tview/inputfield.go

663 lines
21 KiB
Go

package tview
import (
"strconv"
"strings"
"sync"
"github.com/gdamore/tcell/v2"
"github.com/rivo/uniseg"
)
const (
AutocompletedNavigate = iota // The user navigated the autocomplete list (using the errow keys).
AutocompletedTab // The user selected an autocomplete entry using the tab key.
AutocompletedEnter // The user selected an autocomplete entry using the enter key.
AutocompletedClick // The user selected an autocomplete entry by clicking the mouse button on it.
)
// Predefined InputField acceptance functions.
var (
// InputFieldInteger accepts integers.
InputFieldInteger = func(text string, ch rune) bool {
if text == "-" {
return true
}
_, err := strconv.Atoi(text)
return err == nil
}
// InputFieldFloat accepts floating-point numbers.
InputFieldFloat = func(text string, ch rune) bool {
if text == "-" || text == "." || text == "-." {
return true
}
_, err := strconv.ParseFloat(text, 64)
return err == nil
}
// InputFieldMaxLength returns an input field accept handler which accepts
// input strings up to a given length. Use it like this:
//
// inputField.SetAcceptanceFunc(InputFieldMaxLength(10)) // Accept up to 10 characters.
InputFieldMaxLength = func(maxLength int) func(text string, ch rune) bool {
return func(text string, ch rune) bool {
return len([]rune(text)) <= maxLength
}
}
)
// InputField is a one-line box into which the user can enter text. Use
// [InputField.SetAcceptanceFunc] to accept or reject input,
// [InputField.SetChangedFunc] to listen for changes, and
// [InputField.SetMaskCharacter] to hide input from onlookers (e.g. for password
// input).
//
// The input field also has an optional autocomplete feature. It is initialized
// by the [InputField.SetAutocompleteFunc] function. For more control over the
// autocomplete drop-down's behavior, you can also set the
// [InputField.SetAutocompletedFunc].
//
// Navigation and editing is the same as for a [TextArea], with the following
// exceptions:
//
// - Tab, BackTab, Enter, Escape: Finish editing.
//
// If autocomplete functionality is configured:
//
// - Down arrow: Open the autocomplete drop-down.
// - Tab, Enter: Select the current autocomplete entry.
//
// See https://github.com/rivo/tview/wiki/InputField for an example.
type InputField struct {
*Box
// The text area providing the core functionality of the input field.
textArea *TextArea
// The screen width of the input area. A value of 0 means extend as much as
// possible.
fieldWidth int
// An optional autocomplete function which receives the current text of the
// input field and returns a slice of strings to be displayed in a drop-down
// selection.
autocomplete func(text string) []string
// The List object which shows the selectable autocomplete entries. If not
// nil, the list's main texts represent the current autocomplete entries.
autocompleteList *List
autocompleteListMutex sync.Mutex
// The styles of the autocomplete entries.
autocompleteStyles struct {
main tcell.Style
selected tcell.Style
background tcell.Color
}
// An optional function which is called when the user selects an
// autocomplete entry. The text and index of the selected entry (within the
// list) is provided, as well as the user action causing the selection (one
// of the "Autocompleted" values). The function should return true if the
// autocomplete list should be closed. If nil, the input field will be
// updated automatically when the user navigates the autocomplete list.
autocompleted func(text string, index int, source int) bool
// An optional function which may reject the last character that was entered.
accept func(text string, ch rune) bool
// An optional function which is called when the input has changed.
changed func(text string)
// An optional function which is called when the user indicated that they
// are done entering text. The key which was pressed is provided (tab,
// shift-tab, enter, or escape).
done func(tcell.Key)
// A callback function set by the Form class and called when the user leaves
// this form item.
finished func(tcell.Key)
}
// NewInputField returns a new input field.
func NewInputField() *InputField {
i := &InputField{
Box: NewBox(),
textArea: NewTextArea().SetWrap(false),
}
i.textArea.SetChangedFunc(func() {
if i.changed != nil {
i.changed(i.textArea.GetText())
}
})
i.textArea.textStyle = tcell.StyleDefault.Background(Styles.ContrastBackgroundColor).Foreground(Styles.PrimaryTextColor)
i.textArea.placeholderStyle = tcell.StyleDefault.Background(Styles.ContrastBackgroundColor).Foreground(Styles.ContrastSecondaryTextColor)
i.autocompleteStyles.main = tcell.StyleDefault.Foreground(Styles.PrimitiveBackgroundColor)
i.autocompleteStyles.selected = tcell.StyleDefault.Background(Styles.PrimaryTextColor).Foreground(Styles.PrimitiveBackgroundColor)
i.autocompleteStyles.background = Styles.MoreContrastBackgroundColor
return i
}
// SetText sets the current text of the input field. This can be undone by the
// user. Calling this function will also trigger a "changed" event.
