feat: Added syntax highlighting to textfile widget.

textfile/widget.go

@@ -1,12 +1,16 @@
 package textfile
 
 import (
+	"bytes"
 	"fmt"
 	"io/ioutil"
+	"os"
+	"strings"
 
 	"github.com/gdamore/tcell"
 	"github.com/rivo/tview"
 	"github.com/senorprogrammer/wtf/wtf"
+	"github.com/zyedidia/highlight"
 )
 
 const HelpText = `
@@ -57,7 +61,87 @@ func (widget *Widget) Refresh() {
 	if err != nil {
 		widget.View.SetText(err.Error())
 	} else {
-		widget.View.SetText(string(fileData))
+		var (
+			defs   []*highlight.Def
+			buffer bytes.Buffer
+		)
+
+		gopath := os.Getenv("GOPATH")
+		files, err := ioutil.ReadDir(gopath + "/src/github.com/senorprogrammer/wtf/vendor/github.com/zyedidia/highlight/syntax_files")
+		if err != nil {
+			widget.View.SetText(err.Error())
+			return
+		}
+
+		// Iterate over available syntax files if any def matches.
+		for _, f := range files {
+			if strings.HasSuffix(f.Name(), ".yaml") {
+				input, _ := ioutil.ReadFile(gopath + "/src/github.com/senorprogrammer/wtf/vendor/github.com/zyedidia/highlight/syntax_files/" + f.Name())
+				d, err := highlight.ParseDef(input)
+				if err != nil {
+					fmt.Println(err)
+					continue
+				}
+				defs = append(defs, d)
+			}
+		}
+
+		highlight.ResolveIncludes(defs)
+		// Attempt to detect the filetype.
+		def := highlight.DetectFiletype(defs, filePath, bytes.Split(fileData, []byte("\n"))[0])
+		// If no highlighter found, dont modify.
+		if def == nil {
+			widget.View.SetText(string(fileData))
+			return
+		}
+
+		// Add highlight information to the text based on matches.
+		h := highlight.NewHighlighter(def)
+		matches := h.HighlightString(string(fileData))
+
+		lines := strings.Split(string(fileData), "\n")
+		for lineN, l := range lines {
+			colN := 0
+			for _, c := range l {
+				if group, ok := matches[lineN][colN]; ok {
+					// There are more possible groups available than just these ones
+					if group == highlight.Groups["statement"] {
+						buffer.WriteString("[green]")
+					} else if group == highlight.Groups["identifier"] {
+						buffer.WriteString("[blue]")
+					} else if group == highlight.Groups["preproc"] {
+						buffer.WriteString("[darkred]")
+					} else if group == highlight.Groups["special"] {
+						buffer.WriteString("[red]")
+					} else if group == highlight.Groups["constant.string"] {
+						buffer.WriteString("[cyan]")
+					} else if group == highlight.Groups["constant"] {
+						buffer.WriteString("[lightcyan]")
+					} else if group == highlight.Groups["constant.specialChar"] {
+						buffer.WriteString("[magenta]")
+					} else if group == highlight.Groups["type"] {
+						buffer.WriteString("[yellow]")
+					} else if group == highlight.Groups["constant.number"] {
+						buffer.WriteString("[darkcyan]")
+					} else if group == highlight.Groups["comment"] {
+						buffer.WriteString("[darkgreen]")
+					} else {
+						buffer.WriteString("[default]")
+					}
+				}
+				buffer.WriteString(string(c))
+				colN++
+			}
+			if group, ok := matches[lineN][colN]; ok {
+				if group == highlight.Groups["default"] || group == highlight.Groups[""] {
+					buffer.WriteString("[default]") // Handle default fallback after setting.
+				}
+			}
+
+			buffer.WriteString("\n")
+		}
+
+		widget.View.SetText(buffer.String())
 	}
 }