v0.2.1 tui enhancement and better narrow layouts

go.mod

@@ -1,9 +1,9 @@
 module github.com/lixenwraith/terminal
 
-go 1.27.1
+go 1.27.2
 
 require (
 	github.com/lixenwraith/color v0.1.3
-	golang.org/x/sys v0.48.0
-	golang.org/x/term v0.46.0
+	golang.org/x/sys v0.49.0
+	golang.org/x/term v0.47.0
 )

go.sum

@@ -4,5 +4,9 @@ github.com/lixenwraith/color v0.1.3 h1:vSuvtU4zh1mIZS/7UGHmMdsTr+a7eCjUYGbou7kzF
 github.com/lixenwraith/color v0.1.3/go.mod h1:L/I3Vxp6pqslAIzWyZGgKCm2lyStHCA4vKaUoMUm7bU=
 golang.org/x/sys v0.48.0 h1:bbX/i/6MgT9BVLM9RT1thmxL04yeTAhbEz4SyadbXoo=
 golang.org/x/sys v0.48.0/go.mod h1:hNLxWAXmnKAxqDtdwIYC4bM9oQPEecfsnNMuSxOs3og=
+golang.org/x/sys v0.49.0 h1:XbzkgYJHdqh/8m2Uu0W/dQv8nktxx4BFHp1M0gROTXA=
+golang.org/x/sys v0.49.0/go.mod h1:hNLxWAXmnKAxqDtdwIYC4bM9oQPEecfsnNMuSxOs3og=
 golang.org/x/term v0.46.0 h1:3+OXuTbaKDgwk8jTi3aSLHRlmWqHEUDUtxnbFigO4YE=
 golang.org/x/term v0.46.0/go.mod h1:+K02xbkittuwc0Am4abfA3Fc+XRGXkvBXNO88NCXPoc=
+golang.org/x/term v0.47.0 h1:cpyOwQkr2Nzxe2p6KnrTG7Ei2wtzjsuSjhpXXepZ/BM=
+golang.org/x/term v0.47.0/go.mod h1:efAfAuG6RKABvg1ArGebRkvX6LXul14SM67o2e4mUCY=

tui/README.md

@@ -94,7 +94,8 @@ r.TextStyled(x, y, s, tui.Style{Fg: fg, Bg: bg, Attr: attr})
 
 String utilities operate on rune counts: `RuneLen`, `Truncate` /
 `TruncateLeft` / `TruncateMiddle` (ellipsis variants), `PadLeft` / `PadRight` /
-`PadCenter`, `WrapText`.
+`PadCenter`, `WrapText` (at line breaks and spaces; a path or key longer than
+the line breaks after `.`, `,`, `:`, `/`, `[` or `]`).
 
 `Style{Fg, Bg, Attr}` bundles cell appearance; most widget option structs
 accept it.
@@ -105,7 +106,7 @@ Widgets are stateless render functions (mostly `Region` methods). Application
 state lives in plain structs passed by pointer. Available renderers:
 
 boxes and lines (`Box`, `BoxFilled`, `HLine`, `VLine` — single, double,
-rounded, heavy line types), `List`, `Table`, `Tree`, `TabBar`, `KeyValue` /
+rounded, heavy, dashed and ASCII line types), `List`, `Table`, `Tree`, `TabBar`, `KeyValue` /
 `KeyValueWrap`, `Progress` / `ProgressV` / `Gauge` / `Spinner`,
 `ProgressOverlay`, `Sparkline` / `SparklineV`, `Input` / `TextField`,
 `Editor`, `Modal` / `Overlay` / `ConfirmDialog`, `ScrollBar` /
@@ -122,9 +123,11 @@ role's `Attr` may carry color bits, a palette index or the terminal's own
 color, so an application builds one theme per color tier and every control
 draws alike in each: `DefaultTheme` is dark true color, `Theme16` uses the
 ANSI 16 on the terminal's own background, `MonoTheme` uses attributes
-alone, and `ThemeFor(term.ColorMode())` picks among them. A selection always changes a glyph (brackets, a pointer,
-the focus mark), so it reads without color. `GlyphsUnicode`, `GlyphsCP437`
-(text consoles) and `GlyphsASCII` (outside UTF-8) are the glyph sets.
+alone, and `ThemeFor(term.ColorMode())` picks among them. A selection
+always changes a glyph (a radio mark, a pointer, the focus mark), so it reads
+without color. `GlyphsUnicode`, `GlyphsCP437` (text consoles) and
+`GlyphsASCII` (outside UTF-8) are the glyph sets; `Glyphs.Line` is the line
+type of frames, rules and wires.
 
 ```go
 th := tui.DefaultTheme
@@ -136,7 +139,7 @@ value.TextInput(port, "8080", focus.Index == 0, th) // the default as placeholde
 y += rows
 
 value, rows = form.Field(y, 10, tui.Field{Label: "format"}, focus.Index == 1, th)
-value.Choice(0, 0, []string{"raw", "txt", "json"}, format, th) // raw [txt] json
+value.Radio(0, 0, []string{"raw", "txt", "json"}, format, th) // ○ raw  ● txt  ○ json
 y += rows
 
 form.Group(y, "tls", "on, pinned", tlsOpen, focus.Index == 2, th)
@@ -144,16 +147,29 @@ form.Group(y, "tls", "on, pinned", tlsOpen, focus.Index == 2, th)
 
 - `Focus` is the focus ring: `HandleKey` moves it on Tab and Shift+Tab.
 - `Field` draws the focus mark, the label, the required mark, and the error,
-  or the help while focused, and returns the region for the value.
-- `TextInput` draws a `TextFieldState`, its placeholder muted while empty.
+  or the help while focused, wrapped, and returns the region for the value.
+  The label leaves the value at least half the row; label width 0 stacks the
+  label above the value, for narrow screens.
+- `TextInput` draws a `TextFieldState`, its placeholder muted while empty,
+  scrolled to the cursor with a muted `…` where text is out of view.
   `TextFieldState.Accept` filters typed and pasted runes (`AcceptInteger`,
   `AcceptNumber`); `Paste` inserts an `EventPaste`'s text with line breaks
   as spaces and control characters dropped.
-- `Choice` draws a segmented choice; `StepChoice` moves it on Left and Right.
