Add auto icon mode fallback and Nerd Font docs

README.md

@@ -9,6 +9,20 @@
 - Asynchronous copy/move with progress and background mode
 - Theme support and configurable layout/columns
 
+## Font requirement (icons)
+
+For file icons, `vcom` expects a Nerd Font in your terminal profile.
+
+Default behavior is `ui.icon_mode = "auto"`:
+
+- if a Nerd Font is detected, `vcom` uses Nerd icons
+- if not, `vcom` falls back to ASCII icons automatically
+
+You can force behavior in config:
+
+- `ui.icon_mode = "nerd"`: always use Nerd icons
+- `ui.icon_mode = "ascii"`: always use ASCII icons
+
 Preview mode (`F9` / `i`) temporarily replaces the inactive pane and shows:
 
 - directory listing preview
@@ -60,6 +74,17 @@ Download the release `.deb` for `v0.1.2`, then install:
 sudo apt install ./vcom_0.1.2_amd64.deb
 ```
 
+Install a Nerd Font (example):
+
+```bash
+wget -qO /tmp/JetBrainsMono.zip https://github.com/ryanoasis/nerd-fonts/releases/latest/download/JetBrainsMono.zip
+mkdir -p ~/.local/share/fonts/JetBrainsMonoNerd
+unzip -o /tmp/JetBrainsMono.zip -d ~/.local/share/fonts/JetBrainsMonoNerd
+fc-cache -fv
+```
+
+Then set your terminal font to a Nerd Font variant (for example, `JetBrainsMono Nerd Font`).
+
 ### Arch Linux
 
 A `PKGBUILD` is included in the repository:
@@ -80,6 +105,13 @@ Optional config lookup order:
 
 Reference config: [vcom.toml](/home/vrubel/projects/vcom/vcom.toml)
 
+Icon mode example:
+
+```toml
+[ui]
+icon_mode = "auto" # auto | nerd | ascii
+```
+
 ## Themes
 
 Built-in themes:

internal/config/config.go

@@ -26,6 +26,7 @@ type StartupConfig struct {
 type UIConfig struct {
 	AppTitle           string `toml:"app_title"`
 	Theme              string `toml:"theme"`
+	IconMode           string `toml:"icon_mode"`
 	ShowTitleBar       bool   `toml:"show_title_bar"`
 	ShowFooter         bool   `toml:"show_footer"`
 	Border             string `toml:"border"`
@@ -76,6 +77,7 @@ func Default() Config {
 		UI: UIConfig{
 			AppTitle:           "vcom",
 			Theme:              "catppuccin-mocha",
+			IconMode:           "auto",
 			ShowTitleBar:       true,
 			ShowFooter:         true,
 			Border:             "rounded",
@@ -138,10 +140,49 @@ func Load(explicitPath string) (Config, string, error) {
 	return cfg, path, nil
 }
 
+func Save(cfg Config, path string) (string, error) {
+	if err := cfg.Validate(); err != nil {
+		return "", err
+	}
+
+	targetPath := strings.TrimSpace(path)
+	if targetPath == "" {
+		var err error
+		targetPath, err = DefaultUserPath()
+		if err != nil {
+			return "", err
+		}
+	}
+
+	absPath, err := filepath.Abs(targetPath)
+	if err != nil {
+		return "", fmt.Errorf("resolve %s: %w", targetPath, err)
+	}
+	if err := os.MkdirAll(filepath.Dir(absPath), 0o755); err != nil {
+		return "", fmt.Errorf("mkdir %s: %w", filepath.Dir(absPath), err)
+	}
+
+	data, err := toml.Marshal(cfg)
+	if err != nil {
+		return "", fmt.Errorf("marshal config: %w", err)
+	}
+	if err := os.WriteFile(absPath, data, 0o644); err != nil {
+		return "", fmt.Errorf("write %s: %w", absPath, err)
+	}
+	return absPath, nil
+}
+
 func (c *Config) Validate() error {
 	if c.UI.Theme == "" {
 		return errors.New("ui.theme must not be empty")
 	}
+	switch strings.ToLower(strings.TrimSpace(c.UI.IconMode)) {
+	case "", "auto":
+		c.UI.IconMode = "auto"
+	case "nerd", "ascii":
+	default:
