package ui import ( "math" "time" "github.com/gdamore/tcell" "github.com/mattn/go-runewidth" ) // TODO: Attach history providers // TODO: scrolling type TextInput struct { Invalidatable cells int ctx *Context focus bool index int password bool prompt string scroll int text []rune change []func(ti *TextInput) tabcomplete func(s string) []string completions []string completeIndex int completeDelay time.Duration completeDebouncer *time.Timer } // 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) Password(password bool) *TextInput { ti.password = password return ti } func (ti *TextInput) Prompt(prompt string) *TextInput { ti.prompt = prompt return ti } func (ti *TextInput) TabComplete( tabcomplete func(s string) []string, d time.Duration) *TextInput { ti.tabcomplete = tabcomplete ti.completeDelay = d return ti } func (ti *TextInput) String() string { return string(ti.text) } func (ti *TextInput) StringLeft() string { return string(ti.text[:ti.index]) } func (ti *TextInput) StringRight() string { return string(ti.text[ti.index:]) } func (ti *TextInput) Set(value string) *TextInput { ti.text = []rune(value) ti.index = len(ti.text) return ti } func (ti *TextInput) Invalidate() { ti.DoInvalidate(ti) } func (ti *TextInput) Draw(ctx *Context) { scroll := ti.scroll if !ti.focus { scroll = 0 } else { ti.ensureScroll() } ti.ctx = ctx // gross ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', tcell.StyleDefault) text := ti.text[scroll:] sindex := ti.index - scroll if ti.password { x := ctx.Printf(0, 0, tcell.StyleDefault, "%s", ti.prompt) cells := runewidth.StringWidth(string(text)) ctx.Fill(x, 0, cells, 1, '*', tcell.StyleDefault) } else { ctx.Printf(0, 0, tcell.StyleDefault, "%s%s", ti.prompt, string(text)) } cells := runewidth.StringWidth(string(text[:sindex]) + ti.prompt) if ti.focus { ctx.SetCursor(cells, 0) ti.drawPopover(ctx) } } func (ti *TextInput) drawPopover(ctx *Context) { if len(ti.completions) == 0 { return } cmp := &completions{ options: ti.completions, idx: ti.completeIndex, stringLeft: ti.StringLeft(), onSelect: func(idx int) { ti.completeIndex = idx ti.Invalidate() }, onExec: func() { ti.executeCompletion() ti.invalidateCompletions() ti.Invalidate() }, onStem: func(stem string) { ti.Set(stem + ti.StringRight()) ti.Invalidate() }, } width := maxLen(ti.completions) + 3 height := len(ti.completions) ctx.Popover(0, 0, width, height, cmp) } func (ti *TextInput) MouseEvent(localX int, localY int, event tcell.Event) { switch event := event.(type) { case *tcell.EventMouse: switch event.Buttons() { case tcell.Button1: if localX >= len(ti.prompt)+1 && localX <= len(ti.text[ti.scroll:])+len(ti.prompt)+1 { ti.index = localX - len(ti.prompt) - 1 ti.ensureScroll() ti.Invalidate() } } } } 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) ensureScroll() { if ti.ctx == nil { return } // God why am I this lazy for ti.index-ti.scroll >= ti.ctx.Width() { ti.scroll++ } for ti.index-ti.scroll < 0 { ti.scroll-- } } 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.ensureScroll() 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.ensureScroll() ti.Invalidate() ti.onChange() } func (ti *TextInput) deleteLineForward() { if len(ti.text) == 0 || len(ti.text) == ti.index { return } ti.text = ti.text[:ti.index] ti.ensureScroll() ti.Invalidate() ti.onChange() } func (ti *TextInput) deleteLineBackward() { if len(ti.text) == 0 || ti.index == 0 { return } ti.text = ti.text[ti.index:] ti.index = 0 ti.ensureScroll() 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.ensureScroll() 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.ensureScroll() ti.Invalidate() ti.onChange() } } func (ti *TextInput) executeCompletion() { if len(ti.completions) > 0 { ti.Set(ti.completions[ti.completeIndex] + ti.StringRight()) } } func (ti *TextInput) invalidateCompletions() { ti.completions = nil } func (ti *TextInput) onChange() { ti.updateCompletions() for _, change := range ti.change { change(ti) } } func (ti *TextInput) updateCompletions() { if ti.tabcomplete == nil { // no completer return } if ti.completeDebouncer == nil { ti.completeDebouncer = time.AfterFunc(ti.completeDelay, func() { ti.showCompletions() }) } else { ti.completeDebouncer.Stop() ti.completeDebouncer.Reset(ti.completeDelay) } } func (ti *TextInput) showCompletions() { if ti.tabcomplete == nil { // no completer return } ti.completions = ti.tabcomplete(ti.StringLeft()) ti.completeIndex = -1 ti.Invalidate() } 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.invalidateCompletions() ti.backspace() case tcell.KeyCtrlD, tcell.KeyDelete: ti.invalidateCompletions() ti.deleteChar() case tcell.KeyCtrlB, tcell.KeyLeft: ti.invalidateCompletions() if ti.index > 0 { ti.index-- ti.ensureScroll() ti.Invalidate() } case tcell.KeyCtrlF, tcell.KeyRight: ti.invalidateCompletions() if ti.index < len(ti.text) { ti.index++ ti.ensureScroll() ti.Invalidate() } case tcell.KeyCtrlA, tcell.KeyHome: ti.invalidateCompletions() ti.index = 0 ti.ensureScroll() ti.Invalidate() case tcell.KeyCtrlE, tcell.KeyEnd: ti.invalidateCompletions() ti.index = len(ti.text) ti.ensureScroll() ti.Invalidate() case tcell.KeyCtrlK: ti.invalidateCompletions() ti.deleteLineForward() case tcell.KeyCtrlW: ti.invalidateCompletions() ti.deleteWord() case tcell.KeyCtrlU: ti.invalidateCompletions() ti.deleteLineBackward() case tcell.KeyESC: if ti.completions != nil { ti.invalidateCompletions() ti.Invalidate() } case tcell.KeyTab: ti.showCompletions() case tcell.KeyRune: ti.invalidateCompletions() ti.insert(event.Rune()) } } return true } type completions struct { options []string stringLeft string idx int onSelect func(int) onExec func() onStem func(string) } func maxLen(ss []string) int { max := 0 for _, s := range ss { l := runewidth.StringWidth(s) if l > max { max = l } } return max } func (c *completions) Draw(ctx *Context) { bg := tcell.StyleDefault sel := tcell.StyleDefault.Reverse(true) gutter := tcell.StyleDefault pill := tcell.StyleDefault.Reverse(true) ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', bg) numVisible := ctx.Height() startIdx := 0 if len(c.options) > numVisible && c.idx+1 > numVisible { startIdx = c.idx - (numVisible - 1) } endIdx := startIdx + numVisible - 1 for idx, opt := range c.options { if idx < startIdx { continue } if idx > endIdx { continue } if c.idx == idx { ctx.Fill(0, idx-startIdx, ctx.Width(), 1, ' ', sel) ctx.Printf(0, idx-startIdx, sel, " %s ", opt) } else { ctx.Printf(0, idx-startIdx, bg, " %s ", opt) } } percentVisible := float64(numVisible) / float64(len(c.options)) if percentVisible >= 1.0 { return } // gutter ctx.Fill(ctx.Width()-1, 0, 1, ctx.Height(), ' ', gutter) pillSize := int(math.Ceil(float64(ctx.Height()) * percentVisible)) percentScrolled := float64(startIdx) / float64(len(c.options)) pillOffset := int(math.Floor(float64(ctx.Height()) * percentScrolled)) ctx.Fill(ctx.Width()-1, pillOffset, 1, pillSize, ' ', pill) } func (c *completions) next() { idx := c.idx idx++ if idx > len(c.options)-1 { idx = -1 } c.onSelect(idx) } func (c *completions) prev() { idx := c.idx idx-- if idx < -1 { idx = len(c.options) - 1 } c.onSelect(idx) } func (c *completions) Event(e tcell.Event) bool { switch e := e.(type) { case *tcell.EventKey: switch e.Key() { case tcell.KeyTab: if len(c.options) == 1 && c.idx >= 0 { c.onExec() } else { stem := findStem(c.options) if stem != "" && stem != c.stringLeft { c.onStem(stem) } else { c.next() } } return true case tcell.KeyCtrlN, tcell.KeyDown: c.next() return true case tcell.KeyBacktab, tcell.KeyCtrlP, tcell.KeyUp: c.prev() return true case tcell.KeyEnter: if c.idx >= 0 { c.onExec() return true } } } return false } func findStem(words []string) string { if len(words) <= 0 { return "" } if len(words) == 1 { return words[0] } var stem string stemLen := 1 firstWord := []rune(words[0]) for { if len(firstWord) < stemLen { return stem } var r rune = firstWord[stemLen-1] for _, word := range words[1:] { runes := []rune(word) if len(runes) < stemLen { return stem } if runes[stemLen-1] != r { return stem } } stem = stem + string(r) stemLen++ } } func (c *completions) Focus(_ bool) {} func (c *completions) Invalidate() {} func (c *completions) OnInvalidate(_ func(Drawable)) {}