Add footer

Options:
  --footer=STR             String to print as footer
  --footer-border[=STYLE]  Draw border around the footer section
                           [rounded|sharp|bold|block|thinblock|double|horizontal|vertical|
                            top|bottom|left|right|line|none] (default: line)
  --footer-label=LABEL     Label to print on the footer border
  --footer-label-pos=COL   Position of the footer label
                           [POSITIVE_INTEGER: columns from left|
                            NEGATIVE_INTEGER: columns from right][:bottom]
                           (default: 0 or center)

The default border type for footer is 'line', which draws a single
separator between the footer and the list. It changes its position
depending on `--layout`, so you don't have to manually switch between
'top' and 'bottom'

The 'line' style is now supported by other border types as well.
`--list-border` is the only exception.

src/terminal.go

@@ -180,14 +180,18 @@ type itemLine struct {
 	other     bool
 }
 
+func (t *Terminal) inListWindow() bool {
+	return t.window != t.inputWindow && t.window != t.headerWindow && t.window != t.headerLinesWindow && t.window != t.footerWindow
+}
+
 func (t *Terminal) markEmptyLine(line int) {
-	if t.window != t.inputWindow && t.window != t.headerWindow {
+	if t.inListWindow() {
 		t.prevLines[line] = itemLine{valid: true, firstLine: line, empty: true}
 	}
 }
 