func (i *InputField) SetText(text string) *InputField {
i.textArea.Replace(0, i.textArea.GetTextLength(), text)
return i
}
// GetText returns the current text of the input field.
func (i *InputField) GetText() string {
return i.textArea.GetText()
}
// SetLabel sets the text to be displayed before the input area.
func (i *InputField) SetLabel(label string) *InputField {
i.textArea.SetLabel(label)
return i
}
// GetLabel returns the text to be displayed before the input area.
func (i *InputField) GetLabel() string {
return i.textArea.GetLabel()
}
// SetLabelWidth sets the screen width of the label. A value of 0 will cause the
// primitive to use the width of the label string.
func (i *InputField) SetLabelWidth(width int) *InputField {
i.textArea.SetLabelWidth(width)
return i
}
// SetPlaceholder sets the text to be displayed when the input text is empty.
func (i *InputField) SetPlaceholder(text string) *InputField {
i.textArea.SetPlaceholder(text)
return i
}
// SetLabelColor sets the text color of the label.
func (i *InputField) SetLabelColor(color tcell.Color) *InputField {
i.textArea.SetLabelStyle(i.textArea.GetLabelStyle().Foreground(color))
return i
}
// SetLabelStyle sets the style of the label.
func (i *InputField) SetLabelStyle(style tcell.Style) *InputField {
i.textArea.SetLabelStyle(style)
return i
}
// GetLabelStyle returns the style of the label.
func (i *InputField) GetLabelStyle() tcell.Style {
return i.textArea.GetLabelStyle()
}
// SetFieldBackgroundColor sets the background color of the input area.
func (i *InputField) SetFieldBackgroundColor(color tcell.Color) *InputField {
i.textArea.SetTextStyle(i.textArea.GetTextStyle().Background(color))
return i
}
// SetFieldTextColor sets the text color of the input area.
func (i *InputField) SetFieldTextColor(color tcell.Color) *InputField {
i.textArea.SetTextStyle(i.textArea.GetTextStyle().Foreground(color))
return i
}
// SetFieldStyle sets the style of the input area (when no placeholder is
// shown).
func (i *InputField) SetFieldStyle(style tcell.Style) *InputField {
i.textArea.SetTextStyle(style)
return i
}
// GetFieldStyle returns the style of the input area (when no placeholder is
// shown).
func (i *InputField) GetFieldStyle() tcell.Style {
return i.textArea.GetTextStyle()
}
// SetPlaceholderTextColor sets the text color of placeholder text.
func (i *InputField) SetPlaceholderTextColor(color tcell.Color) *InputField {
i.textArea.SetPlaceholderStyle(i.textArea.GetPlaceholderStyle().Foreground(color))
return i
}
// SetPlaceholderStyle sets the style of the input area (when a placeholder is
// shown).
func (i *InputField) SetPlaceholderStyle(style tcell.Style) *InputField {
i.textArea.SetPlaceholderStyle(style)
return i
}
// GetPlaceholderStyle returns the style of the input area (when a placeholder
// is shown).
func (i *InputField) GetPlaceholderStyle() tcell.Style {
return i.textArea.GetPlaceholderStyle()
}
// SetAutocompleteStyles sets the colors and style of the autocomplete entries.