+- `Radio` draws radio buttons in a row, the chosen one marked; too wide, it
+  shows the chosen one and its neighbours. `StepChoice` moves it on Left and
+  Right.
 - `Toggle` draws an on/off switch.
 - `Group` draws a foldable group's header, and its summary while folded.
 - `OptionListState` and `OptionList` filter options by what is typed,
-  matching name or hint regardless of case.
+  matching name or hint regardless of case. Hints sit beside the names, or,
+  narrow, the cursor's hint wraps below them; `Rows(w)` is the height to
+  size a dialog by. With `Menu` there is no filter and `Pick` finds an
+  option by its `Key`, shown before its name.
+- `Frame` fills a region, borders it with its title, and returns the inside;
+  sized with `Center` to what it holds, a dialog ends on its last line.
+- `Rule` draws a line with a title and a hint, dropping the hint first.
+- `Wires` lay lines on a grid by the arms that meet in each cell (`H`, `V`),
+  and `DrawWires` draws every junction, tee and crossing joined.
 
 ### Scrollable list with scrollbar
 
@@ -229,7 +245,9 @@ Pure logic, no rendering — usable independently:
 - `ScrollState` — item-index scrolling with selection
   (`SelectNext/Prev`, `EnsureVisible`, `PageUp/Down`, `AtTop/AtBottom`)
 - `ViewportScroll` — row-based content scrolling with viewport clipping
-  (`ClipToViewport` maps content rows to visible rows)
+  (`ClipToViewport` maps content rows to visible rows, `EnsureRange` keeps a
+  range in view); `Region.Window` draws content taller than the region off
+  screen and shows the rows in view
 - `TreeState` + `TreeExpansion` + `TreeBuilder` — cursor/scroll, expand/collapse
   keyed state, hierarchical → flat visible-node list
 - `EditorState`, `TextFieldState` — text content, cursor, scroll, key handling

tui/border.go

@@ -1,6 +1,8 @@
 package tui
 
 import (
+	"strings"
+
 	"github.com/lixenwraith/color"
 	"github.com/lixenwraith/terminal"
 )
@@ -14,26 +16,39 @@ const (
 	LineRounded                 // ╭─╮│╰╯
 	LineHeavy                   // ┏━┓┃┗┛
 	LineNone                    // spaces (invisible border with padding)
+	LineASCII                   // +-+|++, for a terminal outside UTF-8
+	LineDashed                  // ╭╌╮╎╰╯
 )
 
-// boxChars contains box drawing character sets indexed by LineType
-var boxChars = [...][6]rune{
-	LineSingle:  {'┌', '─', '┐', '│', '└', '┘'},
-	LineDouble:  {'╔', '═', '╗', '║', '╚', '╝'},
-	LineRounded: {'╭', '─', '╮', '│', '╰', '╯'},
-	LineHeavy:   {'┏', '━', '┓', '┃', '┗', '┛'},
-	LineNone:    {' ', ' ', ' ', ' ', ' ', ' '},
+// lineChars are each LineType's runes by the arms that meet in a cell: up 1,
+// right 2, down 4, left 8, so corners, tees and crossings all join
+var lineChars = [...]string{
+	LineSingle:  " │─└││┌├─┘─┴┐┤┬┼",
+	LineDouble:  " ║═╚║║╔╠═╝═╩╗╣╦╬",
+	LineRounded: " │─╰││╭├─╯─┴╮┤┬┼",
+	LineHeavy:   " ┃━┗┃┃┏┣━┛━┻┓┫┳╋",
+	LineNone:    "                ",
+	LineASCII:   " |-+||++-+-+++++",
+	LineDashed:  " ╎╌╰╎╎╭├╌╯╌┴╮┤┬┼",
 }
 
 const (
-	boxTL = 0 // top-left
-	boxH  = 1 // horizontal
-	boxTR = 2 // top-right
-	boxV  = 3 // vertical
-	boxBL = 4 // bottom-left
-	boxBR = 5 // bottom-right
+	boxTL = 6  // top-left
+	boxH  = 10 // horizontal
+	boxTR = 12 // top-right
+	boxV  = 5  // vertical
+	boxBL = 3  // bottom-left
+	boxBR = 9  // bottom-right
 )
 
+// runes returns the line's runes by arms; an unknown type draws single
+func (l LineType) runes() []rune {
+	if l >= LineType(len(lineChars)) {
+		l = LineSingle
+	}
+	return []rune(lineChars[l])
+}
+
 // --- Box Rendering ---
 
 // Box draws border around region edge
@@ -45,37 +60,35 @@ func (r Region) Box(line LineType, fg color.RGB) {
 // with off rows scrolled past its top edge. Rows outside the box are skipped,
 // so a partially visible box keeps its sides and grows no false edges.
