diff kitten: Automatically use dark/light color scheme based on the color scheme of the parent terminal

Fixes #8170

kittens/diff/highlight.go

@@ -158,6 +158,30 @@ func ansi_formatter(w io.Writer, style *chroma.Style, it chroma.Iterator) (err e
 	return nil
 }
 
+func resolved_chroma_style() *chroma.Style {
+	name := utils.IfElse(use_dark_colors, conf.Dark_pygments_style, conf.Pygments_style)
+	var style *chroma.Style
+	if name == "default" {
+		style = DefaultStyle()
+	} else {
+		style = styles.Get(name)
+	}
+	if style == nil {
+		if resolved_colors.Background.IsDark() && !resolved_colors.Foreground.IsDark() {
+			style = styles.Get("monokai")
+			if style == nil {
+				style = styles.Get("github-dark")
+			}
+		} else {
+			style = DefaultStyle()
+		}
+		if style == nil {
+			style = styles.Fallback
+		}
+	}
+	return style
+}
+
 func highlight_file(path string) (highlighted string, err error) {
 	filename_for_detection := filepath.Base(path)
 	ext := filepath.Ext(filename_for_detection)
@@ -174,34 +198,12 @@ func highlight_file(path string) (highlighted string, err error) {
 	}
 	lexer := lexers.Match(filename_for_detection)
 	if lexer == nil {
-		if err == nil {
-			lexer = lexers.Analyse(text)
-		}
+		lexer = lexers.Analyse(text)
 	}
 	if lexer == nil {
 		return "", fmt.Errorf("Cannot highlight %#v: %w", path, ErrNoLexer)
 	}
 	lexer = chroma.Coalesce(lexer)
-	name := conf.Pygments_style
-	var style *chroma.Style
-	if name == "default" {
-		style = DefaultStyle()
-	} else {
-		style = styles.Get(name)
-	}
-	if style == nil {
-		if conf.Background.IsDark() && !conf.Foreground.IsDark() {
-			style = styles.Get("monokai")
-			if style == nil {
-				style = styles.Get("github-dark")
-			}
-		} else {
-			style = DefaultStyle()
-		}
-		if style == nil {
-			style = styles.Fallback
-		}
-	}
 	iterator, err := lexer.Tokenise(nil, text)
 	if err != nil {
 		return "", err
@@ -209,7 +211,7 @@ func highlight_file(path string) (highlighted string, err error) {
 	formatter := chroma.FormatterFunc(ansi_formatter)
 	w := strings.Builder{}
 	w.Grow(len(text) * 2)
-	err = formatter.Format(&w, style, iterator)
+	err = formatter.Format(&w, resolved_chroma_style(), iterator)
 	// os.WriteFile(filepath.Base(path+".highlighted"), []byte(w.String()), 0o600)
 	return w.String(), err
 }

kittens/diff/main.go

@@ -112,7 +112,6 @@ func main(_ *cli.Command, opts_ *Options, args []string) (rc int, err error) {
 		return 1, err
 	}
 	init_caches()
-	create_formatters()
 	defer func() {
 		for tdir := range remote_dirs {
 			os.RemoveAll(tdir)
@@ -154,6 +153,7 @@ func main(_ *cli.Command, opts_ *Options, args []string) (rc int, err error) {
 		if !tc.KeyboardProtocol {
 			return fmt.Errorf("This terminal does not support the kitty keyboard protocol, or you are running inside a terminal multiplexer that is blocking querying for kitty keyboard protocol support. The diff kitten cannot function without it.")
 		}
+		h.on_capabilities_received(tc)
 		return nil
 	}
 	lp.OnWakeup = h.on_wakeup

kittens/diff/main.py

@@ -71,103 +71,90 @@ egr()  # }}}
 # colors {{{
 agr('colors', 'Colors')
 
-opt('pygments_style', 'default',
-    long_text='''
+opt('color_scheme', 'auto', choices=('auto', 'light', 'dark'), long_text='''
+Whether to use the light or dark colors. The default of :code:`auto` means
+to follow the parent terminal color scheme.
+''')
+
+opt('pygments_style', 'default', long_text='''
 The pygments color scheme to use for syntax highlighting. See :link:`pygments
 builtin styles <https://pygments.org/styles/>` for a list of schemes. Note that
 this **does not** change the colors used for diffing,
 only the colors used for syntax highlighting. To change the general colors use the settings below.
+This sets the colors used for light color schemes, use :opt:`dark_pygments_style` to change the
+colors for dark color schemes.
 '''
     )
 
