switch to go-term-text to fix bad underflow for label rendering

1 files changed, 334 insertions, 0 deletions

diff --git a/vendor/github.com/MichaelMure/go-term-text/wrap.go b/vendor/github.com/MichaelMure/go-term-text/wrap.go
new file mode 100644
index 00000000..2fd6ed5f
--- /dev/null
+++ b/vendor/github.com/MichaelMure/go-term-text/wrap.go
@@ -0,0 +1,334 @@
+package text
+
+import (
+	"strings"
+
+	"github.com/mattn/go-runewidth"
+)
+
+// Force runewidth not to treat ambiguous runes as wide chars, so that things
+// like unicode ellipsis/up/down/left/right glyphs can have correct runewidth
+// and can be displayed correctly in terminals.
+func init() {
+	runewidth.DefaultCondition.EastAsianWidth = false
+}
+
+// Wrap a text for a given line size.
+// Handle properly terminal color escape code
+func Wrap(text string, lineWidth int) (string, int) {
+	return WrapLeftPadded(text, lineWidth, 0)
+}
+
+// WrapLeftPadded wrap a text for a given line size with a left padding.
+// Handle properly terminal color escape code
+func WrapLeftPadded(text string, lineWidth int, leftPad int) (string, int) {
+	pad := strings.Repeat(" ", leftPad)
+	return WrapWithPad(text, lineWidth, pad)
+}
+
+// WrapWithPad wrap a text for a given line size with a custom left padding
+// Handle properly terminal color escape code
+func WrapWithPad(text string, lineWidth int, pad string) (string, int) {
+	return WrapWithPadIndent(text, lineWidth, pad, pad)
+}
+
+// WrapWithPad wrap a text for a given line size with a custom left padding
+// This function also align the result depending on the requested alignment.
+// Handle properly terminal color escape code
+func WrapWithPadAlign(text string, lineWidth int, pad string, align Alignment) (string, int) {
+	return WrapWithPadIndentAlign(text, lineWidth, pad, pad, align)
+}
+
+// WrapWithPadIndent wrap a text for a given line size with a custom left padding
+// and a first line indent. The padding is not effective on the first line, indent
+// is used instead, which allow to implement indents and outdents.
+// Handle properly terminal color escape code
+func WrapWithPadIndent(text string, lineWidth int, indent string, pad string) (string, int) {
+	return WrapWithPadIndentAlign(text, lineWidth, indent, pad, NoAlign)
+}
+
+// WrapWithPadIndentAlign wrap a text for a given line size with a custom left padding
+// and a first line indent. The padding is not effective on the first line, indent
+// is used instead, which allow to implement indents and outdents.
+// This function also align the result depending on the requested alignment.
+// Handle properly terminal color escape code
+func WrapWithPadIndentAlign(text string, lineWidth int, indent string, pad string, align Alignment) (string, int) {
+	var lines []string
+	nbLine := 0
+
+	// Start with the indent
+	padStr := indent
+	padLen := Len(indent)
+
+	// tabs are formatted as 4 spaces
+	text = strings.Replace(text, "\t", "    ", -1)
+
+	// NOTE: text is first segmented into lines so that softwrapLine can handle.
+	for i, line := range strings.Split(text, "\n") {
+		// on the second line, use the padding instead
+		if i == 1 {
+			padStr = pad
+			padLen = Len(pad)
+		}
+
+		if line == "" || strings.TrimSpace(line) == "" {
+			// nothing in the line, we just add the non-empty part of the padding
+			lines = append(lines, strings.TrimRight(padStr, " "))
+			nbLine++
+			continue
+		}
+
+		wrapped := softwrapLine(line, lineWidth-padLen)
+		split := strings.Split(wrapped, "\n")
+
+		if i == 0 && len(split) > 1 {
+			// the very first line got wrapped
+			// that means we need to switch to the normal padding
+			// use the first wrapped line, ignore everything else and
+			// wrap the remaining of the line with the normal padding.
+
+			content := LineAlign(strings.TrimRight(split[0], " "), lineWidth-padLen, align)
+			lines = append(lines, padStr+content)
+			nbLine++
+			line = strings.TrimPrefix(line, split[0])
+			line = strings.TrimLeft(line, " ")
+
+			padStr = pad
+			padLen = Len(pad)
+			wrapped = softwrapLine(line, lineWidth-padLen)
+			split = strings.Split(wrapped, "\n")
+		}
+
+		for j, seg := range split {
+			if j == 0 {
+				// keep the left padding of the wrapped line
+				content := LineAlign(strings.TrimRight(seg, " "), lineWidth-padLen, align)
+				lines = append(lines, padStr+content)
+			} else {
+				content := LineAlign(strings.TrimSpace(seg), lineWidth-padLen, align)
+				lines = append(lines, padStr+content)
+			}
+			nbLine++
+		}
+	}
+
+	return strings.Join(lines, "\n"), nbLine
+}
+
+// Break a line into several lines so that each line consumes at most
+// 'textWidth' cells.  Lines break at groups of white spaces and multibyte
+// chars. Nothing is removed from the original text so that it behaves like a
+// softwrap.
+//
+// Required: The line shall not contain '\n'
+//
+// WRAPPING ALGORITHM: The line is broken into non-breakable chunks, then line
+// breaks ("\n") are inserted between these groups so that the total length
+// between breaks does not exceed the required width. Words that are longer than
+// the textWidth are broken into pieces no longer than textWidth.
