Add --border-label and --border-label-pos

Close #3022

3 files changed, 178 insertions, 86 deletions

diff --git a/src/options.go b/src/options.go
index acf67281..80ca3e11 100644
--- a/src/options.go
+++ b/src/options.go
@@ -18,97 +18,101 @@ import (
 const usage = `usage: fzf [options]
 
   Search
-    -x, --extended        Extended-search mode
-                          (enabled by default; +x or --no-extended to disable)
-    -e, --exact           Enable Exact-match
-    -i                    Case-insensitive match (default: smart-case match)
-    +i                    Case-sensitive match
-    --scheme=SCHEME       Scoring scheme [default|path|history]
-    --literal             Do not normalize latin script letters before matching
-    -n, --nth=N[,..]      Comma-separated list of field index expressions
-                          for limiting search scope. Each can be a non-zero
-                          integer or a range expression ([BEGIN]..[END]).
-    --with-nth=N[,..]     Transform the presentation of each line using
-                          field index expressions
-    -d, --delimiter=STR   Field delimiter regex (default: AWK-style)
-    +s, --no-sort         Do not sort the result
-    --tac                 Reverse the order of the input
-    --disabled            Do not perform search
-    --tiebreak=CRI[,..]   Comma-separated list of sort criteria to apply
-                          when the scores are tied [length|chunk|begin|end|index]
-                          (default: length)
+    -x, --extended         Extended-search mode
+                           (enabled by default; +x or --no-extended to disable)
+    -e, --exact            Enable Exact-match
+    -i                     Case-insensitive match (default: smart-case match)
+    +i                     Case-sensitive match
+    --scheme=SCHEME        Scoring scheme [default|path|history]
+    --literal              Do not normalize latin script letters before matching
+    -n, --nth=N[,..]       Comma-separated list of field index expressions
+                           for limiting search scope. Each can be a non-zero
+                           integer or a range expression ([BEGIN]..[END]).
+    --with-nth=N[,..]      Transform the presentation of each line using
+                           field index expressions
+    -d, --delimiter=STR    Field delimiter regex (default: AWK-style)
+    +s, --no-sort          Do not sort the result
+    --tac                  Reverse the order of the input
+    --disabled             Do not perform search
+    --tiebreak=CRI[,..]    Comma-separated list of sort criteria to apply
+                           when the scores are tied [length|chunk|begin|end|index]
+                           (default: length)
 
   Interface
-    -m, --multi[=MAX]     Enable multi-select with tab/shift-tab
-    --no-mouse            Disable mouse
-    --bind=KEYBINDS       Custom key bindings. Refer to the man page.
-    --cycle               Enable cyclic scroll
-    --keep-right          Keep the right end of the line visible on overflow
-    --scroll-off=LINES    Number of screen lines to keep above or below when
-                          scrolling to the top or to the bottom (default: 0)
-    --no-hscroll          Disable horizontal scroll
-    --hscroll-off=COLS    Number of screen columns to keep to the right of the
-                          highlighted substring (default: 10)
-    --filepath-word       Make word-wise movements respect path separators
-    --jump-labels=CHARS   Label characters for jump and jump-accept
+    -m, --multi[=MAX]      Enable multi-select with tab/shift-tab
+    --no-mouse             Disable mouse
+    --bind=KEYBINDS        Custom key bindings. Refer to the man page.
+    --cycle                Enable cyclic scroll
+    --keep-right           Keep the right end of the line visible on overflow
+    --scroll-off=LINES     Number of screen lines to keep above or below when
+                           scrolling to the top or to the bottom (default: 0)
+    --no-hscroll           Disable horizontal scroll
+    --hscroll-off=COLS     Number of screen columns to keep to the right of the
+                           highlighted substring (default: 10)
+    --filepath-word        Make word-wise movements respect path separators
+    --jump-labels=CHARS    Label characters for jump and jump-accept
 
