feat(ui): add emacs-style ctrl-n/ctrl-p aliases for down/up

fix: reserve 2 lines for view

README.md

@@ -10,7 +10,7 @@
 </p>
 
 <p align="center">
-  <img src= "https://github.com/user-attachments/assets/2cecb580-fe35-47ae-886b-8315226d122b" alt="difi_demo" />
+  <img src= "https://github.com/user-attachments/assets/3695cfd2-148c-463d-9630-547d152adde0" alt="difi_demo" />
 </p>
 
 ## Why difi?
@@ -172,3 +172,4 @@ Contributions are especially welcome in:
 
 <p align="center"> Made with ❤️ by <a href="https://github.com/oug-t">oug-t</a> </p>
 
+

cmd/difi/main.go

@@ -16,6 +16,7 @@ var version = "dev"
 func main() {
 	showVersion := flag.Bool("version", false, "Show version")
 	plain := flag.Bool("plain", false, "Print a plain, non-interactive summary and exit")
+	flat := flag.Bool("flat", false, "Start in flat file list mode")
 
 	flag.Usage = func() {
 		w := os.Stderr
@@ -52,6 +53,7 @@ func main() {
 	}
 
 	cfg := config.Load()
+	cfg.Flat = *flat
 
 	p := tea.NewProgram(ui.NewModel(cfg, target), tea.WithAltScreen())
 	if _, err := p.Run(); err != nil {

internal/config/config.go

@@ -1,7 +1,8 @@
 package config
 
 type Config struct {
-	UI UIConfig
+	UI   UIConfig
+	Flat bool
 }
 
 type UIConfig struct {

internal/tree/tree.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"github.com/charmbracelet/bubbles/list"
+	"github.com/charmbracelet/lipgloss"
 )
 
 // FileTree holds the state of the entire file graph.
@@ -32,6 +33,7 @@ type TreeItem struct {
 	Depth    int
 	Expanded bool
 	Icon     string
+	Flat     bool
 }
 
 // Implement list.Item interface
@@ -104,6 +106,40 @@ func (t *FileTree) Items() []list.Item {
 	return items
 }
 
+// FlatItems returns all leaf (file) nodes as a flat list with full paths.
+func (t *FileTree) FlatItems() []list.Item {
+	var items []list.Item
+	collectLeaves(t.Root, &items)
+	return items
+}
+
+// collectLeaves recursively collects all file (non-directory) nodes.
+func collectLeaves(node *Node, items *[]list.Item) {
+	children := make([]*Node, 0, len(node.Children))
+	for _, child := range node.Children {
+		children = append(children, child)
+	}
+
+	sort.Slice(children, func(i, j int) bool {
+		return strings.ToLower(children[i].FullPath) < strings.ToLower(children[j].FullPath)
+	})
+
+	for _, child := range children {
+		if child.IsDir {
+			collectLeaves(child, items)
+		} else {
+			*items = append(*items, TreeItem{
+				Name:     child.Name,
+				FullPath: child.FullPath,
+				IsDir:    false,
+				Depth:    0,
+				Icon:     getIcon(child.Name, false),
+				Flat:     true,
+			})
+		}
+	}
+}
+
 // flatten recursively builds the list, respecting expansion state.
 func flatten(node *Node, items *[]list.Item) {
 	// Collect children to sort
@@ -189,3 +225,22 @@ func getIcon(name string, isDir bool) string {
 		return ""
 	}
 }
+
+// ShortenPath truncates a path from the left to fit within maxWidth display columns.
+// "internal/tree/tree.go" → "…nal/tree/tree.go"
+func ShortenPath(path string, maxWidth int) string {
+	if lipgloss.Width(path) <= maxWidth {
+		return path
+	}
+	ellipsis := "…"
+	avail := maxWidth - lipgloss.Width(ellipsis)
+	if avail <= 0 {
+		return ellipsis
+	}
+	// Trim runes from the left until the remainder fits
+	runes := []rune(path)
+	for len(runes) > 0 && lipgloss.Width(string(runes)) > avail {
+		runes = runes[1:]
+	}
+	return ellipsis + string(runes)
+}

internal/ui/delegate.go

@@ -7,6 +7,7 @@ import (
 	"github.com/charmbracelet/bubbles/list"
 	tea "github.com/charmbracelet/bubbletea"
 	"github.com/charmbracelet/lipgloss"
+	"github.com/charmbracelet/x/ansi"
 	"github.com/oug-t/difi/internal/tree"
 )
 
@@ -24,7 +25,15 @@ func (d TreeDelegate) Render(w io.Writer, m list.Model, index int, item list.Ite
 		return
 	}
 