 func (t *Terminal) markOtherLine(line int) {
-	if t.window != t.inputWindow && t.window != t.headerWindow {
+	if t.inListWindow() {
 		t.prevLines[line] = itemLine{valid: true, firstLine: line, other: true}
 	}
 }
@@ -254,6 +258,9 @@ type Terminal struct {
 	headerLabel        labelPrinter
 	headerLabelLen     int
 	headerLabelOpts    labelOpts
+	footerLabel        labelPrinter
+	footerLabelLen     int
+	footerLabelOpts    labelOpts
 	pointer            string
 	pointerLen         int
 	pointerEmpty       string
@@ -301,6 +308,7 @@ type Terminal struct {
 	headerLines        int
 	header             []string
 	header0            []string
+	footer             []string
 	ellipsis           string
 	scrollbar          string
 	previewScrollbar   string
@@ -322,6 +330,7 @@ type Terminal struct {
 	inputBorderShape   tui.BorderShape
 	headerBorderShape  tui.BorderShape
 	headerLinesShape   tui.BorderShape
+	footerBorderShape  tui.BorderShape
 	listLabel          labelPrinter
 	listLabelLen       int
 	listLabelOpts      labelOpts
@@ -337,6 +346,8 @@ type Terminal struct {
 	headerBorder       tui.Window
 	headerLinesWindow  tui.Window
 	headerLinesBorder  tui.Window
+	footerWindow       tui.Window
+	footerBorder       tui.Window
 	wborder            tui.Window
 	pborder            tui.Window
 	pwindow            tui.Window
@@ -426,6 +437,7 @@ const (
 	reqPrompt util.EventType = iota
 	reqInfo
 	reqHeader
+	reqFooter
 	reqList
 	reqJump
 	reqActivate
@@ -434,6 +446,7 @@ const (
 	reqResize
 	reqRedrawInputLabel
 	reqRedrawHeaderLabel
+	reqRedrawFooterLabel
 	reqRedrawListLabel
 	reqRedrawBorderLabel
 	reqRedrawPreviewLabel
@@ -479,7 +492,9 @@ const (
 	actChangeBorderLabel
 	actChangeGhost
 	actChangeHeader
+	actChangeFooter
 	actChangeHeaderLabel
+	actChangeFooterLabel
 	actChangeInputLabel
 	actChangeListLabel
 	actChangeMulti
@@ -550,7 +565,9 @@ const (
 	actTransformBorderLabel
 	actTransformGhost
 	actTransformHeader
+	actTransformFooter
 	actTransformHeaderLabel
+	actTransformFooterLabel
 	actTransformInputLabel
 	actTransformListLabel
 	actTransformNth
@@ -907,6 +924,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox, executor *util.Executor
 		inputBorderShape:   opts.InputBorderShape,
 		headerBorderShape:  opts.HeaderBorderShape,
 		headerLinesShape:   opts.HeaderLinesShape,
+		footerBorderShape:  opts.FooterBorderShape,
 		borderWidth:        1,
 		listLabel:          nil,
 		listLabelOpts:      opts.ListLabel,
@@ -918,6 +936,8 @@ func NewTerminal(opts *Options, eventBox *util.EventBox, executor *util.Executor
 		inputLabelOpts:     opts.InputLabel,
 		headerLabel:        nil,
 		headerLabelOpts:    opts.HeaderLabel,
+		footerLabel:        nil,
+		footerLabelOpts:    opts.FooterLabel,
 		cleanExit:          opts.ClearOnExit,
 		executor:           executor,
 		paused:             opts.Phony,
@@ -929,6 +949,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox, executor *util.Executor
 		headerLines:        opts.HeaderLines,
 		gap:                opts.Gap,
 		header:             []string{},
+		footer:             opts.Footer,
 		header0:            opts.Header,
 		ansi:               opts.Ansi,
 		nthAttr:            opts.Theme.Nth.Attr,
@@ -992,6 +1013,52 @@ func NewTerminal(opts *Options, eventBox *util.EventBox, executor *util.Executor
 	t.previewLabel, t.previewLabelLen = t.ansiLabelPrinter(opts.PreviewLabel.label, &tui.ColPreviewLabel, false)
 	t.inputLabel, t.inputLabelLen = t.ansiLabelPrinter(opts.InputLabel.label, &tui.ColInputLabel, false)
 	t.headerLabel, t.headerLabelLen = t.ansiLabelPrinter(opts.HeaderLabel.label, &tui.ColHeaderLabel, false)
+	t.footerLabel, t.footerLabelLen = t.ansiLabelPrinter(opts.FooterLabel.label, &tui.ColFooterLabel, false)
+
+	// Determine border shape
+	if t.borderShape == tui.BorderLine {
+		if t.fullscreen {
+			t.borderShape = tui.BorderNone
+		} else {
+			t.borderShape = tui.BorderTop
+		}
+	}
+
+	// Determine input border shape
+	if t.inputBorderShape == tui.BorderLine {
+		if t.layout == layoutReverse {
+			t.inputBorderShape = tui.BorderBottom
+		} else {
+			t.inputBorderShape = tui.BorderTop
+		}
+	}
+
+	// Determine header border shape
+	if t.headerBorderShape == tui.BorderLine {
+		if t.layout == layoutReverse {
+			t.headerBorderShape = tui.BorderBottom
+		} else {
+			t.headerBorderShape = tui.BorderTop
+		}
+	}
+
+	// Determine header lines border shape
+	if t.headerLinesShape == tui.BorderLine {
+		if t.layout == layoutDefault {
+			t.headerLinesShape = tui.BorderTop
+		} else {
+			t.headerLinesShape = tui.BorderBottom
+		}
+	}
+
+	// Determine footer border shape
+	if t.footerBorderShape == tui.BorderLine {
+		if t.layout == layoutReverse {
+			t.footerBorderShape = tui.BorderTop
+		} else {
+			t.footerBorderShape = tui.BorderBottom
+		}
+	}
 
 	// Disable separator by default if input border is set
 	if opts.Separator == nil && !t.inputBorderShape.Visible() || opts.Separator != nil && len(*opts.Separator) > 0 {
@@ -1208,6 +1275,10 @@ func (t *Terminal) extraLines() int {
 		}
 		extra += t.headerLines
 	}
+	if len(t.footer) > 0 {
+		extra += borderLines(t.footerBorderShape)
+		extra += len(t.footer)
+	}
 	return extra
 }
 
