git-gui: Improve annotated file display.

Rather than trying to mark the background color of the line numbers
to show which lines have annotated data loaded, we now show a ruler
between the line numbers and the file data.  This ruler is just 1
character wide and its background color is set to grey to denote
which lines have annotation ready.  I had to make this change as I
kept loosing the annotation marker when a line was no longer colored
as part of the current selection.

We now color the lines blamed on the current commit in yellow, the
lines in the commit which came after (descendant) in red (hotter,
less tested) and the lines in the commit before (ancestor) in blue
(cooler, better tested).

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

git-gui.sh

@@ -3245,6 +3245,15 @@ proc show_blame {commit path} {
 	pack $w.path -side top -fill x
 
 	frame $w.out
+	text $w.out.loaded_t \
+		-background white -borderwidth 0 \
+		-state disabled \
+		-wrap none \
+		-height 40 \
+		-width 1 \
+		-font font_diff
+	$w.out.loaded_t tag conf annotated -background grey
+
 	text $w.out.linenumber_t \
 		-background white -borderwidth 0 \
 		-state disabled \
@@ -3252,7 +3261,6 @@ proc show_blame {commit path} {
 		-height 40 \
 		-width 5 \
 		-font font_diff
-	$w.out.linenumber_t tag conf annotated -background grey
 	$w.out.linenumber_t tag conf linenumber -justify right
 
 	text $w.out.file_t \
@@ -3267,12 +3275,18 @@ proc show_blame {commit path} {
 	scrollbar $w.out.sbx -orient h -command [list $w.out.file_t xview]
 	scrollbar $w.out.sby -orient v \
 		-command [list scrollbar2many [list \
+		$w.out.loaded_t \
 		$w.out.linenumber_t \
 		$w.out.file_t \
 		] yview]
-	grid $w.out.linenumber_t $w.out.file_t $w.out.sby -sticky nsew
+	grid \
-	grid conf $w.out.sbx -column 1 -sticky we
+		$w.out.linenumber_t \
-	grid columnconfigure $w.out 1 -weight 1
+		$w.out.loaded_t \
+		$w.out.file_t \
+		$w.out.sby \
+		-sticky nsew
+	grid conf $w.out.sbx -column 2 -sticky we
+	grid columnconfigure $w.out 2 -weight 1
 	grid rowconfigure $w.out 0 -weight 1
 	pack $w.out -fill both -expand 1
 
@@ -3306,17 +3320,21 @@ proc show_blame {commit path} {
 		-font font_ui \
 		-command "blame_copycommit $w \$cursorW @\$cursorX,\$cursorY"
 
-	foreach i [list $w.out.linenumber_t $w.out.file_t] {
+	foreach i [list \
+		$w.out.loaded_t \
+		$w.out.linenumber_t \
+		$w.out.file_t] {
 		$i tag conf in_sel \
 			-background [$i cget -foreground] \
 			-foreground [$i cget -background]
 		$i conf -yscrollcommand \
 			[list many2scrollbar [list \
+			$w.out.loaded_t \
 			$w.out.linenumber_t \
 			$w.out.file_t \
 			] yview $w.out.sby]
 		bind $i <Button-1> "
-			blame_highlight {$w} \\
+			blame_click {$w} \\
 				$w.cm.t \\
 				$w.out.linenumber_t \\
 				$w.out.file_t \\
@@ -3338,19 +3356,22 @@ proc show_blame {commit path} {
 	"
 	wm title $tl "[appname] ([reponame]): File Viewer"
 
+	set blame_data($w,commit_count) 0
+	set blame_data($w,commit_list) {}
 	set blame_data($w,total_lines) 0
 	set blame_data($w,blame_lines) 0
 	set blame_data($w,highlight_commit) {}
 	set blame_data($w,highlight_line) -1
+
 	set cmd [list git cat-file blob "$commit:$path"]
 	set fd [open "| $cmd" r]
 	fconfigure $fd -blocking 0 -translation lf -encoding binary
 	fileevent $fd readable [list read_blame_catfile \
 		$fd $w $commit $path \
-		$w.cm.t $w.out.linenumber_t $w.out.file_t]
+		$w.cm.t $w.out.loaded_t $w.out.linenumber_t $w.out.file_t]
 }
 
-proc read_blame_catfile {fd w commit path w_cmit w_line w_file} {
+proc read_blame_catfile {fd w commit path w_cmit w_load w_line w_file} {
 	global blame_status blame_data
 
 	if {![winfo exists $w_file]} {
@@ -3359,14 +3380,17 @@ proc read_blame_catfile {fd w commit path w_cmit w_line w_file} {
 	}
 
 	set n $blame_data($w,total_lines)
+	$w_load conf -state normal
 	$w_line conf -state normal
 	$w_file conf -state normal
 	while {[gets $fd line] >= 0} {
 		regsub "\r\$" $line {} line
 		incr n
+		$w_load insert end "\n"
 		$w_line insert end "$n\n" linenumber
 		$w_file insert end "$line\n"
 	}
+	$w_load conf -state disabled
 	$w_line conf -state disabled
 	$w_file conf -state disabled
 	set blame_data($w,total_lines) $n
@@ -3379,11 +3403,11 @@ proc read_blame_catfile {fd w commit path w_cmit w_line w_file} {
 		set fd [open "| $cmd" r]
 		fconfigure $fd -blocking 0 -translation lf -encoding binary
 		fileevent $fd readable [list read_blame_incremental $fd $w \
-			$w_cmit $w_line $w_file]
+			$w_load $w_cmit $w_line $w_file]
 	}
 }
 
