package tview import ( "fmt" "math" "regexp" "strconv" "strings" "unicode" "maunium.net/go/tcell" runewidth "github.com/mattn/go-runewidth" ) // Text alignment within a box. const ( AlignLeft = iota AlignCenter AlignRight ) // Semigraphical runes. const ( GraphicsHoriBar = '\u2500' GraphicsVertBar = '\u2502' GraphicsTopLeftCorner = '\u250c' GraphicsTopRightCorner = '\u2510' GraphicsBottomLeftCorner = '\u2514' GraphicsBottomRightCorner = '\u2518' GraphicsLeftT = '\u251c' GraphicsRightT = '\u2524' GraphicsTopT = '\u252c' GraphicsBottomT = '\u2534' GraphicsCross = '\u253c' GraphicsDbVertBar = '\u2550' GraphicsDbHorBar = '\u2551' GraphicsDbTopLeftCorner = '\u2554' GraphicsDbTopRightCorner = '\u2557' GraphicsDbBottomRightCorner = '\u255d' GraphicsDbBottomLeftCorner = '\u255a' GraphicsEllipsis = '\u2026' ) // joints maps combinations of two graphical runes to the rune that results // when joining the two in the same screen cell. The keys of this map are // two-rune strings where the value of the first rune is lower than the value // of the second rune. Identical runes are not contained. var joints = map[string]rune{ "\u2500\u2502": GraphicsCross, "\u2500\u250c": GraphicsTopT, "\u2500\u2510": GraphicsTopT, "\u2500\u2514": GraphicsBottomT, "\u2500\u2518": GraphicsBottomT, "\u2500\u251c": GraphicsCross, "\u2500\u2524": GraphicsCross, "\u2500\u252c": GraphicsTopT, "\u2500\u2534": GraphicsBottomT, "\u2500\u253c": GraphicsCross, "\u2502\u250c": GraphicsLeftT, "\u2502\u2510": GraphicsRightT, "\u2502\u2514": GraphicsLeftT, "\u2502\u2518": GraphicsRightT, "\u2502\u251c": GraphicsLeftT, "\u2502\u2524": GraphicsRightT, "\u2502\u252c": GraphicsCross, "\u2502\u2534": GraphicsCross, "\u2502\u253c": GraphicsCross, "\u250c\u2510": GraphicsTopT, "\u250c\u2514": GraphicsLeftT, "\u250c\u2518": GraphicsCross, "\u250c\u251c": GraphicsLeftT, "\u250c\u2524": GraphicsCross, "\u250c\u252c": GraphicsTopT, "\u250c\u2534": GraphicsCross, "\u250c\u253c": GraphicsCross, "\u2510\u2514": GraphicsCross, "\u2510\u2518": GraphicsRightT, "\u2510\u251c": GraphicsCross, "\u2510\u2524": GraphicsRightT, "\u2510\u252c": GraphicsTopT, "\u2510\u2534": GraphicsCross, "\u2510\u253c": GraphicsCross, "\u2514\u2518": GraphicsBottomT, "\u2514\u251c": GraphicsLeftT, "\u2514\u2524": GraphicsCross, "\u2514\u252c": GraphicsCross, "\u2514\u2534": GraphicsBottomT, "\u2514\u253c": GraphicsCross, "\u2518\u251c": GraphicsCross, "\u2518\u2524": GraphicsRightT, "\u2518\u252c": GraphicsCross, "\u2518\u2534": GraphicsBottomT, "\u2518\u253c": GraphicsCross, "\u251c\u2524": GraphicsCross, "\u251c\u252c": GraphicsCross, "\u251c\u2534": GraphicsCross, "\u251c\u253c": GraphicsCross, "\u2524\u252c": GraphicsCross, "\u2524\u2534": GraphicsCross, "\u2524\u253c": GraphicsCross, "\u252c\u2534": GraphicsCross, "\u252c\u253c": GraphicsCross, "\u2534\u253c": GraphicsCross, } // Common regular expressions. var ( colorPattern = regexp.MustCompile(`\[([a-zA-Z]+|#[0-9a-zA-Z]{6}|\-)?(:([a-zA-Z]+|#[0-9a-zA-Z]{6}|\-)?(:([lbdru]+|\-)?)?)?\]`) regionPattern = regexp.MustCompile(`\["([a-zA-Z0-9_,;: \-\.]*)"\]`) escapePattern = regexp.MustCompile(`\[([a-zA-Z0-9_,;: \-\."#]+)\[(\[*)\]`) nonEscapePattern = regexp.MustCompile(`(\[[a-zA-Z0-9_,;: \-\."#]+\[*)\]`) boundaryPattern = regexp.MustCompile("([[:punct:]]\\s*|\\s+)") spacePattern = regexp.MustCompile(`\s+`) ) // Positions of substrings in regular expressions. const ( colorForegroundPos = 1 colorBackgroundPos = 3 colorFlagPos = 5 ) // Predefined InputField acceptance functions. 