+		return errors.New("ui.icon_mode must be one of: auto, nerd, ascii")
+	}
 	if strings.TrimSpace(c.UI.AppTitle) == "" {
 		c.UI.AppTitle = "vcom"
 	}
@@ -213,3 +254,15 @@ func resolvePath(explicitPath string) (string, bool, error) {
 
 	return "", false, nil
 }
+
+func DefaultUserPath() (string, error) {
+	homeDir, err := os.UserHomeDir()
+	if err != nil {
+		return "", fmt.Errorf("resolve home dir: %w", err)
+	}
+	xdgDir := os.Getenv("XDG_CONFIG_HOME")
+	if xdgDir == "" {
+		xdgDir = filepath.Join(homeDir, ".config")
+	}
+	return filepath.Join(xdgDir, "vcom", "vcom.toml"), nil
+}

internal/fs/preview.go

@@ -64,6 +64,7 @@ type PreviewOptions struct {
 	DirectoryPreviewLimit int
 	HumanReadableSize     bool
 	ThemeName             string
+	UseNerdIcons          bool
 }
 
 func BuildPreview(entry Entry, options PreviewOptions) Preview {
@@ -317,7 +318,7 @@ func buildDirectoryPreview(path string, options PreviewOptions) string {
 		if entry.IsParent {
 			continue
 		}
-		icon := previewIcon(entry)
+		icon := previewIcon(entry, options.UseNerdIcons)
 
 		size := ""
 		if !entry.IsDir {
@@ -338,7 +339,26 @@ func buildDirectoryPreview(path string, options PreviewOptions) string {
 	return strings.Join(lines, "\n")
 }
 
-func previewIcon(entry Entry) string {
+func previewIcon(entry Entry, useNerdIcons bool) string {
+	if !useNerdIcons {
+		switch entry.Category() {
+		case "directory":
+			return "[D]"
+		case "config":
+			return "[C]"
+		case "text":
+			return "[T]"
+		case "image":
+			return "[I]"
+		case "executable":
+			return "[X]"
+		case "archive":
+			return "[A]"
+		default:
+			return "[F]"
+		}
+	}
+
 	switch entry.Category() {
 	case "directory":
 		return ""

internal/ui/icon_mode.go

@@ -0,0 +1,37 @@
+package ui
+
+import (
+	"os/exec"
+	"runtime"
+	"strings"
+)
+
+func resolveIconMode(mode string) (bool, string) {
+	switch strings.ToLower(strings.TrimSpace(mode)) {
+	case "ascii":
+		return false, "Icon mode: ASCII"
+	case "nerd":
+		return true, ""
+	case "", "auto":
+	default:
+		return true, ""
+	}
+
+	if runtime.GOOS != "linux" {
+		return true, ""
+	}
+	if _, err := exec.LookPath("fc-list"); err != nil {
+		return true, ""
+	}
+
+	out, err := exec.Command("fc-list", ":", "family").Output()
+	if err != nil {
+		return true, ""
+	}
+	text := strings.ToLower(string(out))
+	if strings.Contains(text, "nerd font") {
+		return true, ""
+	}
+
+	return false, "Nerd Font not found: using ASCII icons"
+}

internal/ui/model.go

@@ -141,6 +141,7 @@ type Model struct {
 	configPath string
 	palette    theme.Palette
 	keys       KeyMap
+	nerdIcons  bool
 
 	width  int
 	height int
@@ -199,6 +200,10 @@ func NewModel(cfg config.Config, configPath string) (Model, error) {
 		status:       "Ready",
 		copyProgress: make(chan tea.Msg, 256),
 	}
+	model.nerdIcons, model.status = resolveIconMode(cfg.UI.IconMode)
+	if model.status == "" {
+		model.status = "Ready"
+	}
 
 	model.previewModel = viewport.New(0, 0)
 	if err := model.reloadPane(PaneLeft, ""); err != nil {
@@ -546,7 +551,7 @@ func (m Model) View() string {
 		if m.active == PaneLeft {
 			panels = lipgloss.JoinHorizontal(
 				lipgloss.Top,
-				renderPane(m.left, m.cfg, m.palette, leftWidth, bodyHeight, true, m.hoverIndexFor(PaneLeft)),
+				renderPane(m.left, m.cfg, m.palette, leftWidth, bodyHeight, true, m.hoverIndexFor(PaneLeft), m.nerdIcons),
