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.

README.md

@@ -56,7 +56,11 @@ options.
 
 ## Progress
 
-<img src="https://stuff.charm.sh/bubbles-examples/progress.gif" width="800" alt="Progressbar Example">
+<picture>
+  <source media="(max-width: 800px)" srcset="https://stuff.charm.sh/bubbles-examples/progress.gif">
+  <source media="(min-width: 800px)" width="800" srcset="https://stuff.charm.sh/bubbles-examples/progress.gif">
+  <img src="https://stuff.charm.sh/bubbles-examples/progress.gif" alt="Progressbar Example">
+</picture>
 
 A simple, customizable progress meter, with optional animation via
 [Harmonica][harmonica]. Supports solid and gradient fills. The empty and filled
@@ -83,7 +87,11 @@ logic and visualize pagination however you like.
 
 ## Viewport
 
-<img src="https://stuff.charm.sh/bubbles-examples/viewport.gif?0" width="600" alt="Viewport Example">
+<picture>
+  <source media="(max-width: 600px)" srcset="https://stuff.charm.sh/bubbles-examples/viewport.gif?0">
+  <source media="(min-width: 600px)" width="600" srcset="https://stuff.charm.sh/bubbles-examples/viewport.gif?0">
+  <img src="https://stuff.charm.sh/bubbles-examples/viewport.gif?0" alt="Viewport Example">
+</picture>
 
 A viewport for vertically scrolling content. Optionally includes standard
 pager keybindings and mouse wheel support. A high performance mode is available
@@ -99,7 +107,11 @@ indenting and text wrapping.
 
 ## List
 
-<img src="https://stuff.charm.sh/bubbles-examples/list.gif" width="600" alt="List Example">
+<picture>
+  <source media="(max-width: 600px)" srcset="https://stuff.charm.sh/bubbles-examples/list.gif">
+  <source media="(min-width: 600px)" width="600" srcset="https://stuff.charm.sh/bubbles-examples/list.gif">
+  <img src="https://stuff.charm.sh/bubbles-examples/list.gif" alt="List Example">
+</picture>
 
 A customizable, batteries-included component for browsing a set of items.
 Features pagination, fuzzy filtering, auto-generated help, an activity spinner,
@@ -133,7 +145,11 @@ can be customized as you see fit.
 
 ## Help
 
-<img src="https://stuff.charm.sh/bubbles-examples/help.gif" width="500" alt="Help Example">
+<picture>
+  <source media="(max-width: 500px)" srcset="https://stuff.charm.sh/bubbles-examples/help.gif">
+  <source media="(min-width: 500px)" width="500" srcset="https://stuff.charm.sh/bubbles-examples/help.gif">
+  <img src="https://stuff.charm.sh/bubbles-examples/help.gif" alt="Help Example">
+</picture>
 
 A customizable horizontal mini help view that automatically generates itself
 from your keybindings. It features single and multi-line modes, which the user

key/key.go

@@ -106,7 +106,7 @@ func (b Binding) Help() Help {
 // keybindings won't be activated and won't show up in help. Keybindings are
 // enabled by default.
 func (b Binding) Enabled() bool {
-	return !b.disabled
+	return !b.disabled && b.keys != nil
 }
 
 // SetEnabled enables or disables the keybinding.
@@ -130,9 +130,10 @@ type Help struct {
 
 // Matches checks if the given KeyMsg matches the given bindings.
 func Matches(k tea.KeyMsg, b ...Binding) bool {
+	keys := k.String()
 	for _, binding := range b {
 		for _, v := range binding.keys {
-			if k.String() == v && binding.Enabled() {
+			if keys == v && binding.Enabled() {
 				return true
 			}
 		}

key/key_test.go

@@ -0,0 +1,26 @@
+package key
+
+import (
+	"testing"
+)
+
+func TestBinding_Enabled(t *testing.T) {
+	binding := NewBinding(
+		WithKeys("k", "up"),
+		WithHelp("↑/k", "move up"),
+	)
+	if !binding.Enabled() {
+		t.Errorf("expected key to be Enabled")
+	}
+
+	binding.SetEnabled(false)
+	if binding.Enabled() {
+		t.Errorf("expected key not to be Enabled")
+	}
+
+	binding.SetEnabled(true)
+	binding.Unbind()
+	if binding.Enabled() {
+		t.Errorf("expected key not to be Enabled")
+	}
+}

list/list.go

@@ -534,6 +534,15 @@ func (m Model) SettingFilter() bool {
 	return m.filterState == Filtering
 }
 