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 == "." || 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 } } } // styleFromTag takes the given style, defined by a foreground color (fgColor), // a background color (bgColor), and style attributes, and modifies it based on // the substrings (tagSubstrings) extracted by the regular expression for color // tags. The new colors and attributes are returned where empty strings mean // "don't modify" and a dash ("-") means "reset to default". func styleFromTag(fgColor, bgColor, attributes string, tagSubstrings []string) (newFgColor, newBgColor, newAttributes string) { if tagSubstrings[colorForegroundPos] != "" { color := tagSubstrings[colorForegroundPos] if color == "-" { fgColor = "-" } else if color != "" { fgColor = color } } if tagSubstrings[colorBackgroundPos-1] != "" { color := tagSubstrings[colorBackgroundPos] if color == "-" { bgColor = "-" } else if color != "" { bgColor = color } } if tagSubstrings[colorFlagPos-1] != "" { flags := tagSubstrings[colorFlagPos] if flags == "-" { attributes = "-" } else if flags != "" { attributes = flags } } return fgColor, bgColor, attributes } // overlayStyle mixes a background color with a foreground color (fgColor), // a (possibly new) background color (bgColor), and style attributes, and // returns the resulting style. For a definition of the colors and attributes, // see styleFromTag(). Reset instructions cause the corresponding part of the // default style to be used. func overlayStyle(background tcell.Color, defaultStyle tcell.Style, fgColor, bgColor, attributes string) tcell.Style { defFg, defBg, defAttr := defaultStyle.Decompose() style := defaultStyle.Background(background) if fgColor == "-" { style = style.Foreground(defFg) } else if fgColor != "" { style = style.Foreground(tcell.GetColor(fgColor)) } if bgColor == "-" { style = style.Background(defBg) } else if bgColor != "" { style = style.Background(tcell.GetColor(bgColor)) } if attributes == "-" { style = style.Bold(defAttr&tcell.AttrBold > 0) style = style.Blink(defAttr&tcell.AttrBlink > 0) style = style.Reverse(defAttr&tcell.AttrReverse > 0) style = style.Underline(defAttr&tcell.AttrUnderline > 0) style = style.Dim(defAttr&tcell.AttrDim > 0) } else if attributes != "" { style = style.Normal() for _, flag := range attributes { switch flag { case 'l': style = style.Blink(true) case 'b': style = style.Bold(true) case 'd': style = style.Dim(true) case 'r': style = style.Reverse(true) case 'u': style = style.Underline(true) } } } return style } // decomposeString returns information about a string which may contain color // tags. It returns the indices of the color tags (as returned by // re.FindAllStringIndex()), the color tags themselves (as returned by // re.FindAllStringSubmatch()), the indices of an escaped tags, the string // stripped by any color tags and escaped, and the screen width of the stripped // string. func decomposeString(text string) (colorIndices [][]int, colors [][]string, escapeIndices [][]int, stripped string, width int) { // Get positions of color and escape tags. colorIndices = colorPattern.FindAllStringIndex(text, -1) colors = colorPattern.FindAllStringSubmatch(text, -1) escapeIndices = escapePattern.FindAllStringIndex(text, -1) // Because the color pattern detects empty tags, we need to filter them out. for i := len(colorIndices) - 1; i >= 0; i-- { if colorIndices[i][1]-colorIndices[i][0] == 2 { colorIndices = append(colorIndices[:i], colorIndices[i+1:]...) colors = append(colors[:i], colors[i+1:]...) } } // Remove the color tags from the original string. var from