 				gap,
 				renderPreviewPane(m.previewData, &m.previewModel, m.cfg, m.palette, previewWidth, bodyHeight),
 			)
@@ -555,15 +560,15 @@ func (m Model) View() string {
 				lipgloss.Top,
 				renderPreviewPane(m.previewData, &m.previewModel, m.cfg, m.palette, previewWidth, bodyHeight),
 				gap,
-				renderPane(m.right, m.cfg, m.palette, rightWidth, bodyHeight, true, m.hoverIndexFor(PaneRight)),
+				renderPane(m.right, m.cfg, m.palette, rightWidth, bodyHeight, true, m.hoverIndexFor(PaneRight), m.nerdIcons),
 			)
 		}
 	} else {
 		panels = lipgloss.JoinHorizontal(
 			lipgloss.Top,
-			renderPane(m.left, m.cfg, m.palette, leftWidth, bodyHeight, m.active == PaneLeft, m.hoverIndexFor(PaneLeft)),
+			renderPane(m.left, m.cfg, m.palette, leftWidth, bodyHeight, m.active == PaneLeft, m.hoverIndexFor(PaneLeft), m.nerdIcons),
 			gap,
-			renderPane(m.right, m.cfg, m.palette, rightWidth, bodyHeight, m.active == PaneRight, m.hoverIndexFor(PaneRight)),
+			renderPane(m.right, m.cfg, m.palette, rightWidth, bodyHeight, m.active == PaneRight, m.hoverIndexFor(PaneRight), m.nerdIcons),
 		)
 	}
 
@@ -841,6 +846,7 @@ func (m Model) loadPreviewCmd() tea.Cmd {
 		DirectoryPreviewLimit: m.cfg.Preview.DirectoryPreviewLimit,
 		HumanReadableSize:     m.cfg.Browser.HumanReadableSize,
 		ThemeName:             m.cfg.UI.Theme,
+		UseNerdIcons:          m.nerdIcons,
 	}
 
 	return func() tea.Msg {
@@ -1150,7 +1156,13 @@ func (m *Model) cycleTheme() (tea.Model, tea.Cmd) {
 	}
 	m.cfg.UI.Theme = next
 	m.palette = palette
-	m.status = fmt.Sprintf("Theme: %s", next)
+	savedPath, saveErr := config.Save(m.cfg, m.configPath)
+	if saveErr != nil {
+		m.status = fmt.Sprintf("Theme: %s (save failed: %v)", next, saveErr)
+		return m, nil
+	}
+	m.configPath = savedPath
+	m.status = fmt.Sprintf("Theme: %s (saved)", next)
 	return m, nil
 }
 

internal/ui/pane.go

@@ -179,6 +179,7 @@ func renderPane(
 	height int,
 	active bool,
 	hoverIndex int,
+	useNerdIcons bool,
 ) string {
 	if width <= 0 || height <= 0 {
 		return ""
@@ -208,8 +209,8 @@ func renderPane(
 		Render(renderPaneHeader(pane, cfg, palette, innerWidth, active, headerBg))
 
 	rowsHeight := max(innerHeight-2, 1)
-	headerRow := renderColumnsHeader(cfg, innerWidth, palette, bodyBg)
+	headerRow := renderColumnsHeader(cfg, innerWidth, palette, bodyBg, useNerdIcons)
-	rows := renderPaneRows(pane, cfg, palette, innerWidth, rowsHeight, active, hoverIndex, bodyBg)
+	rows := renderPaneRows(pane, cfg, palette, innerWidth, rowsHeight, active, hoverIndex, bodyBg, useNerdIcons)
 	content := lipgloss.JoinVertical(lipgloss.Left, header, headerRow, rows)
 	return box.Render(content)
 }
@@ -231,8 +232,8 @@ func renderPaneHeader(pane BrowserPane, cfg config.Config, palette theme.Palette
 		Render(pathStyle.Render(truncateMiddle(compactPath(pane.Path, cfg.UI.PathDisplay), pathWidth)))
 }
 
-func renderColumnsHeader(cfg config.Config, width int, palette theme.Palette, background lipgloss.Color) string {
+func renderColumnsHeader(cfg config.Config, width int, palette theme.Palette, background lipgloss.Color, useNerdIcons bool) string {
-	columns := buildColumns(cfg, width)
+	columns := buildColumns(cfg, width, useNerdIcons)
 	parts := make([]string, 0, len(columns))
 	for idx, column := range columns {
 		style := lipgloss.NewStyle().
