fix(table): append headers/columns to zero sized string slice

There are many "interesting" cases:

- logical content is wider than display width (long lines).
  In this case, we truncate.
- logical content is smaller than display height (fewer lines
  than visible).
  In this case, we pad with empty lines up to the specified height.
- logical content is higher than display height (more lines than
  visible).
  In this case, we truncate.

- style specifies a width wider than the display width.
  In this case, we ignore the style width and
  fit in the display width.
- style specifies a height higher than the display height.
  Same as width, we ignore the style and fit in the display height.
- style specifies a narrower width or smaller height than the display.
  In this case we obey the style.

table/table.go

@@ -59,11 +59,11 @@ func DefaultKeyMap() KeyMap {
 		),
 		PageUp: key.NewBinding(
 			key.WithKeys("b", "pgup"),
-			key.WithHelp("b", "page up"),
+			key.WithHelp("b/pgup", "page up"),
 		),
 		PageDown: key.NewBinding(
-			key.WithKeys("f", "pgup", spacebar),
+			key.WithKeys("f", "pgdown", spacebar),
-			key.WithHelp("f", "page down"),
+			key.WithHelp("f/pgdn", "page down"),
 		),
 		HalfPageUp: key.NewBinding(
 			key.WithKeys("u", "ctrl+u"),
@@ -291,6 +291,12 @@ func (m Model) Cursor() int {
 	return m.cursor
 }
 
+// SetCursor sets the cursor position in the table.
+func (m *Model) SetCursor(n int) {
+	m.cursor = clamp(n, 0, len(m.rows)-1)
+	m.UpdateViewport()
+}
+
 // MoveUp moves the selection up by any number of row.
 // It can not go above the first row.
 func (m *Model) MoveUp(n int) {
@@ -340,7 +346,7 @@ func (m *Model) FromValues(value, separator string) {
 }
 
 func (m Model) headersView() string {
-	var s = make([]string, len(m.cols))
+	var s = make([]string, 0, len(m.cols))
 	for _, col := range m.cols {
 		style := lipgloss.NewStyle().Width(col.Width).MaxWidth(col.Width).Inline(true)
 		renderedCell := style.Render(runewidth.Truncate(col.Title, col.Width, "…"))
@@ -350,7 +356,7 @@ func (m Model) headersView() string {
 }
 
 func (m *Model) renderRow(rowID int) string {
-	var s = make([]string, len(m.cols))
+	var s = make([]string, 0, len(m.cols))
 	for i, value := range m.rows[rowID] {
 		style := lipgloss.NewStyle().Width(m.cols[i].Width).MaxWidth(m.cols[i].Width).Inline(true)
 		renderedCell := m.styles.Cell.Render(style.Render(runewidth.Truncate(value, m.cols[i].Width, "…")))