-	title := i.Title()
+	var title string
+	if i.Flat {
+		iconWidth := lipgloss.Width(i.Icon) + 1 // icon + space
+		path := tree.ShortenPath(i.FullPath, m.Width()-2-iconWidth)
+		title = fmt.Sprintf("%s %s", i.Icon, path)
+	} else {
+		title = i.Title()
+	}
+	title = ansi.Truncate(title, m.Width()-2, "…")
 
 	if index == m.Index() {
 		style := lipgloss.NewStyle().

internal/ui/model.go

@@ -46,6 +46,9 @@ type Model struct {
 	statsAdded   int
 	statsDeleted int
 
+	currentFileAdded   int
+	currentFileDeleted int
+
 	diffContent string
 	diffLines   []string
 	diffCursor  int
@@ -53,8 +56,10 @@ type Model struct {
 	inputBuffer string
 	pendingZ    bool
 
-	focus    Focus
-	showHelp bool
+	focus      Focus
+	showHelp   bool
+	flatMode   bool
+	treeHidden bool
 
 	width, height int
 }
@@ -65,7 +70,12 @@ func NewModel(cfg config.Config, targetBranch string) Model {
 	files, _ := git.ListChangedFiles(targetBranch)
 
 	t := tree.New(files)
-	items := t.Items()
+	var items []list.Item
+	if cfg.Flat {
+		items = t.FlatItems()
+	} else {
+		items = t.Items()
+	}
 
 	delegate := TreeDelegate{Focused: true}
 	l := list.New(items, delegate, 0, 0)
@@ -87,6 +97,7 @@ func NewModel(cfg config.Config, targetBranch string) Model {
 		targetBranch:  targetBranch,
 		repoName:      git.GetRepoName(),
 		showHelp:      false,
+		flatMode:      cfg.Flat,
 		inputBuffer:   "",
 		pendingZ:      false,
 	}
@@ -192,6 +203,9 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 
 		switch msg.String() {
 		case "tab":
+			if m.treeHidden {
+				return m, nil
+			}
 			if m.focus == FocusTree {
 				if item, ok := m.fileList.SelectedItem().(tree.TreeItem); ok && item.IsDir {
 					return m, nil
@@ -214,12 +228,14 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			m.inputBuffer = ""
 
 		case "h", "[", "ctrl+h", "left":
-			m.focus = FocusTree
-			m.updateTreeFocus()
+			if !m.treeHidden {
+				m.focus = FocusTree
+				m.updateTreeFocus()
+			}
 			m.inputBuffer = ""
 
 		case "enter":
-			if m.focus == FocusTree {
+			if m.focus == FocusTree && !m.flatMode {
 				if i, ok := m.fileList.SelectedItem().(tree.TreeItem); ok && i.IsDir {
 					m.treeState.ToggleExpand(i.FullPath)
 					m.fileList.SetItems(m.treeState.Items())
@@ -252,6 +268,49 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 				return m, openFugitive(m.selectedPath, line)
 			}
 
+		case "f":
+			m.flatMode = !m.flatMode
+			prevPath := m.selectedPath
+			if m.flatMode {
+				m.fileList.SetItems(m.treeState.FlatItems())
+			} else {
+				m.fileList.SetItems(m.treeState.Items())
+			}
+			// Restore selection to the same file if possible
+			restored := false
+			for idx, item := range m.fileList.Items() {
+				if ti, ok := item.(tree.TreeItem); ok && ti.FullPath == prevPath {
+					m.fileList.Select(idx)
+					restored = true
+					break
+				}
+			}
+			// In flat mode, auto-select the first file if nothing was restored
+			if m.flatMode && !restored {
+				if first, ok := m.fileList.Items()[0].(tree.TreeItem); ok {
+					m.fileList.Select(0)
+					m.selectedPath = first.FullPath
+					m.diffCursor = 0
+					m.diffViewport.GotoTop()
+					m.inputBuffer = ""
+					return m, git.DiffCmd(m.targetBranch, m.selectedPath)
+				}
+			}
+			m.inputBuffer = ""
+			return m, nil
+
+		case "t":
+			m.treeHidden = !m.treeHidden
+			if m.treeHidden {
+				m.focus = FocusDiff
+			} else {
+				m.focus = FocusTree
+			}
+			m.updateTreeFocus()
+			m.updateSizes()
+			m.inputBuffer = ""
+			return m, nil
+
 		case "z":
 			if m.focus == FocusDiff {
 				m.pendingZ = true
@@ -305,7 +364,7 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			}
 			m.inputBuffer = ""
 
-		case "j", "down":
+		case "j", "down", "ctrl+n":
 			keyHandled = true
 			count := m.getRepeatCount()
 			for i := 0; i < count; i++ {
@@ -322,7 +381,7 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			}
 			m.inputBuffer = ""
 