 func (r Region) BoxClipped(line LineType, fg color.RGB, totalH, off int) {
+	r.boxStyled(line, Style{Fg: fg}, totalH, off)
+}
+
+// BoxStyle draws a border around the region's edge in a theme's style
+func (r Region) BoxStyle(line LineType, s Style) {
+	r.boxStyled(line, s, r.H, 0)
+}
+
+func (r Region) boxStyled(line LineType, s Style, totalH, off int) {
 	if r.W < 2 || r.H < 1 || totalH < 2 {
 		return
 	}
-	if line >= LineType(len(boxChars)) {
-		line = LineSingle
+	chars := line.runes()
+	edge := func(y int, left, right rune) {
+		r.TextStyled(0, y, string(left), s)
+		r.TextStyled(r.W-1, y, string(right), s)
 	}
-
-	chars := boxChars[line]
-	bg := color.RGB{} // Transparent (use existing bg)
-
 	for y := range r.H {
-		c := off + y
-		if c < 0 || c >= totalH {
-			continue
-		}
-		switch c {
-		case 0:
-			r.Cell(0, y, chars[boxTL], fg, bg, terminal.AttrNone)
-			r.Cell(r.W-1, y, chars[boxTR], fg, bg, terminal.AttrNone)
-			for x := 1; x < r.W-1; x++ {
-				r.Cell(x, y, chars[boxH], fg, bg, terminal.AttrNone)
-			}
-		case totalH - 1:
-			r.Cell(0, y, chars[boxBL], fg, bg, terminal.AttrNone)
-			r.Cell(r.W-1, y, chars[boxBR], fg, bg, terminal.AttrNone)
-			for x := 1; x < r.W-1; x++ {
-				r.Cell(x, y, chars[boxH], fg, bg, terminal.AttrNone)
+		switch c := off + y; {
+		case c < 0 || c >= totalH:
+		case c == 0 || c == totalH-1:
+			left, right := chars[boxTL], chars[boxTR]
+			if c > 0 {
+				left, right = chars[boxBL], chars[boxBR]
 			}
+			r.TextStyled(1, y, strings.Repeat(string(chars[boxH]), max(0, r.W-2)), s)
+			edge(y, left, right)
 		default:
-			r.Cell(0, y, chars[boxV], fg, bg, terminal.AttrNone)
-			r.Cell(r.W-1, y, chars[boxV], fg, bg, terminal.AttrNone)
+			edge(y, chars[boxV], chars[boxV])
 		}
 	}
 }
@@ -99,10 +112,7 @@ func (r Region) HLine(y int, line LineType, fg color.RGB) {
 	if y < 0 || y >= r.H {
 		return
 	}
-	if line >= LineType(len(boxChars)) {
-		line = LineSingle
-	}
-	ch := boxChars[line][boxH]
+	ch := line.runes()[boxH]
 	for x := 0; x < r.W; x++ {
 		r.Cell(x, y, ch, fg, color.RGB{}, terminal.AttrNone)
 	}
@@ -113,10 +123,7 @@ func (r Region) VLine(x int, line LineType, fg color.RGB) {
 	if x < 0 || x >= r.W {
 		return
 	}
-	if line >= LineType(len(boxChars)) {
-		line = LineSingle
-	}
-	ch := boxChars[line][boxV]
+	ch := line.runes()[boxV]
 	for y := 0; y < r.H; y++ {
 		r.Cell(x, y, ch, fg, color.RGB{}, terminal.AttrNone)
 	}
@@ -127,11 +134,7 @@ func (r Region) Divider(y int, label string, line LineType, fg color.RGB) {
 	if y < 0 || y >= r.H {
 		return
 	}
-	if line >= LineType(len(boxChars)) {
-		line = LineSingle
-	}
-
-	hChar := boxChars[line][boxH]
+	hChar := line.runes()[boxH]
 
 	// Fill with horizontal line
 	for x := 0; x < r.W; x++ {
@@ -171,3 +174,77 @@ func (r Region) Card(title string, line LineType, fg color.RGB) Region {
 
 	return r.Inset(1)
 }
+
+// --- Themed frames, rules and wires ---
+
+// Frame fills the region with the theme's text style and draws its border
+// in Glyphs.Line, the title on the top edge, and returns the inside with a
+// column of padding each side. Callers size it to its content, with Center.
+func (r Region) Frame(title string, th Theme) Region {
+	r.FillStyle(th.Text)
+	r.BoxStyle(th.Glyphs.Line, th.Border)
+	if title != "" && r.W > 6 {
+		r.TextStyled(2, 0, " "+Truncate(title, r.W-6)+" ", th.Accent)
+	}
+	return r.Sub(2, 1, r.W-4, r.H-2)
+}
+
+// Rule draws a line across row y, the title at its third column and the
+// hint muted at its end. The title keeps its room: the hint is dropped where
+// both do not fit.
+func (r Region) Rule(y int, title, hint string, th Theme) {
+	r.TextStyled(0, y, strings.Repeat(string(th.Glyphs.Line.runes()[boxH]), max(0, r.W)), th.Border)
+	if title != "" && r.W > 6 {
+		title = " " + Truncate(title, r.W-6) + " "
+		r.TextStyled(2, y, title, th.Text)
+	}
+	if hint != "" && RuneLen(title)+RuneLen(hint)+6 <= r.W {
+		r.TextStyled(r.W-RuneLen(hint)-3, y, " "+hint+" ", th.Muted)
+	}
+}
+
+// Wires are lines on a grid, each cell holding the arms that meet there: up
+// 1, right 2, down 4, left 8. Wherever lines branch or cross, the cell draws
+// the junction, whatever order they were laid in.
+type Wires struct {
+	W    int
+	Arms []uint8
+}
+
+// NewWires creates an empty grid w by h
+func NewWires(w, h int) Wires {
+	return Wires{W: w, Arms: make([]uint8, max(0, w*h))}
+}
+
+// H lays a wire along row y between columns x0 and x1
+func (g Wires) H(y, x0, x1 int) {
+	for x := min(x0, x1); x < max(x0, x1); x++ {
+		g.arm(x, y, 2)
+		g.arm(x+1, y, 8)
+	}
+}
+
+// V lays a wire down column x between rows y0 and y1
+func (g Wires) V(x, y0, y1 int) {
+	for y := min(y0, y1); y < max(y0, y1); y++ {
+		g.arm(x, y, 4)
+		g.arm(x, y+1, 1)
+	}
+}
+
+// arm adds an arm to a cell; one off the grid is dropped
+func (g Wires) arm(x, y int, a uint8) {
+	if i := y*g.W + x; x >= 0 && x < g.W && y >= 0 && i < len(g.Arms) {
+		g.Arms[i] |= a
+	}
+}
+
+// DrawWires draws every cell of the grid that has arms, in the line type
+func (r Region) DrawWires(g Wires, line LineType, s Style) {
+	chars := line.runes()
+	for i, arms := range g.Arms {
+		if arms != 0 {
+			r.TextStyled(i%g.W, i/g.W, string(chars[arms&15]), s)
+		}
+	}
+}

tui/choice.go

@@ -2,20 +2,51 @@ package tui
 
 import "github.com/lixenwraith/terminal"
 
-// Choice draws options in a row at (x, y), the chosen one bracketed in the
-// accent style and the rest muted ("raw [txt] json"), and returns the
-// columns it drew
-func (r Region) Choice(x, y int, options []string, chosen int, th Theme) int {
-	start := x
-	for i, o := range options {
-		open, close, style := " ", " ", th.Muted
-		if i == chosen {
-			open, close, style = "[", "]", th.Accent
+// Radio draws options as radio buttons in a row at (x, y): the chosen one
+// with the On glyph in the accent style, the rest with Off, muted ("○ raw
+// ● txt  ○ json"); chosen -1 marks none. Where the row does not fit, it shows
+// the options around the chosen one, a muted '…' where others are hidden.
