Support single-user WriteFreely instances

This removes the requirement to supply a username.

cmd/wfgraphic-cli/main.go

@@ -24,19 +24,13 @@ var (
 	outputFile = flag.String("o", "out.png", "Image output filename")
 	font       = flag.String("font", "serif", "Post font (options: \"serif\", \"sans\", \"mono\") - NOT IMPLEMENTED YET")
 	instance   = flag.String("i", "write.as", "WriteFreely instance hostname (e.g. pencil.writefree.ly)")
-	author     = flag.String("u", "", "WriteFreely author username")
+	author     = flag.String("u", "", "WriteFreely author username (for multi-user instances)")
 )
 
 func main() {
 	log.Info("Starting...")
 	flag.Parse()
 
-	if *author == "" {
-		log.Info("Aborting. -u flag is required")
-		flag.Usage()
-		os.Exit(1)
-	}
-
 	log.Info("Reading input...")
 	in, err := ioutil.ReadAll(os.Stdin)
 	if err != nil {

textpic.go

@@ -73,7 +73,10 @@ func GenerateImage(opt *ContentOptions, outputFilename string) error {
 	}
 	dc.SetColor(color.Black)
 
-	userPath := "/" + opt.Username
+	var userPath = ""
+	if opt.Username != "" {
+		userPath = "/" + opt.Username
+	}
 	userTextWidth, _ := dc.MeasureString(userPath)
 	// x = canvas halfway point - total text width halfway point
 	x = wf/2 - (baseTextWidth+userTextWidth)/2