textarea/modal.go

@@ -1,791 +0,0 @@
-package textarea
-
-import (
-	"strconv"
-	"strings"
-	"unicode"
-
-	"github.com/charmbracelet/bubbles/cursor"
-	tea "github.com/charmbracelet/bubbletea"
-	rw "github.com/mattn/go-runewidth"
-)
-
-// Mode is the possible modes of the textarea for modal editing.
-type Mode string
-
-const (
-	// ModeNormal is the normal mode for navigating around text.
-	ModeNormal Mode = "normal"
-	// ModeInsert is the insert mode for inserting text.
-	ModeInsert Mode = "insert"
-)
-
-// SetMode sets the mode of the textarea.
-func (m *Model) SetMode(mode Mode) tea.Cmd {
-	switch mode {
-	case ModeInsert:
-		m.mode = ModeInsert
-		return m.Cursor.SetCursorMode(cursor.CursorBlink)
-	case ModeNormal:
-		m.mode = ModeNormal
-		m.col = clamp(m.col-1, 0, len(m.value[m.row]))
-		return m.Cursor.SetCursorMode(cursor.CursorStatic)
-	}
-	return nil
-}
-
-// Action is the type of action that will be performed when the user completes
-// a key combination.
-type Action int
-
-const (
-	// ActionMove moves the cursor.
-	ActionMove Action = iota
-	// ActionReplace replaces text.
-	ActionReplace
-	// ActionDelete deletes text.
-	ActionDelete
-	// ActionYank yanks text.
-	ActionYank
-	// ActionChange deletes text and enters insert mode.
-	ActionChange
-)
-
-// Position is a (row, column) pair representing a position of the cursor or
-// any character.
-type Position struct {
-	Row int
-	Col int
-}
-
-// Range is a range of characters in the text area.
-type Range struct {
-	Start Position
-	End   Position
-}
-
-// NormalCommand is a helper for keeping track of the various relevant information
-// when performing vim motions in the textarea.
-type NormalCommand struct {
-	// Buffer is the buffer of keys that have been press for the current
-	// command.
-	Buffer string
-	// Count is the number of times to replay the action. This is usually
-	// optional and defaults to 1.
-	Count int
-	// Action is the action to be performed.
-	Action Action
-	// Range is the range of characters to perform the action on.
-	Range Range
-	// Seeking is the type of seeking that is in progress.
-	Seeking SeekType
-}
-
-// SeekType are the possible types of seeking that can be in progress.
-type SeekType int
-
-const (
-	// SeekNone is the default seeking action.
-	SeekNone SeekType = iota
-	// SeekForwardTo is the seeking action for f.
-	SeekForwardTo // f
-	// SeekBackwardTo is the seeking action for F.
-	SeekBackwardTo // F
-	// SeekForwardUntil is the seeking action for t.
-	SeekForwardUntil // t
-	// SeekBackwardUntil is the seeking action for T.
-	SeekBackwardUntil // T
-	// SeekAround is the seeking action for a.
-	SeekAround // a
-	// SeekInner is the seeking action for i.
-	SeekInner // i
-)
-
-// IsSeeking returns whether the command is in the middle of seeking a range.
-func (n *NormalCommand) IsSeeking() bool {
-	return n.Seeking != SeekNone
-}
-
-// IsSeekingForward returns whether the seeking action is in the forward direction (f, t).
-func (n *NormalCommand) IsSeekingForward() bool {
-	return n.Seeking == SeekForwardTo || n.Seeking == SeekForwardUntil
-}
-
-// IsSeekingBackward returns whether the seeking action is in the backward direction (F, T).
-func (n *NormalCommand) IsSeekingBackward() bool {
-	return n.Seeking == SeekBackwardTo || n.Seeking == SeekBackwardUntil
-}
-
-// executeMsg executes a command.
-type executeMsg NormalCommand
-
-// executeCmd implements tea.Cmd for an executeMsg.
-func executeCmd(n NormalCommand) tea.Cmd {
-	return func() tea.Msg {
-		return executeMsg(n)
-	}
-}
-
-func (m *Model) insertUpdate(msg tea.Msg) tea.Cmd {
-	switch msg := msg.(type) {
-	case tea.KeyMsg:
-		switch msg.String() {
-		case "esc":
-			return m.SetMode(ModeNormal)
-		case "ctrl+k":
-			m.col = clamp(m.col, 0, len(m.value[m.row]))
-			if m.col >= len(m.value[m.row]) {
-				m.mergeLineBelow(m.row)
-				break
-			}
-			m.deleteAfterCursor()
-		case "ctrl+u":
-			m.col = clamp(m.col, 0, len(m.value[m.row]))
-			if m.col <= 0 {
-				m.mergeLineAbove(m.row)
-				break
-			}
-			m.deleteBeforeCursor()
-		case "backspace", "ctrl+h":
-			m.col = clamp(m.col, 0, len(m.value[m.row]))
-			if m.col <= 0 {
-				m.mergeLineAbove(m.row)
-				break
-			}
-			if len(m.value[m.row]) > 0 {
-				m.value[m.row] = append(m.value[m.row][:max(0, m.col-1)], m.value[m.row][m.col:]...)
-				if m.col > 0 {
-					m.SetCursor(m.col - 1)
-				}
-			}
-		case "delete", "ctrl+d":
-			if len(m.value[m.row]) > 0 && m.col < len(m.value[m.row]) {
-				m.value[m.row] = append(m.value[m.row][:m.col], m.value[m.row][m.col+1:]...)
-			}
-			if m.col >= len(m.value[m.row]) {
-				m.mergeLineBelow(m.row)
-				break
-			}
-		case "alt+backspace", "ctrl+w":
-			if m.col <= 0 {
-				m.mergeLineAbove(m.row)
-				break
-			}
-			m.deleteWordLeft()
-		case "alt+delete", "alt+d":
-			m.col = clamp(m.col, 0, len(m.value[m.row]))
-			if m.col >= len(m.value[m.row]) {
-				m.mergeLineBelow(m.row)
-				break
-			}
-			m.deleteWordRight()
-		case "enter", "ctrl+m":
-			if len(m.value) >= maxHeight {
-				return nil
-			}
-			m.col = clamp(m.col, 0, len(m.value[m.row]))
-			m.splitLine(m.row, m.col)
-		case "end", "ctrl+e":
-			m.CursorEnd()
-		case "home", "ctrl+a":
-			m.CursorStart()
-		case "right", "ctrl+f":
-			if m.col < len(m.value[m.row]) {
-				m.SetCursor(m.col + 1)
-			} else {
-				if m.row < len(m.value)-1 {
-					m.row++
-					m.CursorStart()
-				}
-			}
-		case "down", "ctrl+n":
-			m.CursorDown()
-		case "alt+right", "alt+f":
-			m.wordRight()
-		case "ctrl+v":
-			return Paste
-		case "left", "ctrl+b":
-			if m.col == 0 && m.row != 0 {
-				m.row--
-				m.CursorEnd()
-				break
-			}
-			if m.col > 0 {
-				m.SetCursor(m.col - 1)
-			}
-		case "up", "ctrl+p":
-			m.CursorUp()
-		case "alt+left", "alt+b":
-			m.wordLeft()
-		default:
-			if m.CharLimit > 0 && rw.StringWidth(m.Value()) >= m.CharLimit {
-				break
-			}
-
-			m.col = min(m.col, len(m.value[m.row]))
-			m.value[m.row] = append(m.value[m.row][:m.col], append(msg.Runes, m.value[m.row][m.col:]...)...)
-			m.SetCursor(m.col + len(msg.Runes))
-		}
-
-	case pasteMsg:
-		m.handlePaste(string(msg))
-
-	case pasteErrMsg:
-		m.Err = msg
-	}
-
-	return nil
-}
-
-func (m *Model) normalUpdate(msg tea.Msg) tea.Cmd {
-	switch msg := msg.(type) {
-	case tea.KeyMsg:
-		if m.command.IsSeeking() {
-			return m.seekingUpdate(msg)
-		}
-
-		if m.command.Action == ActionReplace {
-			for i := m.col; i < m.col+max(m.command.Count, 1); i++ {
-				if i >= len(m.value[m.row]) || len(msg.Runes) <= 0 {
-					break
-				}
-				m.value[m.row][i] = msg.Runes[0]
-			}
-			m.command = &NormalCommand{}
-			break
-		}
-
-		if !strings.ContainsAny(msg.String(), "jk") {
-			m.lastCharOffset = 0
-		}
-
-		switch msg.String() {
-		case "esc":
-			m.command = &NormalCommand{}
-			return m.SetMode(ModeNormal)