-		case "k", "up":
+		case "k", "up", "ctrl+p":
 			keyHandled = true
 			count := m.getRepeatCount()
 			for i := 0; i < count; i++ {
@@ -362,9 +421,41 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 
 	switch msg := msg.(type) {
 	case git.DiffMsg:
-		m.diffContent = msg.Content
-		m.diffLines = strings.Split(msg.Content, "\n")
-		m.diffViewport.SetContent(msg.Content)
+		fullLines := strings.Split(msg.Content, "\n")
+
+		var cleanLines []string
+		var added, deleted int
+		foundHunk := false
+
+		for _, line := range fullLines {
+			cleanLine := stripAnsi(line)
+
+			if strings.HasPrefix(cleanLine, "@@") {
+				foundHunk = true
+			}
+
+			if !foundHunk {
+				continue
+			}
+
+			cleanLines = append(cleanLines, line)
+
+			// Check "+++" to avoid counting file header
+			if strings.HasPrefix(cleanLine, "+") && !strings.HasPrefix(cleanLine, "+++") {
+				added++
+			} else if strings.HasPrefix(cleanLine, "-") && !strings.HasPrefix(cleanLine, "---") {
+				deleted++
+			}
+		}
+
+		m.diffLines = cleanLines
+		m.currentFileAdded = added
+		m.currentFileDeleted = deleted
+
+		newContent := strings.Join(cleanLines, "\n")
+		m.diffContent = newContent
+		m.diffViewport.SetContent(newContent)
+		m.diffViewport.GotoTop()
 
 	case git.EditorFinishedMsg:
 		return m, git.DiffCmd(m.targetBranch, m.selectedPath)
@@ -397,7 +488,7 @@ func (m *Model) updateSizes() {
 	// 1 line Top Bar + 1 line Bottom Bar = 2 reserved
 	reservedHeight := 2
 	if m.showHelp {
-		reservedHeight += 6
+		reservedHeight += 7
 	}
 
 	contentHeight := m.height - reservedHeight
@@ -405,20 +496,25 @@ func (m *Model) updateSizes() {
 		contentHeight = 1
 	}
 
-	treeWidth := int(float64(m.width) * 0.20)
-	if treeWidth < 20 {
-		treeWidth = 20
-	}
-
 	// Subtract border height (2) from contentHeight
 	listHeight := contentHeight - 2
 	if listHeight < 1 {
 		listHeight = 1
 	}
-	m.fileList.SetSize(treeWidth, listHeight)
 
-	m.diffViewport.Width = m.width - treeWidth - 4 // border (2) + padding (2) from tree pane
-	m.diffViewport.Height = listHeight
+	if m.treeHidden {
+		m.fileList.SetSize(0, listHeight)
+		m.diffViewport.Width = m.width - 2 // border (2)
+		m.diffViewport.Height = listHeight
+	} else {
+		treeWidth := int(float64(m.width) * 0.20)
+		if treeWidth < 20 {
+			treeWidth = 20
+		}
+		m.fileList.SetSize(treeWidth, listHeight)
+		m.diffViewport.Width = m.width - treeWidth - 4 // border (2) + padding (2) from tree pane
+		m.diffViewport.Height = listHeight
+	}
 }
 
 func (m *Model) updateTreeFocus() {
@@ -436,7 +532,7 @@ func (m Model) View() string {
 	var mainContent string
 	contentHeight := m.height - 2
 	if m.showHelp {
-		contentHeight -= 6
+		contentHeight -= 7
 	}
 	if contentHeight < 0 {
 		contentHeight = 0
@@ -448,8 +544,6 @@ func (m Model) View() string {
 		treeStyle := PaneStyle
 		if m.focus == FocusTree {
 			treeStyle = FocusedPaneStyle
-		} else {
-			treeStyle = PaneStyle
 		}
 
 		treeView := treeStyle.Copy().
@@ -458,33 +552,84 @@ func (m Model) View() string {
 			Render(m.fileList.View())
 
 		var rightPaneView string
-
 		selectedItem, ok := m.fileList.SelectedItem().(tree.TreeItem)
+
 		if ok && selectedItem.IsDir {
 			rightPaneView = m.renderEmptyState(m.diffViewport.Width, m.diffViewport.Height, "Directory: "+selectedItem.Name)
 		} else {
 			var renderedDiff strings.Builder
+
+			// Reserve 2 line for the file header
+			viewportHeight := m.diffViewport.Height - 2
 			start := m.diffViewport.YOffset
-			end := start + m.diffViewport.Height
+			end := start + viewportHeight
 			if end > len(m.diffLines) {
 				end = len(m.diffLines)
 			}
 
