From db286ac0c1305f9f6338acc37da7c24ebdc9243b Mon Sep 17 00:00:00 2001
From: Cristian Maglie <c.maglie@bug.st>
Date: Thu, 6 Jun 2013 15:41:23 +0200
Subject: [PATCH] Added support for Flash string on String class.

---
 cores/arduino/WString.cpp | 44 +++++++++++++++++++++++++++++++++++++++
 cores/arduino/WString.h   |  8 ++++++-
 2 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/cores/arduino/WString.cpp b/cores/arduino/WString.cpp
index 77bdd8a..5951a64 100644
--- a/cores/arduino/WString.cpp
+++ b/cores/arduino/WString.cpp
@@ -38,6 +38,12 @@ String::String(const String &value)
 	*this = value;
 }
 
+String::String(const __FlashStringHelper *pstr)
+{
+	init();
+	*this = pstr;
+}
+
 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 String::String(String &&rval)
 {
@@ -160,6 +166,17 @@ String & String::copy(const char *cstr, unsigned int length)
 	return *this;
 }
 
+String & String::copy(const __FlashStringHelper *pstr, unsigned int length)
+{
+	if (!reserve(length)) {
+		invalidate();
+		return *this;
+	}
+	len = length;
+	strcpy_P(buffer, (const prog_char *)pstr);
+	return *this;
+}
+
 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 void String::move(String &rhs)
 {
@@ -214,6 +231,14 @@ String & String::operator = (const char *cstr)
 	return *this;
 }
 
+String & String::operator = (const __FlashStringHelper *pstr)
+{
+	if (pstr) copy(pstr, strlen_P((const prog_char *)pstr));
+	else invalidate();
+
+	return *this;
+}
+
 /*********************************************/
 /*  concat                                   */
 /*********************************************/
@@ -283,6 +308,18 @@ unsigned char String::concat(unsigned long num)
 	return concat(buf, strlen(buf));
 }
 
+unsigned char String::concat(const __FlashStringHelper * str)
+{
+	if (!str) return 0;
+	int length = strlen_P((const char *) str);
+	if (length == 0) return 1;
+	unsigned int newlen = len + length;
+	if (!reserve(newlen)) return 0;
+	strcpy_P(buffer + len, (const char *) str);
+	len = newlen;
+	return 1;
+}
+
 /*********************************************/
 /*  Concatenate                              */
 /*********************************************/
@@ -343,6 +380,13 @@ StringSumHelper & operator + (const StringSumHelper &lhs, unsigned long num)
 	return a;
 }
 
+StringSumHelper & operator + (const StringSumHelper &lhs, const __FlashStringHelper *rhs)
+{
+	StringSumHelper &a = const_cast<StringSumHelper&>(lhs);
+	if (!a.concat(rhs))	a.invalidate();
+	return a;
+}
+
 /*********************************************/
 /*  Comparison                               */
 /*********************************************/
diff --git a/cores/arduino/WString.h b/cores/arduino/WString.h
index 8938bf9..c07e1a9 100644
--- a/cores/arduino/WString.h
+++ b/cores/arduino/WString.h
@@ -58,6 +58,7 @@ public:
 	// be false).
 	String(const char *cstr = "");
 	String(const String &str);
+	String(const __FlashStringHelper *str);
 	#ifdef __GXX_EXPERIMENTAL_CXX0X__
 	String(String &&rval);
 	String(StringSumHelper &&rval);
@@ -82,6 +83,7 @@ public:
 	// marked as invalid ("if (s)" will be false).
 	String & operator = (const String &rhs);
 	String & operator = (const char *cstr);
+	String & operator = (const __FlashStringHelper *str);
 	#ifdef __GXX_EXPERIMENTAL_CXX0X__
 	String & operator = (String &&rval);
 	String & operator = (StringSumHelper &&rval);
@@ -100,17 +102,19 @@ public:
 	unsigned char concat(unsigned int num);
 	unsigned char concat(long num);
 	unsigned char concat(unsigned long num);
+	unsigned char concat(const __FlashStringHelper * str);
 	
 	// if there's not enough memory for the concatenated value, the string
 	// will be left unchanged (but this isn't signalled in any way)
 	String & operator += (const String &rhs)	{concat(rhs); return (*this);}
 	String & operator += (const char *cstr)		{concat(cstr); return (*this);}
 	String & operator += (char c)			{concat(c); return (*this);}
-	String & operator += (unsigned char num)		{concat(num); return (*this);}
+	String & operator += (unsigned char num)	{concat(num); return (*this);}
 	String & operator += (int num)			{concat(num); return (*this);}
 	String & operator += (unsigned int num)		{concat(num); return (*this);}
 	String & operator += (long num)			{concat(num); return (*this);}
 	String & operator += (unsigned long num)	{concat(num); return (*this);}
+	String & operator += (const __FlashStringHelper *str){concat(str); return (*this);}
 
 	friend StringSumHelper & operator + (const StringSumHelper &lhs, const String &rhs);
 	friend StringSumHelper & operator + (const StringSumHelper &lhs, const char *cstr);
@@ -120,6 +124,7 @@ public:
 	friend StringSumHelper & operator + (const StringSumHelper &lhs, unsigned int num);
 	friend StringSumHelper & operator + (const StringSumHelper &lhs, long num);
 	friend StringSumHelper & operator + (const StringSumHelper &lhs, unsigned long num);
+	friend StringSumHelper & operator + (const StringSumHelper &lhs, const __FlashStringHelper *rhs);
 
 	// comparison (only works w/ Strings and "strings")
 	operator StringIfHelperType() const { return buffer ? &String::StringIfHelper : 0; }
@@ -184,6 +189,7 @@ protected:
 
 	// copy and move
 	String & copy(const char *cstr, unsigned int length);
+	String & copy(const __FlashStringHelper *pstr, unsigned int length);
 	#ifdef __GXX_EXPERIMENTAL_CXX0X__
 	void move(String &rhs);
 	#endif