-		case "0", "1", "2", "3", "4", "5", "6", "7", "8", "9":
-			if m.command.Count == 0 && msg.String() == "0" {
-				m.command.Range = Range{
-					Start: Position{Row: m.row, Col: m.col},
-					End:   Position{Row: m.row, Col: 0},
-				}
-				return executeCmd(*m.command)
-			}
-
-			v := m.command.Buffer + msg.String()
-			count, err := strconv.Atoi(v)
-			if err != nil {
-				count, _ = strconv.Atoi(msg.String())
-				m.command.Buffer = msg.String()
-				m.command.Count = count
-			} else {
-				m.command.Buffer = v
-				m.command.Count = count
-			}
-		case "o":
-			m.CursorEnd()
-			m.splitLine(m.row, m.col)
-			return m.SetMode(ModeInsert)
-		case "O":
-			m.CursorStart()
-			m.splitLine(m.row, m.col)
-			m.CursorUp()
-			return m.SetMode(ModeInsert)
-		case "G":
-			var row int
-			if m.command.Count > 0 {
-				row = m.command.Count - 1
-			} else {
-				row = len(m.value) - 1
-			}
-			m.command.Range = Range{
-				Start: Position{Row: row, Col: m.col},
-				End:   Position{Row: clamp(row, 0, len(m.value)-1), Col: m.col},
-			}
-			return executeCmd(*m.command)
-		case "g":
-			if m.command.Buffer == "g" {
-				m.command.Range = Range{
-					Start: Position{Row: 0, Col: m.col},
-					End:   Position{Row: 0, Col: clamp(m.col, 0, len(m.value[0]))},
-				}
-				return executeCmd(*m.command)
-			}
-			m.command.Buffer = "g"
-		case "x":
-			m.command.Action = ActionDelete
-			m.command.Range = Range{
-				Start: Position{Row: m.row, Col: m.col},
-				End:   Position{Row: m.row, Col: m.col + max(m.command.Count, 1)},
-			}
-			return executeCmd(*m.command)
-		case "X":
-			m.command.Action = ActionDelete
-			m.command.Range = Range{
-				Start: Position{Row: m.row, Col: m.col},
-				End:   Position{Row: m.row, Col: m.col - max(m.command.Count, 1)},
-			}
-			return executeCmd(*m.command)
-		case "c":
-			if m.command.Action == ActionChange {
-				m.CursorStart()
-				m.deleteAfterCursor()
-				m.command = &NormalCommand{}
-				return m.SetMode(ModeInsert)
-			}
-			m.command.Action = ActionChange
-		case "d":
-			if m.command.Action == ActionDelete {
-				for i := 0; i < max(m.command.Count, 1); i++ {
-					m.value[m.row] = []rune{}
-					if m.row < len(m.value)-1 {
-						m.mergeLineBelow(m.row)
-					} else {
-						m.mergeLineAbove(m.row)
-					}
-				}
-				m.command = &NormalCommand{}
-				return nil
-			}
-			m.command.Action = ActionDelete
-		case "y":
-			m.command.Action = ActionYank
-		case "t", "T", "f", "F":
-			m.command.Buffer = msg.String()
-			switch msg.String() {
-			case "t":
-				m.command.Seeking = SeekForwardUntil
-			case "T":
-				m.command.Seeking = SeekBackwardUntil
-			case "f":
-				m.command.Seeking = SeekForwardTo
-			case "F":
-				m.command.Seeking = SeekBackwardTo
-			}
-		case "r":
-			m.command.Action = ActionReplace
-		case "i":
-			if m.command.Action != ActionMove {
-				m.command.Buffer = "i"
-				m.command.Seeking = SeekInner
-				return nil
-			}
-			m.command.Range = Range{
-				Start: Position{Row: m.row, Col: m.col},
-				End:   Position{Row: m.row, Col: m.col},
-			}
-			return tea.Sequentially(executeCmd(*m.command), m.SetMode(ModeInsert))
-		case "I":
-			m.command.Range = Range{
-				Start: Position{Row: m.row, Col: m.col},
-				End:   Position{Row: m.row, Col: 0},
-			}
-			return tea.Sequentially(executeCmd(*m.command), m.SetMode(ModeInsert))
-		case "a":
-			if m.command.Action != ActionMove {
-				m.command.Buffer = "a"
-				m.command.Seeking = SeekAround
-				return nil
-			}
-
-			m.command.Range = Range{
-				Start: Position{Row: m.row, Col: m.col},
-				End:   Position{Row: m.row, Col: m.col + 1},
-			}
-			return tea.Sequentially(executeCmd(*m.command), m.SetMode(ModeInsert))
-		case "A":
-			m.command.Range = Range{
-				Start: Position{Row: m.row, Col: m.col},
-				End:   Position{Row: m.row, Col: len(m.value[m.row]) + 1},
-			}
-			return tea.Sequentially(executeCmd(*m.command), m.SetMode(ModeInsert))
-		case "^":
-			m.command.Range = Range{
-				Start: Position{m.row, m.col},
-				End:   Position{m.row, 0},
-			}
-			return executeCmd(*m.command)
-		case "$":
-			m.command.Range = Range{
-				Start: Position{m.row, m.col},
-				End:   Position{m.row, len(m.value[m.row])},
-			}
-			return executeCmd(*m.command)
-		case "e", "E":
-			end := m.findWordEndRight(max(m.command.Count, 1), msg.String() == "E")
-			if m.command.Action == ActionDelete || m.command.Action == ActionChange {
-				end.Col = min(end.Col+1, len(m.value[end.Row]))
-			}
-			m.command.Range = Range{
-				Start: Position{m.row, m.col},
-				End:   end,
-			}
-			return executeCmd(*m.command)
-		case "w", "W":
-			m.command.Range = Range{
-				Start: Position{m.row, m.col},
-				End:   m.findWordStartRight(max(m.command.Count, 1), msg.String() == "W"),
-			}
-			return executeCmd(*m.command)
-		case "b", "B":
-			m.command.Range = Range{
-				Start: Position{m.row, m.col},
-				End:   m.findWordLeft(max(m.command.Count, 1), msg.String() == "B"),
-			}
-			return executeCmd(*m.command)
-		case "h", "l":
-			direction := 1
-			if msg.String() == "h" {
-				direction = -1
-			}
-			m.command.Range = Range{
-				Start: Position{m.row, m.col},
-				End:   Position{m.row, clamp(m.col+(direction*max(m.command.Count, 1)), 0, len(m.value[m.row]))},
-			}
-			return executeCmd(*m.command)
-		case "j", "k":
-			direction := 1
-			if msg.String() == "k" {
-				direction = -1
-			}
-			row := clamp(m.row+(direction*max(m.command.Count, 1)), 0, len(m.value)-1)
-			li := m.LineInfo()
-			charOffset := max(m.lastCharOffset, li.CharOffset)
-			m.lastCharOffset = charOffset
-
-			rowContent := m.value[row]
-			charWidth := rw.StringWidth(string(rowContent))
-
-			col := 0
-			offset := 0
-
-			for offset < charOffset {
-				if col > len(m.value[row]) || offset >= charWidth-1 {
-					break
-				}
-				offset += rw.RuneWidth(m.value[row][col])
-				col++
-			}
-
-			m.command.Range = Range{
-				Start: Position{m.row, m.col},
-				End:   Position{row, col},
-			}
-			return executeCmd(*m.command)
-		case "C":
-			m.deleteAfterCursor()
-			m.command = &NormalCommand{}
-			return m.SetMode(ModeInsert)
-		case "D":
-			m.deleteAfterCursor()
-			m.command = &NormalCommand{}
-			return nil
-		case "J":
-			m.CursorEnd()
-			m.mergeLineBelow(m.row)
-			m.command = &NormalCommand{}
-			return nil
-		case "p":
-			return Paste
-		}
-	case executeMsg:
-		switch m.command.Action {
-		case ActionDelete:
-			m.deleteRange(m.command.Range)
-		case ActionChange:
-			m.deleteRange(m.command.Range)
-			return m.SetMode(ModeInsert)
-		case ActionMove:
-			row := clamp(m.command.Range.End.Row, 0, len(m.value)-1)
-			m.row = row
-			m.col = clamp(m.command.Range.End.Col, 0, len(m.value[row]))
-		}
-		m.command = &NormalCommand{}
-
-	case pasteMsg:
-		m.handlePaste(string(msg))
-	}
-