+func softwrapLine(line string, textWidth int) string {
+	escaped, escapes := ExtractTermEscapes(line)
+
+	chunks := segmentLine(escaped)
+	// Reverse the chunk array so we can use it as a stack.
+	for i, j := 0, len(chunks)-1; i < j; i, j = i+1, j-1 {
+		chunks[i], chunks[j] = chunks[j], chunks[i]
+	}
+
+	// for readability, minimal implementation of a stack:
+
+	pop := func() string {
+		result := chunks[len(chunks)-1]
+		chunks = chunks[:len(chunks)-1]
+		return result
+	}
+
+	push := func(chunk string) {
+		chunks = append(chunks, chunk)
+	}
+
+	peek := func() string {
+		return chunks[len(chunks)-1]
+	}
+
+	empty := func() bool {
+		return len(chunks) == 0
+	}
+
+	var out strings.Builder
+
+	// helper to write in the output while interleaving the escape
+	// sequence at the correct places.
+	// note: the final algorithm will add additional line break in the original
+	// text. Those line break are *not* fed to this helper so the positions don't
+	// need to be offset, which make the whole thing much easier.
+	currPos := 0
+	currItem := 0
+	outputString := func(s string) {
+		for _, r := range s {
+			for currItem < len(escapes) && currPos == escapes[currItem].Pos {
+				out.WriteString(escapes[currItem].Item)
+				currItem++
+			}
+			out.WriteRune(r)
+			currPos++
+		}
+	}
+
+	width := 0
+
+	for !empty() {
+		wl := Len(peek())
+
+		if width+wl <= textWidth {
+			// the chunk fit in the available space
+			outputString(pop())
+			width += wl
+			if width == textWidth && !empty() {
+				// only add line break when there is more chunk to come
+				out.WriteRune('\n')
+				width = 0
+			}
+		} else if wl > textWidth {
+			// words too long for a full line are split to fill the remaining space.
+			// But if the long words is the first non-space word in the middle of the
+			// line, preceding spaces shall not be counted in word splitting.
+			splitWidth := textWidth - width
+			if strings.HasSuffix(out.String(), "\n"+strings.Repeat(" ", width)) {
+				splitWidth += width
+			}
+			left, right := splitWord(pop(), splitWidth)
+			// remainder is pushed back to the stack for next round
+			push(right)
+			outputString(left)
+			out.WriteRune('\n')
+			width = 0
+		} else {
+			// normal line overflow, we add a line break and try again
+			out.WriteRune('\n')
+			width = 0
+		}
+	}
+
+	// Don't forget the trailing escapes, if any.
+	for currItem < len(escapes) && currPos >= escapes[currItem].Pos {
+		out.WriteString(escapes[currItem].Item)
+		currItem++
+	}
+
+	return out.String()
+}
+
+// Segment a line into chunks, where each chunk consists of chars with the same
+// type and is not breakable.
+func segmentLine(s string) []string {
+	var chunks []string
+
+	var word string
+	wordType := none
+	flushWord := func() {
+		chunks = append(chunks, word)
+		word = ""
+		wordType = none
+	}
+
+	for _, r := range s {
+		// A WIDE_CHAR itself constitutes a chunk.
+		thisType := runeType(r)
+		if thisType == wideChar {
+			if wordType != none {
+				flushWord()
+			}
+			chunks = append(chunks, string(r))
+			continue
+		}
+		// Other type of chunks starts with a char of that type, and ends with a
+		// char with different type or end of string.
+		if thisType != wordType {
+			if wordType != none {
+				flushWord()
+			}
+			word = string(r)
+			wordType = thisType
+		} else {
+			word += string(r)
+		}
+	}
+	if word != "" {
+		flushWord()
+	}
+
+	return chunks
+}
+
+type RuneType int
+
+// Rune categories
+//
+// These categories are so defined that each category forms a non-breakable
+// chunk. It IS NOT the same as unicode code point categories.
+const (
+	none RuneType = iota
+	wideChar
+	invisible
+	shortUnicode
+	space
+	visibleAscii
+)
+
+// Determine the category of a rune.
+func runeType(r rune) RuneType {
+	rw := runewidth.RuneWidth(r)
+	if rw > 1 {
+		return wideChar
+	} else if rw == 0 {
+		return invisible
+	} else if r > 127 {
+		return shortUnicode
+	} else if r == ' ' {
+		return space
+	} else {
+		return visibleAscii
+	}
+}
+
+// splitWord split a word at the given length, while ignoring the terminal escape sequences
+func splitWord(word string, length int) (string, string) {
+	runes := []rune(word)
+	var result []rune
+	added := 0
+	escape := false
+
+	if length == 0 {
+		return "", word
+	}
+
+	for _, r := range runes {
+		if r == '\x1b' {
+			escape = true
+		}
+
+		width := runewidth.RuneWidth(r)
+		if width+added > length {
+			// wide character made the length overflow
+			break
+		}
+
+		result = append(result, r)
+
+		if !escape {
+			added += width
+			if added >= length {
+				break
+			}
+		}
+
+		if r == 'm' {
+			escape = false
+		}
+	}
+
+	leftover := runes[len(result):]
+
+	return string(result), string(leftover)
+}