   Layout
-    --height=[~]HEIGHT[%] Display fzf window below the cursor with the given
-                          height instead of using fullscreen.
-                          If prefixed with '~', fzf will determine the height
-                          according to the input size.
-    --min-height=HEIGHT   Minimum height when --height is given in percent
-                          (default: 10)
-    --layout=LAYOUT       Choose layout: [default|reverse|reverse-list]
-    --border[=STYLE]      Draw border around the finder
-                          [rounded|sharp|horizontal|vertical|
-                           top|bottom|left|right|none] (default: rounded)
-    --margin=MARGIN       Screen margin (TRBL | TB,RL | T,RL,B | T,R,B,L)
-    --padding=PADDING     Padding inside border (TRBL | TB,RL | T,RL,B | T,R,B,L)
-    --info=STYLE          Finder info style [default|inline|hidden]
-    --prompt=STR          Input prompt (default: '> ')
-    --pointer=STR         Pointer to the current line (default: '>')
-    --marker=STR          Multi-select marker (default: '>')
-    --header=STR          String to print as header
-    --header-lines=N      The first N lines of the input are treated as header
-    --header-first        Print header before the prompt line
-    --ellipsis=STR        Ellipsis to show when line is truncated (default: '..')
+    --height=[~]HEIGHT[%]  Display fzf window below the cursor with the given
+                           height instead of using fullscreen.
+                           If prefixed with '~', fzf will determine the height
+                           according to the input size.
+    --min-height=HEIGHT    Minimum height when --height is given in percent
+                           (default: 10)
+    --layout=LAYOUT        Choose layout: [default|reverse|reverse-list]
+    --border[=STYLE]       Draw border around the finder
+                           [rounded|sharp|horizontal|vertical|
+                            top|bottom|left|right|none] (default: rounded)
+    --border-label=LABEL   Label to print on the border
+    --border-label-pos=COL Position of the border label
+                           [POSITIVE_INTEGER: columns from left|
+                            NEGATIVE_INTEGER: columns from right] (default: 0)
+    --margin=MARGIN        Screen margin (TRBL | TB,RL | T,RL,B | T,R,B,L)
+    --padding=PADDING      Padding inside border (TRBL | TB,RL | T,RL,B | T,R,B,L)
+    --info=STYLE           Finder info style [default|inline|hidden]
+    --prompt=STR           Input prompt (default: '> ')
+    --pointer=STR          Pointer to the current line (default: '>')
+    --marker=STR           Multi-select marker (default: '>')
+    --header=STR           String to print as header
+    --header-lines=N       The first N lines of the input are treated as header
+    --header-first         Print header before the prompt line
+    --ellipsis=STR         Ellipsis to show when line is truncated (default: '..')
 
   Display
-    --ansi                Enable processing of ANSI color codes
-    --tabstop=SPACES      Number of spaces for a tab character (default: 8)
-    --color=COLSPEC       Base scheme (dark|light|16|bw) and/or custom colors
-    --no-bold             Do not use bold text
+    --ansi                 Enable processing of ANSI color codes
+    --tabstop=SPACES       Number of spaces for a tab character (default: 8)
+    --color=COLSPEC        Base scheme (dark|light|16|bw) and/or custom colors
+    --no-bold              Do not use bold text
 
   History
-    --history=FILE        History file
-    --history-size=N      Maximum number of history entries (default: 1000)
+    --history=FILE         History file
+    --history-size=N       Maximum number of history entries (default: 1000)
 
   Preview
-    --preview=COMMAND     Command to preview highlighted line ({})
-    --preview-window=OPT  Preview window layout (default: right:50%)
-                          [up|down|left|right][,SIZE[%]]
-                          [,[no]wrap][,[no]cycle][,[no]follow][,[no]hidden]
-                          [,border-BORDER_OPT]
-                          [,+SCROLL[OFFSETS][/DENOM]][,~HEADER_LINES]
-                          [,default][,<SIZE_THRESHOLD(ALTERNATIVE_LAYOUT)]
+    --preview=COMMAND      Command to preview highlighted line ({})
+    --preview-window=OPT   Preview window layout (default: right:50%)
+                           [up|down|left|right][,SIZE[%]]
+                           [,[no]wrap][,[no]cycle][,[no]follow][,[no]hidden]
+                           [,border-BORDER_OPT]
+                           [,+SCROLL[OFFSETS][/DENOM]][,~HEADER_LINES]
+                           [,default][,<SIZE_THRESHOLD(ALTERNATIVE_LAYOUT)]
 
   Scripting
-    -q, --query=STR       Start the finder with the given query
-    -1, --select-1        Automatically select the only match
-    -0, --exit-0          Exit immediately when there's no match
-    -f, --filter=STR      Filter mode. Do not start interactive finder.
-    --print-query         Print query as the first line
-    --expect=KEYS         Comma-separated list of keys to complete fzf
-    --read0               Read input delimited by ASCII NUL characters
-    --print0              Print output delimited by ASCII NUL characters
-    --sync                Synchronous search for multi-staged filtering
-    --version             Display version information and exit
+    -q, --query=STR        Start the finder with the given query
+    -1, --select-1         Automatically select the only match
+    -0, --exit-0           Exit immediately when there's no match
+    -f, --filter=STR       Filter mode. Do not start interactive finder.
+    --print-query          Print query as the first line
+    --expect=KEYS          Comma-separated list of keys to complete fzf
+    --read0                Read input delimited by ASCII NUL characters
+    --print0               Print output delimited by ASCII NUL characters
+    --sync                 Synchronous search for multi-staged filtering
+    --version              Display version information and exit
 