-	return nil
-}
-
-func (m *Model) seekingUpdate(msg tea.KeyMsg) tea.Cmd {
-	if len(msg.Runes) <= 0 {
-		m.command = &NormalCommand{}
-	}
-	if msg.Runes[0] == 'w' || msg.Runes[0] == 'W' {
-		m.command.Range = m.findPairRange(msg.Runes[0])
-		return executeCmd(*m.command)
-	}
-	switch m.command.Buffer {
-	case "a":
-		m.command.Range = m.findPairRange(msg.Runes[0])
-		return executeCmd(*m.command)
-	case "i":
-		pr := m.findPairRange(msg.Runes[0])
-
-		pr.Start.Col++
-		pr.End.Col--
-
-		m.command.Range = pr
-		return executeCmd(*m.command)
-	case "f":
-		end := m.findCharRight(msg.Runes[0])
-		m.command.Range = Range{
-			Start: Position{m.row, m.col},
-			End:   end,
-		}
-	case "F":
-		start := m.findCharLeft(msg.Runes[0])
-		m.command.Range = Range{
-			Start: start,
-			End:   Position{m.row, m.col},
-		}
-	case "t":
-		end := m.findCharRight(msg.Runes[0])
-		end.Col--
-		m.command.Range = Range{
-			Start: Position{m.row, m.col},
-			End:   end,
-		}
-	case "T":
-		start := m.findCharLeft(msg.Runes[0])
-		start.Col++
-		m.command.Range = Range{
-			Start: start,
-			End:   Position{m.row, m.col},
-		}
-	}
-	return executeCmd(*m.command)
-}
-
-func (m *Model) findCharLeft(r rune) Position {
-	col := m.col
-
-	for col > 0 {
-		col--
-		if m.value[m.row][col] == r {
-			return Position{m.row, col}
-		}
-	}
-	return Position{m.row, m.col}
-}
-
-func (m *Model) findCharRight(r rune) Position {
-	col := m.col
-
-	for col < len(m.value[m.row]) {
-		if m.value[m.row][col] == r {
-			return Position{m.row, col}
-		}
-		col++
-	}
-	return Position{m.row, m.col}
-}
-
-func (m *Model) findPairRange(r rune) Range {
-	var startRune, endRune rune
-
-	switch r {
-	case 'w', 'W':
-		return Range{
-			Start: m.findWordLeft(0, r == 'W'),
-			End:   m.findWordEndRight(1, true),
-		}
-	case '(', ')':
-		startRune, endRune = '(', ')'
-	case '{', '}':
-		startRune, endRune = '{', '}'
-	case '[', ']':
-		startRune, endRune = '[', ']'
-	case '<', '>':
-		startRune, endRune = '<', '>'
-	case '"', '\'':
-		startRune, endRune = r, r
-	default:
-		m.command = &NormalCommand{}
-		return Range{
-			Start: Position{m.row, m.col},
-			End:   Position{m.row, m.col},
-		}
-	}
-
-	return Range{
-		Start: m.findCharLeft(startRune),
-		End:   m.findCharRight(endRune),
-	}
-}
-
-// findWordLeft locates the start of the word on the left of the current word.
-// It takes whether or not to break words on spaces or any non-alpha-numeric
-// character as an argument.
-func (m *Model) findWordLeft(count int, ignorePunctuation bool) Position {
-	wordBreak := isSoftWordBreak
-	if ignorePunctuation {
-		wordBreak = isWordBreak
-	}
-
-	if count == 0 {
-		if wordBreak(m.value[m.row][m.col-1]) {
-			return Position{m.row, m.col}
-		}
-		count = 1
-	}
-
-	row, col := m.row, m.col
-
-	for count > 0 {
-		if col <= 0 && row > 0 {
-			row--
-			col = len(m.value[row]) - 1
-		}
-
-		// Skip all spaces (and punctuation) to the left of the cursor.
-		for col > 0 && wordBreak(m.value[row][col-1]) {
-			col--
-		}
-
-		// Then skip all non-spaces to the left of the cursor.
-		for col > 0 && !wordBreak(m.value[row][col-1]) {
-			col--
-		}
-
-		count--
-
-		if row <= 0 && col <= 0 {
-			break
-		}
-	}
-
-	return Position{Row: row, Col: col}
-}
-
-// findWordStartRight locates the start of the next word. It takes whether or not to
-// break words on spaces or any non-alpha-numeric character as an argument.
-func (m *Model) findWordStartRight(count int, ignorePunctuation bool) Position {
-	wordBreak := isSoftWordBreak
-	if ignorePunctuation {
-		wordBreak = isWordBreak
-	}
-
-	row, col := m.row, m.col
-
-	for count > 0 {
-		if col >= len(m.value[row])-1 && row < len(m.value)-1 {
-			row++
-			col = 0
-		}
-
-		// Skip until the start of a word is found.
-		for col < len(m.value[row]) && !wordBreak(m.value[row][col]) {
-			col++
-		}
-		// Skip all spaces to the right of the cursor.
-		for col < len(m.value[row])-1 && wordBreak(m.value[row][col]) {
-			col++
-		}
-		count--
-
-		if row >= len(m.value)-1 && col >= len(m.value[row])-1 {
-			break
-		}
-	}
-
-	return Position{Row: row, Col: col}
-}
-
-// findWordEndRight locates the start of the next word. It takes whether or not to
-// break words on spaces or any non-alpha-numeric character as an argument.
-func (m *Model) findWordEndRight(count int, ignorePunctuation bool) Position {
-	wordBreak := isSoftWordBreak
-	if ignorePunctuation {
-		wordBreak = isWordBreak
-	}
-
-	row, col := m.row, m.col
-
-	for count > 0 {
-		if col > len(m.value[row]) && row < len(m.value)-1 {
-			row++
-			col = 0
-		}
-
-		// Skip all spaces to the right of the cursor.
-		for col < len(m.value[row])-1 && wordBreak(m.value[row][col+1]) {
-			col++
-		}
-
-		// Then skip all non-spaces to the right of the cursor.
-		for col < len(m.value[row])-1 && !wordBreak(m.value[row][col+1]) {
-			col++
-		}
-
-		count--
-
-		if row <= 0 && col <= 0 {
-			break
-		}
-	}
-
-	return Position{Row: row, Col: col}
-}
-
-func isWordBreak(char rune) bool {
-	return unicode.IsSpace(char)
-}
-
-func isSoftWordBreak(char rune) bool {
-	return unicode.IsSpace(char) || unicode.IsPunct(char)
-}
-
-func (m *Model) deleteRange(r Range) {
-	if r.Start.Row == r.End.Row && r.Start.Col == r.End.Col {
-		return
-	}
-
-	minCol, maxCol := min(r.Start.Col, r.End.Col), max(r.Start.Col, r.End.Col)
-
-	minCol = clamp(minCol, 0, len(m.value[r.Start.Row]))
-	maxCol = clamp(maxCol, 0, len(m.value[r.Start.Row]))
-
-	if r.Start.Row == r.End.Row {
-		// If the action is delete and from a seek action, we need to delete
-		// the range inclusively.
-		if m.command.IsSeeking() {
-			if m.command.IsSeekingForward() {
-				maxCol = min(maxCol+1, len(m.value[r.Start.Row]))
-			} else if m.command.IsSeekingBackward() {
-				minCol = max(minCol-1, 0)
-			} else if m.command.Seeking == SeekAround || m.command.Seeking == SeekInner {
-				maxCol = min(maxCol+1, len(m.value[r.Start.Row]))
-			}
-		}
-
-		m.value[r.Start.Row] = append(m.value[r.Start.Row][:minCol], m.value[r.Start.Row][maxCol:]...)
-		m.SetCursor(minCol)
-		return
-	}
-
-	minRow, maxRow := min(r.Start.Row, r.End.Row), max(r.Start.Row, r.End.Row)
-
-	if maxRow-minRow == 1 {
-		if r.Start.Row < r.End.Row {
-			m.value[r.Start.Row] = append([]rune{}, m.value[r.Start.Row][:r.Start.Col]...)
-			m.value[r.End.Row] = append([]rune{}, m.value[r.End.Row][r.End.Col:]...)
-			m.mergeLineBelow(minRow)
-		} else {
-			m.value[r.Start.Row] = append([]rune{}, m.value[r.Start.Row][r.Start.Col:]...)
-			m.value[r.End.Row] = append([]rune{}, m.value[r.End.Row][:r.End.Col]...)
-			m.mergeLineAbove(maxRow)
-		}
-		return
-	}
-
-	for i := max(minRow, 0); i <= min(maxRow, len(m.value)-1); i++ {
-		m.value[i] = []rune{}
-	}
-
-	m.value = append(m.value[:minRow], m.value[maxRow:]...)
-
-	m.row = clamp(0, minRow, len(m.value))
-}

