From dab8c6144c646f6179ab32fff83c28e04bde3314 Mon Sep 17 00:00:00 2001
From: MCUdude <mcudude@users.noreply.github.com>
Date: Thu, 28 Feb 2019 17:54:03 +0100
Subject: [PATCH] Add printf to print class

---
 api/Print.cpp | 28 ++++++++++++++++++++++++++++
 api/Print.h   |  5 ++++-
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/api/Print.cpp b/api/Print.cpp
index 4f0016c4..bef414a6 100644
--- a/api/Print.cpp
+++ b/api/Print.cpp
@@ -233,6 +233,34 @@ size_t Print::println(const Printable& x)
   return n;
 }
 
+static int16_t printf_putchar(char c, FILE *fp)
+{
+  ((class Print *)(fdev_get_udata(fp)))->write((uint8_t)c);
+  return 0;
+}
+
+int16_t Print::printf(const char *format, ...)
+{
+  FILE f;
+  va_list ap;
+
+  fdev_setup_stream(&f, printf_putchar, NULL, _FDEV_SETUP_WRITE);
+  fdev_set_udata(&f, this);
+  va_start(ap, format);
+  return vfprintf(&f, format, ap);
+}
+
+int16_t Print::printf(const __FlashStringHelper *format, ...)
+{
+  FILE f;
+  va_list ap;
+
+  fdev_setup_stream(&f, printf_putchar, NULL, _FDEV_SETUP_WRITE);
+  fdev_set_udata(&f, this);
+  va_start(ap, format);
+  return vfprintf_P(&f, (const char *)format, ap);
+}
+
 // Private Methods /////////////////////////////////////////////////////////////
 
 size_t Print::printNumber(unsigned long n, uint8_t base)
diff --git a/api/Print.h b/api/Print.h
index 6a06bad6..5355cbc1 100644
--- a/api/Print.h
+++ b/api/Print.h
@@ -20,7 +20,7 @@
 
 #include <inttypes.h>
 #include <stdio.h> // for size_t
-
+#include <stdarg.h>
 #include "String.h"
 #include "Printable.h"
 
@@ -82,5 +82,8 @@ class Print
     size_t println(double, int = 2);
     size_t println(const Printable&);
     size_t println(void);
+
+    int16_t printf(const char *format, ...);
+    int16_t printf(const __FlashStringHelper *format, ...);
 };