-opt('foreground', 'black',
-    option_type='to_color',
-    long_text='Basic colors'
-    )
+opt('dark_pygments_style', 'github-dark', long_text='''
+The pygments color scheme to use for syntax highlighting with dark colors. See :link:`pygments
+builtin styles <https://pygments.org/styles/>` for a list of schemes. Note that
+this **does not** change the colors used for diffing,
+only the colors used for syntax highlighting. To change the general colors use the settings below.
+This sets the colors used for dark color schemes, use :opt:`pygments_style` to change the
+colors for light color schemes.''')
 
-opt('background', 'white',
-    option_type='to_color',
-    )
+opt('foreground', 'black', option_type='to_color', long_text='Basic colors')
+opt('dark_foreground', '#f8f8f2', option_type='to_color', long_text='Basic colors')
 
-opt('title_fg', 'black',
-    option_type='to_color',
-    long_text='Title colors'
-    )
+dark_bg = '#212830'
+opt('background', 'white', option_type='to_color',)
+opt('dark_background', dark_bg, option_type='to_color',)
 
-opt('title_bg', 'white',
-    option_type='to_color',
-    )
+opt('title_fg', 'black', option_type='to_color', long_text='Title colors')
+opt('dark_title_fg', 'white', option_type='to_color')
 
-opt('margin_bg', '#fafbfc',
-    option_type='to_color',
-    long_text='Margin colors'
-    )
+opt('title_bg', 'white', option_type='to_color',)
+opt('dark_title_bg', dark_bg, option_type='to_color',)
 
-opt('margin_fg', '#aaaaaa',
-    option_type='to_color',
-    )
+opt('margin_bg', '#fafbfc', option_type='to_color', long_text='Margin colors')
+opt('dark_margin_bg', dark_bg, option_type='to_color')
 
-opt('removed_bg', '#ffeef0',
-    option_type='to_color',
-    long_text='Removed text backgrounds'
-    )
+opt('margin_fg', '#aaaaaa', option_type='to_color')
+opt('dark_margin_fg', '#aaaaaa', option_type='to_color')
 
-opt('highlight_removed_bg', '#fdb8c0',
-    option_type='to_color',
-    )
+opt('removed_bg', '#ffeef0', option_type='to_color', long_text='Removed text backgrounds')
+opt('dark_removed_bg', '#352c33', option_type='to_color')
 
-opt('removed_margin_bg', '#ffdce0',
-    option_type='to_color',
-    )
+opt('highlight_removed_bg', '#fdb8c0', option_type='to_color')
+opt('dark_highlight_removed_bg', '#5c3539', option_type='to_color')
 
-opt('added_bg', '#e6ffed',
-    option_type='to_color',
-    long_text='Added text backgrounds'
-    )
+opt('removed_margin_bg', '#ffdce0', option_type='to_color')
+opt('dark_removed_margin_bg', '#5c3539', option_type='to_color')
 
-opt('highlight_added_bg', '#acf2bd',
-    option_type='to_color',
-    )
+opt('added_bg', '#e6ffed', option_type='to_color', long_text='Added text backgrounds')
+opt('dark_added_bg', '#263834', option_type='to_color')
 
-opt('added_margin_bg', '#cdffd8',
-    option_type='to_color',
-    )
+opt('highlight_added_bg', '#acf2bd', option_type='to_color')
+opt('dark_highlight_added_bg', '#31503d', option_type='to_color')
 
-opt('filler_bg', '#fafbfc',
-    option_type='to_color',
-    long_text='Filler (empty) line background'
-    )
+opt('added_margin_bg', '#cdffd8', option_type='to_color')
+opt('dark_added_margin_bg', '#31503d', option_type='to_color')
 
-opt('margin_filler_bg', 'none',
-    option_type='to_color_or_none',
-    long_text='Filler (empty) line background in margins, defaults to the filler background'
-    )
+opt('filler_bg', '#fafbfc', option_type='to_color', long_text='Filler (empty) line background')
+opt('dark_filler_bg', '#262c36', option_type='to_color')
 
