package ui
import (
"github.com/gdamore/tcell"
"github.com/mattn/go-runewidth"
)
// TODO: Attach history and tab completion providers
// TODO: scrolling
type TextInput struct {
Invalidatable
cells int
ctx *Context
focus bool
index int
prompt string
scroll int
text []rune
change []func(ti *TextInput)
}
// Creates a new TextInput. TextInputs will render a "textbox" in the entire
// context they're given, and process keypresses to build a string from user
// input.
func NewTextInput(text string) *TextInput {
return &TextInput{
cells: -1,
text: []rune(text),
index: len([]rune(text)),
}
}
func (ti *TextInput) Prompt(prompt string) *TextInput {
ti.prompt = prompt
return ti
}
func (ti *TextInput) String() string {
return string(ti.text)
}
func (ti *TextInput) Invalidate() {
ti.DoInvalidate(ti)
}
func (ti *TextInput) Draw(ctx *Context) {
ti.ctx = ctx // gross
ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', tcell.StyleDefault)
ctx.Printf(0, 0, tcell.StyleDefault, "%s%s", ti.prompt, string(ti.text))
cells := runewidth.StringWidth(string(ti.text[:ti.index]) + ti.prompt)
if cells != ti.cells && ti.focus {
ctx.SetCursor(cells, 0)
}
}
func (ti *TextInput) Focus(focus bool) {
ti.focus = focus
if focus && ti.ctx != nil {
cells := runewidth.StringWidth(string(ti.text[:ti.index]))
ti.ctx.SetCursor(cells+1, 0)
} else if !focus && ti.ctx != nil {
ti.ctx.HideCursor()
}
}
func (ti *TextInput) insert(ch rune) {
left := ti.text[:ti.index]
right := ti.text[ti.index:]
ti.text = append(left, append([]rune{ch}, right...)...)
ti.index++
ti.Invalidate()
ti.onChange()
}
func (ti *TextInput) deleteWord() {
// TODO: Break on any of / " '
if len(ti.text) == 0 {
return
}
i := ti.index - 1
if ti.text[i] == ' ' {
i--
}
for ; i >= 0; i-- {
if ti.text[i] == ' ' {
break
}
}
ti.text = append(ti.text[:i+1], ti.text[ti.index:]...)
ti.index = i + 1
ti.Invalidate()
ti.onChange()
}
func (ti *TextInput) deleteChar() {
if len(ti.text) > 0 && ti.index != len(ti.text) {
ti.text = append(ti.text[:ti.index], ti.text[ti.index+1:]...)
ti.Invalidate()
ti.onChange()
}
}
func (ti *TextInput) backspace() {
if len(ti.text) > 0 && ti.index != 0 {
ti.text = append(ti.text[:ti.index-1], ti.text[ti.index:]...)
ti.index--
ti.Invalidate()
ti.onChange()
}
}
func (ti *TextInput) onChange() {
for _, change := range ti.change {
change(ti)
}
}
func (ti *TextInput) OnChange(onChange func(ti *TextInput)) {
ti.change = append(ti.change, onChange)
}
func (ti *TextInput) Event(event tcell.Event) bool {
switch event := event.(type) {
case *tcell.EventKey:
switch event.Key() {
case tcell.KeyBackspace, tcell.KeyBackspace2:
ti.backspace()
case tcell.KeyCtrlD, tcell.KeyDelete:
ti.deleteChar()
case tcell.KeyCtrlB, tcell.KeyLeft:
if ti.index > 0 {
ti.index--
ti.Invalidate()
}
case tcell.KeyCtrlF, tcell.KeyRight:
if ti.index < len(ti.text) {
ti.index++
ti.Invalidate()
}
case tcell.KeyCtrlA, tcell.KeyHome:
ti.index = 0
ti.Invalidate()
case tcell.KeyCtrlE, tcell.KeyEnd:
ti.index = len(ti.text)
ti.Invalidate()
case tcell.KeyCtrlW:
ti.deleteWord()
case tcell.KeyRune:
ti.insert(event.Rune())
}
}
return true
}