textarea/textarea.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/atotto/clipboard"
 	"github.com/charmbracelet/bubbles/cursor"
+	"github.com/charmbracelet/bubbles/key"
 	"github.com/charmbracelet/bubbles/viewport"
 	tea "github.com/charmbracelet/bubbletea"
 	"github.com/charmbracelet/lipgloss"
@@ -27,6 +28,63 @@ const (
 type pasteMsg string
 type pasteErrMsg struct{ error }
 
+// KeyMap is the key bindings for different actions within the textarea.
+type KeyMap struct {
+	CharacterBackward       key.Binding
+	CharacterForward        key.Binding
+	DeleteAfterCursor       key.Binding
+	DeleteBeforeCursor      key.Binding
+	DeleteCharacterBackward key.Binding
+	DeleteCharacterForward  key.Binding
+	DeleteWordBackward      key.Binding
+	DeleteWordForward       key.Binding
+	InsertNewline           key.Binding
+	LineEnd                 key.Binding
+	LineNext                key.Binding
+	LinePrevious            key.Binding
+	LineStart               key.Binding
+	Paste                   key.Binding
+	WordBackward            key.Binding
+	WordForward             key.Binding
+	InputBegin              key.Binding
+	InputEnd                key.Binding
+
+	UppercaseWordForward  key.Binding
+	LowercaseWordForward  key.Binding
+	CapitalizeWordForward key.Binding
+
+	TransposeCharacterBackward key.Binding
+}
+
+// DefaultKeyMap is the default set of key bindings for navigating and acting
+// upon the textarea.
+var DefaultKeyMap = KeyMap{
+	CharacterForward:        key.NewBinding(key.WithKeys("right", "ctrl+f")),
+	CharacterBackward:       key.NewBinding(key.WithKeys("left", "ctrl+b")),
+	WordForward:             key.NewBinding(key.WithKeys("alt+right", "alt+f")),
+	WordBackward:            key.NewBinding(key.WithKeys("alt+left", "alt+b")),
+	LineNext:                key.NewBinding(key.WithKeys("down", "ctrl+n")),
+	LinePrevious:            key.NewBinding(key.WithKeys("up", "ctrl+p")),
+	DeleteWordBackward:      key.NewBinding(key.WithKeys("alt+backspace", "ctrl+w")),
+	DeleteWordForward:       key.NewBinding(key.WithKeys("alt+delete", "alt+d")),
+	DeleteAfterCursor:       key.NewBinding(key.WithKeys("ctrl+k")),
+	DeleteBeforeCursor:      key.NewBinding(key.WithKeys("ctrl+u")),
+	InsertNewline:           key.NewBinding(key.WithKeys("enter", "ctrl+m")),
+	DeleteCharacterBackward: key.NewBinding(key.WithKeys("backspace", "ctrl+h")),
+	DeleteCharacterForward:  key.NewBinding(key.WithKeys("delete", "ctrl+d")),
+	LineStart:               key.NewBinding(key.WithKeys("home", "ctrl+a")),
+	LineEnd:                 key.NewBinding(key.WithKeys("end", "ctrl+e")),
+	Paste:                   key.NewBinding(key.WithKeys("ctrl+v")),
+	InputBegin:              key.NewBinding(key.WithKeys("alt+<", "ctrl+home")),
+	InputEnd:                key.NewBinding(key.WithKeys("alt+>", "ctrl+end")),
+
+	CapitalizeWordForward: key.NewBinding(key.WithKeys("alt+c")),
+	LowercaseWordForward:  key.NewBinding(key.WithKeys("alt+l")),
+	UppercaseWordForward:  key.NewBinding(key.WithKeys("alt+u")),
+
+	TransposeCharacterBackward: key.NewBinding(key.WithKeys("ctrl+t")),
+}
+
 // LineInfo is a helper for keeping track of line information regarding
 // soft-wrapped lines.
 type LineInfo struct {
@@ -75,11 +133,29 @@ type Model struct {
 	Err error
 
