Allow customizing the color of preview scrollbar via 'preview-scrollbar'

man/man1/fzf.1

@@ -446,8 +446,10 @@ color mappings.
       \fBdisabled          \fRQuery string when search is disabled (\fB--disabled\fR)
     \fBinfo                \fRInfo line (match counters)
     \fBborder              \fRBorder around the window (\fB--border\fR and \fB--preview\fR)
-      \fBseparator     \fRHorizontal separator on info line
       \fBscrollbar         \fRScrollbar
+      \fBpreview-border    \fRBorder around the preview window (\fB--preview\fR)
+      \fBpreview-scrollbar \fRScrollbar
+      \fBseparator         \fRHorizontal separator on info line
     \fBlabel               \fRBorder label (\fB--border-label\fR and \fB--preview-label\fR)
       \fBpreview-label     \fRBorder label of the preview window (\fB--preview-label\fR)
     \fBprompt              \fRPrompt

src/options.go

@@ -888,10 +888,14 @@ func parseTheme(defaultTheme *tui.ColorTheme, str string) *tui.ColorTheme {
 				mergeAttr(&theme.CurrentMatch)
 			case "border":
 				mergeAttr(&theme.Border)
+			case "preview-border":
+				mergeAttr(&theme.PreviewBorder)
 			case "separator":
 				mergeAttr(&theme.Separator)
 			case "scrollbar":
 				mergeAttr(&theme.Scrollbar)
+			case "preview-scrollbar":
+				mergeAttr(&theme.PreviewScrollbar)
 			case "label":
 				mergeAttr(&theme.BorderLabel)
 			case "preview-label":

src/terminal.go

@@ -1930,7 +1930,9 @@ func (t *Terminal) renderPreviewText(height int, lines []string, lineNo int, unc
 func (t *Terminal) renderPreviewScrollbar(yoff int, barLength int, barStart int) {
 	height := t.pwindow.Height()
 	w := t.pborder.Width()
+	redraw := false
 	if len(t.previewer.bar) != height {
+		redraw = true
 		t.previewer.bar = make([]bool, height)
 	}
 	xshift := -1 - t.borderWidth
@@ -1947,7 +1949,7 @@ func (t *Terminal) renderPreviewScrollbar(yoff int, barLength int, barStart int)
 
 		// Avoid unnecessary redraws
 		bar := i >= yoff+barStart && i < yoff+barStart+barLength
-		if bar == t.previewer.bar[i] && !t.tui.NeedScrollbarRedraw() {
+		if !redraw && bar == t.previewer.bar[i] && !t.tui.NeedScrollbarRedraw() {
 			continue
 		}
 
@@ -1956,7 +1958,7 @@ func (t *Terminal) renderPreviewScrollbar(yoff int, barLength int, barStart int)
 		if i >= yoff+barStart && i < yoff+barStart+barLength {
 			t.pborder.CPrint(tui.ColPreviewScrollbar, t.scrollbar)
 		} else {
-			t.pborder.Print(" ")
+			t.pborder.CPrint(tui.ColPreviewScrollbar, " ")
 		}
 	}
 }