-opt('hunk_margin_bg', '#dbedff',
-    option_type='to_color',
-    long_text='Hunk header colors'
-    )
+opt('margin_filler_bg', 'none', option_type='to_color_or_none', long_text='Filler (empty) line background in margins, defaults to the filler background')
+opt('dark_margin_filler_bg', 'none', option_type='to_color_or_none')
 
-opt('hunk_bg', '#f1f8ff',
-    option_type='to_color',
-    )
 
-opt('search_bg', '#444',
-    option_type='to_color',
-    long_text='Highlighting'
-    )
+opt('hunk_margin_bg', '#dbedff', option_type='to_color', long_text='Hunk header colors')
+opt('dark_hunk_margin_bg', '#0c2d6b', option_type='to_color')
 
-opt('search_fg', 'white',
-    option_type='to_color',
-    )
+opt('hunk_bg', '#f1f8ff', option_type='to_color')
+opt('dark_hunk_bg', '#253142', option_type='to_color')
 
-opt('select_bg', '#b4d5fe',
-    option_type='to_color',
-    )
+opt('search_bg', '#444', option_type='to_color', long_text='Highlighting')
+opt('dark_search_bg', '#2c599c', option_type='to_color')
 
-opt('select_fg', 'black',
-    option_type='to_color_or_none',
-    )
+opt('search_fg', 'white', option_type='to_color')
+opt('dark_search_fg', 'white', option_type='to_color')
+
+opt('select_bg', '#b4d5fe', option_type='to_color')
+opt('dark_select_bg', '#2c599c', option_type='to_color')
+
+opt('select_fg', 'black', option_type='to_color_or_none')
+opt('dark_select_fg', 'white', option_type='to_color_or_none')
 egr()  # }}}
 
 # shortcuts {{{

kittens/diff/render.go

@@ -160,37 +160,107 @@ var format_as_sgr struct {
 }
 
 var statusline_format, added_count_format, removed_count_format, message_format func(...any) string
+var use_dark_colors bool = true
+
+type ResolvedColors struct {
+	Added_bg             style.RGBA
+	Added_margin_bg      style.RGBA
+	Background           style.RGBA
+	Filler_bg            style.RGBA
+	Foreground           style.RGBA
+	Highlight_added_bg   style.RGBA
+	Highlight_removed_bg style.RGBA
+	Hunk_bg              style.RGBA
+	Hunk_margin_bg       style.RGBA
+	Margin_bg            style.RGBA
+	Margin_fg            style.RGBA
+	Margin_filler_bg     style.NullableColor
+	Removed_bg           style.RGBA
+	Removed_margin_bg    style.RGBA
+	Search_bg            style.RGBA
+	Search_fg            style.RGBA
+	Select_bg            style.RGBA
+	Select_fg            style.NullableColor
+	Title_bg             style.RGBA
+	Title_fg             style.RGBA
+}
+
+var resolved_colors ResolvedColors
 