+// It returns the columns it drew.
+func (r Region) Radio(x, y int, options []string, chosen int, th Theme) int {
+	width := func(lo, hi int) int { // the window [lo, hi), its '…' marks included
+		w := -2
+		for _, o := range options[lo:hi] {
+			w += RuneLen(o) + 4
 		}
-		r.TextStyled(x, y, open+o+close, style)
-		x += RuneLen(o) + 2
+		return w + 2*min(lo, 1) + 3*min(len(options)-hi, 1)
 	}
-	return x - start
+	lo, hi := 0, len(options)
+	if width(lo, hi) > r.W-x && hi > 0 {
+		lo = max(0, min(chosen, hi-1))
+		hi = lo + 1
+		for grown := true; grown; {
+			grown = false
+			if hi < len(options) && width(lo, hi+1) <= r.W-x {
+				hi, grown = hi+1, true
+			}
+			if lo > 0 && width(lo-1, hi) <= r.W-x {
+				lo, grown = lo-1, true
+			}
+		}
+	}
+	start := x
+	if lo > 0 {
+		r.TextStyled(x, y, "…", th.Muted)
+		x += 2
+	}
+	for i := lo; i < hi; i++ {
+		mark, style := th.Glyphs.Off, th.Muted
+		if i == chosen {
+			mark, style = th.Glyphs.On, th.Accent
+		}
+		r.TextStyled(x, y, Truncate(string(mark)+" "+options[i], max(0, r.W-x)), style)
+		x += RuneLen(options[i]) + 4
+	}
+	if hi < len(options) {
+		r.TextStyled(x, y, "…", th.Muted)
+		x += 3
+	}
+	return max(0, min(x-2, r.W)-start)
 }
 
 // StepChoice moves a choice among n options on Left or Right (h, l),

tui/document.go

@@ -203,11 +203,7 @@ func (r Region) docSection(y, x, w int, label string, opts DocOpts) {
 		r.TextStyled(x, y, label, opts.HeaderStyle)
 		return
 	}
-	line := opts.Rule
-	if line >= LineType(len(boxChars)) {
-		line = LineSingle
-	}
-	ch := boxChars[line][boxH]
+	ch := opts.Rule.runes()[boxH]
 	for i := range w {
 		r.Cell(x+i, y, ch, opts.RuleStyle.Fg, opts.RuleStyle.Bg, opts.RuleStyle.Attr)
 	}

tui/field.go

@@ -36,36 +36,49 @@ type Field struct {
 
 // Field draws a form row at y: the focus mark, the label in a column labelW
 // wide with the required mark, and below, the error, or the help while
-// focused. It returns the region for the value beside the label, where the
-// caller draws a TextInput, Choice or Toggle, and the rows it used.
+// focused, wrapped. The label column leaves the value half the row; labelW 0
+// stacks the label on its own row and the value under it, indented. It
+// returns the region for the value, where the caller draws a TextInput,
+// Radio or Toggle, and the rows it used.
 func (r Region) Field(y, labelW int, f Field, focused bool, th Theme) (Region, int) {
 	label := th.Muted
 	if focused {
 		label = th.Text
 		r.TextStyled(0, y, string(th.Glyphs.Focus), th.Accent)
 	}
+	x, rows := 4, 2 // stacked: the label's own row, the value under it
+	if labelW > 0 {
+		labelW = min(labelW, max(1, (r.W-3)/2))
+		x, rows = 2+labelW+1, 1
+	} else {
+		labelW = r.W - 2
+	}
 	name := f.Label
 	if f.Required {
 		name = Truncate(name, labelW-2)
 		r.TextStyled(2+RuneLen(name)+1, y, string(th.Glyphs.Required), th.Accent)
 	}
 	r.TextStyled(2, y, Truncate(name, labelW), label)
+	value := r.Sub(x, y+rows-1, r.W-x, 1)
 
-	x := 2 + labelW + 1
 	note, style := f.Error, th.Error
 	if note == "" && focused {
 		note, style = f.Help, th.Muted
 	}
 	if note == "" {
-		return r.Sub(x, y, r.W-x, 1), 1
+		return value, rows
 	}
-	r.TextStyled(x, y+1, Truncate(note, r.W-x), style)
-	return r.Sub(x, y, r.W-x, 1), 2
+	lines := WrapText(note, r.W-x)
+	for i, l := range lines {
+		r.TextStyled(x, y+rows+i, l, style)
+	}
+	return value, rows + len(lines)
 }
 
 // TextInput draws state's text on r's first row, or, empty, the placeholder
 // muted: a default shows what an empty value means. Focused, it draws on the
-// Input background with the cursor, scrolling to keep the cursor in view.
+// Input background with the cursor, scrolling to keep the cursor in view; a
+// muted '…' marks text out of view.
 func (r Region) TextInput(state *TextFieldState, placeholder string, focused bool, th Theme) {
 	if r.W < 1 || r.H < 1 {
 		return
@@ -75,7 +88,7 @@ func (r Region) TextInput(state *TextFieldState, placeholder string, focused boo
 		bg = th.Input
 	}
 	state.AdjustScroll(r.W)
-	text, style := []rune(placeholder), th.Muted.On(bg)
+	text, style := []rune(Truncate(placeholder, r.W)), th.Muted.On(bg)
 	if len(state.Text) > 0 {
 		text, style = state.Text[state.Scroll:], th.Text.On(bg)
 	}
@@ -86,6 +99,14 @@ func (r Region) TextInput(state *TextFieldState, placeholder string, focused boo
 		}
 		r.Cell(x, 0, ch, style.Fg, style.Bg, style.Attr)
 	}
+	// Text scrolled out of view on either side is marked, never under the cursor
+	hidden := th.Muted.On(bg)
+	if state.Scroll > 0 && (state.Cursor != state.Scroll || !focused) {
+		r.Cell(0, 0, '…', hidden.Fg, hidden.Bg, hidden.Attr)
+	}
+	if end := r.W - 1; len(text) > r.W && (state.Cursor-state.Scroll != end || !focused) {
+		r.Cell(end, 0, '…', hidden.Fg, hidden.Bg, hidden.Attr)
+	}
 	if focused {
 		x, ch := state.Cursor-state.Scroll, ' '
 		if x < len(text) {

tui/optionlist.go

@@ -10,17 +10,24 @@ import (
 type Option struct {
 	Name string // what is chosen
 	Hint string // a line about it
+	Key  rune   // in a menu, the key that picks it at once
 }
 
 // OptionListState filters options by the text typed into it, matching name
-// or hint regardless of case, and keeps a cursor on the matches
+// or hint regardless of case, and keeps a cursor on the matches. A menu has
+// no filter: each option's Key picks it.