   Environment variables
-    FZF_DEFAULT_COMMAND   Default command to use when input is tty
-    FZF_DEFAULT_OPTS      Default options
-                          (e.g. '--layout=reverse --inline-info')
+    FZF_DEFAULT_COMMAND    Default command to use when input is tty
+    FZF_DEFAULT_OPTS       Default options
+                           (e.g. '--layout=reverse --inline-info')
 
 `
 
@@ -188,6 +192,13 @@ type previewOpts struct {
 	alternative *previewOpts
 }
 
+func parseLabelPosition(arg string) int {
+	if strings.ToLower(arg) == "center" {
+		return 0
+	}
+	return atoi(arg)
+}
+
 func (a previewOpts) aboveOrBelow() bool {
 	return a.size.size > 0 && (a.position == posUp || a.position == posDown)
 }
@@ -258,6 +269,8 @@ type Options struct {
 	Margin      [4]sizeSpec
 	Padding     [4]sizeSpec
 	BorderShape tui.BorderShape
+	Label       string
+	LabelPos    int
 	Unicode     bool
 	Tabstop     int
 	ClearOnExit bool
@@ -324,6 +337,8 @@ func defaultOptions() *Options {
 		Padding:     defaultMargin(),
 		Unicode:     true,
 		Tabstop:     8,
+		Label:       "",
+		LabelPos:    0,
 		ClearOnExit: true,
 		Version:     false}
 }
@@ -798,6 +813,8 @@ func parseTheme(defaultTheme *tui.ColorTheme, str string) *tui.ColorTheme {
 				mergeAttr(&theme.CurrentMatch)
 			case "border":
 				mergeAttr(&theme.Border)
+			case "label":
+				mergeAttr(&theme.BorderLabel)
 			case "prompt":
 				mergeAttr(&theme.Prompt)
 			case "spinner":
@@ -1556,6 +1573,11 @@ func parseOptions(opts *Options, allArgs []string) {
 		case "--border":
 			hasArg, arg := optionalNextString(allArgs, &i)
 			opts.BorderShape = parseBorder(arg, !hasArg)
+		case "--border-label":
+			opts.Label = nextString(allArgs, &i, "label required")
+		case "--border-label-pos":
+			pos := nextString(allArgs, &i, "label position required (positive or negative integer or 'center')")
+			opts.LabelPos = parseLabelPosition(pos)
 		case "--no-unicode":
 			opts.Unicode = false
 		case "--unicode":
@@ -1591,6 +1613,10 @@ func parseOptions(opts *Options, allArgs []string) {
 				opts.Delimiter = delimiterRegexp(value)
 			} else if match, value := optString(arg, "--border="); match {
 				opts.BorderShape = parseBorder(value, false)
+			} else if match, value := optString(arg, "--border-label="); match {
+				opts.Label = value
+			} else if match, value := optString(arg, "--border-label-pos="); match {
+				opts.LabelPos = parseLabelPosition(value)
 			} else if match, value := optString(arg, "--prompt="); match {
 				opts.Prompt = value
 			} else if match, value := optString(arg, "--pointer="); match {
diff --git a/src/terminal.go b/src/terminal.go
index 369bc418..c28b5335 100644
--- a/src/terminal.go
+++ b/src/terminal.go
@@ -114,6 +114,9 @@ type Terminal struct {
 	spinner            []string
 	prompt             func()
 	promptLen          int
+	borderLabel        func()
+	borderLabelLen     int
+	borderLabelPos     int
 	pointer            string
 	pointerLen         int
 	pointerEmpty       string
@@ -544,6 +547,8 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		padding:            opts.Padding,
 		unicode:            opts.Unicode,
 		borderShape:        opts.BorderShape,
+		borderLabel:        nil,
+		borderLabelPos:     opts.LabelPos,
 		cleanExit:          opts.ClearOnExit,
 		paused:             opts.Phony,
 		strong:             strongAttr,
@@ -587,6 +592,9 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 	// Pre-calculated empty pointer and marker signs
 	t.pointerEmpty = strings.Repeat(" ", t.pointerLen)
 	t.markerEmpty = strings.Repeat(" ", t.markerLen)
+	if len(opts.Label) > 0 {
+		t.borderLabel, t.borderLabelLen = t.parseBorderLabel(opts.Label)
+	}
 
 	return &t
 }
@@ -617,6 +625,25 @@ func (t *Terminal) MaxFitAndPad(opts *Options) (int, int) {
 	return fit, padHeight
 }
 