+// IsFiltered returns whether or not the list is currently filtered.
+// It's purely a convenience method for the following:
+//
+//	 m.FilterState() == FilterApplied
+//
+func (m Model) IsFiltered() bool {
+	return m.filterState == FilterApplied
+}
+
 // Width returns the current width setting.
 func (m Model) Width() int {
 	return m.width

table/table.go

@@ -0,0 +1,393 @@
+package table
+
+import (
+	"strings"
+
+	"github.com/charmbracelet/bubbles/key"
+	"github.com/charmbracelet/bubbles/viewport"
+	tea "github.com/charmbracelet/bubbletea"
+	"github.com/charmbracelet/lipgloss"
+	"github.com/mattn/go-runewidth"
+)
+
+// Model defines a state for the table widget.
+type Model struct {
+	KeyMap KeyMap
+
+	cols   []Column
+	rows   []Row
+	cursor int
+	focus  bool
+	styles Styles
+
+	viewport viewport.Model
+}
+
+// Row represents one line in the table.
+type Row []string
+
+// Column defines the table structure.
+type Column struct {
+	Title string
+	Width int
+}
+
+// KeyMap defines keybindings. It satisfies to the help.KeyMap interface, which
+// is used to render the menu menu.
+type KeyMap struct {
+	LineUp       key.Binding
+	LineDown     key.Binding
+	PageUp       key.Binding
+	PageDown     key.Binding
+	HalfPageUp   key.Binding
+	HalfPageDown key.Binding
+	GotoTop      key.Binding
+	GotoBottom   key.Binding
+}
+
+// DefaultKeyMap returns a default set of keybindings.
+func DefaultKeyMap() KeyMap {
+	const spacebar = " "
+	return KeyMap{
+		LineUp: key.NewBinding(
+			key.WithKeys("up", "k"),
+			key.WithHelp("↑/k", "up"),
+		),
+		LineDown: key.NewBinding(
+			key.WithKeys("down", "j"),
+			key.WithHelp("↓/j", "down"),
+		),
+		PageUp: key.NewBinding(
+			key.WithKeys("b", "pgup"),
+			key.WithHelp("b/pgup", "page up"),
+		),
+		PageDown: key.NewBinding(
+			key.WithKeys("f", "pgdown", spacebar),
+			key.WithHelp("f/pgdn", "page down"),
+		),
+		HalfPageUp: key.NewBinding(
+			key.WithKeys("u", "ctrl+u"),
+			key.WithHelp("u", "½ page up"),
+		),
+		HalfPageDown: key.NewBinding(
+			key.WithKeys("d", "ctrl+d"),
+			key.WithHelp("d", "½ page down"),
+		),
+		GotoTop: key.NewBinding(
+			key.WithKeys("home", "g"),
+			key.WithHelp("g/home", "go to start"),
+		),
+		GotoBottom: key.NewBinding(
+			key.WithKeys("end", "G"),
+			key.WithHelp("G/end", "go to end"),
+		),
+	}
+}
+
+// Styles contains style definitions for this list component. By default, these
+// values are generated by DefaultStyles.
+type Styles struct {
+	Header   lipgloss.Style
+	Cell     lipgloss.Style
+	Selected lipgloss.Style
+}
+
+// DefaultStyles returns a set of default style definitions for this table.
+func DefaultStyles() Styles {
+	return Styles{
+		Selected: lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("212")),
+		Header:   lipgloss.NewStyle().Bold(true).Padding(0, 1),
+		Cell:     lipgloss.NewStyle().Padding(0, 1),
+	}
+}
+
+// SetStyles sets the table styles.
+func (m *Model) SetStyles(s Styles) {
+	m.styles = s
+	m.UpdateViewport()
+}
+
+// Option is used to set options in New. For example:
+//
+//    table := New(WithColumns([]Column{{Title: "ID", Width: 10}}))
+//
+type Option func(*Model)
+
+// New creates a new model for the table widget.
+func New(opts ...Option) Model {
+	m := Model{
+		cursor:   0,
+		viewport: viewport.New(0, 20),
+
+		KeyMap: DefaultKeyMap(),
+		styles: DefaultStyles(),
+	}
+
+	for _, opt := range opts {
+		opt(&m)
+	}
+
+	m.UpdateViewport()
+
+	return m
+}
+
+// WithColumns sets the table columns (headers).
+func WithColumns(cols []Column) Option {
+	return func(m *Model) {
+		m.cols = cols
+	}
+}
+
+// WithRows sets the table rows (data).
+func WithRows(rows []Row) Option {
+	return func(m *Model) {
+		m.rows = rows
+	}
+}
+
+// WithHeight sets the height of the table.
+func WithHeight(h int) Option {
+	return func(m *Model) {
+		m.viewport.Height = h
+	}
+}
+
+// WithWidth sets the width of the table.
+func WithWidth(w int) Option {
+	return func(m *Model) {
+		m.viewport.Width = w
+	}
+}
+
+// WithFocused sets the focus state of the table.
+func WithFocused(f bool) Option {
+	return func(m *Model) {
+		m.focus = f
+	}
+}
+
+// WithStyles sets the table styles.
+func WithStyles(s Styles) Option {
+	return func(m *Model) {
+		m.styles = s
+	}
+}
+
+// WithKeyMap sets the key map.
+func WithKeyMap(km KeyMap) Option {
+	return func(m *Model) {
+		m.KeyMap = km
+	}
+}
+
+// Update is the Bubble Tea update loop.
+func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
