From 83290714f76a990010ead7c87daeda2b5707e5df Mon Sep 17 00:00:00 2001
From: drmpf <drmpf@users.noreply.github.com>
Date: Tue, 29 Dec 2020 15:22:52 +1100
Subject: [PATCH] availableForWrite

added availableForWrite to Print.h to make compatible with Arduino Print.h
---
 cores/esp32/Print.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/cores/esp32/Print.h b/cores/esp32/Print.h
index 15d07357ae9..4493d4f819f 100644
--- a/cores/esp32/Print.h
+++ b/cores/esp32/Print.h
@@ -73,6 +73,11 @@ class Print
     }
 
     size_t printf(const char * format, ...)  __attribute__ ((format (printf, 2, 3)));
+
+    // add availableForWrite to make compatible with Arduino Print.h
+    // default to zero, meaning "a single write may block"
+    // should be overriden by subclasses with buffering
+    virtual int availableForWrite() { return 0; }
     size_t print(const __FlashStringHelper *);
     size_t print(const String &);
     size_t print(const char[]);