feat(ui): accept a percentage for ui.max-width

README.md

@@ -328,7 +328,7 @@ ghost-text = 1         # 0 = off, 1 = menu + ghost text, 2 = ghost text only
 hidden-files = false   # include dotfiles in suggestions
 max-suggestions = 100  # max suggestions ranked before display
 max-height = 6         # max visible rows in the menu
-max-width = 0          # max menu width, 0 = auto
+max-width = 0          # menu width: columns (80) or a share ("80%"), 0 = default
 nerd-fonts = true      # use nerd-font icons
 
 [keybindings]

integration/overlay.go

@@ -666,7 +666,7 @@ func (o *Overlay) draw() string {
 	// current line. When the prompt is wider than the terminal the cursor has
 	// wrapped, so using PromptLen directly overflows the screen and the box
 	// lands at the wrong horizontal position.
-	boxWidth := config.Get().UI.MaxWidth
+	boxWidth := config.Get().UI.MaxWidth.Resolve(width)
 	if boxWidth <= 0 {
 		boxWidth = 76 // Default if 0
 	}

internal/config/config.go

@@ -86,7 +86,7 @@ type UIConfig struct {
 	ShowHiddenFiles bool          `toml:"hidden-files"`
 	MaxSuggestions  int           `toml:"max-suggestions"`
 	MaxHeight       int           `toml:"max-height"`
-	MaxWidth        int           `toml:"max-width"`
+	MaxWidth        Width         `toml:"max-width"`
 	NerdFonts       bool          `toml:"nerd-fonts"`
 }
 
@@ -352,6 +352,9 @@ func validate(cfg *Config) error {
 		return fmt.Errorf("ui.max-suggestions: must be between 1 and 500")
 	}
 
+	if err := cfg.UI.MaxWidth.validate(); err != nil {
+		return fmt.Errorf("ui.max-width: %w", err)
+	}
 	if cfg.UI.MaxHeight < 1 || cfg.UI.MaxHeight > 50 {
 		return fmt.Errorf("ui.max-height: must be between 1 and 50")
 	}

internal/config/defaults.go

@@ -23,7 +23,7 @@ func DefaultConfig() *Config {
 			ShowHiddenFiles: false,
 			MaxSuggestions:  100,
 			MaxHeight:       6,
-			MaxWidth:        0, // 0 means no limit, fallback to terminal width
+			MaxWidth:        Width{}, // unset; the overlay falls back to its own default width
 			NerdFonts:       true,
 		},
 		Git: GitConfig{

internal/config/width.go

@@ -0,0 +1,72 @@
+package config
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+// Width is a width setting written either as a column count (80) or as a share
+// of the terminal ("80%"). Percentages only mean something once the terminal
+// size is known, so both forms are carried through to draw time and resolved
+// there.
+type Width struct {
+	n       int
+	percent bool
+}
+
+// Resolve returns the column count this setting asks for on a terminal of the
+// given width. Zero means unset, and is left for the caller to default.
+func (w Width) Resolve(term int) int {
+	if !w.percent {
+		return w.n
+	}
+	if term <= 0 {
+		return 0
+	}
+	return term * w.n / 100
+}
+
+func (w Width) String() string {
+	if w.percent {
+		return strconv.Itoa(w.n) + "%"
+	}
+	return strconv.Itoa(w.n)
+}
+
+func (w *Width) UnmarshalTOML(v any) error {
+	switch t := v.(type) {
+	case int64:
+		*w = Width{n: int(t)}
+		return nil
+	case string:
+		body, percent := strings.CutSuffix(strings.TrimSpace(t), "%")
+		n, err := strconv.Atoi(strings.TrimSpace(body))
+		if err != nil {
+			return fmt.Errorf("invalid value %q (want a column count like 80, or a share like \"80%%\")", t)
+		}
+		*w = Width{n: n, percent: percent}
+		return nil
+	}
+	return fmt.Errorf("invalid value of type %T (want a column count like 80, or a share like \"80%%\")", v)
+}
+
+func (w Width) MarshalTOML() ([]byte, error) {
+	if w.percent {
+		return []byte(strconv.Quote(w.String())), nil
+	}
+	return []byte(w.String()), nil
+}
+
+func (w Width) validate() error {
+	if w.percent {
+		if w.n < 1 || w.n > 100 {
+			return fmt.Errorf("must be between 1%% and 100%%")
+		}
+		return nil
+	}
+	if w.n < 0 {
+		return fmt.Errorf("must not be negative")
+	}
+	return nil
+}