-			// 5 for line number (Width 4 + MarginRight 1), 2 for indent
+			// Calculate stats
+			added, deleted := 0, 0
+			for _, line := range m.diffLines {
+				clean := stripAnsi(line)
+				if strings.HasPrefix(clean, "+") && !strings.HasPrefix(clean, "+++") {
+					added++
+				} else if strings.HasPrefix(clean, "-") && !strings.HasPrefix(clean, "---") {
+					deleted++
+				}
+			}
+
+			headerStyle := lipgloss.NewStyle().
+				Foreground(lipgloss.Color("240")).
+				Border(lipgloss.NormalBorder(), false, false, true, false).
+				BorderForeground(lipgloss.Color("236")).
+				Width(m.diffViewport.Width).
+				Padding(0, 1)
+
+			headerText := fmt.Sprintf("%s  (+%d / -%d)", m.selectedPath, added, deleted)
+			header := headerStyle.Render(headerText)
+
 			maxLineWidth := m.diffViewport.Width - 7
 			if maxLineWidth < 1 {
 				maxLineWidth = 1
 			}
 
 			for i := start; i < end; i++ {
-				line := ansi.Truncate(m.diffLines[i], maxLineWidth, "")
+				rawLine := m.diffLines[i]
+				cleanLine := stripAnsi(rawLine)
+				line := ansi.Truncate(rawLine, maxLineWidth, "")
+
+				// Skip Git metadata noise
+				if strings.HasPrefix(cleanLine, "diff --git") ||
+					strings.HasPrefix(cleanLine, "index ") ||
+					strings.HasPrefix(cleanLine, "new file mode") ||
+					strings.HasPrefix(cleanLine, "old mode") ||
+					strings.HasPrefix(cleanLine, "--- /dev/") ||
+					strings.HasPrefix(cleanLine, "+++ b/") {
+					continue
+				}
+
+				// Handle Hunk Headers
+				if strings.HasPrefix(cleanLine, "@@") {
+					content := cleanLine
+					if idx := strings.LastIndex(content, "@@"); idx != -1 {
+						content = content[idx+2:]
+					}
+					content = strings.TrimSpace(content)
+
+					if content == "" {
+						content = "..."
+					}
+
+					divider := lipgloss.NewStyle().Foreground(lipgloss.Color("245")).Render("  › " + content)
+
+					renderedDiff.WriteString("     " + divider + "\n")
+					continue
+				}
 
 				var numStr string
 				mode := "relative"
 
-				if mode == "hidden" {
-					numStr = ""
-				} else {
+				if mode != "hidden" {
 					isCursor := (i == m.diffCursor)
 					if isCursor && mode == "hybrid" {
 						realLine := git.CalculateFileLine(m.diffContent, m.diffCursor)
@@ -505,7 +650,6 @@ func (m Model) View() string {
 				}
 
 				if m.focus == FocusDiff && i == m.diffCursor {
-					cleanLine := stripAnsi(line)
 					line = DiffSelectionStyle.Render("  " + cleanLine)
 				} else {
 					line = "  " + line
@@ -516,13 +660,19 @@ func (m Model) View() string {
 
 			diffContentStr := strings.TrimRight(renderedDiff.String(), "\n")
 
-			rightPaneView = DiffStyle.Copy().
+			diffView := DiffStyle.Copy().
 				Width(m.diffViewport.Width).
-				Height(m.diffViewport.Height).
+				Height(viewportHeight).
 				Render(diffContentStr)
+
+			rightPaneView = lipgloss.JoinVertical(lipgloss.Top, header, diffView)
 		}
 
-		mainContent = lipgloss.JoinHorizontal(lipgloss.Top, treeView, rightPaneView)
+		if m.treeHidden {
+			mainContent = rightPaneView
+		} else {
+			mainContent = lipgloss.JoinHorizontal(lipgloss.Top, treeView, rightPaneView)
+		}
 	}
 
 	var bottomBar string
@@ -573,7 +723,7 @@ func (m Model) renderTopBar() string {
 }
 
 func (m Model) viewStatusBar() string {
-	shortcuts := StatusKeyStyle.Render("? Help  q Quit  Tab Switch")
+	shortcuts := StatusKeyStyle.Render("? Help  q Quit  Tab Switch  f Flat  t Tree")
 	return StatusBarStyle.Width(m.width).Render(shortcuts)
 }
 
@@ -592,7 +742,9 @@ func (m Model) renderHelpDrawer() string {
 	)
 	col4 := lipgloss.JoinVertical(lipgloss.Left,
 		HelpTextStyle.Render("H/M/L Move Cursor"),
-		HelpTextStyle.Render("e      Edit File"),
+		HelpTextStyle.Render("e     Edit File"),
+		HelpTextStyle.Render("f     Flat Tree"),
+		HelpTextStyle.Render("t     Toggle Tree"),
 	)
 
 	return HelpDrawerStyle.Copy().