverid) 0]
     set ymax [lindex [$canv cget -scrollregion] 3]

@@ -8227,7 +8228,7 @@ proc linehover {} {
     set x1 [expr {$x + [font measure mainfont $text] + 2 * $lthickness}]
     set y1 [expr {$y + $linespc + 2 * $lthickness}]
     set t [$canv create rectangle $x0 $y0 $x1 $y1 \
-	       -fill \#ffff80 -outline black -width 1 -tags hover]
+	       -fill \#ffff80 -outline $fgcolor -width 1 -tags hover]
     $canv raise $t
     set t [$canv create text $x $y -anchor nw -text $text -tags hover \
 	       -font mainfont]

@@ -10886,6 +10887,7 @@ proc setfg {c} {
     allcanvs itemconf text -fill $c
     $canv itemconf circle -outline $c
     $canv itemconf markid -outline $c
+    $canv itemconf line -fill $c
 }
 
 proc prefscan {} {

@@ -6233,6 +6233,7 @@ proc drawtags {id x xt y1} {
     global idtags idheads idotherrefs mainhead
     global linespc lthickness
     global canv rowtextx curview fgcolor bgcolor ctxbut
+    global tagcolor branchcolor remotecolor
 
     set marks {}
     set ntags 0

@@ -6280,29 +6281,32 @@ proc drawtags {id x xt y1} {
 	    # draw a tag
 	    set t [$canv create polygon $x [expr {$yt + $delta}] $xl $yt \
 		       $xr $yt $xr $yb $xl $yb $x [expr {$yb - $delta}] \
-		       -width 1 -outline $fgcolor -fill yellow -tags tag.$id]
+		       -width 1 -outline $fgcolor -fill $tagcolor -tags \
+		       [list tag.$id tagcolor]]
 	    $canv bind $t <1> [list showtag $tag 1]
 	    set rowtextx([rowofcommit $id]) [expr {$xr + $linespc}]
 	} else {
 	    # draw a head or other ref
 	    if {[incr nheads -1] >= 0} {
-		set col green
+		set col $branchcolor
+		set t [list tag.$id branchcolor]
 		if {$tag eq $mainhead} {
 		    set font mainfontbold
 		}
 	    } else {
 		set col "#ddddff"
+		set t tag.$id
 	    }
 	    set xl [expr {$xl - $delta/2}]
 	    $canv create polygon $x $yt $xr $yt $xr $yb $x $yb \
-		-width 1 -outline $fgcolor -fill $col -tags tag.$id
+		-width 1 -outline $fgcolor -fill $col -tags $t
 	    if {[regexp {^(remotes/.*/|remotes/)} $tag match remoteprefix]} {
 	        set rwid [font measure mainfont $remoteprefix]
 		set xi [expr {$x + 1}]
 		set yti [expr {$yt + 1}]
 		set xri [expr {$x + $rwid}]
 		$canv create polygon $xi $yti $xri $yti $xri $yb $xi $yb \
-			-width 0 -fill "#ffddaa" -tags tag.$id
+			-width 0 -fill $remotecolor -tags [list tag.$id remotecolor]
 	    }
 	}
 	set t [$canv create text $xl $y1 -anchor w -text $tag -fill $fgcolor \

@@ -10877,6 +10881,30 @@ proc setbg {c} {
     }
 }
 
+proc setfill {c} {
+    global tagcolor branchcolor remotecolor
+    global canv;
+
+    set fg [winfo rgb . $c]
+    if {[lindex $fg 0] + 1.5 * [lindex $fg 1] + 0.5 * [lindex $fg 2] > 100000} {
+	# dark fill to read a light foreground font
+	set tagcolor yellow4
+	set branchcolor green4
+	set remotecolor "#806F55"
+    } else {
+	# light fill to read a dark foreground font
+        set tagcolor yellow
+        set branchcolor green
+        set remotecolor "#ffddaa"
+    }
+    # update tags assocated with non-text elements
+    if {[info exists canv]} {
+        $canv itemconf tagcolor -fill $tagcolor
+        $canv itemconf branchcolor -fill $branchcolor
+        $canv itemconf remotecolor -fill $remotecolor
+    }
+}
+
 proc setfg {c} {
     global fglist canv
 

@@ -10887,6 +10915,10 @@ proc setfg {c} {
     $canv itemconf circle -outline $c
     $canv itemconf markid -outline $c
     $canv itemconf line -fill $c
+    $canv itemconf tagcolor -outline $c
+    $canv itemconf branchcolor -outline $c
+
+    setfill $c
 }
 
 # update hunksep and each link foreground color

@@ -11436,6 +11468,7 @@ namespace import ::msgcat::mc
 ::msgcat::mcload $gitk_msgsdir
 
 catch {source ~/.gitk}
+setfill $fgcolor
 
 parsefont mainfont $mainfont
 eval font create mainfont [fontflags mainfont]

@@ -6673,7 +6673,7 @@ proc appendwithlinks {text tags} {
 }
 
 proc setlink {id lk} {
-    global curview ctext pendinglinks
+    global curview ctext pendinglinks diffcolors
 
     set known 0
     if {[string length $id] < 40} {

@@ -6687,7 +6687,7 @@ proc setlink {id lk} {
 	set known [commitinview $id $curview]
     }
     if {$known} {
-	$ctext tag conf $lk -foreground blue -underline 1
+	$ctext tag conf $lk -foreground [lindex $diffcolors 2] -underline 1
 	$ctext tag bind $lk <1> [list selbyid $id]
 	$ctext tag bind $lk <Enter> {linkcursor %W 1}
 	$ctext tag bind $lk <Leave> {linkcursor %W -1}

@@ -10792,8 +10792,7 @@ proc doprefs {} {
     label $top.hunksep -padx 40 -relief sunk -background [lindex $diffcolors 2]
     ${NS}::button $top.hunksepbut -text [mc "Diff: hunk header"] \
 	-command [list choosecolor diffcolors 2 $top.hunksep \
-		      [mc "diff hunk header"] \
-		      [list $ctext tag conf hunksep -foreground]]
+		      [mc "diff hunk header"] sethunksep ]
     grid x $top.hunksepbut $top.hunksep -sticky w
     label $top.markbgsep -padx 40 -relief sunk -background $markbgcolor
     ${NS}::button $top.markbgbut -text [mc "Marked line bg"] \

@@ -10890,6 +10889,19 @@ proc setfg {c} {
     $canv itemconf line -fill $c
 }
 
+# update hunksep and each link foreground color
+proc sethunksep {c} {
+    global ctext linknum
+
+    $ctext tag conf hunksep -foreground $c
+    for {set i 0} {$i < $linknum} {incr i} {
+        # Use -underline to determine if it is a known link and gets this color
+        if {[$ctext tag cget link$i -underline] != ""} {
+            $ctext tag conf link$i -foreground $c
+        }
+    }
+}
+
 proc prefscan {} {
     global oldprefs prefstop