 func create_formatters() {
+	rc := &resolved_colors
+	if use_dark_colors {
+		rc.Added_bg = conf.Dark_added_bg
+		rc.Added_margin_bg = conf.Dark_added_margin_bg
+		rc.Background = conf.Dark_background
+		rc.Filler_bg = conf.Dark_filler_bg
+		rc.Foreground = conf.Dark_foreground
+		rc.Highlight_added_bg = conf.Dark_highlight_added_bg
+		rc.Highlight_removed_bg = conf.Dark_highlight_removed_bg
+		rc.Hunk_bg = conf.Dark_hunk_bg
+		rc.Hunk_margin_bg = conf.Dark_hunk_margin_bg
+		rc.Margin_bg = conf.Dark_margin_bg
+		rc.Margin_fg = conf.Dark_margin_fg
+		rc.Margin_filler_bg = conf.Dark_margin_filler_bg
+		rc.Removed_bg = conf.Dark_removed_bg
+		rc.Removed_margin_bg = conf.Dark_removed_margin_bg
+		rc.Search_bg = conf.Dark_search_bg
+		rc.Search_fg = conf.Dark_search_fg
+		rc.Select_bg = conf.Dark_select_bg
+		rc.Select_fg = conf.Dark_select_fg
+		rc.Title_bg = conf.Dark_title_bg
+		rc.Title_fg = conf.Dark_title_fg
+	} else {
+		rc.Added_bg = conf.Added_bg
+		rc.Added_margin_bg = conf.Added_margin_bg
+		rc.Background = conf.Background
+		rc.Filler_bg = conf.Filler_bg
+		rc.Foreground = conf.Foreground
+		rc.Highlight_added_bg = conf.Highlight_added_bg
+		rc.Highlight_removed_bg = conf.Highlight_removed_bg
+		rc.Hunk_bg = conf.Hunk_bg
+		rc.Hunk_margin_bg = conf.Hunk_margin_bg
+		rc.Margin_bg = conf.Margin_bg
+		rc.Margin_fg = conf.Margin_fg
+		rc.Margin_filler_bg = conf.Margin_filler_bg
+		rc.Removed_bg = conf.Removed_bg
+		rc.Removed_margin_bg = conf.Removed_margin_bg
+		rc.Search_bg = conf.Search_bg
+		rc.Search_fg = conf.Search_fg
+		rc.Select_bg = conf.Select_bg
+		rc.Select_fg = conf.Select_fg
+		rc.Title_bg = conf.Title_bg
+		rc.Title_fg = conf.Title_fg
+	}
 	ctx := style.Context{AllowEscapeCodes: true}
 	only_open := func(x string) string {
 		ans := ctx.SprintFunc(x)("|")
 		ans, _, _ = strings.Cut(ans, "|")
 		return ans
 	}
-	format_as_sgr.filler = only_open("bg=" + conf.Filler_bg.AsRGBSharp())
-	if conf.Margin_filler_bg.IsSet {
-		format_as_sgr.margin_filler = only_open("bg=" + conf.Margin_filler_bg.Color.AsRGBSharp())
+	format_as_sgr.filler = only_open("bg=" + rc.Filler_bg.AsRGBSharp())
+	if rc.Margin_filler_bg.IsSet {
+		format_as_sgr.margin_filler = only_open("bg=" + rc.Margin_filler_bg.Color.AsRGBSharp())
 	} else {
-		format_as_sgr.margin_filler = only_open("bg=" + conf.Filler_bg.AsRGBSharp())
+		format_as_sgr.margin_filler = only_open("bg=" + rc.Filler_bg.AsRGBSharp())
 	}
-	format_as_sgr.added = only_open("bg=" + conf.Added_bg.AsRGBSharp())
-	format_as_sgr.added_margin = only_open(fmt.Sprintf("fg=%s bg=%s", conf.Margin_fg.AsRGBSharp(), conf.Added_margin_bg.AsRGBSharp()))
-	format_as_sgr.removed = only_open("bg=" + conf.Removed_bg.AsRGBSharp())
-	format_as_sgr.removed_margin = only_open(fmt.Sprintf("fg=%s bg=%s", conf.Margin_fg.AsRGBSharp(), conf.Removed_margin_bg.AsRGBSharp()))
-	format_as_sgr.title = only_open(fmt.Sprintf("fg=%s bg=%s bold", conf.Title_fg.AsRGBSharp(), conf.Title_bg.AsRGBSharp()))
-	format_as_sgr.margin = only_open(fmt.Sprintf("fg=%s bg=%s", conf.Margin_fg.AsRGBSharp(), conf.Margin_bg.AsRGBSharp()))
-	format_as_sgr.hunk = only_open(fmt.Sprintf("fg=%s bg=%s", conf.Margin_fg.AsRGBSharp(), conf.Hunk_bg.AsRGBSharp()))
-	format_as_sgr.hunk_margin = only_open(fmt.Sprintf("fg=%s bg=%s", conf.Margin_fg.AsRGBSharp(), conf.Hunk_margin_bg.AsRGBSharp()))
-	format_as_sgr.search = only_open(fmt.Sprintf("fg=%s bg=%s", conf.Search_fg.AsRGBSharp(), conf.Search_bg.AsRGBSharp()))
-	statusline_format = ctx.SprintFunc(fmt.Sprintf("fg=%s", conf.Margin_fg.AsRGBSharp()))
-	added_count_format = ctx.SprintFunc(fmt.Sprintf("fg=%s", conf.Highlight_added_bg.AsRGBSharp()))
-	removed_count_format = ctx.SprintFunc(fmt.Sprintf("fg=%s", conf.Highlight_removed_bg.AsRGBSharp()))
+	format_as_sgr.added = only_open("bg=" + rc.Added_bg.AsRGBSharp())
+	format_as_sgr.added_margin = only_open(fmt.Sprintf("fg=%s bg=%s", rc.Margin_fg.AsRGBSharp(), rc.Added_margin_bg.AsRGBSharp()))
+	format_as_sgr.removed = only_open("bg=" + rc.Removed_bg.AsRGBSharp())
+	format_as_sgr.removed_margin = only_open(fmt.Sprintf("fg=%s bg=%s", rc.Margin_fg.AsRGBSharp(), rc.Removed_margin_bg.AsRGBSharp()))
+	format_as_sgr.title = only_open(fmt.Sprintf("fg=%s bg=%s bold", rc.Title_fg.AsRGBSharp(), rc.Title_bg.AsRGBSharp()))
+	format_as_sgr.margin = only_open(fmt.Sprintf("fg=%s bg=%s", rc.Margin_fg.AsRGBSharp(), rc.Margin_bg.AsRGBSharp()))
+	format_as_sgr.hunk = only_open(fmt.Sprintf("fg=%s bg=%s", rc.Margin_fg.AsRGBSharp(), rc.Hunk_bg.AsRGBSharp()))
+	format_as_sgr.hunk_margin = only_open(fmt.Sprintf("fg=%s bg=%s", rc.Margin_fg.AsRGBSharp(), rc.Hunk_margin_bg.AsRGBSharp()))
+	format_as_sgr.search = only_open(fmt.Sprintf("fg=%s bg=%s", rc.Search_fg.AsRGBSharp(), rc.Search_bg.AsRGBSharp()))
+	statusline_format = ctx.SprintFunc(fmt.Sprintf("fg=%s", rc.Margin_fg.AsRGBSharp()))
+	added_count_format = ctx.SprintFunc(fmt.Sprintf("fg=%s", rc.Highlight_added_bg.AsRGBSharp()))
+	removed_count_format = ctx.SprintFunc(fmt.Sprintf("fg=%s", rc.Highlight_removed_bg.AsRGBSharp()))
 	message_format = ctx.SprintFunc("bold")
-	if conf.Select_fg.IsSet {
-		format_as_sgr.selection = only_open(fmt.Sprintf("fg=%s bg=%s", conf.Select_fg.Color.AsRGBSharp(), conf.Select_bg.AsRGBSharp()))
+	if rc.Select_fg.IsSet {
+		format_as_sgr.selection = only_open(fmt.Sprintf("fg=%s bg=%s", rc.Select_fg.Color.AsRGBSharp(), rc.Select_bg.AsRGBSharp()))
 	} else {
-		format_as_sgr.selection = only_open("bg=" + conf.Select_bg.AsRGBSharp())
+		format_as_sgr.selection = only_open("bg=" + rc.Select_bg.AsRGBSharp())
 	}
 }
 