@@ -1475,6 +1546,16 @@ func (t *Terminal) changeHeader(header string) bool {
 	return needFullRedraw
 }
 
+func (t *Terminal) changeFooter(footer string) bool {
+	var lines []string
+	if len(footer) > 0 {
+		lines = strings.Split(strings.TrimSuffix(footer, "\n"), "\n")
+	}
+	needFullRedraw := len(t.footer) != len(lines)
+	t.footer = lines
+	return needFullRedraw
+}
+
 // UpdateHeader updates the header
 func (t *Terminal) UpdateHeader(header []string) {
 	t.mutex.Lock()
@@ -1835,6 +1916,12 @@ func (t *Terminal) resizeWindows(forcePreview bool, redrawBorder bool) {
 	if t.headerBorder != nil {
 		t.headerBorder = nil
 	}
+	if t.footerWindow != nil {
+		t.footerWindow = nil
+	}
+	if t.footerBorder != nil {
+		t.footerBorder = nil
+	}
 	if t.headerLinesWindow != nil {
 		t.headerLinesWindow = nil
 	}
@@ -1889,17 +1976,19 @@ func (t *Terminal) resizeWindows(forcePreview bool, redrawBorder bool) {
 	// Adjust position and size of the list window if input border is set
 	inputBorderHeight := 0
 	availableLines := height
+
 	shift := 0
 	shrink := 0
 	hasHeaderWindow := t.hasHeaderWindow()
+	hasFooterWindow := len(t.footer) > 0
 	hasHeaderLinesWindow, headerLinesShape := t.determineHeaderLinesShape()
 	hasInputWindow := !t.inputless && (t.inputBorderShape.Visible() || hasHeaderWindow || hasHeaderLinesWindow)
+	inputWindowHeight := 2
+	if t.noSeparatorLine() {
+		inputWindowHeight--
+	}
 	if hasInputWindow {
-		inputWindowHeight := 2
-		if t.noSeparatorLine() {
-			inputWindowHeight--
-		}
-		inputBorderHeight = util.Min(availableLines, borderLines(t.inputBorderShape)+inputWindowHeight)
+		inputBorderHeight = util.Constrain(borderLines(t.inputBorderShape)+inputWindowHeight, 0, availableLines)
 		if t.layout == layoutReverse {
 			shift = inputBorderHeight
 			shrink = inputBorderHeight
@@ -1907,6 +1996,17 @@ func (t *Terminal) resizeWindows(forcePreview bool, redrawBorder bool) {
 			shrink = inputBorderHeight
 		}
 		availableLines -= inputBorderHeight
+	} else if !t.inputless {
+		availableLines -= inputWindowHeight
+	}
+
+	// FIXME: Needed?
+	if t.needPreviewWindow() {
+		_, minPreviewHeight := t.minPreviewSize(t.activePreviewOpts)
+		switch t.activePreviewOpts.position {
+		case posUp, posDown:
+			availableLines -= minPreviewHeight
+		}
 	}
 
 	// Adjust position and size of the list window if header border is set
@@ -1916,7 +2016,7 @@ func (t *Terminal) resizeWindows(forcePreview bool, redrawBorder bool) {
 		if hasHeaderLinesWindow {
 			headerWindowHeight -= t.headerLines
 		}
-		headerBorderHeight = util.Min(availableLines, borderLines(t.headerBorderShape)+headerWindowHeight)
+		headerBorderHeight = util.Constrain(borderLines(t.headerBorderShape)+headerWindowHeight, 0, availableLines)
 		if t.layout == layoutReverse {
 			shift += headerBorderHeight
 			shrink += headerBorderHeight
@@ -1928,7 +2028,7 @@ func (t *Terminal) resizeWindows(forcePreview bool, redrawBorder bool) {
 
 	headerLinesHeight := 0
 	if hasHeaderLinesWindow {
-		headerLinesHeight = util.Min(availableLines, borderLines(headerLinesShape)+t.headerLines)
+		headerLinesHeight = util.Constrain(borderLines(headerLinesShape)+t.headerLines, 0, availableLines)
 		if t.layout != layoutDefault {
 			shift += headerLinesHeight
 			shrink += headerLinesHeight
@@ -1938,6 +2038,17 @@ func (t *Terminal) resizeWindows(forcePreview bool, redrawBorder bool) {
 		availableLines -= headerLinesHeight
 	}
 