+func (t *Terminal) parseBorderLabel(borderLabel string) (func(), int) {
+	text, colors, _ := extractColor(borderLabel, nil, nil)
+	runes := []rune(text)
+	item := &Item{text: util.RunesToChars(runes), colors: colors}
+	result := Result{item: item}
+
+	var offsets []colorOffset
+	borderLabelFn := func() {
+		if offsets == nil {
+			// tui.Col* are not initialized until renderer.Init()
+			offsets = result.colorOffsets(nil, t.theme, tui.ColBorderLabel, tui.ColBorderLabel, false)
+		}
+		text, _ := t.trimRight(runes, t.border.Width())
+		t.printColoredString(t.border, text, offsets, tui.ColBorderLabel)
+	}
+	borderLabelLen := runewidth.StringWidth(text)
+	return borderLabelFn, borderLabelLen
+}
+
 func (t *Terminal) parsePrompt(prompt string) (func(), int) {
 	var state *ansiState
 	trimmed, colors, _ := extractColor(prompt, state, nil)
@@ -911,6 +938,27 @@ func (t *Terminal) resizeWindows() {
 			false, tui.MakeBorderStyle(t.borderShape, t.unicode))
 	}
 
+	// Print border label
+	if t.border != nil && t.borderLabel != nil {
+		switch t.borderShape {
+		case tui.BorderHorizontal, tui.BorderTop, tui.BorderBottom, tui.BorderRounded, tui.BorderSharp:
+			var col int
+			if t.borderLabelPos == 0 {
+				col = util.Max(0, (t.border.Width()-t.borderLabelLen)/2)
+			} else if t.borderLabelPos < 0 {
+				col = util.Max(0, t.border.Width()+t.borderLabelPos+1-t.borderLabelLen)
+			} else {
+				col = util.Min(t.borderLabelPos-1, t.border.Width()-t.borderLabelLen)
+			}
+			row := 0
+			if t.borderShape == tui.BorderBottom {
+				row = t.border.Height() - 1
+			}
+			t.border.Move(row, col)
+			t.borderLabel()
+		}
+	}
+
 	// Add padding to margin
 	for idx, val := range paddingInt {
 		marginInt[idx] += val
@@ -1394,6 +1442,11 @@ func (t *Terminal) printHighlighted(result Result, colBase tui.ColorPair, colMat
 		displayWidth = t.displayWidthWithLimit(text, 0, displayWidth)
 	}
 
+	t.printColoredString(t.window, text, offsets, colBase)
+	return displayWidth
+}
+
+func (t *Terminal) printColoredString(window tui.Window, text []rune, offsets []colorOffset, colBase tui.ColorPair) {
 	var index int32
 	var substr string
 	var prefixWidth int
@@ -1403,11 +1456,11 @@ func (t *Terminal) printHighlighted(result Result, colBase tui.ColorPair, colMat
 		e := util.Constrain32(offset.offset[1], index, maxOffset)
 
 		substr, prefixWidth = t.processTabs(text[index:b], prefixWidth)
-		t.window.CPrint(colBase, substr)
+		window.CPrint(colBase, substr)
 
 		if b < e {
 			substr, prefixWidth = t.processTabs(text[b:e], prefixWidth)
-			t.window.CPrint(offset.color, substr)
+			window.CPrint(offset.color, substr)
 		}
 
 		index = e
@@ -1417,9 +1470,8 @@ func (t *Terminal) printHighlighted(result Result, colBase tui.ColorPair, colMat
 	}
 	if index < maxOffset {
 		substr, _ = t.processTabs(text[index:], prefixWidth)
-		t.window.CPrint(colBase, substr)
+		window.CPrint(colBase, substr)
 	}
-	return displayWidth
 }
 