@@ -254,7 +255,7 @@ func renderColumnsHeader(cfg config.Config, width int, palette theme.Palette, ba
 		Render(strings.Join(parts, ""))
 }
 
-func renderPaneRows(pane BrowserPane, cfg config.Config, palette theme.Palette, width int, height int, active bool, hoverIndex int, background lipgloss.Color) string {
+func renderPaneRows(pane BrowserPane, cfg config.Config, palette theme.Palette, width int, height int, active bool, hoverIndex int, background lipgloss.Color, useNerdIcons bool) string {
 	if len(pane.Entries) == 0 {
 		return lipgloss.NewStyle().
 			Width(width).
@@ -274,7 +275,7 @@ func renderPaneRows(pane BrowserPane, cfg config.Config, palette theme.Palette,
 		entry := pane.Entries[idx]
 		isSelected := idx == pane.Cursor && active
 		marked := !entry.IsParent && pane.IsMarked(entry.Path)
-		row := renderEntryRow(entry, cfg, width, isSelected, marked, idx == hoverIndex, active, palette, background)
+		row := renderEntryRow(entry, cfg, width, isSelected, marked, idx == hoverIndex, active, palette, background, useNerdIcons)
 		lines = append(lines, row)
 	}
 	for len(lines) < visibleHeight {
@@ -287,8 +288,8 @@ func renderPaneRows(pane BrowserPane, cfg config.Config, palette theme.Palette,
 		Render(strings.Join(lines, "\n"))
 }
 
-func renderEntryRow(entry vfs.Entry, cfg config.Config, width int, selected bool, marked bool, hovered bool, active bool, palette theme.Palette, baseBackground lipgloss.Color) string {
+func renderEntryRow(entry vfs.Entry, cfg config.Config, width int, selected bool, marked bool, hovered bool, active bool, palette theme.Palette, baseBackground lipgloss.Color, useNerdIcons bool) string {
-	columns := buildColumns(cfg, width)
+	columns := buildColumns(cfg, width, useNerdIcons)
 	rowBackground := baseBackground
 	switch {
 	case marked:
@@ -340,7 +341,7 @@ type columnSpec struct {
 	Value      func(entry vfs.Entry, human bool) string
 }
 
-func buildColumns(cfg config.Config, totalWidth int) []columnSpec {
+func buildColumns(cfg config.Config, totalWidth int, useNerdIcons bool) []columnSpec {
 	fixed := []columnSpec{}
 
 	if cfg.Browser.Columns.Permissions {
@@ -453,7 +454,7 @@ func buildColumns(cfg config.Config, totalWidth int) []columnSpec {
 		Width:    nameWidth,
 		MinWidth: minNameWidth,
 		Value: func(entry vfs.Entry, _ bool) string {
-			return entryIcon(entry) + " " + entry.DisplayName()
+			return entryIcon(entry, useNerdIcons) + " " + entry.DisplayName()
 		},
 	}
 
@@ -583,7 +584,27 @@ func trimToWidthLeft(value string, maxWidth int) string {
 	return string(runes[start:])
 }
 
-func entryIcon(entry vfs.Entry) string {
+func entryIcon(entry vfs.Entry, useNerdIcons bool) string {
+	if !useNerdIcons {
+		switch entry.Category() {
+		case "parent":
+			return "<-"
+		case "directory":
+			return "[D]"
+		case "config":
+			return "[C]"
+		case "text":
+			return "[T]"
+		case "image":
+			return "[I]"
+		case "executable":
+			return "[X]"
+		case "archive":
+			return "[A]"
+		default:
+			return "[F]"
+		}
+	}
 	switch entry.Category() {
 	case "parent":
 		return "↩"