locks + message helper rename

contactcard.go

@@ -159,10 +159,10 @@ func (Contact *ContactCard) WriteQr(filename string) error {
 	return nil
 }
 
-func ReadQr(Filename string) ContactCard {
+func ReadQr(filename string) *ContactCard {
 	var contact ContactCard
 	// open and decode image file
-	file, _ := os.Open("qrcode.jpg")
+	file, _ := os.Open(filename)
 	img, _, _ := image.Decode(file)
 
 	// prepare BinaryBitmap
@@ -173,5 +173,5 @@ func ReadQr(Filename string) ContactCard {
 	result, _ := qrReader.Decode(bmp, nil)
 
 	fmt.Println(result)
-	return contact
+	return &contact
 }