internal/config/width_test.go

@@ -0,0 +1,100 @@
+package config
+
+import (
+	"testing"
+
+	"github.com/BurntSushi/toml"
+)
+
+func TestWidthAcceptsBothForms(t *testing.T) {
+	cases := []struct {
+		toml string
+		want Width
+	}{
+		{`max-width = 80`, Width{n: 80}},
+		{`max-width = 0`, Width{}},
+		{`max-width = "80%"`, Width{n: 80, percent: true}},
+		{`max-width = "100%"`, Width{n: 100, percent: true}},
+		{`max-width = " 60 % "`, Width{n: 60, percent: true}},
+		{`max-width = "80"`, Width{n: 80}},
+	}
+	for _, c := range cases {
+		var got struct {
+			MaxWidth Width `toml:"max-width"`
+		}
+		if _, err := toml.Decode(c.toml, &got); err != nil {
+			t.Errorf("decode %q: %v", c.toml, err)
+			continue
+		}
+		if got.MaxWidth != c.want {
+			t.Errorf("decode %q = %+v; want %+v", c.toml, got.MaxWidth, c.want)
+		}
+	}
+}
+
+func TestWidthRejectsNonsense(t *testing.T) {
+	for _, in := range []string{`max-width = "wide"`, `max-width = "%"`, `max-width = "8 0%"`, `max-width = true`} {
+		var got struct {
+			MaxWidth Width `toml:"max-width"`
+		}
+		if _, err := toml.Decode(in, &got); err == nil {
+			t.Errorf("decode %q: want an error, got %+v", in, got.MaxWidth)
+		}
+	}
+}
+
+func TestWidthResolve(t *testing.T) {
+	cases := []struct {
+		w    Width
+		term int
+		want int
+	}{
+		{Width{n: 80}, 200, 80},              // absolute ignores the terminal
+		{Width{n: 80, percent: true}, 200, 160},
+		{Width{n: 50, percent: true}, 81, 40}, // truncates rather than rounds up
+		{Width{n: 80, percent: true}, 0, 0},   // unknown terminal falls through
+		{Width{}, 200, 0},                     // unset falls through
+	}
+	for _, c := range cases {
+		if got := c.w.Resolve(c.term); got != c.want {
+			t.Errorf("Width%+v.Resolve(%d) = %d; want %d", c.w, c.term, got, c.want)
+		}
+	}
+}
+
+func TestWidthValidate(t *testing.T) {
+	ok := []Width{{}, {n: 80}, {n: 1, percent: true}, {n: 100, percent: true}}
+	for _, w := range ok {
+		if err := w.validate(); err != nil {
+			t.Errorf("Width%+v.validate() = %v; want nil", w, err)
+		}
+	}
+	bad := []Width{{n: -1}, {n: 0, percent: true}, {n: 101, percent: true}}
+	for _, w := range bad {
+		if err := w.validate(); err == nil {
+			t.Errorf("Width%+v.validate() = nil; want an error", w)
+		}
+	}
+}
+
+// iris config show round-trips the config through the encoder, so both forms
+// have to come back out the way they went in.
+func TestWidthRoundTrips(t *testing.T) {
+	for _, in := range []string{`max-width = 80`, `max-width = "80%"`} {
+		var cfg struct {
+			MaxWidth Width `toml:"max-width"`
+		}
+		if _, err := toml.Decode(in, &cfg); err != nil {
+			t.Fatal(err)
+		}
+		var out []byte
+		b, err := cfg.MaxWidth.MarshalTOML()
+		if err != nil {
+			t.Fatal(err)
+		}
+		out = append([]byte("max-width = "), b...)
+		if string(out) != in {
+			t.Errorf("round trip of %q = %q", in, out)
+		}
+	}
+}

root/config_cmd.go

@@ -92,7 +92,8 @@ max-suggestions = 100
 # maximum suggestion rows shown in the menu
 max-height = 6
 
-# maximum width of the overlay (0 = responsive to terminal)
+# overlay width, as columns (80) or a share of the terminal ("80%")
+# 0 keeps the built-in default width
 max-width = 0
 
 [git]

root/init.go

@@ -279,7 +279,8 @@ max-suggestions = 100
 # maximum suggestion rows shown in the menu
 max-height = 6
 
-# maximum width of the overlay (0 = responsive to terminal)
+# overlay width, as columns (80) or a share of the terminal ("80%")
+# 0 keeps the built-in default width
 max-width = 0
 
 [git]

tests/tui/maxwidth_test.go

@@ -0,0 +1,71 @@
+package tui
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/Gaurav-Gosain/tuitest"
+)
+
+// boxWidth measures the drawn box from its top border.
+func boxWidth(t *testing.T, term *tuitest.Terminal) int {
+	t.Helper()
+	b := findBox(term)
+	if b.top < 0 || len(b.rows) == 0 {
+		t.Fatalf("no box on screen:\n%s", screen(term))
+	}
+	top := b.rows[0]
+	start := strings.Index(top, "╭")
+	end := strings.LastIndex(top, "╮")
+	if start < 0 || end < 0 {
+		t.Fatalf("no top border on screen:\n%s", screen(term))
+	}
+	return len([]rune(top[start:])) - len([]rune(top[end:])) + 1
+}
+
+func startWithMaxWidth(t *testing.T, value string) *tuitest.Terminal {
+	t.Helper()
+	home := t.TempDir()
+	for _, sub := range []string{".config/iris", ".local/share/iris", ".cache"} {
+		if err := os.MkdirAll(filepath.Join(home, sub), 0o755); err != nil {
+			t.Fatal(err)
+		}
+	}
+	cfg := "version = 1\n\n[ui]\nmax-width = " + value + "\n"
+	if err := os.WriteFile(filepath.Join(home, ".config/iris/config.toml"), []byte(cfg), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	term := startIn(t, home)
+	if err := term.Type("nvi"); err != nil {
+		t.Fatal(err)
+	}
+	if err := term.WaitForText("Accept", 10*time.Second); err != nil {
+		t.Fatalf("menu never appeared: %v\n%s", err, screen(term))
+	}
+	return term
+}
+
+// A percentage has to scale with the terminal; a column count must not.
+func TestMaxWidthAcceptsColumnsAndPercentages(t *testing.T) {
+	cases := []struct {
+		value string
+		want  int
+	}{
+		{"90", 90},
+		{`"80%"`, cols * 80 / 100},
+		{`"50%"`, cols * 50 / 100},
+		{"0", 76}, // unset keeps the overlay's own default
+	}
+	for _, c := range cases {
+		t.Run(c.value, func(t *testing.T) {
+			term := startWithMaxWidth(t, c.value)
+			defer func() { _ = term.Close() }()
+			if got := boxWidth(t, term); got != c.want {
+				t.Errorf("max-width = %s drew a box %d columns wide; want %d\n%s", c.value, got, c.want, screen(term))
+			}
+		})
+	}
+}