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 }