 	// General settings.
-	Prompt               string
+
-	Placeholder          string
+	// Prompt is printed at the beginning of each line.
-	ShowLineNumbers      bool
+	//
+	// When changing the value of Prompt after the model has been
+	// initialized, ensure that SetWidth() gets called afterwards.
+	//
+	// See also SetPromptFunc().
+	Prompt string
+
+	// Placeholder is the text displayed when the user
+	// hasn't entered anything yet.
+	Placeholder string
+
+	// ShowLineNumbers, if enabled, causes line numbers to be printed
+	// after the prompt.
+	ShowLineNumbers bool
+
+	// EndOfBufferCharacter is displayed at the end of the input.
 	EndOfBufferCharacter rune
 
+	// KeyMap encodes the keybindings recognized by the widget.
+	KeyMap KeyMap
+
 	// Styling. FocusedStyle and BlurredStyle are used to style the textarea in
 	// focused and blurred states.
 	FocusedStyle Style
@@ -97,6 +173,13 @@ type Model struct {
 	// accept. If 0 or less, there's no limit.
 	CharLimit int
 
+	// If promptFunc is set, it replaces Prompt as a generator for
+	// prompt strings at the beginning of each line.
+	promptFunc func(line int) string
+
+	// promptWidth is the width of the prompt.
+	promptWidth int
+
 	// width is the maximum number of characters that can be displayed at once.
 	// If 0 or less this setting is ignored.
 	width int
@@ -119,12 +202,6 @@ type Model struct {
 	// Cursor row.
 	row int
 
-	// mode is the current mode of the textarea.
-	mode Mode
-
-	// command is the normal command of the textarea.
-	command *NormalCommand
-
 	// Last character offset, used to maintain state when the cursor is moved
 	// vertically such that we can maintain the same navigating position.
 	lastCharOffset int
@@ -154,14 +231,13 @@ func New() Model {
 		EndOfBufferCharacter: '~',
 		ShowLineNumbers:      true,
 		Cursor:               cur,
+		KeyMap:               DefaultKeyMap,
 
 		value:            make([][]rune, minHeight, maxHeight),
-		mode:             ModeInsert,
 		focus:            false,
 		col:              0,
 		row:              0,
 		lineNumberFormat: "%2v ",
-		command:          &NormalCommand{},
 
 		viewport: &vp,
 	}
@@ -263,11 +339,6 @@ func (m Model) Line() int {
 	return m.row
 }
 
-// NormalCommand returns the normal command.
-func (m *Model) NormalCommand() *NormalCommand {
-	return m.command
-}
-
 // CursorDown moves the cursor down by one line.
 // Returns whether or not the cursor blink should be reset.
 func (m *Model) CursorDown() {
@@ -442,6 +513,24 @@ func (m *Model) deleteAfterCursor() {
 	m.SetCursor(len(m.value[m.row]))
 }
 
+// transposeLeft exchanges the runes at the cursor and immediately
+// before. No-op if the cursor is at the beginning of the line.  If
+// the cursor is not at the end of the line yet, moves the cursor to
+// the right.
+func (m *Model) transposeLeft() {
+	if m.col == 0 || len(m.value[m.row]) < 2 {
+		return
+	}
+	if m.col >= len(m.value[m.row]) {
+		m.SetCursor(m.col - 1)
+	}
+	m.value[m.row][m.col-1], m.value[m.row][m.col] =
+		m.value[m.row][m.col], m.value[m.row][m.col-1]
+	if m.col < len(m.value[m.row]) {
+		m.SetCursor(m.col + 1)
+	}
+}
+
 // deleteWordLeft deletes the word left to the cursor. Returns whether or not
 // the cursor blink should be reset.
 func (m *Model) deleteWordLeft() {
@@ -516,31 +605,50 @@ func (m *Model) deleteWordRight() {
 	m.SetCursor(oldCol)
 }
 
+// characterRight moves the cursor one character to the right.
+func (m *Model) characterRight() {
+	if m.col < len(m.value[m.row]) {
+		m.SetCursor(m.col + 1)
+	} else {
+		if m.row < len(m.value)-1 {
+			m.row++
+			m.CursorStart()
+		}
+	}
+}
+
+// characterLeft moves the cursor one character to the left.
+// If insideLine is set, the cursor is moved to the last
+// character in the previous line, instead of one past that.
+func (m *Model) characterLeft(insideLine bool) {
+	if m.col == 0 && m.row != 0 {
+		m.row--
+		m.CursorEnd()
+		if !insideLine {
+			return
+		}
+	}
+	if m.col > 0 {
+		m.SetCursor(m.col - 1)
+	}
+}
+
 // wordLeft moves the cursor one word to the left. Returns whether or not the
 // cursor blink should be reset. If input is masked, move input to the start
 // so as not to reveal word breaks in the masked input.
 func (m *Model) wordLeft() {
-	if m.col == 0 || len(m.value[m.row]) == 0 {
+	for {
-		return
+		m.characterLeft(true /* insideLine */)
-	}
+		if m.col < len(m.value[m.row]) && !unicode.IsSpace(m.value[m.row][m.col]) {
-
-	i := m.col - 1
-	for i >= 0 {
-		if unicode.IsSpace(m.value[m.row][min(i, len(m.value[m.row])-1)]) {
-			m.SetCursor(m.col - 1)
-			i--
-		} else {
 			break
 		}
 	}
 
-	for i >= 0 {
+	for m.col > 0 {
-		if !unicode.IsSpace(m.value[m.row][min(i, len(m.value[m.row])-1)]) {
+		if unicode.IsSpace(m.value[m.row][m.col-1]) {
-			m.SetCursor(m.col - 1)
-			i--
-		} else {
 			break
 		}
+		m.SetCursor(m.col - 1)
 	}
 }
 
@@ -548,28 +656,54 @@ func (m *Model) wordLeft() {
 // cursor blink should be reset. If the input is masked, move input to the end
 // so as not to reveal word breaks in the masked input.
 func (m *Model) wordRight() {
-	if m.col >= len(m.value[m.row]) || len(m.value[m.row]) == 0 {
+	m.doWordRight(func(int, int) { /* nothing */ })
-		return
+}
-	}
 
