package tview import ( "math" "regexp" "strings" "unicode/utf8" "github.com/gdamore/tcell" runewidth "github.com/mattn/go-runewidth" ) // InputField is a one-line box (three lines if there is a title) where the // user can enter text. // // Use SetMaskCharacter() to hide input from onlookers (e.g. for password // input). // // See https://github.com/rivo/tview/wiki/InputField for an example. type InputField struct { *Box // The text that was entered. text string // The text to be displayed before the input area. label string // The text to be displayed in the input area when "text" is empty. placeholder 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 text color of the placeholder. placeholderTextColor tcell.Color // The screen width of the input area. A value of 0 means extend as much as // possible. fieldWidth int // A character to mask entered text (useful for password fields). A value of 0 // disables masking. maskCharacter rune // 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) } // NewInputField returns a new input field. func NewInputField() *InputField { return &InputField{ Box: NewBox(), labelColor: Styles.SecondaryTextColor, fieldBackgroundColor: Styles.ContrastBackgroundColor, fieldTextColor: Styles.PrimaryTextColor, placeholderTextColor: Styles.ContrastSecondaryTextColor, } } // SetText sets the current text of the input field. func (i *InputField) SetText(text string) *InputField { i.text = text if i.changed != nil { i.changed(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 } // SetPlaceholder sets the text to be displayed when the input text is empty. func (i *InputField) SetPlaceholder(text string) *InputField { i.placeholder = text return i } // 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 } // SetPlaceholderExtColor sets the text color of placeholder text. func (i *InputField) SetPlaceholderExtColor(color tcell.Color) *InputField { i.placeholderTextColor = color return i } // SetFormAttributes sets attributes shared by all form items. func (i *InputField) SetFormAttributes(label string, labelColor, bgColor, fieldTextColor, fieldBgColor tcell.Color) FormItem { i.label = label i.labelColor = labelColor i.backgroundColor = bgColor i.fieldTextColor = fieldTextColor i.fieldBackgroundColor = 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 } // SetMaskCharacter sets a character that masks user input on a screen. A value // of 0 disables masking. func (i *InputField) SetMaskCharacter(mask rune) *InputField { i.maskCharacter = mask 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 } // 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 calls SetDoneFunc(). func (i *InputField) SetFinishedFunc(handler func(key tcell.Key)) FormItem { return i.SetDoneFunc(handler) } // Draw draws this primitive onto the screen. func (i *InputField) Draw(screen tcell.Screen) { i.Box.Draw(screen) // Prepare x, y, width, height := i.GetInnerRect() rightLimit := x + width if height < 1 || rightLimit <= x { return } // Draw label. _, drawnWidth := Print(screen, i.label, x, y, rightLimit-x, AlignLeft, i.labelColor) x += drawnWidth // Draw input area. fieldWidth := i.fieldWidth if fieldWidth == 0 { fieldWidth = math.MaxInt32 } if rightLimit-x < fieldWidth { fieldWidth = rightLimit - x } fieldStyle := tcell.StyleDefault.Background(i.fieldBackgroundColor) for index := 0; index < fieldWidth; index++ { screen.SetContent(x+index, y, ' ', nil, fieldStyle) } // Draw placeholder text. text := i.text if text == "" && i.placeholder != "" { Print(screen, i.placeholder, x, y, fieldWidth, AlignLeft, i.placeholderTextColor) } // Draw entered text. if i.maskCharacter > 0 { text = strings.Repeat(string(i.maskCharacter), utf8.RuneCountInString(i.text)) } fieldWidth-- // We need one cell for the cursor. if fieldWidth < runewidth.StringWidth(text) { runes := []rune(text) for pos := len(runes) - 1; pos >= 0; pos-- { ch := runes[pos] w := runewidth.RuneWidth(ch) if fieldWidth-w < 0 { break } _, _, style, _ := screen.GetContent(x+fieldWidth-w, y) style = style.Foreground(i.fieldTextColor) for w > 0 { fieldWidth-- screen.SetContent(x+fieldWidth, y, ch, nil, style) w-- } } } else { pos := 0 for _, ch := range text { w := runewidth.RuneWidth(ch) _, _, style, _ := screen.GetContent(x+pos, y) style = style.Foreground(i.fieldTextColor) for w > 0 { screen.SetContent(x+pos, y, ch, nil, style) pos++ w-- } } } // Set cursor. if i.focus.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 } fieldWidth := runewidth.StringWidth(i.text) if i.fieldWidth > 0 && fieldWidth > i.fieldWidth-1 { fieldWidth = i.fieldWidth - 1 } x += StringWidth(i.label) + fieldWidth 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, setFocus func(p Primitive)) { return i.WrapInputHandler(func(event *tcell.EventKey, setFocus func(p Primitive)) { // Trigger changed events. currentText := i.text defer func() { if i.text != currentText && i.changed != nil { i.changed(i.text) } }() // 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(i.text) == 0 { break } runes := []rune(i.text) i.text = string(runes[:len(runes)-1]) case tcell.KeyEnter, tcell.KeyTab, tcell.KeyBacktab, tcell.KeyEscape: // We're done. if i.done != nil { i.done(key) } } }) }