+	footerBorderHeight := 0
+	if hasFooterWindow {
+		// Footer lines should not take all available lines
+		footerBorderHeight = util.Constrain(borderLines(t.footerBorderShape)+len(t.footer), 0, availableLines)
+		shrink += footerBorderHeight
+		if t.layout != layoutReverse {
+			shift += footerBorderHeight
+		}
+		availableLines -= footerBorderHeight
+	}
+
 	// Set up list border
 	hasListBorder := t.listBorderShape.Visible()
 	innerWidth := width
@@ -2041,13 +2152,8 @@ func (t *Terminal) resizeWindows(forcePreview bool, redrawBorder bool) {
 					width++
 				}
 
-				maxPreviewLines := availableLines
-				if t.wborder != nil {
-					maxPreviewLines -= t.wborder.Height()
-				} else {
-					maxPreviewLines -= util.Max(0, innerHeight-pheight-shrink)
-				}
-				pheight = util.Min(pheight, maxPreviewLines)
+				pheight = util.Constrain(pheight, minPreviewHeight, availableLines)
+
 				if previewOpts.position == posUp {
 					innerBorderFn(marginInt[0]+pheight, marginInt[3], width, height-pheight)
 					t.window = t.tui.NewWindow(
@@ -2210,7 +2316,7 @@ func (t *Terminal) resizeWindows(forcePreview bool, redrawBorder bool) {
 			case layoutDefault:
 				btop = w.Top() + w.Height() + headerBorderHeight + headerLinesHeight
 			case layoutReverse:
-				btop = w.Top() - shrink
+				btop = w.Top() - shrink + footerBorderHeight
 			case layoutReverseList:
 				btop = w.Top() + w.Height() + headerBorderHeight
 			}
@@ -2238,7 +2344,7 @@ func (t *Terminal) resizeWindows(forcePreview bool, redrawBorder bool) {
 		var btop int
 		if hasInputWindow && t.headerFirst {
 			if t.layout == layoutReverse {
-				btop = w.Top() - shrink
+				btop = w.Top() - shrink + footerBorderHeight
 			} else if t.layout == layoutReverseList {
 				btop = w.Top() + w.Height() + inputBorderHeight
 			} else {
@@ -2294,12 +2400,31 @@ func (t *Terminal) resizeWindows(forcePreview bool, redrawBorder bool) {
 		t.headerLinesWindow = createInnerWindow(t.headerLinesBorder, headerLinesShape, tui.WindowHeader, 0)
 	}
 
+	// Set up footer
+	if hasFooterWindow {
+		var btop int
+		if t.layout == layoutReverse {
+			btop = w.Top() + w.Height()
+		} else if t.layout == layoutReverseList {
+			btop = w.Top() - footerBorderHeight - headerLinesHeight
+		} else {
+			btop = w.Top() - footerBorderHeight
+		}
+		t.footerBorder = t.tui.NewWindow(
+			btop,
+			w.Left(),
+			w.Width(),
+			footerBorderHeight, tui.WindowFooter, tui.MakeBorderStyle(t.footerBorderShape, t.unicode), true)
+		t.footerWindow = createInnerWindow(t.footerBorder, t.footerBorderShape, tui.WindowFooter, 0)
+	}
+
 	// Print border label
 	t.printLabel(t.wborder, t.listLabel, t.listLabelOpts, t.listLabelLen, t.listBorderShape, false)
 	t.printLabel(t.border, t.borderLabel, t.borderLabelOpts, t.borderLabelLen, t.borderShape, false)
 	t.printLabel(t.pborder, t.previewLabel, t.previewLabelOpts, t.previewLabelLen, t.activePreviewOpts.Border(), false)
 	t.printLabel(t.inputBorder, t.inputLabel, t.inputLabelOpts, t.inputLabelLen, t.inputBorderShape, false)
 	t.printLabel(t.headerBorder, t.headerLabel, t.headerLabelOpts, t.headerLabelLen, t.headerBorderShape, false)
+	t.printLabel(t.footerBorder, t.footerLabel, t.footerLabelOpts, t.footerLabelLen, t.footerBorderShape, false)
 }
 