-	i := m.col
+func (m *Model) doWordRight(fn func(charIdx int, pos int)) {
-	for i < len(m.value[m.row]) {
+	// Skip spaces forward.
-		if unicode.IsSpace(m.value[m.row][i]) {
+	for {
-			m.SetCursor(m.col + 1)
+		if m.col < len(m.value[m.row]) && !unicode.IsSpace(m.value[m.row][m.col]) {
-			i++
-		} else {
 			break
 		}
-	}
+		if m.row == len(m.value)-1 && m.col == len(m.value[m.row]) {
-
+			// End of text.
-	for i < len(m.value[m.row]) {
-		if !unicode.IsSpace(m.value[m.row][i]) {
-			m.SetCursor(m.col + 1)
-			i++
-		} else {
 			break
 		}
+		m.characterRight()
 	}
+
+	charIdx := 0
+	for m.col < len(m.value[m.row]) {
+		if unicode.IsSpace(m.value[m.row][m.col]) {
+			break
+		}
+		fn(charIdx, m.col)
+		m.SetCursor(m.col + 1)
+		charIdx++
+	}
+}
+
+// uppercaseRight changes the word to the right to uppercase.
+func (m *Model) uppercaseRight() {
+	m.doWordRight(func(_ int, i int) {
+		m.value[m.row][i] = unicode.ToUpper(m.value[m.row][i])
+	})
+}
+
+// lowercaseRight changes the word to the right to lowercase.
+func (m *Model) lowercaseRight() {
+	m.doWordRight(func(_ int, i int) {
+		m.value[m.row][i] = unicode.ToLower(m.value[m.row][i])
+	})
+}
+
+// capitalizeRight changes the word to the right to title case.
+func (m *Model) capitalizeRight() {
+	m.doWordRight(func(charIdx int, i int) {
+		if charIdx == 0 {
+			m.value[m.row][i] = unicode.ToTitle(m.value[m.row][i])
+		}
+	})
 }
 
 // LineInfo returns the number of characters from the start of the
@@ -631,6 +765,18 @@ func (m Model) Width() int {
 	return m.width
 }
 
+// moveToBegin moves the cursor to the beginning of the input.
+func (m *Model) moveToBegin() {
+	m.row = 0
+	m.SetCursor(0)
+}
+
+// moveToEnd moves the cursor to the end of the input.
+func (m *Model) moveToEnd() {
+	m.row = len(m.value) - 1
+	m.SetCursor(len(m.value[m.row]))
+}
+
 // SetWidth sets the width of the textarea to fit exactly within the given width.
 // This means that the textarea will account for the width of the prompt and
 // whether or not line numbers are being shown.
@@ -651,10 +797,26 @@ func (m *Model) SetWidth(w int) {
 	// Account for base style borders and padding.
 	inputWidth -= m.style.Base.GetHorizontalFrameSize()
 
-	inputWidth -= rw.StringWidth(m.Prompt)
+	if m.promptFunc == nil {
+		m.promptWidth = rw.StringWidth(m.Prompt)
+	}
+
+	inputWidth -= m.promptWidth
 	m.width = clamp(inputWidth, minWidth, maxWidth)
 }
 
+// SetPromptFunc supersedes the Prompt field and sets a dynamic prompt
+// instead.
+// If the function returns a prompt that is shorter than the
+// specified promptWidth, it will be padded to the left.
+// If it returns a prompt that is longer, display artifacts
+// may occur; the caller is responsible for computing an adequate
+// promptWidth.
+func (m *Model) SetPromptFunc(promptWidth int, fn func(lineIdx int) string) {
+	m.promptFunc = fn
+	m.promptWidth = promptWidth
+}
+
 // Height returns the current height of the textarea.
 func (m Model) Height() int {
 	return m.height
@@ -682,21 +844,108 @@ func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
 		m.value[m.row] = make([]rune, 0)
 	}
 
-	var cmd tea.Cmd
+	switch msg := msg.(type) {
+	case tea.KeyMsg:
+		switch {
+		case key.Matches(msg, m.KeyMap.DeleteAfterCursor):
+			m.col = clamp(m.col, 0, len(m.value[m.row]))
+			if m.col >= len(m.value[m.row]) {
+				m.mergeLineBelow(m.row)
+				break
+			}
+			m.deleteAfterCursor()
+		case key.Matches(msg, m.KeyMap.DeleteBeforeCursor):
+			m.col = clamp(m.col, 0, len(m.value[m.row]))
+			if m.col <= 0 {
+				m.mergeLineAbove(m.row)
+				break
+			}
+			m.deleteBeforeCursor()
+		case key.Matches(msg, m.KeyMap.DeleteCharacterBackward):
+			m.col = clamp(m.col, 0, len(m.value[m.row]))
+			if m.col <= 0 {
+				m.mergeLineAbove(m.row)
+				break
+			}
+			if len(m.value[m.row]) > 0 {
+				m.value[m.row] = append(m.value[m.row][:max(0, m.col-1)], m.value[m.row][m.col:]...)
+				if m.col > 0 {
+					m.SetCursor(m.col - 1)
+				}
+			}
+		case key.Matches(msg, m.KeyMap.DeleteCharacterForward):
+			if len(m.value[m.row]) > 0 && m.col < len(m.value[m.row]) {
+				m.value[m.row] = append(m.value[m.row][:m.col], m.value[m.row][m.col+1:]...)
+			}
+			if m.col >= len(m.value[m.row]) {
+				m.mergeLineBelow(m.row)
+				break
+			}
+		case key.Matches(msg, m.KeyMap.DeleteWordBackward):
+			if m.col <= 0 {
+				m.mergeLineAbove(m.row)
+				break
+			}
+			m.deleteWordLeft()
+		case key.Matches(msg, m.KeyMap.DeleteWordForward):
+			m.col = clamp(m.col, 0, len(m.value[m.row]))
+			if m.col >= len(m.value[m.row]) {
+				m.mergeLineBelow(m.row)
+				break
+			}
+			m.deleteWordRight()
+		case key.Matches(msg, m.KeyMap.InsertNewline):
+			if len(m.value) >= maxHeight {
+				return m, nil
+			}
+			m.col = clamp(m.col, 0, len(m.value[m.row]))
+			m.splitLine(m.row, m.col)
+		case key.Matches(msg, m.KeyMap.LineEnd):
+			m.CursorEnd()
+		case key.Matches(msg, m.KeyMap.LineStart):
+			m.CursorStart()
+		case key.Matches(msg, m.KeyMap.CharacterForward):
+			m.characterRight()
+		case key.Matches(msg, m.KeyMap.LineNext):
+			m.CursorDown()
+		case key.Matches(msg, m.KeyMap.WordForward):
+			m.wordRight()
+		case key.Matches(msg, m.KeyMap.Paste):
+			return m, Paste
+		case key.Matches(msg, m.KeyMap.CharacterBackward):
+			m.characterLeft(false /* insideLine */)
+		case key.Matches(msg, m.KeyMap.LinePrevious):
+			m.CursorUp()
+		case key.Matches(msg, m.KeyMap.WordBackward):
+			m.wordLeft()
+		case key.Matches(msg, m.KeyMap.InputBegin):
+			m.moveToBegin()
+		case key.Matches(msg, m.KeyMap.InputEnd):
+			m.moveToEnd()
+		case key.Matches(msg, m.KeyMap.LowercaseWordForward):
+			m.lowercaseRight()
+		case key.Matches(msg, m.KeyMap.UppercaseWordForward):
+			m.uppercaseRight()
+		case key.Matches(msg, m.KeyMap.CapitalizeWordForward):
+			m.capitalizeRight()
+		case key.Matches(msg, m.KeyMap.TransposeCharacterBackward):
+			m.transposeLeft()
 