+	if !m.focus {
+		return m, nil
+	}
+
+	var cmds []tea.Cmd
+
+	switch msg := msg.(type) {
+	case tea.KeyMsg:
+		switch {
+		case key.Matches(msg, m.KeyMap.LineUp):
+			m.MoveUp(1)
+		case key.Matches(msg, m.KeyMap.LineDown):
+			m.MoveDown(1)
+		case key.Matches(msg, m.KeyMap.PageUp):
+			m.MoveUp(m.viewport.Height)
+		case key.Matches(msg, m.KeyMap.PageDown):
+			m.MoveDown(m.viewport.Height)
+		case key.Matches(msg, m.KeyMap.HalfPageUp):
+			m.MoveUp(m.viewport.Height / 2)
+		case key.Matches(msg, m.KeyMap.HalfPageDown):
+			m.MoveDown(m.viewport.Height / 2)
+		case key.Matches(msg, m.KeyMap.LineDown):
+			m.MoveDown(1)
+		case key.Matches(msg, m.KeyMap.GotoTop):
+			m.GotoTop()
+		case key.Matches(msg, m.KeyMap.GotoBottom):
+			m.GotoBottom()
+		}
+	}
+
+	return m, tea.Batch(cmds...)
+}
+
+// Focused returns the focus state of the table.
+func (m Model) Focused() bool {
+	return m.focus
+}
+
+// Focus focusses the table, allowing the user to move around the rows and
+// interact.
+func (m *Model) Focus() {
+	m.focus = true
+	m.UpdateViewport()
+}
+
+// Blur blurs the table, preventing selection or movement.
+func (m *Model) Blur() {
+	m.focus = false
+	m.UpdateViewport()
+}
+
+// View renders the component.
+func (m Model) View() string {
+	return m.headersView() + "\n" + m.viewport.View()
+}
+
+// UpdateViewport updates the list content based on the previously defined
+// columns and rows.
+func (m *Model) UpdateViewport() {
+	renderedRows := make([]string, 0, len(m.rows))
+	for i := range m.rows {
+		renderedRows = append(renderedRows, m.renderRow(i))
+	}
+
+	m.viewport.SetContent(
+		lipgloss.JoinVertical(lipgloss.Left, renderedRows...),
+	)
+}
+
+// SelectedRow returns the selected row.
+// You can cast it to your own implementation.
+func (m Model) SelectedRow() Row {
+	return m.rows[m.cursor]
+}
+
+// SetRows set a new rows state.
+func (m *Model) SetRows(r []Row) {
+	m.rows = r
+	m.UpdateViewport()
+}
+
+// SetWidth sets the width of the viewport of the table.
+func (m *Model) SetWidth(w int) {
+	m.viewport.Width = w
+	m.UpdateViewport()
+}
+
+// SetHeight sets the height of the viewport of the table.
+func (m *Model) SetHeight(h int) {
+	m.viewport.Height = h
+	m.UpdateViewport()
+}
+
+// Height returns the viewport height of the table.
+func (m Model) Height() int {
+	return m.viewport.Height
+}
+
+// Width returns the viewport width of the table.
+func (m Model) Width() int {
+	return m.viewport.Width
+}
+
+// Cursor returns the index of the selected row.
+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) {
+	m.cursor = clamp(m.cursor-n, 0, len(m.rows)-1)
+	m.UpdateViewport()
+
+	if m.cursor < m.viewport.YOffset {
+		m.viewport.SetYOffset(m.cursor)
+	}
+}
+
+// MoveDown moves the selection down by any number of row.
+// It can not go below the last row.
+func (m *Model) MoveDown(n int) {
+	m.cursor = clamp(m.cursor+n, 0, len(m.rows)-1)
+	m.UpdateViewport()
+
+	if m.cursor > (m.viewport.YOffset + (m.viewport.Height - 1)) {
+		m.viewport.SetYOffset(m.cursor - (m.viewport.Height - 1))
+	}
+}
+
+// GotoTop moves the selection to the first row.
+func (m *Model) GotoTop() {
+	m.MoveUp(m.cursor)
+}
+
+// GotoBottom moves the selection to the last row.
+func (m *Model) GotoBottom() {
+	m.MoveDown(len(m.rows))
+}
+
+// FromValues create the table rows from a simple string. It uses `\n` by
+// default for getting all the rows and the given separator for the fields on
+// each row.
+func (m *Model) FromValues(value, separator string) {
+	rows := []Row{}
+	for _, line := range strings.Split(value, "\n") {
+		r := Row{}
+		for _, field := range strings.Split(line, separator) {
+			r = append(r, field)
+		}
+		rows = append(rows, r)
+	}
+
+	m.SetRows(rows)
+}
+
+func (m Model) headersView() string {
+	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, "…"))
+		s = append(s, m.styles.Header.Render(renderedCell))
+	}
+	return lipgloss.JoinHorizontal(lipgloss.Left, s...)
+}
+
+func (m *Model) renderRow(rowID int) string {
+	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, "…")))
+		s = append(s, renderedCell)
+	}
+
+	row := lipgloss.JoinHorizontal(lipgloss.Left, s...)
+
+	if rowID == m.cursor {
+		return m.styles.Selected.Render(row)
+	}
+
+	return row
+}
+
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+
+	return b
+}
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+
+	return b
+}
+
+func clamp(v, low, high int) int {
+	return min(max(v, low), high)
+}