 func (t *Terminal) printLabel(window tui.Window, render labelPrinter, opts labelOpts, length int, borderShape tui.BorderShape, redrawBorder bool) {
@@ -2343,7 +2468,7 @@ func (t *Terminal) move(y int, x int, clear bool) {
 	case layoutDefault:
 		y = h - y - 1
 	case layoutReverseList:
-		if t.window == t.inputWindow || t.window == t.headerWindow {
+		if !t.inListWindow() && t.window != t.headerLinesWindow {
 			// From bottom to top
 			y = h - y - 1
 		} else {
@@ -2690,8 +2815,10 @@ func (t *Terminal) resizeIfNeeded() bool {
 	if t.hasHeaderLinesWindow() {
 		primaryHeaderLines -= t.headerLines
 	}
+	// FIXME: Full redraw is triggered if there are too many lines in the header
+	// so that the header window cannot display all of them.
 	needHeaderLinesWindow := t.hasHeaderLinesWindow()
-	if (t.headerBorderShape.Visible() || t.hasHeaderLinesWindow()) &&
+	if (t.headerBorderShape.Visible() || needHeaderLinesWindow) &&
 		(t.headerWindow == nil && primaryHeaderLines > 0 || t.headerWindow != nil && primaryHeaderLines != t.headerWindow.Height()) ||
 		needHeaderLinesWindow && (t.headerLinesWindow == nil || t.headerLinesWindow != nil && t.headerLines != t.headerLinesWindow.Height()) ||
 		!needHeaderLinesWindow && t.headerLinesWindow != nil {
@@ -2720,6 +2847,41 @@ func (t *Terminal) printHeader() {
 	}
 }
 
+func (t *Terminal) printFooter() {
+	if len(t.footer) == 0 {
+		return
+	}
+	indentSize := t.headerIndent(t.footerBorderShape)
+	indent := strings.Repeat(" ", indentSize)
+	max := util.Min(len(t.footer), t.footerWindow.Height())
+
+	// Wrapping is not supported for footer
+	wrap := t.wrap
+	t.wrap = false
+	t.withWindow(t.footerWindow, func() {
+		var state *ansiState
+		for idx, lineStr := range t.footer[:max] {
+			line := idx
+			if t.layout != layoutReverse {
+				line = max - idx - 1
+			}
+			trimmed, colors, newState := extractColor(lineStr, state, nil)
+			state = newState
+			item := &Item{
+				text:   util.ToChars([]byte(trimmed)),
+				colors: colors}
+
+			t.printHighlighted(Result{item: item},
+				tui.ColFooter, tui.ColFooter, false, false, line, line, true,
+				func(markerClass) int {
+					t.footerWindow.Print(indent)
+					return indentSize
+				}, nil)
+		}
+	})
+	t.wrap = wrap
+}
+
 func (t *Terminal) headerIndent(borderShape tui.BorderShape) int {
 	indentSize := t.pointerLen + t.markerLen
 	if t.listBorderShape.HasLeft() {
@@ -2792,7 +2954,7 @@ func (t *Terminal) printHeaderImpl(window tui.Window, borderShape tui.BorderShap
 }
 
 func (t *Terminal) canSpanMultiLines() bool {
-	return t.multiLine || t.wrap || t.gap > 0
+	return (t.multiLine || t.wrap || t.gap > 0) && t.inListWindow()
 }
 
 func (t *Terminal) renderBar(line int, barRange [2]int) {
@@ -3767,6 +3929,7 @@ func (t *Terminal) printAll() {
 	t.printPrompt()
 	t.printInfo()
 	t.printHeader()
+	t.printFooter()
 	t.printPreview()
 }
 