 func (t *Terminal) renderPreviewSpinner() {
diff --git a/src/tui/tui.go b/src/tui/tui.go
index 90c5327e..1a9c748a 100644
--- a/src/tui/tui.go
+++ b/src/tui/tui.go
@@ -268,6 +268,7 @@ type ColorTheme struct {
 	Selected     ColorAttr
 	Header       ColorAttr
 	Border       ColorAttr
+	BorderLabel  ColorAttr
 }
 
 type Event struct {
@@ -441,6 +442,7 @@ var (
 	ColBorder               ColorPair
 	ColPreview              ColorPair
 	ColPreviewBorder        ColorPair
+	ColBorderLabel          ColorPair
 )
 
 func EmptyTheme() *ColorTheme {
@@ -463,7 +465,9 @@ func EmptyTheme() *ColorTheme {
 		Cursor:       ColorAttr{colUndefined, AttrUndefined},
 		Selected:     ColorAttr{colUndefined, AttrUndefined},
 		Header:       ColorAttr{colUndefined, AttrUndefined},
-		Border:       ColorAttr{colUndefined, AttrUndefined}}
+		Border:       ColorAttr{colUndefined, AttrUndefined},
+		BorderLabel:  ColorAttr{colUndefined, AttrUndefined},
+	}
 }
 
 func NoColorTheme() *ColorTheme {
@@ -486,7 +490,9 @@ func NoColorTheme() *ColorTheme {
 		Cursor:       ColorAttr{colDefault, AttrRegular},
 		Selected:     ColorAttr{colDefault, AttrRegular},
 		Header:       ColorAttr{colDefault, AttrRegular},
-		Border:       ColorAttr{colDefault, AttrRegular}}
+		Border:       ColorAttr{colDefault, AttrRegular},
+		BorderLabel:  ColorAttr{colDefault, AttrRegular},
+	}
 }
 
 func errorExit(message string) {
@@ -514,7 +520,9 @@ func init() {
 		Cursor:       ColorAttr{colRed, AttrUndefined},
 		Selected:     ColorAttr{colMagenta, AttrUndefined},
 		Header:       ColorAttr{colCyan, AttrUndefined},
-		Border:       ColorAttr{colBlack, AttrUndefined}}
+		Border:       ColorAttr{colBlack, AttrUndefined},
+		BorderLabel:  ColorAttr{colWhite, AttrUndefined},
+	}
 	Dark256 = &ColorTheme{
 		Colored:      true,
 		Input:        ColorAttr{colDefault, AttrUndefined},
@@ -534,7 +542,9 @@ func init() {
 		Cursor:       ColorAttr{161, AttrUndefined},
 		Selected:     ColorAttr{168, AttrUndefined},
 		Header:       ColorAttr{109, AttrUndefined},
-		Border:       ColorAttr{59, AttrUndefined}}
+		Border:       ColorAttr{59, AttrUndefined},
+		BorderLabel:  ColorAttr{145, AttrUndefined},
+	}
 	Light256 = &ColorTheme{
 		Colored:      true,
 		Input:        ColorAttr{colDefault, AttrUndefined},
@@ -554,7 +564,9 @@ func init() {
 		Cursor:       ColorAttr{161, AttrUndefined},
 		Selected:     ColorAttr{168, AttrUndefined},
 		Header:       ColorAttr{31, AttrUndefined},
-		Border:       ColorAttr{145, AttrUndefined}}
+		Border:       ColorAttr{145, AttrUndefined},
+		BorderLabel:  ColorAttr{59, AttrUndefined},
+	}
 }
 
 func initTheme(theme *ColorTheme, baseTheme *ColorTheme, forceBlack bool) {
@@ -590,6 +602,7 @@ func initTheme(theme *ColorTheme, baseTheme *ColorTheme, forceBlack bool) {
 	theme.Selected = o(baseTheme.Selected, theme.Selected)
 	theme.Header = o(baseTheme.Header, theme.Header)
 	theme.Border = o(baseTheme.Border, theme.Border)
+	theme.BorderLabel = o(baseTheme.BorderLabel, theme.BorderLabel)
 
 	initPalette(theme)
 }
@@ -622,6 +635,7 @@ func initPalette(theme *ColorTheme) {
 	ColInfo = pair(theme.Info, theme.Bg)
 	ColHeader = pair(theme.Header, theme.Bg)
 	ColBorder = pair(theme.Border, theme.Bg)
+	ColBorderLabel = pair(theme.BorderLabel, theme.Bg)
 	ColPreview = pair(theme.PreviewFg, theme.PreviewBg)
 	ColPreviewBorder = pair(theme.Border, theme.PreviewBg)
 }