table/table_test.go

@@ -0,0 +1,54 @@
+package table
+
+import "testing"
+
+func TestFromValues(t *testing.T) {
+	input := "foo1,bar1\nfoo2,bar2\nfoo3,bar3"
+	table := New(WithColumns([]Column{{Title: "Foo"}, {Title: "Bar"}}))
+	table.FromValues(input, ",")
+
+	if len(table.rows) != 3 {
+		t.Fatalf("expect table to have 3 rows but it has %d", len(table.rows))
+	}
+
+	expect := []Row{
+		{"foo1", "bar1"},
+		{"foo2", "bar2"},
+		{"foo3", "bar3"},
+	}
+	if !deepEqual(table.rows, expect) {
+		t.Fatal("table rows is not equals to the input")
+	}
+}
+
+func TestFromValuesWithTabSeparator(t *testing.T) {
+	input := "foo1.\tbar1\nfoo,bar,baz\tbar,2"
+	table := New(WithColumns([]Column{{Title: "Foo"}, {Title: "Bar"}}))
+	table.FromValues(input, "\t")
+
+	if len(table.rows) != 2 {
+		t.Fatalf("expect table to have 2 rows but it has %d", len(table.rows))
+	}
+
+	expect := []Row{
+		{"foo1.", "bar1"},
+		{"foo,bar,baz", "bar,2"},
+	}
+	if !deepEqual(table.rows, expect) {
+		t.Fatal("table rows is not equals to the input")
+	}
+}
+
+func deepEqual(a, b []Row) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i, r := range a {
+		for j, f := range r {
+			if f != b[i][j] {
+				return false
+			}
+		}
+	}
+	return true
+}

textarea/textarea.go

@@ -46,6 +46,14 @@ type KeyMap struct {
 	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
@@ -67,6 +75,14 @@ var DefaultKeyMap = KeyMap{
 	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
@@ -117,10 +133,27 @@ type Model struct {
 	Err error
 