-proc read_blame_incremental {fd w w_cmit w_line w_file} {
+proc read_blame_incremental {fd w w_load w_cmit w_line w_file} {
 	global blame_status blame_data
 
 	if {![winfo exists $w_file]} {
@@ -3399,12 +3423,14 @@ proc read_blame_incremental {fd w w_cmit w_line w_file} {
 			set blame_data($w,final_line) $final_line
 			set blame_data($w,line_count) $line_count
 
-			if {[catch {set g $blame_data($w,$cmit,seen)}]} {
+			if {[catch {set g $blame_data($w,$cmit,order)}]} {
 				$w_line tag conf g$cmit
 				$w_file tag conf g$cmit
 				$w_line tag raise in_sel
 				$w_file tag raise in_sel
-				set blame_data($w,$cmit,seen) 1
+				set blame_data($w,$cmit,order) $blame_data($w,commit_count)
+				incr blame_data($w,commit_count)
+				lappend blame_data($w,commit_list) $cmit
 			}
 		} elseif {[string match {filename *} $line]} {
 			set file [string range $line 9 end]
@@ -3414,7 +3440,7 @@ proc read_blame_incremental {fd w w_cmit w_line w_file} {
 
 			while {$n > 0} {
 				if {[catch {set g g$blame_data($w,line$lno,commit)}]} {
-					$w_line tag add annotated $lno.0 "$lno.0 lineend + 1c"
+					$w_load tag add annotated $lno.0 "$lno.0 lineend + 1c"
 				} else {
 					$w_line tag remove g$g $lno.0 "$lno.0 lineend + 1c"
 					$w_file tag remove g$g $lno.0 "$lno.0 lineend + 1c"
@@ -3438,6 +3464,14 @@ proc read_blame_incremental {fd w w_cmit w_line w_file} {
 				incr lno
 				incr blame_data($w,blame_lines)
 			}
+
+			set hc $blame_data($w,highlight_commit)
+			if {$hc ne {}
+				&& [expr {$blame_data($w,$hc,order) + 1}]
+					== $blame_data($w,$cmit,order)} {
+				blame_showcommit $w $w_cmit $w_line $w_file \
+					$blame_data($w,highlight_line)
+			}
 		} elseif {[regexp {^([a-z-]+) (.*)$} $line line header data]} {
 			set blame_data($w,$blame_data($w,commit),$header) $data
 		}
@@ -3462,7 +3496,7 @@ proc blame_incremental_status {w} {
 			/ $blame_data($w,total_lines)}]]
 }
 
-proc blame_highlight {w w_cmit w_line w_file cur_w pos} {
+proc blame_click {w w_cmit w_line w_file cur_w pos} {
 	set lno [lindex [split [$cur_w index $pos] .] 0]
 	if {$lno eq {}} return
 
@@ -3474,25 +3508,41 @@ proc blame_highlight {w w_cmit w_line w_file cur_w pos} {
 	blame_showcommit $w $w_cmit $w_line $w_file $lno
 }
 
+set blame_colors {
+	#ff4040
+	#ff40ff
+	#4040ff
+}
+
 proc blame_showcommit {w w_cmit w_line w_file lno} {
-	global blame_data repo_config
+	global blame_colors blame_data repo_config
 
 	set cmit $blame_data($w,highlight_commit)
 	if {$cmit ne {}} {
-		$w_line tag conf g$cmit -background white
+		set idx $blame_data($w,$cmit,order)
-		$w_file tag conf g$cmit -background white
+		set i 0
-		$w_line tag raise annotated g$cmit
+		foreach c $blame_colors {
+			set h [lindex $blame_data($w,commit_list) [expr {$idx - 1 + $i}]]
+			$w_line tag conf g$h -background white
+			$w_file tag conf g$h -background white
+			incr i
+		}
 	}
 
 	$w_cmit conf -state normal
 	$w_cmit delete 0.0 end
 	if {[catch {set cmit $blame_data($w,line$lno,commit)}]} {
 		set cmit {}
-		$w_cmit insert end "Computing..."
+		$w_cmit insert end "Loading annotation..."
 	} else {
-		$w_line tag conf g$cmit -background yellow
+		set idx $blame_data($w,$cmit,order)
-		$w_file tag conf g$cmit -background yellow
+		set i 0
-		$w_line tag raise g$cmit annotated
+		foreach c $blame_colors {
+			set h [lindex $blame_data($w,commit_list) [expr {$idx - 1 + $i}]]
+			$w_line tag conf g$h -background $c
+			$w_file tag conf g$h -background $c
+			incr i
+		}
 
 		if {[catch {set msg $blame_data($w,$cmit,message)}]} {
 			set msg {}