Added MarkdownRenderer.

textRender.go

@@ -0,0 +1,82 @@
+package termui
+
+import (
+	"regexp"
+	"strings"
+)
+
+// TextRender adds common methods for rendering a text on screeen.
+type TextRender interface {
+	NormalizedText(text string) string
+	RenderSequence(text string, lastColor, background Attribute) RenderedSubsequence
+}
+
+type subSecequence struct {
+	start int
+	end   int
+	color Attribute
+}
+
+// MarkdownRegex is used by MarkdownTextRenderer to determine how to format the
+// text.
+const MarkdownRegex = `(?:\[([[a-z]+)\])\(([a-z\s,]+)\)`
+
+// unexported because a pattern can't be a constant and we don't want anyone
+// messing with the regex.
+var markdownPattern = regexp.MustCompile(MarkdownRegex)
+
+// MarkdownTextRenderer is used for rendering the text with colors using
+// markdown-like syntax.
+// See: https://github.com/gizak/termui/issues/4#issuecomment-87270635
+type MarkdownTextRenderer struct{}
+
+// NormalizedText returns the text the user will see (without colors).
+// It strips out all formatting option and only preserves plain text.
+func (r MarkdownTextRenderer) NormalizedText(text string) string {
+	lText := strings.ToLower(text)
+	indexes := markdownPattern.FindAllStringSubmatchIndex(lText, -1)
+
+	// Interate through indexes in reverse order.
+	for i := len(indexes) - 1; i >= 0; i-- {
+		theIndex := indexes[i]
+		start, end := theIndex[0], theIndex[1]
+		contentStart, contentEnd := theIndex[2], theIndex[3]
+
+		text = text[:start] + text[contentStart:contentEnd] + text[end:]
+	}
+
+	return text
+}
+
+// RenderedSubsequence is a string sequence that is capable of returning the
+// Buffer used by termui for displaying the colorful string.
+type RenderedSubsequence struct {
+	RawText         string
+	NormalizedText  string
+	LastColor       Attribute
+	BackgroundColor Attribute
+
+	sequences subSecequence
+}
+
+// Buffer returns the colorful formatted buffer and the last color that was
+// used.
+func (s *RenderedSubsequence) Buffer(x, y int) ([]Point, Attribute) {
+	// var buffer []Point
+	// dx := 0
+	// for _, r := range []rune(s.NormalizedText) {
+	// 	p := Point{
+	// 		Ch: r,
+	// 		X:  x + dx,
+	// 		Y:  y,
+	// 		Fg: Attribute(rand.Intn(8)),
+	// 		Bg: background,
+	// 	}
+	//
+	// 	buffer = append(buffer, p)
+	// 	dx += charWidth(r)
+	// }
+	//
+	// return buffer
+	return nil, s.LastColor
+}