src/tui/tui.go

@@ -274,6 +274,8 @@ type ColorTheme struct {
 	Separator        ColorAttr
 	Scrollbar        ColorAttr
 	Border           ColorAttr
+	PreviewBorder    ColorAttr
+	PreviewScrollbar ColorAttr
 	BorderLabel      ColorAttr
 	PreviewLabel     ColorAttr
 }
@@ -528,6 +530,8 @@ func EmptyTheme() *ColorTheme {
 		PreviewFg:        ColorAttr{colUndefined, AttrUndefined},
 		PreviewBg:        ColorAttr{colUndefined, AttrUndefined},
 		Gutter:           ColorAttr{colUndefined, AttrUndefined},
+		PreviewBorder:    ColorAttr{colUndefined, AttrUndefined},
+		PreviewScrollbar: ColorAttr{colUndefined, AttrUndefined},
 		PreviewLabel:     ColorAttr{colUndefined, AttrUndefined},
 		Separator:        ColorAttr{colUndefined, AttrUndefined},
 		Scrollbar:        ColorAttr{colUndefined, AttrUndefined},
@@ -556,6 +560,8 @@ func NoColorTheme() *ColorTheme {
 		PreviewFg:        ColorAttr{colDefault, AttrUndefined},
 		PreviewBg:        ColorAttr{colDefault, AttrUndefined},
 		Gutter:           ColorAttr{colDefault, AttrUndefined},
+		PreviewBorder:    ColorAttr{colDefault, AttrUndefined},
+		PreviewScrollbar: ColorAttr{colDefault, AttrUndefined},
 		PreviewLabel:     ColorAttr{colDefault, AttrUndefined},
 		Separator:        ColorAttr{colDefault, AttrUndefined},
 		Scrollbar:        ColorAttr{colDefault, AttrUndefined},
@@ -589,6 +595,8 @@ func init() {
 		PreviewFg:        ColorAttr{colUndefined, AttrUndefined},
 		PreviewBg:        ColorAttr{colUndefined, AttrUndefined},
 		Gutter:           ColorAttr{colUndefined, AttrUndefined},
+		PreviewBorder:    ColorAttr{colUndefined, AttrUndefined},
+		PreviewScrollbar: ColorAttr{colUndefined, AttrUndefined},
 		PreviewLabel:     ColorAttr{colUndefined, AttrUndefined},
 		Separator:        ColorAttr{colUndefined, AttrUndefined},
 		Scrollbar:        ColorAttr{colUndefined, AttrUndefined},
@@ -614,6 +622,8 @@ func init() {
 		PreviewFg:        ColorAttr{colUndefined, AttrUndefined},
 		PreviewBg:        ColorAttr{colUndefined, AttrUndefined},
 		Gutter:           ColorAttr{colUndefined, AttrUndefined},
+		PreviewBorder:    ColorAttr{colUndefined, AttrUndefined},
+		PreviewScrollbar: ColorAttr{colUndefined, AttrUndefined},
 		PreviewLabel:     ColorAttr{colUndefined, AttrUndefined},
 		Separator:        ColorAttr{colUndefined, AttrUndefined},
 		Scrollbar:        ColorAttr{colUndefined, AttrUndefined},
@@ -639,6 +649,8 @@ func init() {
 		PreviewFg:        ColorAttr{colUndefined, AttrUndefined},
 		PreviewBg:        ColorAttr{colUndefined, AttrUndefined},
 		Gutter:           ColorAttr{colUndefined, AttrUndefined},
+		PreviewBorder:    ColorAttr{colUndefined, AttrUndefined},
+		PreviewScrollbar: ColorAttr{colUndefined, AttrUndefined},
 		PreviewLabel:     ColorAttr{colUndefined, AttrUndefined},
 		Separator:        ColorAttr{colUndefined, AttrUndefined},
 		Scrollbar:        ColorAttr{colUndefined, AttrUndefined},
@@ -682,8 +694,10 @@ func initTheme(theme *ColorTheme, baseTheme *ColorTheme, forceBlack bool) {
 	theme.PreviewFg = o(theme.Fg, theme.PreviewFg)
 	theme.PreviewBg = o(theme.Bg, theme.PreviewBg)
 	theme.PreviewLabel = o(theme.BorderLabel, theme.PreviewLabel)
+	theme.PreviewBorder = o(theme.Border, theme.PreviewBorder)
 	theme.Separator = o(theme.Border, theme.Separator)
 	theme.Scrollbar = o(theme.Border, theme.Scrollbar)
+	theme.PreviewScrollbar = o(theme.PreviewBorder, theme.PreviewScrollbar)
 
 	initPalette(theme)
 }
@@ -721,6 +735,6 @@ func initPalette(theme *ColorTheme) {
 	ColBorderLabel = pair(theme.BorderLabel, theme.Bg)
 	ColPreviewLabel = pair(theme.PreviewLabel, theme.PreviewBg)
 	ColPreview = pair(theme.PreviewFg, theme.PreviewBg)
-	ColPreviewBorder = pair(theme.Border, theme.PreviewBg)
+	ColPreviewBorder = pair(theme.PreviewBorder, theme.PreviewBg)
-	ColPreviewScrollbar = pair(theme.Scrollbar, theme.PreviewBg)
+	ColPreviewScrollbar = pair(theme.PreviewScrollbar, theme.PreviewBg)
 }