@@ -198,9 +268,9 @@ func center_span(ltype string, offset, size int) *sgr.Span {
 	ans := sgr.NewSpan(offset, size)
 	switch ltype {
 	case "add":
-		ans.SetBackground(conf.Highlight_added_bg).SetClosingBackground(conf.Added_bg)
+		ans.SetBackground(resolved_colors.Highlight_added_bg).SetClosingBackground(resolved_colors.Added_bg)
 	case "remove":
-		ans.SetBackground(conf.Highlight_removed_bg).SetClosingBackground(conf.Removed_bg)
+		ans.SetBackground(resolved_colors.Highlight_removed_bg).SetClosingBackground(resolved_colors.Removed_bg)
 	}
 	return ans
 }
@@ -469,7 +539,7 @@ func hunk_title(hunk *Hunk) string {
 	return fmt.Sprintf("@@ -%d,%d +%d,%d @@ %s", hunk.left_start+1, hunk.left_count, hunk.right_start+1, hunk.right_count, hunk.title)
 }
 
-func lines_for_context_chunk(data *DiffData, hunk_num int, chunk *Chunk, chunk_num int, ans []*LogicalLine) []*LogicalLine {
+func lines_for_context_chunk(data *DiffData, _ int, chunk *Chunk, _ int, ans []*LogicalLine) []*LogicalLine {
 	for i := 0; i < chunk.left_count; i++ {
 		left_line_number := chunk.left_start + i
 		right_line_number := chunk.right_start + i
@@ -514,7 +584,7 @@ func render_half_line(line_number int, line, ltype string, available_cols int, c
 	return ans
 }
 
