Re: [PATCH] git-gui: apply color information from git diff output

> This patch extracts the ANSI color sequences from git diff output and
> applies these to the diff view window. This ensures that the gui view
> makes use of the current git configuration for whitespace display.
>
> ANSI codes may include attributes, foreground and background in a single
> sequence. Handle this and support bold and reverse attributes. Ignore
> all other attributes.
>
> Suggested-by: Tor Arvid Lund <torarvid@gmail.com>
> Suggested-by: Junio C Hamano <gitster@pobox.com>
> Signed-off-by: Pat Thoyts <patthoyts@users.sourceforge.net>
> ---

> Kevin Ballard <kevin@sb.org> writes:
>
>>On Oct 21, 2010, at 8:22 AM, Pat Thoyts wrote:
>>
>>> +    while {[regexp -indices -start $start "\033\\\[(\\d+)?m" $line match code]} {
>>
>>Git currently doesn't emit combined escapes (e.g. \e[0;31m to reset and then turn on red text), but I can imagine it being enhanced to do this in the future. I would recommend handling it here if you can.
>>
>>-Kevin Ballard
>
> It turns out that such sequences will be generated by git if the user
> configures the color.diff.whitespace (eg: bold cyan magenta). This patch
> handles these cases. I don't see any point trying to handle blink. I
> could add underline but I don't see that being so appropriate for a
> GUI. It seems more like something that is configured for a monochrome
> terminal.
>
>  git-gui.sh   |   10 +++++++++-
>  lib/diff.tcl |   34 +++++++++++++++++++++++++++++++++-
>  2 files changed, 42 insertions(+), 2 deletions(-)
>
> diff --git a/git-gui.sh b/git-gui.sh
> index 1ccaba1..1fb0254 100755
> --- a/git-gui.sh
> +++ b/git-gui.sh
> @@ -3322,8 +3322,16 @@ pack $ui_diff -side left -fill both -expand 1
>  pack .vpane.lower.diff.header -side top -fill x
>  pack .vpane.lower.diff.body -side bottom -fill both -expand 1
>
> +foreach {n c} {0 black 1 red4 2 green4 3 yellow4 4 blue4 5 magenta4 6 cyan4 7 grey60} {
> +       $ui_diff tag configure clr4$n -background $c
> +       $ui_diff tag configure clri4$n -foreground $c
> +       $ui_diff tag configure clr3$n -foreground $c
> +       $ui_diff tag configure clri3$n -background $c
> +}
> +$ui_diff tag configure clr1 -font font_diffbold
> +
>  $ui_diff tag conf d_cr -elide true
> -$ui_diff tag conf d_@ -foreground blue -font font_diffbold
> +$ui_diff tag conf d_@ -font font_diffbold
>  $ui_diff tag conf d_+ -foreground {#00a000}
>  $ui_diff tag conf d_- -foreground red
>
> diff --git a/lib/diff.tcl b/lib/diff.tcl
> index c628750..dcf0711 100644
> --- a/lib/diff.tcl
> +++ b/lib/diff.tcl
> @@ -294,7 +294,7 @@ proc start_show_diff {cont_info {add_opts {}}} {
>        }
>
>        lappend cmd -p
> -       lappend cmd --no-color
> +       lappend cmd --color
>        if {$repo_config(gui.diffcontext) >= 1} {
>                lappend cmd "-U$repo_config(gui.diffcontext)"
>        }
> @@ -332,6 +332,23 @@ proc start_show_diff {cont_info {add_opts {}}} {
>        fileevent $fd readable [list read_diff $fd $cont_info]
>  }
>
> +proc parse_color_line {line} {
> +       set start 0
> +       set result ""
> +       set markup [list]
> +       set regexp {\033\[((?:\d+;)*\d+)?m}
> +       while {[regexp -indices -start $start $regexp $line match code]} {
> +               foreach {begin end} $match break
> +               append result [string range $line $start [expr {$begin - 1}]]
> +               lappend markup [string length $result] \
> +                       [eval [linsert $code 0 string range $line]]
> +               set start [incr end]
> +       }
> +       append result [string range $line $start end]
> +       if {[llength $markup] < 4} {set markup {}}
> +       return [list $result $markup]
> +}
> +
>  proc read_diff {fd cont_info} {
>        global ui_diff diff_active is_submodule_diff
>        global is_3way_diff is_conflict_diff current_diff_header
> @@ -340,6 +357,9 @@ proc read_diff {fd cont_info} {
>
>        $ui_diff conf -state normal
>        while {[gets $fd line] >= 0} {
> +               foreach {line markup} [parse_color_line $line] break
> +               set line [string map {\033 ^} $line]
> +
>                # -- Cleanup uninteresting diff header lines.
>                #
>                if {$::current_diff_inheader} {
> @@ -434,11 +454,23 @@ proc read_diff {fd cont_info} {
>                        }
>                        }
>                }
> +               set mark [$ui_diff index "end - 1 line linestart"]
>                $ui_diff insert end $line $tags
>                if {[string index $line end] eq "\r"} {
>                        $ui_diff tag add d_cr {end - 2c}
>                }
>                $ui_diff insert end "\n" $tags
> +
> +               foreach {posbegin colbegin posend colend} $markup {
> +                       set prefix clr
> +                       foreach style [split $colbegin ";"] {
> +                               if {$style eq "7"} {append prefix i; continue}
> +                               if {$style < 30 || $style > 47} {continue}
> +                               set a "$mark linestart + $posbegin chars"
> +                               set b "$mark linestart + $posend chars"
> +                               catch {$ui_diff tag add $prefix$style $a $b}
> +                       }
> +               }
>        }
>        $ui_diff conf -state disabled
>
> --
> 1.7.3.1.msysgit.0
>
>
>