-	switch m.mode {
+		default:
-	case ModeInsert:
+			if m.CharLimit > 0 && rw.StringWidth(m.Value()) >= m.CharLimit {
-		cmd = m.insertUpdate(msg)
+				break
-		cmds = append(cmds, cmd)
+			}
-		// Sometimes, we need to enter insert mode after executing a command.
+
-		switch msg.(type) {
+			m.col = min(m.col, len(m.value[m.row]))
-		case executeMsg:
+			m.value[m.row] = append(m.value[m.row][:m.col], append(msg.Runes, m.value[m.row][m.col:]...)...)
-			cmd = m.normalUpdate(msg)
+			m.SetCursor(m.col + len(msg.Runes))
-			cmds = append(cmds, cmd)
 		}
-	case ModeNormal:
+
-		cmd = m.normalUpdate(msg)
+	case pasteMsg:
-		cmds = append(cmds, cmd)
+		m.handlePaste(string(msg))
+
+	case pasteErrMsg:
+		m.Err = msg
 	}
 
 	vp, cmd := m.viewport.Update(msg)
@@ -705,7 +954,7 @@ func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
 
 	newRow, newCol := m.cursorLineNumber(), m.col
 	m.Cursor, cmd = m.Cursor.Update(msg)
-	if m.mode == ModeInsert && (newRow != oldRow || newCol != oldCol) {
+	if newRow != oldRow || newCol != oldCol {
 		m.Cursor.Blink = false
 		cmd = m.Cursor.BlinkCmd()
 	}
@@ -729,6 +978,7 @@ func (m Model) View() string {
 
 	var newLines int
 
+	displayLine := 0
 	for l, line := range m.value {
 		wrappedLines := wrap(line, m.width)
 
@@ -739,7 +989,10 @@ func (m Model) View() string {
 		}
 
 		for wl, wrappedLine := range wrappedLines {
-			s.WriteString(style.Render(m.style.Prompt.Render(m.Prompt)))
+			prompt := m.getPromptString(displayLine)
+			prompt = m.style.Prompt.Render(prompt)
+			s.WriteString(style.Render(prompt))
+			displayLine++
 
 			if m.ShowLineNumbers {
 				if wl == 0 {
@@ -788,7 +1041,10 @@ func (m Model) View() string {
 	// Always show at least `m.Height` lines at all times.
 	// To do this we can simply pad out a few extra new lines in the view.
 	for i := 0; i < m.height; i++ {
-		s.WriteString(m.style.Prompt.Render(m.Prompt))
+		prompt := m.getPromptString(displayLine)
+		prompt = m.style.Prompt.Render(prompt)
+		s.WriteString(prompt)
+		displayLine++
 
 		if m.ShowLineNumbers {
 			lineNumber := m.style.EndOfBuffer.Render((fmt.Sprintf(m.lineNumberFormat, string(m.EndOfBufferCharacter))))
@@ -801,6 +1057,19 @@ func (m Model) View() string {
 	return m.style.Base.Render(m.viewport.View())
 }
 
+func (m Model) getPromptString(displayLine int) (prompt string) {
+	prompt = m.Prompt
+	if m.promptFunc == nil {
+		return prompt
+	}
+	prompt = m.promptFunc(displayLine)
+	pl := rw.StringWidth(prompt)
+	if pl < m.promptWidth {
+		prompt = fmt.Sprintf("%*s%s", m.promptWidth-pl, "", prompt)
+	}
+	return prompt
+}
+
 // placeholderView returns the prompt and placeholder view, if any.
 func (m Model) placeholderView() string {
 	var (
@@ -809,7 +1078,8 @@ func (m Model) placeholderView() string {
 		style = m.style.Placeholder.Inline(true)
 	)
 
-	prompt := m.style.Prompt.Render(m.Prompt)
+	prompt := m.getPromptString(0)
+	prompt = m.style.Prompt.Render(prompt)
 	s.WriteString(m.style.CursorLine.Render(prompt))
 
 	if m.ShowLineNumbers {
@@ -826,6 +1096,8 @@ func (m Model) placeholderView() string {
 	// The rest of the new lines
 	for i := 1; i < m.height; i++ {
 		s.WriteRune('\n')
+		prompt := m.getPromptString(i)
+		prompt = m.style.Prompt.Render(prompt)
 		s.WriteString(prompt)
 
 		if m.ShowLineNumbers {

viewport/viewport.go

@@ -350,18 +350,23 @@ func (m Model) View() string {
 		return strings.Repeat("\n", max(0, m.Height-1))
 	}
 
-	lines := m.visibleLines()
+	w, h := m.Width, m.Height
-
+	if sw := m.Style.GetWidth(); sw != 0 {
-	// Fill empty space with newlines
+		w = min(w, sw)
-	extraLines := ""
-	if len(lines) < m.Height {
-		extraLines = strings.Repeat("\n", max(0, m.Height-len(lines)))
 	}
-
+	if sh := m.Style.GetHeight(); sh != 0 {
+		h = min(h, sh)
+	}
+	contentWidth := w - m.Style.GetHorizontalFrameSize()
+	contentHeight := h - m.Style.GetVerticalFrameSize()
+	contents := lipgloss.NewStyle().
+		Height(contentHeight).    // pad to height.
+		MaxHeight(contentHeight). // truncate height if taller.
+		MaxWidth(contentWidth).   // truncate width.
+		Render(strings.Join(m.visibleLines(), "\n"))
 	return m.Style.Copy().
-		UnsetWidth().
+		UnsetWidth().UnsetHeight(). // Style size already applied in contents.
-		UnsetHeight().
+		Render(contents)
-		Render(strings.Join(lines, "\n") + extraLines)
 }
 
 func clamp(v, low, high int) int {