// For details, see List.SetMainTextStyle(), List.SetSelectedStyle(), and
// Box.SetBackgroundColor().
func (i *InputField) SetAutocompleteStyles(background tcell.Color, main, selected tcell.Style) *InputField {
i.autocompleteStyles.background = background
i.autocompleteStyles.main = main
i.autocompleteStyles.selected = selected
return i
}
// SetFormAttributes sets attributes shared by all form items.
func (i *InputField) SetFormAttributes(labelWidth int, labelColor, bgColor, fieldTextColor, fieldBgColor tcell.Color) FormItem {
i.textArea.SetFormAttributes(labelWidth, labelColor, bgColor, fieldTextColor, fieldBgColor)
return i
}
// SetFieldWidth sets the screen width of the input area. A value of 0 means
// extend as much as possible.
func (i *InputField) SetFieldWidth(width int) *InputField {
i.fieldWidth = width
return i
}
// GetFieldWidth returns this primitive's field width.
func (i *InputField) GetFieldWidth() int {
return i.fieldWidth
}
// GetFieldHeight returns this primitive's field height.
func (i *InputField) GetFieldHeight() int {
return 1
}
// SetDisabled sets whether or not the item is disabled / read-only.
func (i *InputField) SetDisabled(disabled bool) FormItem {
i.textArea.SetDisabled(disabled)
if i.finished != nil {
i.finished(-1)
}
return i
}
// SetMaskCharacter sets a character that masks user input on a screen. A value
// of 0 disables masking.
func (i *InputField) SetMaskCharacter(mask rune) *InputField {
if mask == 0 {
i.textArea.setTransform(nil)
return i
}
maskStr := string(mask)
maskWidth := uniseg.StringWidth(maskStr)
i.textArea.setTransform(func(cluster, rest string, boundaries int) (newCluster string, newBoundaries int) {
return maskStr, maskWidth << uniseg.ShiftWidth
})
return i
}
// SetAutocompleteFunc sets an autocomplete callback function which may return
// strings to be selected from a drop-down based on the current text of the
// input field. The drop-down appears only if len(entries) > 0. The callback is
// invoked in this function and whenever the current text changes or when
// [InputField.Autocomplete] is called. Entries are cleared when the user
// selects an entry or presses Escape.
func (i *InputField) SetAutocompleteFunc(callback func(currentText string) (entries []string)) *InputField {
i.autocomplete = callback
i.Autocomplete()
return i
}
// SetAutocompletedFunc sets a callback function which is invoked when the user
// selects an entry from the autocomplete drop-down list. The function is passed
// the text of the selected entry (stripped of any style tags), the index of the
// entry, and the user action that caused the selection, for example
// [AutocompletedNavigate]. It returns true if the autocomplete drop-down should
// be closed after the callback returns or false if it should remain open, in
// which case [InputField.Autocomplete] is called to update the drop-down's
// contents.
//
// If no such callback is set (or nil is provided), the input field will be
// updated with the selection any time the user navigates the autocomplete
// drop-down list. So this function essentially gives you more control over the
// autocomplete functionality.
func (i *InputField) SetAutocompletedFunc(autocompleted func(text string, index int, source int) bool) *InputField {
i.autocompleted = autocompleted
return i
}
// Autocomplete invokes the autocomplete callback (if there is one, see
// [InputField.SetAutocompleteFunc]). If the length of the returned autocomplete
// entries slice is greater than 0, the input field will present the user with a
// corresponding drop-down list the next time the input field is drawn.
//
// It is safe to call this function from any goroutine. Note that the input
// field is not redrawn automatically unless called from the main goroutine
// (e.g. in response to events).
func (i *InputField) Autocomplete() *InputField {
i.autocompleteListMutex.Lock()
defer i.autocompleteListMutex.Unlock()
if i.autocomplete == nil {
return i
}
// Do we have any autocomplete entries?
text := i.textArea.GetText()
entries := i.autocomplete(text)
if len(entries) == 0 {
// No entries, no list.
i.autocompleteList = nil
return i
}
// Make a list if we have none.
if i.autocompleteList == nil {
i.autocompleteList = NewList()
i.autocompleteList.ShowSecondaryText(false).
SetMainTextStyle(i.autocompleteStyles.main).
SetSelectedStyle(i.autocompleteStyles.selected).
SetHighlightFullLine(true).
SetBackgroundColor(i.autocompleteStyles.background)
}
// Fill it with the entries.
currentEntry := -1
suffixLength := 9999 // I'm just waiting for the day somebody opens an issue with this number being too small.
i.autocompleteList.Clear()
for index, entry := range entries {
i.autocompleteList.AddItem(entry, "", 0, nil)
if strings.HasPrefix(entry, text) && len(entry)-len(text) < suffixLength {
currentEntry = index
suffixLength = len(text) - len(entry)
}
}
// Set the selection if we have one.
if currentEntry >= 0 {
i.autocompleteList.SetCurrentItem(currentEntry)
}
return i
}
// SetAcceptanceFunc sets a handler which may reject the last character that was
// entered, by returning false. The handler receives the text as it would be
// after the change and the last character entered. If the handler is nil, all
// input is accepted. The function is only called when a single rune is inserted
// at the current cursor position.