 	// General settings.
+
+	// Prompt is printed at the beginning of each line.
+	//
+	// 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
@@ -140,6 +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
@@ -193,7 +233,7 @@ func New() Model {
 		Cursor:               cur,
 		KeyMap:               DefaultKeyMap,
 
-		value:            make([][]rune, minHeight, maxWidth),
+		value:            make([][]rune, minHeight, maxHeight),
 		focus:            false,
 		col:              0,
 		row:              0,
@@ -217,7 +257,7 @@ func DefaultStyles() (Style, Style) {
 		CursorLineNumber: lipgloss.NewStyle().Foreground(lipgloss.AdaptiveColor{Light: "240"}),
 		EndOfBuffer:      lipgloss.NewStyle().Foreground(lipgloss.AdaptiveColor{Light: "254", Dark: "0"}),
 		LineNumber:       lipgloss.NewStyle().Foreground(lipgloss.AdaptiveColor{Light: "249", Dark: "7"}),
-		Placeholder:      lipgloss.NewStyle().Foreground(lipgloss.Color("7")),
+		Placeholder:      lipgloss.NewStyle().Foreground(lipgloss.Color("240")),
 		Prompt:           lipgloss.NewStyle().Foreground(lipgloss.Color("7")),
 		Text:             lipgloss.NewStyle(),
 	}
@@ -227,7 +267,7 @@ func DefaultStyles() (Style, Style) {
 		CursorLineNumber: lipgloss.NewStyle().Foreground(lipgloss.AdaptiveColor{Light: "249", Dark: "7"}),
 		EndOfBuffer:      lipgloss.NewStyle().Foreground(lipgloss.AdaptiveColor{Light: "254", Dark: "0"}),
 		LineNumber:       lipgloss.NewStyle().Foreground(lipgloss.AdaptiveColor{Light: "249", Dark: "7"}),
-		Placeholder:      lipgloss.NewStyle().Foreground(lipgloss.Color("7")),
+		Placeholder:      lipgloss.NewStyle().Foreground(lipgloss.Color("240")),
 		Prompt:           lipgloss.NewStyle().Foreground(lipgloss.Color("7")),
 		Text:             lipgloss.NewStyle().Foreground(lipgloss.AdaptiveColor{Light: "245", Dark: "7"}),
 	}
@@ -271,13 +311,13 @@ func (m Model) Value() string {
 		return ""
 	}
 
-	var v string
+	var v strings.Builder
 	for _, l := range m.value {
-		v += string(l)
-		v += "\n"
+		v.WriteString(string(l))
+		v.WriteByte('\n')
 	}
 
-	return strings.TrimSuffix(v, "\n")
+	return strings.TrimSuffix(v.String(), "\n")
 }
 
 // Length returns the number of characters currently in the text input.
@@ -286,7 +326,12 @@ func (m *Model) Length() int {
 	for _, row := range m.value {
 		l += rw.StringWidth(string(row))
 	}
-	return l
+	return l + len(m.value) - 1
+}
+
+// LineCount returns the number of lines that are currently in the text input.
+func (m *Model) LineCount() int {
+	return len(m.value)
 }
 
 // Line returns the line position.
@@ -404,7 +449,7 @@ func (m *Model) Blur() {
 
 // Reset sets the input to its default state with no input.
 func (m *Model) Reset() {
-	m.value = make([][]rune, minHeight, maxWidth)
+	m.value = make([][]rune, minHeight, maxHeight)
 	m.col = 0
 	m.row = 0
 	m.viewport.GotoTop()
@@ -468,6 +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() {
@@ -542,31 +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 {
-		return
-	}
-
-	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 {
+	for {
+		m.characterLeft(true /* insideLine */)
+		if m.col < len(m.value[m.row]) && !unicode.IsSpace(m.value[m.row][m.col]) {
 			break
 		}
 	}
 
-	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 {
+	for m.col > 0 {
+		if unicode.IsSpace(m.value[m.row][m.col-1]) {
 			break
 		}
+		m.SetCursor(m.col - 1)
 	}
 }
 
@@ -574,28 +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 {
-		return
-	}
+	m.doWordRight(func(int, int) { /* nothing */ })
+}
 