@@ -4515,6 +4678,7 @@ func (t *Terminal) Loop() error {
 		t.reqBox.Set(reqPrompt, nil)
 		t.reqBox.Set(reqInfo, nil)
 		t.reqBox.Set(reqHeader, nil)
+		t.reqBox.Set(reqFooter, nil)
 		if t.initDelay > 0 {
 			go func() {
 				timer := time.NewTimer(t.initDelay)
@@ -4797,6 +4961,10 @@ func (t *Terminal) Loop() error {
 						if !t.resizeIfNeeded() {
 							t.printHeader()
 						}
+					case reqFooter:
+						if !t.resizeIfNeeded() {
+							t.printFooter()
+						}
 					case reqActivate:
 						t.suppress = false
 						if t.hasPreviewer() {
@@ -4806,6 +4974,8 @@ func (t *Terminal) Loop() error {
 						t.printLabel(t.inputBorder, t.inputLabel, t.inputLabelOpts, t.inputLabelLen, t.inputBorderShape, true)
 					case reqRedrawHeaderLabel:
 						t.printLabel(t.headerBorder, t.headerLabel, t.headerLabelOpts, t.headerLabelLen, t.headerBorderShape, true)
+					case reqRedrawFooterLabel:
+						t.printLabel(t.footerBorder, t.footerLabel, t.footerLabelOpts, t.footerLabelLen, t.footerBorderShape, true)
 					case reqRedrawListLabel:
 						t.printLabel(t.wborder, t.listLabel, t.listLabelOpts, t.listLabelLen, t.listBorderShape, true)
 					case reqRedrawBorderLabel:
@@ -4996,7 +5166,7 @@ func (t *Terminal) Loop() error {
 		}
 		updatePreviewWindow := func(forcePreview bool) {
 			t.resizeWindows(forcePreview, false)
-			req(reqPrompt, reqList, reqInfo, reqHeader)
+			req(reqPrompt, reqList, reqInfo, reqHeader, reqFooter)
 		}
 		toggle := func() bool {
 			current := t.currentItem()
@@ -5271,6 +5441,16 @@ func (t *Terminal) Loop() error {
 				} else {
 					req(reqHeader)
 				}
+			case actChangeFooter, actTransformFooter:
+				footer := a.a
+				if a.t == actTransformFooter {
+					footer = t.captureLines(a.a)
+				}
+				if t.changeFooter(footer) {
+					req(reqFullRedraw)
+				} else {
+					req(reqFooter)
+				}
 			case actChangeHeaderLabel, actTransformHeaderLabel:
 				label := a.a
 				if a.t == actTransformHeaderLabel {
@@ -5279,6 +5459,14 @@ func (t *Terminal) Loop() error {
 				t.headerLabelOpts.label = label
 				t.headerLabel, t.headerLabelLen = t.ansiLabelPrinter(label, &tui.ColHeaderLabel, false)
 				req(reqRedrawHeaderLabel)
+			case actChangeFooterLabel, actTransformFooterLabel:
+				label := a.a
+				if a.t == actTransformFooterLabel {
+					label = t.captureLine(a.a)
+				}
+				t.footerLabelOpts.label = label
+				t.footerLabel, t.footerLabelLen = t.ansiLabelPrinter(label, &tui.ColFooterLabel, false)
+				req(reqRedrawFooterLabel)
 			case actChangeInputLabel, actTransformInputLabel:
 				label := a.a
 				if a.t == actTransformInputLabel {