//
// This package defines a number of variables prefixed with InputField which may
// be used for common input (e.g. numbers, maximum text length). See for example
// [InputFieldInteger].
func (i *InputField) SetAcceptanceFunc(handler func(textToCheck string, lastChar rune) bool) *InputField {
i.accept = handler
return i
}
// SetChangedFunc sets a handler which is called whenever the text of the input
// field has changed. It receives the current text (after the change).
func (i *InputField) SetChangedFunc(handler func(text string)) *InputField {
i.changed = handler
return i
}
// SetDoneFunc sets a handler which is called when the user is done entering
// text. The callback function is provided with the key that was pressed, which
// is one of the following:
//
// - KeyEnter: Done entering text.
// - KeyEscape: Abort text input.
// - KeyTab: Move to the next field.
// - KeyBacktab: Move to the previous field.
func (i *InputField) SetDoneFunc(handler func(key tcell.Key)) *InputField {
i.done = handler
return i
}
// SetFinishedFunc sets a callback invoked when the user leaves this form item.
func (i *InputField) SetFinishedFunc(handler func(key tcell.Key)) FormItem {
i.finished = handler
return i
}
// Focus is called when this primitive receives focus.
func (i *InputField) Focus(delegate func(p Primitive)) {
// If we're part of a form and this item is disabled, there's nothing the
// user can do here so we're finished.
if i.finished != nil && i.textArea.GetDisabled() {
i.finished(-1)
return
}
i.Box.Focus(delegate)
}
// HasFocus returns whether or not this primitive has focus.
func (i *InputField) HasFocus() bool {
return i.textArea.HasFocus() || i.Box.HasFocus()
}
// Blur is called when this primitive loses focus.
func (i *InputField) Blur() {
i.textArea.Blur()
i.Box.Blur()
i.autocompleteList = nil // Hide the autocomplete drop-down.
}
// Draw draws this primitive onto the screen.
func (i *InputField) Draw(screen tcell.Screen) {
i.Box.DrawForSubclass(screen, i)
// Prepare
x, y, width, height := i.GetInnerRect()
if height < 1 || width < 1 {
return
}
// Resize text area.
labelWidth := i.textArea.GetLabelWidth()
if labelWidth == 0 {
labelWidth = TaggedStringWidth(i.textArea.GetLabel())
}
fieldWidth := i.fieldWidth
if fieldWidth == 0 {
fieldWidth = width - labelWidth
}
i.textArea.SetRect(x, y, labelWidth+fieldWidth, 1)
i.textArea.setMinCursorPadding(fieldWidth-1, 1)
// Draw text area.
i.textArea.hasFocus = i.HasFocus() // Force cursor positioning.
i.textArea.Draw(screen)
// Draw autocomplete list.
i.autocompleteListMutex.Lock()
defer i.autocompleteListMutex.Unlock()
if i.autocompleteList != nil {
// How much space do we need?
lheight := i.autocompleteList.GetItemCount()
lwidth := 0
for index := 0; index < lheight; index++ {
entry, _ := i.autocompleteList.GetItemText(index)
width := TaggedStringWidth(entry)
if width > lwidth {
lwidth = width
}
}
// We prefer to drop down but if there is no space, maybe drop up?
lx := x + labelWidth
ly := y + 1
_, sheight := screen.Size()
if ly+lheight >= sheight && ly-2 > lheight-ly {
ly = y - lheight
if ly < 0 {
ly = 0
}
}
if ly+lheight >= sheight {
lheight = sheight - ly
}
i.autocompleteList.SetRect(lx, ly, lwidth, lheight)
i.autocompleteList.Draw(screen)
}
}
// InputHandler returns the handler for this primitive.
func (i *InputField) InputHandler() func(event *tcell.EventKey, setFocus func(p Primitive)) {
return i.WrapInputHandler(func(event *tcell.EventKey, setFocus func(p Primitive)) {
if i.textArea.GetDisabled() {
return
}
// Trigger changed events.