int buf := make([]byte, 0, len(text)) for _, indices := range colorIndices { buf = append(buf, []byte(text[from:indices[0]])...) from = indices[1] } buf = append(buf, text[from:]...) // Escape string. stripped = string(escapePattern.ReplaceAll(buf, []byte("[$1$2]"))) // Get the width of the stripped string. width = runewidth.StringWidth(stripped) return } // Print prints text onto the screen into the given box at (x,y,maxWidth,1), // not exceeding that box. "align" is one of AlignLeft, AlignCenter, or // AlignRight. The screen's background color will not be changed. // // You can change the colors and text styles mid-text by inserting a color tag. // See the package description for details. // // Returns the number of actual runes printed (not including color tags) and the // actual width used for the printed runes. func Print(screen tcell.Screen, text string, x, y, maxWidth, align int, color tcell.Color) (int, int) { return printWithStyle(screen, text, x, y, maxWidth, align, tcell.StyleDefault.Foreground(color)) } // printWithStyle works like Print() but it takes a style instead of just a // foreground color. func printWithStyle(screen tcell.Screen, text string, x, y, maxWidth, align int, style tcell.Style) (int, int) { if maxWidth <= 0 || len(text) == 0 { return 0, 0 } // Decompose the text. colorIndices, colors, escapeIndices, strippedText, _ := decomposeString(text) // We deal with runes, not with bytes. runes := []rune(strippedText) // This helper function takes positions for a substring of "runes" and returns // a new string corresponding to this substring, making sure printing that // substring will observe color tags. substring := func(from, to int) string { var ( colorPos, escapePos, runePos, startPos int foregroundColor, backgroundColor, attributes string ) if from >= len(runes) { return "" } for pos := range text { // Handle color tags. if colorPos < len(colorIndices) && pos >= colorIndices[colorPos][0] && pos < colorIndices[colorPos][1] { if pos == colorIndices[colorPos][1]-1 { if runePos <= from { foregroundColor, backgroundColor, attributes = styleFromTag(foregroundColor, backgroundColor, attributes, colors[colorPos]) } colorPos++ } continue } // Handle escape tags. if escapePos < len(escapeIndices) && pos >= escapeIndices[escapePos][0] && pos < escapeIndices[escapePos][1] { if pos == escapeIndices[escapePos][1]-1 { escapePos++ } else if pos == escapeIndices[escapePos][1]-2 { continue } } // Check boundaries. if runePos == from { startPos = pos } else if runePos >= to { return fmt.Sprintf(`[%s:%s:%s]%s`, foregroundColor, backgroundColor, attributes, text[startPos:pos]) } runePos++ } return fmt.Sprintf(`[%s:%s:%s]%s`, foregroundColor, backgroundColor, attributes, text[startPos:]) } // We want to reduce everything to AlignLeft. if align == AlignRight { width := 0 start := len(runes) for index := start - 1; index >= 0; index-- { w := runewidth.RuneWidth(runes[index]) if width+w > maxWidth { break } width += w start = index } for start < len(runes) && runewidth.RuneWidth(runes[start]) == 0 { start++ } return printWithStyle(screen, substring(start, len(runes)), x+maxWidth-width, y, width, AlignLeft, style) } else if align == AlignCenter { width := runewidth.StringWidth(strippedText) if width == maxWidth { // Use the exact space. return printWithStyle(screen, text, x, y, maxWidth, AlignLeft, style) } else if width < maxWidth { // We have more space than we need. half := (maxWidth - width) / 2 return printWithStyle(screen, text, x+half, y, maxWidth-half, AlignLeft, style) } else { // Chop