 type OptionListState struct {
 	Options []Option
 	Filter  TextFieldState
-	Cursor  int // index into Matches
-	Scroll  int // first match shown
+	Cursor  int  // index into Matches
+	Scroll  int  // first match shown
+	Menu    bool // no filter; Pick finds an option by its Key
 }
 
+// minHintW is the narrowest hint column beside the names; narrower, the
+// cursor's hint wraps below the list instead
+const minHintW = 16
+
 // NewOptionListState creates a list showing every option
 func NewOptionListState(options []Option) *OptionListState {
 	return &OptionListState{Options: options}
@@ -59,7 +66,7 @@ func (s *OptionListState) HandleKey(key terminal.Key, r rune, mod terminal.Modif
 		s.Cursor--
 	case key == terminal.KeyDown:
 		s.Cursor++
-	case !s.Filter.HandleKey(key, r, mod):
+	case s.Menu || !s.Filter.HandleKey(key, r, mod):
 		return false
 	case s.Filter.Value() != filter:
 		s.Cursor = 0
@@ -68,49 +75,102 @@ func (s *OptionListState) HandleKey(key terminal.Key, r rune, mod terminal.Modif
 	return true
 }
 
+// Pick returns the index in Options of the option whose Key is r
+func (s *OptionListState) Pick(r rune) (int, bool) {
+	for i, o := range s.Options {
+		if o.Key == r && r != 0 {
+			return i, true
+		}
+	}
+	return 0, false
+}
+
 // Paste adds pasted text to the filter
 func (s *OptionListState) Paste(text string) bool {
-	if !s.Filter.Paste(text) {
+	if s.Menu || !s.Filter.Paste(text) {
 		return false
 	}
 	s.Cursor = 0
 	return true
 }
 
-// OptionList draws the filter on the first row and the matches below it,
-// the cursor row marked with the pointer on the Selected background, each
-// hint muted in a column after the names
+// layout is how the list fits w columns: the names' width, the column the
+// names start at, and the rows below the list that hold the cursor's hint
+// where hints do not fit beside the names
+func (s *OptionListState) layout(w int) (nameW, nameX, hintRows int) {
+	nameX = 2
+	if s.Menu {
+		nameX = 4
+	}
+	for _, o := range s.Options {
+		nameW = max(nameW, RuneLen(o.Name))
+	}
+	nameW = min(nameW, (w-nameX)/2)
+	if w-nameX-nameW-2 >= minHintW {
+		return nameW, nameX, 0
+	}
+	nameW = w - nameX
+	for _, o := range s.Options {
+		if o.Hint != "" {
+			hintRows = max(hintRows, min(3, len(WrapText(o.Hint, max(1, w-2)))))
+		}
+	}
+	return nameW, nameX, hintRows
+}
+
+// Rows returns the rows the list takes at width w to show every option: the
+// filter, a row each, and the cursor's hint where it does not fit beside them
+func (s *OptionListState) Rows(w int) int {
+	_, _, hintRows := s.layout(w)
+	return 1 - boolToInt(s.Menu) + len(s.Options) + hintRows
+}
+
+// OptionList draws the filter on the first row, a menu none, and the
+// matches below, the cursor row marked with the pointer on the Selected
+// background and a menu's keys before the names in the accent style. Hints
+// sit muted beside the names or, where that column would be narrower than
+// 16, the cursor's hint wraps onto the list's last rows.
 func (r Region) OptionList(s *OptionListState, th Theme) {
 	if r.W < 4 || r.H < 2 {
 		return
 	}
-	r.TextStyled(0, 0, "/", th.Muted)
-	r.Sub(2, 0, r.W-2, 1).TextInput(&s.Filter, "type to filter", true, th)
-
+	top := 1
+	if s.Menu {
+		top = 0
+	} else {
+		r.TextStyled(0, 0, "/", th.Muted)
+		r.Sub(2, 0, r.W-2, 1).TextInput(&s.Filter, "type to filter", true, th)
+	}
 	m := s.Matches()
-	rows := r.H - 1
 	if len(m) == 0 {
-		r.TextStyled(2, 1, "no match", th.Muted)
+		r.TextStyled(2, top, "no match", th.Muted)
 		return
 	}
-	s.Scroll = max(0, min(s.Scroll, s.Cursor, len(m)-rows))
-	s.Scroll = max(s.Scroll, s.Cursor-rows+1)
-
-	nameW := 0
-	for _, i := range m {
-		nameW = max(nameW, RuneLen(s.Options[i].Name))
-	}
-	nameW = min(nameW, r.W/2)
+	nameW, nameX, hintRows := s.layout(r.W)
+	rows := max(1, r.H-top-hintRows)
+	s.Scroll = AdjustScroll(s.Cursor, ClampScroll(s.Scroll, rows, len(m)), rows, len(m))
 	for y := 0; y < rows && s.Scroll+y < len(m); y++ {
 		o := s.Options[m[s.Scroll+y]]
-		row := r.Sub(0, 1+y, r.W, 1)
+		row := r.Sub(0, top+y, r.W, 1)
 		var bg Style
 		if s.Scroll+y == s.Cursor {
 			bg = th.Selected
 			row.FillStyle(th.Text.On(bg))
 			row.TextStyled(0, 0, string(th.Glyphs.Pointer), th.Accent.On(bg))
 		}
-		row.TextStyled(2, 0, Truncate(o.Name, nameW), th.Text.On(bg))
-		row.TextStyled(2+nameW+2, 0, Truncate(o.Hint, r.W-nameW-4), th.Muted.On(bg))
+		if s.Menu && o.Key != 0 {
+			row.TextStyled(2, 0, string(o.Key), th.Accent.On(bg))
+		}
+		row.TextStyled(nameX, 0, Truncate(o.Name, nameW), th.Text.On(bg))
+		if hintRows == 0 {
+			row.TextStyled(nameX+nameW+2, 0, Truncate(o.Hint, r.W-nameX-nameW-2), th.Muted.On(bg))
+		}
+	}
+	hint, n := WrapText(s.Options[m[s.Cursor]].Hint, max(1, r.W-2)), min(hintRows, r.H-top-rows)
+	if len(hint) > n && n > 0 { // the last row shown ends in '…'
+		hint = append(hint[:n-1], Truncate(hint[n-1]+" "+hint[n], r.W-2))
+	}
+	for y, l := range hint[:min(n, len(hint))] { // on the last rows, so the list ends on text
+		r.TextStyled(2, r.H-min(n, len(hint))+y, l, th.Muted)
 	}
 }

tui/text.go

@@ -1,6 +1,7 @@
 package tui
 
 import (
+	"strings"
 	"unicode/utf8"
 )
 
@@ -118,13 +119,23 @@ func PadCenter(s string, width int) string {
 
 // --- Text wrapping ---
 
-// WrapText wraps text at word boundaries to fit width
-// Returns slice of lines, each no longer than width
+// WrapText wraps text to fit width: at each line break, at spaces, or, in a
+// word longer than a line, after its last '.', ',', ':', '/', '[' or ']'
+// that fits (a path or a key such as a[0].b); a word without one is cut.