-func lines_for_diff_chunk(data *DiffData, hunk_num int, chunk *Chunk, chunk_num int, ans []*LogicalLine) []*LogicalLine {
+func lines_for_diff_chunk(data *DiffData, _ int, chunk *Chunk, _ int, ans []*LogicalLine) []*LogicalLine {
 	common := utils.Min(chunk.left_count, chunk.right_count)
 	ll, rl := make([]HalfScreenLine, 0, 32), make([]HalfScreenLine, 0, 32)
 	for i := 0; i < utils.Max(chunk.left_count, chunk.right_count); i++ {

kittens/diff/ui.go

@@ -61,6 +61,7 @@ type Handler struct {
 	collection                                          *Collection
 	diff_map                                            map[string]*Patch
 	logical_lines                                       *LogicalLines
+	terminal_capabilities_received                      bool
 	lp                                                  *loop.Loop
 	current_context_count, original_context_count       int
 	added_count, removed_count                          int
@@ -111,6 +112,31 @@ func (self *Handler) finalize() {
 	image_collection.Finalize(self.lp)
 }
 
+func set_terminal_colors(lp *loop.Loop) {
+	create_formatters()
+	lp.SetDefaultColor(loop.FOREGROUND, resolved_colors.Foreground)
+	lp.SetDefaultColor(loop.CURSOR, resolved_colors.Foreground)
+	lp.SetDefaultColor(loop.BACKGROUND, resolved_colors.Background)
+	lp.SetDefaultColor(loop.SELECTION_BG, resolved_colors.Select_bg)
+	if resolved_colors.Select_fg.IsSet {
+		lp.SetDefaultColor(loop.SELECTION_FG, resolved_colors.Select_fg.Color)
+	}
+}
+
+func (self *Handler) on_capabilities_received(tc loop.TerminalCapabilities) {
+	switch conf.Color_scheme {
+	case Color_scheme_auto:
+		use_dark_colors = tc.ColorPreference != loop.LIGHT_COLOR_PREFERENCE
+	case Color_scheme_light:
+		use_dark_colors = false
+	case Color_scheme_dark:
+		use_dark_colors = true
+	}
+	set_terminal_colors(self.lp)
+	self.terminal_capabilities_received = true
+	self.draw_screen()
+}
+
 func (self *Handler) initialize() {
 	self.rl = readline.New(self.lp, readline.RlInit{DontMarkPrompts: true, Prompt: "/"})
 	self.lp.OnEscapeCode = self.on_escape_code
@@ -122,13 +148,6 @@ func (self *Handler) initialize() {
 	sz, _ := self.lp.ScreenSize()
 	self.update_screen_size(sz)
 	self.original_context_count = self.current_context_count
-	self.lp.SetDefaultColor(loop.FOREGROUND, conf.Foreground)
-	self.lp.SetDefaultColor(loop.CURSOR, conf.Foreground)
-	self.lp.SetDefaultColor(loop.BACKGROUND, conf.Background)
-	self.lp.SetDefaultColor(loop.SELECTION_BG, conf.Select_bg)
-	if conf.Select_fg.IsSet {
-		self.lp.SetDefaultColor(loop.SELECTION_FG, conf.Select_fg.Color)
-	}
 	self.async_results = make(chan AsyncResult, 32)
 	go func() {
 		r := AsyncResult{}
@@ -315,7 +334,7 @@ func (self *Handler) render_diff() (err error) {
 	return nil
 }
 
-func (self *Handler) draw_image(key string, num_rows, starting_row int) {
+func (self *Handler) draw_image(key string, _, starting_row int) {
 	image_collection.PlaceImageSubRect(self.lp, key, self.images_resized_to, 0, self.screen_size.cell_height*starting_row, -1, -1)
 }
 
@@ -345,7 +364,7 @@ func (self *Handler) draw_screen() {
 	}
 	lp.MoveCursorTo(1, 1)
 	lp.ClearToEndOfScreen()
-	if self.logical_lines == nil || self.diff_map == nil || self.collection == nil {
+	if self.logical_lines == nil || self.diff_map == nil || self.collection == nil || !self.terminal_capabilities_received {
 		lp.Println(`Calculating diff, please wait...`)
 		return
 	}