off runes until we have a perfect fit. var choppedLeft, choppedRight, leftIndex, rightIndex int rightIndex = len(runes) - 1 for rightIndex > leftIndex && width-choppedLeft-choppedRight > maxWidth { if choppedLeft < choppedRight { leftWidth := runewidth.RuneWidth(runes[leftIndex]) choppedLeft += leftWidth leftIndex++ for leftIndex < len(runes) && leftIndex < rightIndex && runewidth.RuneWidth(runes[leftIndex]) == 0 { leftIndex++ } } else { rightWidth := runewidth.RuneWidth(runes[rightIndex]) choppedRight += rightWidth rightIndex-- } } return printWithStyle(screen, substring(leftIndex, rightIndex), x, y, maxWidth, AlignLeft, style) } } // Draw text. drawn := 0 drawnWidth := 0 var ( colorPos, escapePos int foregroundColor, backgroundColor, attributes string ) runeSequence := make([]rune, 0, 10) runeSeqWidth := 0 flush := func() { if len(runeSequence) == 0 { return // Nothing to flush. } // Print the rune sequence. finalX := x + drawnWidth _, _, finalStyle, _ := screen.GetContent(finalX, y) _, background, _ := finalStyle.Decompose() finalStyle = overlayStyle(background, style, foregroundColor, backgroundColor, attributes) var comb []rune if len(runeSequence) > 1 { // Allocate space for the combining characters only when necessary. comb = make([]rune, len(runeSequence)-1) copy(comb, runeSequence[1:]) } for offset := 0; offset < runeSeqWidth; offset++ { // To avoid undesired effects, we place the same character in all cells. screen.SetContent(finalX+offset, y, runeSequence[0], comb, finalStyle) } // Advance and reset. drawn += len(runeSequence) drawnWidth += runeSeqWidth runeSequence = runeSequence[:0] runeSeqWidth = 0 } for pos, ch := range text { // Handle color tags. if colorPos < len(colorIndices) && pos >= colorIndices[colorPos][0] && pos < colorIndices[colorPos][1] { flush() if pos == colorIndices[colorPos][1]-1 { foregroundColor, backgroundColor, attributes = styleFromTag(foregroundColor, backgroundColor, attributes, colors[colorPos]) colorPos++ } continue } // Handle escape tags. if escapePos < len(escapeIndices) && pos >= escapeIndices[escapePos][0] && pos < escapeIndices[escapePos][1] { flush() if pos == escapeIndices[escapePos][1]-1 { escapePos++ } else if pos == escapeIndices[escapePos][1]-2 { continue } } // Check if we have enough space for this rune. chWidth := runewidth.RuneWidth(ch) if drawnWidth+chWidth > maxWidth { break // No. We're done then. } // Put this rune in the queue. if chWidth == 0 { // If this is not a modifier, we treat it as a space character. if len(runeSequence) == 0 { ch = ' ' chWidth = 1 } } else { // We have a character. Flush all previous runes. flush() } runeSequence = append(runeSequence, ch) runeSeqWidth += chWidth } if drawnWidth+runeSeqWidth <= maxWidth { flush() } return drawn, drawnWidth } // 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.MaxInt32, AlignLeft, Styles.PrimaryTextColor) } // StringWidth returns the width of the given string needed to print it on // screen. The text may contain color tags which are not counted. func StringWidth(text string) int { _, _, _, _, width := decomposeString(text) return width } // WordWrap splits a text such that each resulting line does not exceed the // given screen width. Possible split points are after any punctuation or // whitespace. Whitespace after split points will be dropped. // // This function considers color tags to have no width. // // Text is always split at newline characters ('\n'). func WordWrap(text string, width int) (lines []string) { colorTagIndices, _, escapeIndices, strippedText, _ := decomposeString(text) // Find candidate breakpoints. breakPoints := boundaryPattern.FindAllStringIndex(strippedText, -1) // This helper function adds a new line to the result slice. The provided // positions are in stripped index space. addLine := func(from, to int) { // Shift indices back to original index space. var colorTagIndex, escapeIndex int for colorTagIndex < len(colorTagIndices) && to >= colorTagIndices[colorTagIndex][0] || escapeIndex < len(escapeIndices) && to >= escapeIndices[escapeIndex][0] { past := 0 if colorTagIndex < len(colorTagIndices) { tagWidth := colorTagIndices[colorTagIndex][1] - colorTagIndices[colorTagIndex][0] if colorTagIndices[colorTagIndex][0] < from { from += tagWidth to += tagWidth colorTagIndex++ } else if colorTagIndices[colorTagIndex][0] < to { to += tagWidth colorTagIndex++ } else { past++ } } else { past++ } if escapeIndex < len(escapeIndices) { tagWidth := escapeIndices[escapeIndex][1] - escapeIndices[escapeIndex][0] if escapeIndices[escapeIndex][0] < from { from += tagWidth to += tagWidth escapeIndex++ } else if escapeIndices[escapeIndex][0] < to { to += tagWidth escapeIndex++ } else { past++ } } else { past++ } if past == 2 { break // All other indices are beyond the requested string. } } lines = append(lines, text[from:to]) } // Determine final breakpoints. var start, lastEnd, newStart, breakPoint int for { // What's our candidate string? var candidate string if breakPoint < len(breakPoints) { candidate = text[start:breakPoints[breakPoint][1]] } else { candidate = text[start:] } candidate = strings.TrimRightFunc(candidate, unicode.IsSpace) if runewidth.StringWidth(candidate) >= width { // We're past the available width. if lastEnd > start { // Use the previous candidate. addLine(start, lastEnd) start = newStart } else { // We have no previous candidate. Make a hard break. var lineWidth int for index, ch := range text { if index < start { continue } chWidth := runewidth.RuneWidth(ch) if lineWidth > 0 && lineWidth+chWidth >= width { addLine(start, index) start = index break } lineWidth += chWidth } } } else { // We haven't hit the right border yet. if breakPoint >= len(breakPoints) { // It's the last line. We're done. if len(candidate) > 0 { addLine(start, len(strippedText)) } break } else { // We have a new candidate. lastEnd = start + len(candidate) newStart = breakPoints[breakPoint][1] breakPoint++ } } } return } // PrintJoinedBorder prints a border graphics rune into the screen at the given // position with the given color, joining it with any existing border graphics // rune. Background colors are preserved. At this point, only regular single // line borders are supported. func PrintJoinedBorder(screen tcell.Screen, x, y int, ch rune, color tcell.Color) { previous, _, style, _ := screen.GetContent(x, y) style = style.Foreground(color) // What's the resulting rune? var result rune if ch == previous { result = ch } else { if ch < previous { previous, ch = ch, previous } result = joints[string(previous)+string(ch)] } if result == 0 { result = ch } // We only print something if we have something. screen.SetContent(x, y, result, nil, style) } // Escape escapes the given text such that color and/or region tags are not // recognized and substituted by the print functions of this package. For // example, to include a tag-like string in a box title or in a TextView: // // box.SetTitle(tview.Escape("[squarebrackets]")) // fmt.Fprint(textView, tview.Escape(`["quoted"]`)) func Escape(text string) string { return nonEscapePattern.ReplaceAllString(text, "$1[]") }