+// Returns slice of lines, each no longer than width.
 func WrapText(s string, width int) []string {
 	if width <= 0 {
 		return nil
 	}
+	var lines []string
+	for line := range strings.SplitSeq(s, "\n") {
+		lines = append(lines, wrapLine(line, width)...)
+	}
+	return lines
+}
 
+// wrapLine wraps one line, s holding no line break
+func wrapLine(s string, width int) []string {
 	runes := []rune(s)
 	if len(runes) == 0 {
 		return []string{""}
@@ -132,7 +143,7 @@ func WrapText(s string, width int) []string {
 
 	var lines []string
 	lineStart := 0
-	lastSpace := -1
+	lastSpace, lastMark := -1, -1
 
 	for i := 0; i <= len(runes); i++ {
 		// Check if we need to wrap
@@ -147,9 +158,11 @@ func WrapText(s string, width int) []string {
 
 			// Need to wrap
 			wrapAt := i
-			if lastSpace > lineStart {
-				// Wrap at last space
+			switch {
+			case lastSpace > lineStart:
 				wrapAt = lastSpace
+			case lastMark > lineStart:
+				wrapAt = lastMark
 			}
 
 			lines = append(lines, string(runes[lineStart:wrapAt]))
@@ -160,13 +173,16 @@ func WrapText(s string, width int) []string {
 			} else {
 				lineStart = wrapAt
 			}
-			lastSpace = -1
+			lastSpace, lastMark = -1, -1
 		}
 
-		// Track spaces for word wrapping
+		// Track spaces for word wrapping, and the marks a long word breaks after
 		if i < len(runes) && runes[i] == ' ' {
 			lastSpace = i
 		}
+		if i < len(runes) && strings.ContainsRune(".,:/[]", runes[i]) {
+			lastMark = i + 1
+		}
 	}
 
 	if len(lines) == 0 {
@@ -189,4 +205,3 @@ func RepeatRune(r rune, n int) string {
 	}
 	return string(runes)
 }
-

tui/textfield_state.go

@@ -258,12 +258,14 @@ func (t *TextFieldState) MoveToEnd() {
 
 // --- Scroll management ---
 
-// AdjustScroll updates scroll to keep cursor visible within viewport width
+// AdjustScroll updates scroll to keep the cursor visible within viewport
+// width, and the viewport filled up to the end of the text
 func (t *TextFieldState) AdjustScroll(viewportW int) {
 	if viewportW <= 0 {
 		return
 	}
 	t.clampCursor()
+	t.Scroll = min(t.Scroll, max(0, len(t.Text)+1-viewportW))
 	if t.Cursor < t.Scroll {
 		t.Scroll = t.Cursor
 	}

tui/theme.go

@@ -25,18 +25,19 @@ type Theme struct {
 // it reads without color. A text console's font takes GlyphsCP437, a
 // terminal outside UTF-8 GlyphsASCII.
 type Glyphs struct {
-	Focus    rune // beside the focused control
-	Pointer  rune // the cursor row of a list
-	Folded   rune // a closed group
-	Unfolded rune // an open group
-	On, Off  rune // a toggle
-	Required rune // after a required field's label
+	Focus    rune     // beside the focused control
+	Pointer  rune     // the cursor row of a list
+	Folded   rune     // a closed group
+	Unfolded rune     // an open group
+	On, Off  rune     // a toggle
+	Required rune     // after a required field's label
+	Line     LineType // frames, rules and wires
 }
 
 var (
 	GlyphsUnicode = Glyphs{Focus: '▌', Pointer: '▸', Folded: '▸', Unfolded: '▾', On: '●', Off: '○', Required: '*'}
 	GlyphsCP437   = Glyphs{Focus: '▌', Pointer: '►', Folded: '►', Unfolded: '▼', On: '•', Off: '○', Required: '*'}
-	GlyphsASCII   = Glyphs{Focus: '>', Pointer: '>', Folded: '+', Unfolded: '-', On: '*', Off: '-', Required: '*'}
+	GlyphsASCII   = Glyphs{Focus: '>', Pointer: '>', Folded: '+', Unfolded: '-', On: '*', Off: '-', Required: '*', Line: LineASCII}
 )
 
 // DefaultTheme is a dark theme for true color and 256-color terminals

tui/viewport.go

@@ -1,5 +1,7 @@
 package tui
 
+import "github.com/lixenwraith/terminal"
+
 // ViewportScroll manages row-based scroll for content regions
 // Distinct from ScrollState which is item-index based
 type ViewportScroll struct {
@@ -117,3 +119,24 @@ func (v *ViewportScroll) EnsureRange(y, h int) {
 	}
 	v.clamp()
 }
+
+// Window shows content h rows tall through the region, from v's offset:
+// draw paints a buffer as wide as the region and h tall, filled with bg, and
+// the rows in view are copied. Window sets v's heights; a caller keeping a
+// row in view sets them first and calls EnsureRange.