var skipAutocomplete bool
currentText := i.textArea.GetText()
defer func() {
newText := i.textArea.GetText()
if newText != currentText {
if !skipAutocomplete {
i.Autocomplete()
}
if i.changed != nil {
i.changed(newText)
}
}
}()
// If we have an autocomplete list, there are certain keys we will
// forward to it.
i.autocompleteListMutex.Lock()
defer i.autocompleteListMutex.Unlock()
if i.autocompleteList != nil {
i.autocompleteList.SetChangedFunc(nil)
i.autocompleteList.SetSelectedFunc(nil)
switch key := event.Key(); key {
case tcell.KeyEscape: // Close the list.
i.autocompleteList = nil
return
case tcell.KeyEnter, tcell.KeyTab: // Intentional selection.
index := i.autocompleteList.GetCurrentItem()
text, _ := i.autocompleteList.GetItemText(index)
if i.autocompleted != nil {
source := AutocompletedEnter
if key == tcell.KeyTab {
source = AutocompletedTab
}
if i.autocompleted(stripTags(text), index, source) {
i.autocompleteList = nil
currentText = i.GetText()
}
} else {
i.SetText(text)
skipAutocomplete = true
i.autocompleteList = nil
}
return
case tcell.KeyDown, tcell.KeyUp, tcell.KeyPgDn, tcell.KeyPgUp:
i.autocompleteList.SetChangedFunc(func(index int, text, secondaryText string, shortcut rune) {
text = stripTags(text)
if i.autocompleted != nil {
if i.autocompleted(text, index, AutocompletedNavigate) {
i.autocompleteList = nil
currentText = i.GetText()
}
} else {
i.SetText(text)
currentText = stripTags(text) // We want to keep the autocomplete list open and unchanged.
}
})
i.autocompleteList.InputHandler()(event, setFocus)
return
}
}
// Finish up.
finish := func(key tcell.Key) {
if i.done != nil {
i.done(key)
}
if i.finished != nil {
i.finished(key)
}
}
// Process special key events for the input field.
switch key := event.Key(); key {
case tcell.KeyDown:
i.autocompleteListMutex.Unlock() // We're still holding a lock.
i.Autocomplete()
i.autocompleteListMutex.Lock()
case tcell.KeyEnter, tcell.KeyEscape, tcell.KeyTab, tcell.KeyBacktab:
finish(key)
case tcell.KeyRune:
if event.Modifiers()&tcell.ModAlt == 0 && i.accept != nil {
// Check if this rune is accepted.
r := event.Rune()
if !i.accept(i.textArea.getTextBeforeCursor()+string(r)+i.textArea.getTextAfterCursor(), r) {
return
}
}
fallthrough
default:
// Forward other key events to the text area.
i.textArea.InputHandler()(event, setFocus)
}
})
}
// MouseHandler returns the mouse handler for this primitive.
func (i *InputField) MouseHandler() func(action MouseAction, event *tcell.EventMouse, setFocus func(p Primitive)) (consumed bool, capture Primitive) {
return i.WrapMouseHandler(func(action MouseAction, event *tcell.EventMouse, setFocus func(p Primitive)) (consumed bool, capture Primitive) {
if i.textArea.GetDisabled() {
return false, nil
}
var skipAutocomplete bool
currentText := i.GetText()
defer func() {
newText := i.GetText()
if newText != currentText {
if !skipAutocomplete {
i.Autocomplete()
}
if i.changed != nil {
i.changed(newText)
}
}
}()
// If we have an autocomplete list, forward the mouse event to it.
i.autocompleteListMutex.Lock()
defer i.autocompleteListMutex.Unlock()
if i.autocompleteList != nil {
i.autocompleteList.SetChangedFunc(nil)
i.autocompleteList.SetSelectedFunc(func(index int, text, secondaryText string, shortcut rune) {
text = stripTags(text)
if i.autocompleted != nil {
if i.autocompleted(text, index, AutocompletedClick) {
i.autocompleteList = nil
currentText = i.GetText()
}
return
}
i.SetText(text)
skipAutocomplete = true
i.autocompleteList = nil
})
if consumed, _ = i.autocompleteList.MouseHandler()(action, event, setFocus); consumed {
setFocus(i)
return
}
}
// Is mouse event within the input field?
x, y := event.Position()
if !i.InRect(x, y) {
return false, nil
}
// Forward mouse event to the text area.
consumed, capture = i.textArea.MouseHandler()(action, event, setFocus)
return
})
}