package tview import ( "math" "regexp" "strconv" "strings" "github.com/gdamore/tcell" ) // Text alignment within a box. const ( AlignLeft = iota AlignCenter AlignRight ) // Semigraphical runes. const ( GraphicsHoriBar = '\u2500' GraphicsVertBar = '\u2502' GraphicsTopLeftCorner = '\u250c' GraphicsTopRightCorner = '\u2510' GraphicsBottomRightCorner = '\u2518' GraphicsBottomLeftCorner = '\u2514' GraphicsDbVertBar = '\u2550' GraphicsDbHorBar = '\u2551' GraphicsDbTopLeftCorner = '\u2554' GraphicsDbTopRightCorner = '\u2557' GraphicsDbBottomRightCorner = '\u255d' GraphicsDbBottomLeftCorner = '\u255a' GraphicsRightT = '\u2524' GraphicsLeftT = '\u251c' GraphicsTopT = '\u252c' GraphicsBottomT = '\u2534' GraphicsCross = '\u253c' GraphicsEllipsis = '\u2026' ) 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 input field 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 } } // Regular expressions. var colors string for color := range textColors { if len(colors) > 0 { colors += "|" } colors += color } colorPattern = regexp.MustCompile(`\[(` + colors + `)\]`) } // Print prints text onto the screen into the given box at (x,y,maxWidth,1), // no exceeding that box. "align" is one of AlignLeft, AlignCenter, or // AlignRight. The screen's background color will be maintained. // // Returns the number of actual runes printed. func Print(screen tcell.Screen, text string, x, y, maxWidth, align int, color tcell.Color) int { // We deal with runes, not with bytes. runes := []rune(text) if maxWidth < 0 { return 0 } // AlignCenter is split into two parts. if align == AlignCenter { half := len(runes) / 2 halfWidth := maxWidth / 2 return Print(screen, string(runes[:half]), x, y, halfWidth, AlignRight, color) + Print(screen, string(runes[half:]), x+halfWidth, y, maxWidth-halfWidth, AlignLeft, color) } // Draw text. drawn := 0 for pos, ch := range runes { if pos >= maxWidth { break } finalX := x + pos if align == AlignRight { ch = runes[len(runes)-1-pos] finalX = x + maxWidth - 1 - pos } _, _, style, _ := screen.GetContent(finalX, y) style = style.Foreground(color) screen.SetContent(finalX, y, ch, nil, style) drawn++ } return drawn } // PrintSimple prints white text to the screen at the given position. func PrintSimple(screen tcell.Screen, text string, x, y int) { Print(screen, text, x, y, math.MaxInt64, AlignLeft, tcell.ColorWhite) } // WordWrap splits a text such that each resulting line does not exceed the // given width. Possible split points are after commas, dots, dashes, and any // whitespace. Whitespace at split points will be dropped. // // Text is always split at newline characters ('\n'). func WordWrap(text string, width int) (lines []string) { x := 0 start := 0 candidate := -1 // -1 = no candidate yet. startAfterCandidate := 0 countAfterCandidate := 0 var evaluatingCandidate bool text = strings.TrimSpace(text) for pos, ch := range text { if !evaluatingCandidate && x >= width { // We've exceeded the width, we must split. if candidate >= 0 { lines = append(lines, text[start:candidate]) start = startAfterCandidate x = countAfterCandidate } else { lines = append(lines, text[start:pos]) start = pos x = 0 } candidate = -1 evaluatingCandidate = false } switch ch { // We have a candidate. case ',', '.', '-': if x > 0 { candidate = pos + 1 evaluatingCandidate = true } // If we've had a candidate, skip whitespace. If not, we have a candidate. case ' ', '\t': if x > 0 && !evaluatingCandidate { candidate = pos evaluatingCandidate = true } // Split in any case. case '\n': lines = append(lines, text[start:pos]) start = pos + 1 evaluatingCandidate = false countAfterCandidate = 0 x = 0 continue // If we've had a candidate, we have a new start. default: if evaluatingCandidate { startAfterCandidate = pos evaluatingCandidate = false countAfterCandidate = 0 } } x++ countAfterCandidate++ } // Process remaining text. text = strings.TrimSpace(text[start:]) if len(text) > 0 { lines = append(lines, text) } return }