+func (r Region) Window(h int, v *ViewportScroll, bg Style, draw func(Region)) {
+	h = max(0, h)
+	v.SetDimensions(h, r.H)
+	if r.W <= 0 || r.H <= 0 {
+		return
+	}
+	cells := make([]terminal.Cell, r.W*h)
+	full := NewRegion(cells, r.W, 0, 0, r.W, h)
+	full.FillStyle(bg)
+	draw(full)
+	shown := min(r.H, h-v.Offset)
+	for y := range shown {
+		copy(r.Cells[(r.Y+y)*r.TotalW+r.X:][:r.W], cells[(v.Offset+y)*r.W:][:r.W])
+	}
+	r.Sub(0, shown, r.W, r.H-shown).FillStyle(bg)
+}

tui/widget_test.go

@@ -1,6 +1,9 @@
 package tui
 
 import (
+	"fmt"
+	"runtime"
+	"slices"
 	"strings"
 	"testing"
 
@@ -50,7 +53,7 @@ func TestSelectionChangesAGlyph(t *testing.T) {
 func selectionChangesAGlyph(t *testing.T, th Theme) {
 	options := NewOptionListState([]Option{{Name: "file"}, {Name: "tcp"}})
 	for name, draw := range map[string]func(r Region, on bool){
-		"choice": func(r Region, on bool) { r.Choice(0, 0, []string{"raw", "txt"}, map[bool]int{true: 1}[on], th) },
+		"radio":  func(r Region, on bool) { r.Radio(0, 0, []string{"raw", "txt"}, map[bool]int{true: 1}[on], th) },
 		"toggle": func(r Region, on bool) { r.Toggle(0, 0, on, th) },
 		"field":  func(r Region, on bool) { r.Field(0, 6, Field{Label: "port"}, on, th) },
 		"group":  func(r Region, on bool) { r.Group(0, "tls", "", on, false, th) },
@@ -248,3 +251,199 @@ func TestGroupSummarisesWhileFolded(t *testing.T) {
 		t.Fatalf("%q %q", row(folded, 0), row(open, 0))
 	}
 }
+
+// A radio row too wide for its region shows the chosen option and those
+// around it, a '…' on each side where others are hidden, and reports the
+// columns drawn
+func TestRadioKeepsTheChosenInView(t *testing.T) {
+	options := []string{"alpha", "beta", "gamma", "delta"}
+	for _, c := range []struct {
+		chosen, w int
+		want      string
+	}{
+		{3, 40, "○ alpha  ○ beta  ○ gamma  ● delta"},
+		{3, 30, "… ○ beta  ○ gamma  ● delta"},
+		{3, 16, "… ● delta"},
+		{3, 7, "… ● de…"},
+		{0, 17, "● alpha  …"},
+		{1, 19, "○ alpha  ● beta  …"},
+		{1, 25, "… ● beta  ○ gamma  …"},
+	} {
+		r := canvas(c.w, 1, MonoTheme)
+		if n := r.Radio(0, 0, options, c.chosen, MonoTheme); row(r, 0) != c.want || n != min(c.w, RuneLen(c.want)) {
+			t.Errorf("%d chosen in %d columns: %q, %d drawn; want %q", c.chosen, c.w, row(r, 0), n, c.want)
+		}
+	}
+}
+
+// A field's view pulls back when its text shrinks, so no column is left
+// blank while text is hidden, and a muted '…' marks text out of view, never
+// under the cursor
+func TestTextInputPullsBackAndMarksHiddenText(t *testing.T) {
+	f := NewTextFieldState(strings.Repeat("abcdefghij", 2))
+	draw := func(focused bool) string {
+		r := canvas(10, 1, MonoTheme)
+		r.TextInput(f, "", focused, MonoTheme)
+		return row(r, 0)
+	}
+	if got := draw(true); got != "…cdefghij" {
+		t.Fatalf("the cursor after 20 in 10 columns: %q", got)
+	}
+	for range 8 {
+		f.HandleKey(terminal.KeyBackspace, 0, 0)
+	}
+	if got := draw(true); got != "…efghijab" {
+		t.Fatalf("12 left: %q, scroll %d", got, f.Scroll)
+	}
+	f.HandleKey(terminal.KeyHome, 0, 0)
+	if got := draw(true); got != "abcdefghi…" {
+		t.Fatalf("the cursor at the start: %q", got)
+	}
+}
+
+// A field's label leaves the value at least half the row; label width 0
+// stacks the label on its own row, whole, and the value under it
+func TestFieldLeavesTheValueHalfTheRow(t *testing.T) {
+	for _, w := range []int{12, 30, 80} {
+		r := canvas(w, 3, MonoTheme)
+		if v, rows := r.Field(0, 40, Field{Label: "password_file"}, false, MonoTheme); v.W < (w-3)/2 || rows != 1 {
+			t.Errorf("%d columns: value %d wide, %d rows", w, v.W, rows)
+		}
+		r = canvas(w, 3, MonoTheme)
+		v, rows := r.Field(0, 0, Field{Label: "password_file"}, false, MonoTheme)
+		if label := Truncate("password_file", w-2); row(r, 0) != "  "+label || v.Y != 1 || v.W != w-4 || rows != 2 {
+			t.Errorf("%d columns stacked: %q, value at row %d, %d wide, %d rows", w, row(r, 0), v.Y, v.W, rows)
+		}
+	}
+}
+
+// Text wraps at each line break, keeping an empty line, and a word longer
+// than the line breaks after a '.', ',', ':', '/', '[' or ']'
+func TestWrapTextBreaksAtLinesAndMarks(t *testing.T) {
+	for text, want := range map[string][]string{
+		"ab\ncd ef\n\ngh":                      {"ab", "cd ef", "", "gh"},
+		"key: /etc/logwisp/very/long/path.pem": {"key:", "/etc/logwisp/very/", "long/path.pem"},
+	} {
+		if got := WrapText(text, map[bool]int{true: 5, false: 20}[strings.HasPrefix(text, "ab")]); !slices.Equal(got, want) {
+			t.Errorf("%q: %q, want %q", text, got, want)
+		}
+	}
+}
+
+// Wrapping is linear in the lines: 4000 lines allocate under 1 MiB