-	i := m.col
-	for i < len(m.value[m.row]) {
-		if unicode.IsSpace(m.value[m.row][i]) {
-			m.SetCursor(m.col + 1)
-			i++
-		} else {
+func (m *Model) doWordRight(fn func(charIdx int, pos int)) {
+	// Skip spaces forward.
+	for {
+		if m.col < len(m.value[m.row]) && !unicode.IsSpace(m.value[m.row][m.col]) {
 			break
 		}
-	}
-
-	for i < len(m.value[m.row]) {
-		if !unicode.IsSpace(m.value[m.row][i]) {
-			m.SetCursor(m.col + 1)
-			i++
-		} else {
+		if m.row == len(m.value)-1 && m.col == len(m.value[m.row]) {
+			// End of text.
 			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
@@ -657,6 +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.
@@ -677,10 +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
@@ -769,14 +905,7 @@ func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
 		case key.Matches(msg, m.KeyMap.LineStart):
 			m.CursorStart()
 		case key.Matches(msg, m.KeyMap.CharacterForward):
-			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()
-				}
-			}
+			m.characterRight()
 		case key.Matches(msg, m.KeyMap.LineNext):
 			m.CursorDown()
 		case key.Matches(msg, m.KeyMap.WordForward):
@@ -784,20 +913,26 @@ func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
 		case key.Matches(msg, m.KeyMap.Paste):
 			return m, Paste
 		case key.Matches(msg, m.KeyMap.CharacterBackward):
-			if m.col == 0 && m.row != 0 {
-				m.row--
-				m.CursorEnd()
-				break
-			}
-			if m.col > 0 {
-				m.SetCursor(m.col - 1)
-			}
+			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()
+
 		default:
-			if rw.StringWidth(m.Value()) >= m.CharLimit {
+			if m.CharLimit > 0 && rw.StringWidth(m.Value()) >= m.CharLimit {
 				break
 			}
 
@@ -843,6 +978,7 @@ func (m Model) View() string {
 
 	var newLines int
 
+	displayLine := 0
 	for l, line := range m.value {
 		wrappedLines := wrap(line, m.width)
 
@@ -853,7 +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 {
@@ -902,7 +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))))
@@ -915,6 +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 (
@@ -923,7 +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 {
@@ -940,6 +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 {

textinput/textinput.go

@@ -611,7 +611,7 @@ func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
 	switch msg := msg.(type) {
 	case tea.KeyMsg:
 		switch msg.Type {
-		case tea.KeyBackspace: // delete character before cursor
+		case tea.KeyBackspace, tea.KeyCtrlH: // delete character before cursor
 			m.Err = nil
 
 			if msg.Alt {

viewport/viewport.go

@@ -10,7 +10,7 @@ import (
 )
 
 // New returns a new model with the given width and height as well as default
-// keymappings.
+// key mappings.
 func New(width, height int) (m Model) {
 	m.Width = width
 	m.Height = height
@@ -237,7 +237,7 @@ func Sync(m Model) tea.Cmd {
 }
 
 // ViewDown is a high performance command that moves the viewport up by a given
-// numer of lines. Use Model.ViewDown to get the lines that should be rendered.
+// number of lines. Use Model.ViewDown to get the lines that should be rendered.
 // For example:
 //
 //     lines := model.ViewDown(1)
@@ -344,24 +344,29 @@ func (m Model) updateAsModel(msg tea.Msg) (Model, tea.Cmd) {
 func (m Model) View() string {
 	if m.HighPerformanceRendering {
 		// Just send newlines since we're going to be rendering the actual
-		// content seprately. We still need to send something that equals the
+		// content separately. We still need to send something that equals the
 		// height of this view so that the Bubble Tea standard renderer can
 		// position anything below this view properly.
-		return strings.Repeat("\n", m.Height-1)
+		return strings.Repeat("\n", max(0, m.Height-1))
 	}
 
-	lines := m.visibleLines()
-
-	// Fill empty space with newlines
-	extraLines := ""
-	if len(lines) < m.Height {
-		extraLines = strings.Repeat("\n", max(0, m.Height-len(lines)))
+	w, h := m.Width, m.Height
+	if sw := m.Style.GetWidth(); sw != 0 {
+		w = min(w, sw)
 	}
-
+	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().
-		UnsetHeight().
-		Render(strings.Join(lines, "\n") + extraLines)
+		UnsetWidth().UnsetHeight(). // Style size already applied in contents.
+		Render(contents)
 }
 
 func clamp(v, low, high int) int {