cview/inputfield.go

265 lines
6.7 KiB
Go

package tview
import (
"math"
"regexp"
"strconv"
"github.com/gdamore/tcell"
)
var (
// InputFieldInteger accepts integers.
InputFieldInteger func(text string, ch rune) bool
// InputFieldFloat accepts floating-point numbers.
InputFieldFloat func(text string, ch rune) bool
// 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
)
// Package initialization.
func init() {
// Initialize the predefined handlers.
InputFieldInteger = func(text string, ch rune) bool {
if text == "-" {
return true
}
_, err := strconv.Atoi(text)
return err == nil
}
InputFieldFloat = func(text string, ch rune) bool {
if text == "-" || text == "." {
return true
}
_, err := strconv.ParseFloat(text, 64)
return err == nil
}
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 (three lines if there is a title) where the
// user can enter text.
type InputField struct {
Box
// The text that was entered.
text string
// The text to be displayed before the input area.
label string
// The label color.
labelColor tcell.Color
// The background color of the input area.
fieldBackgroundColor tcell.Color
// The text color of the input area.
fieldTextColor tcell.Color
// The length of the input area. A value of 0 means extend as much as
// possible.
fieldLength int
// 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 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)
}
// NewInputField returns a new input field.
func NewInputField() *InputField {
return &InputField{
Box: *NewBox(),
labelColor: tcell.ColorYellow,
fieldBackgroundColor: tcell.ColorBlue,
fieldTextColor: tcell.ColorWhite,
}
}
// SetText sets the current text of the input field.
func (i *InputField) SetText(text string) *InputField {
i.text = text
return i
}
// GetText returns the current text of the input field.
func (i *InputField) GetText() string {
return i.text
}
// SetLabel sets the text to be displayed before the input area.
func (i *InputField) SetLabel(label string) *InputField {
i.label = label
return i
}
// GetLabel returns the text to be displayed before the input area.
func (i *InputField) GetLabel() string {
return i.label
}
// SetLabelColor sets the color of the label.
func (i *InputField) SetLabelColor(color tcell.Color) *InputField {
i.labelColor = color
return i
}
// SetFieldBackgroundColor sets the background color of the input area.
func (i *InputField) SetFieldBackgroundColor(color tcell.Color) *InputField {
i.fieldBackgroundColor = color
return i
}
// SetFieldTextColor sets the text color of the input area.
func (i *InputField) SetFieldTextColor(color tcell.Color) *InputField {
i.fieldTextColor = color
return i
}
// SetFieldLength sets the length of the input area. A value of 0 means extend
// as much as possible.
func (i *InputField) SetFieldLength(length int) *InputField {
i.fieldLength = length
return i
}
// SetAcceptanceFunc sets a handler which may reject the last character that was
// entered (by returning false).
//
// This package defines a number of variables Prefixed with InputField which may
// be used for common input (e.g. numbers, maximum text length).
func (i *InputField) SetAcceptanceFunc(handler func(textToCheck string, lastChar rune) bool) *InputField {
i.accept = 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
}
// Draw draws this primitive onto the screen.
func (i *InputField) Draw(screen tcell.Screen) {
i.Box.Draw(screen)
// Prepare
x := i.x
y := i.y
rightLimit := x + i.width
height := i.height
if i.border {
x++
y++
rightLimit -= 2
height -= 2
}
if height < 1 || rightLimit <= x {
return
}
// Draw label.
x += Print(screen, i.label, x, y, rightLimit-x, AlignLeft, i.labelColor)
// Draw input area.
fieldLength := i.fieldLength
if fieldLength == 0 {
fieldLength = math.MaxInt64
}
if rightLimit-x < fieldLength {
fieldLength = rightLimit - x
}
fieldStyle := tcell.StyleDefault.Background(i.fieldBackgroundColor)
for index := 0; index < fieldLength; index++ {
screen.SetContent(x+index, y, ' ', nil, fieldStyle)
}
// Draw entered text.
fieldLength-- // We need one cell for the cursor.
if fieldLength < len([]rune(i.text)) {
Print(screen, i.text, x+fieldLength-1, y, fieldLength, AlignRight, i.fieldTextColor)
} else {
Print(screen, i.text, x, y, fieldLength, AlignLeft, i.fieldTextColor)
}
// Set cursor.
if i.hasFocus {
i.setCursor(screen)
}
}
// setCursor sets the cursor position.
func (i *InputField) setCursor(screen tcell.Screen) {
x := i.x
y := i.y
rightLimit := x + i.width
if i.border {
x++
y++
rightLimit -= 2
}
fieldLength := len([]rune(i.text))
if fieldLength > i.fieldLength-1 {
fieldLength = i.fieldLength - 1
}
x += len([]rune(i.label)) + fieldLength
if x >= rightLimit {
x = rightLimit - 1
}
screen.ShowCursor(x, y)
}
// InputHandler returns the handler for this primitive.
func (i *InputField) InputHandler() func(event *tcell.EventKey) {
return func(event *tcell.EventKey) {
// Process key event.
switch key := event.Key(); key {
case tcell.KeyRune: // Regular character.
newText := i.text + string(event.Rune())
if i.accept != nil {
if !i.accept(newText, event.Rune()) {
break
}
}
i.text = newText
case tcell.KeyCtrlU: // Delete all.
i.text = ""
case tcell.KeyCtrlW: // Delete last word.
lastWord := regexp.MustCompile(`\s*\S+\s*$`)
i.text = lastWord.ReplaceAllString(i.text, "")
case tcell.KeyBackspace, tcell.KeyBackspace2: // Delete last character.
if len([]rune(i.text)) == 0 {
break
}
i.text = i.text[:len([]rune(i.text))-1]
case tcell.KeyEnter, tcell.KeyTab, tcell.KeyBacktab, tcell.KeyEscape: // We're done.
if i.done != nil {
i.done(key)
}
}
}
}