+func TestWrapTextIsLinearInLines(t *testing.T) {
+	text := strings.Repeat("x\n", 4000)
+	var before, after runtime.MemStats
+	runtime.ReadMemStats(&before)
+	lines := WrapText(text, 80)
+	runtime.ReadMemStats(&after)
+	if len(lines) != 4001 || after.TotalAlloc-before.TotalAlloc > 1<<20 {
+		t.Fatalf("%d lines, %d bytes allocated", len(lines), after.TotalAlloc-before.TotalAlloc)
+	}
+}
+
+// Where the hint column would be narrow, the list shows names alone and the
+// cursor's hint wraps below them, in rows Rows counts; wide, hints sit beside
+func TestNarrowOptionListShowsTheCursorsHint(t *testing.T) {
+	s := NewOptionListState([]Option{{Name: "pipe", Hint: "standard input to standard output"}, {Name: "tail", Hint: "follow files"}})
+	s.Cursor = 1
+	for w, want := range map[int][]string{
+		60: {"/ type to filter", "  pipe  standard input to standard output", "▸ tail  follow files"},
+		20: {"/ type to filter", "  pipe", "▸ tail", "", "  follow files"},
+	} {
+		r := canvas(w, s.Rows(w), MonoTheme)
+		r.OptionList(s, MonoTheme)
+		var got []string
+		for y := range r.H {
+			got = append(got, row(r, y))
+		}
+		if !slices.Equal(got, want) {
+			t.Errorf("%d columns: %q, want %q", w, got, want)
+		}
+	}
+}
+
+// A menu has no filter: a key picks its option, and typing filters nothing
+func TestMenuPicksByKey(t *testing.T) {
+	s := NewOptionListState([]Option{{Name: "run", Key: 'r'}, {Name: "command", Key: 'c'}})
+	s.Menu = true
+	if i, ok := s.Pick('c'); !ok || i != 1 {
+		t.Fatalf("c: %d, %v", i, ok)
+	}
+	if _, ok := s.Pick('x'); ok || s.HandleKey(terminal.KeyRune, 'x', 0) || s.Paste("r") || s.Filter.Value() != "" {
+		t.Fatalf("x picked or filtered: %q", s.Filter.Value())
+	}
+	r := canvas(20, s.Rows(20), MonoTheme)
+	r.OptionList(s, MonoTheme)
+	if r.H != 2 || row(r, 0) != "▸ r run" || row(r, 1) != "  c command" {
+		t.Fatalf("%d rows: %q %q", r.H, row(r, 0), row(r, 1))
+	}
+}
+
+// A frame's inside is the region within its border and padding, so a frame
+// sized to what it holds ends on it; the border takes the glyphs' line type
+func TestFrameHoldsItsInside(t *testing.T) {
+	ascii := MonoTheme
+	ascii.Glyphs = GlyphsASCII
+	for _, c := range []struct {
+		th   Theme
+		want [3]string
+	}{{MonoTheme, [3]string{"┌─ T ───┐", "│ abcde │", "└───────┘"}}, {ascii, [3]string{"+- T ---+", "| abcde |", "+-------+"}}} {
+		r := canvas(9, 3, c.th)
+		in := r.Frame("T", c.th)
+		in.TextStyled(0, 0, "abcde", c.th.Text)
+		if got := [3]string{row(r, 0), row(r, 1), row(r, 2)}; got != c.want || in.W != 5 || in.H != 1 {
+			t.Errorf("%q, inside %dx%d", got, in.W, in.H)
+		}
+	}
+}
+
+// A rule keeps its title; the hint at its end goes first when both do not fit
+func TestRuleKeepsTheTitleBeforeTheHint(t *testing.T) {
+	for w, want := range map[int]string{40: "── file · source ────────────── ⏎ edit ─", 24: "── file · source ───────"} {
+		r := canvas(w, 1, MonoTheme)
+		if r.Rule(0, "file · source", "⏎ edit", MonoTheme); row(r, 0) != want {
+			t.Errorf("%d columns: %q", w, row(r, 0))
+		}
+	}
+}
+
+// Wires join where they meet: each cell draws the arms laid through it,
+// whatever order they were laid in
+func TestWiresJoinWhereTheyMeet(t *testing.T) {
+	g := NewWires(5, 3)
+	g.V(4, 1, 2)
+	g.H(1, 0, 4)
+	g.V(2, 0, 2)
+	g.H(9, 0, 9) // off the grid
+	for line, want := range map[LineType][3]string{LineSingle: {"  │", "──┼─┐", "  │ │"}, LineASCII: {"  |", "--+-+", "  | |"}} {
+		r := canvas(5, 3, MonoTheme)
+		r.DrawWires(g, line, MonoTheme.Border)
+		if got := [3]string{row(r, 0), row(r, 1), row(r, 2)}; got != want {
+			t.Errorf("%d: %q, want %q", line, got, want)
+		}
+	}
+}
+
+// A window shows the content's rows from the scroll offset, and fills what
+// the content does not reach; a window with no columns draws nothing
+func TestWindowShowsTheRowsInView(t *testing.T) {
+	r := canvas(6, 3, MonoTheme)
+	var v ViewportScroll
+	v.SetDimensions(10, r.H)
+	v.EnsureRange(7, 1)
+	content := func(c Region) {
+		for y := range c.H {
+			c.TextStyled(0, y, fmt.Sprintf("row %d", y), MonoTheme.Text)
+		}
+	}
+	r.Window(10, &v, MonoTheme.Text, content)
+	if got := [3]string{row(r, 0), row(r, 1), row(r, 2)}; got != [3]string{"row 5", "row 6", "row 7"} {
+		t.Fatalf("rows 5-7: %q", got)
+	}
+	r.Window(2, &v, MonoTheme.Text, content)
+	if got := [3]string{row(r, 0), row(r, 1), row(r, 2)}; got != [3]string{"row 0", "row 1", ""} {
+		t.Fatalf("two rows of content: %q", got)
+	}
+	r.Sub(8, 0, 4, 3).Window(10, &v, MonoTheme.Text, content) // no columns, past the right edge
+}