From cd037d914920420f611e8ec06e4f2fec33e6f61d Mon Sep 17 00:00:00 2001
From: Project Nayuki <me@nayuki.io>
Date: Wed, 28 Jul 2021 17:09:16 +0000
Subject: [PATCH] In C++ version: moved QrCode.toSvgString() out of the library
 and into the runnable demo program, slightly adapted some code, updated
 documentation comments.

---
 Readme.markdown             |  4 ++--
 cpp/QrCode.cpp              | 28 ----------------------------
 cpp/QrCode.hpp              |  7 -------
 cpp/QrCodeGeneratorDemo.cpp | 35 ++++++++++++++++++++++++++++++++++-
 4 files changed, 36 insertions(+), 38 deletions(-)

diff --git a/Readme.markdown b/Readme.markdown
index 6fe5a38..c48fb61 100644
--- a/Readme.markdown
+++ b/Readme.markdown
@@ -18,7 +18,7 @@ Core features:
 * Available in 6 programming languages, all with nearly equal functionality: Java, TypeScript/JavaScript, Python, Rust, C++, C
 * Significantly shorter code but more documentation comments compared to competing libraries
 * Supports encoding all 40 versions (sizes) and all 4 error correction levels, as per the QR Code Model 2 standard
-* Output formats: Raw modules/pixels of the QR symbol (all languages), SVG XML string (all languages except C)
+* Output format: Raw modules/pixels of the QR symbol
 * Detects finder-like penalty patterns more accurately than other implementations
 * Encodes numeric and special-alphanumeric text in less space than general text
 * Open source code under the permissive MIT License
@@ -105,7 +105,7 @@ C++ language:
     
     // Simple operation
     QrCode qr0 = QrCode::encodeText("Hello, world!", QrCode::Ecc::MEDIUM);
-    std::string svg = qr0.toSvgString(4);
+    std::string svg = toSvgString(qr0, 4);  // See QrCodeGeneratorDemo
     
     // Manual operation
     std::vector<QrSegment> segs =
diff --git a/cpp/QrCode.cpp b/cpp/QrCode.cpp
index 538204e..ada5969 100644
--- a/cpp/QrCode.cpp
+++ b/cpp/QrCode.cpp
@@ -385,34 +385,6 @@ bool QrCode::getModule(int x, int y) const {
 }
 
 
-std::string QrCode::toSvgString(int border) const {
-	if (border < 0)
-		throw std::domain_error("Border must be non-negative");
-	if (border > INT_MAX / 2 || border * 2 > INT_MAX - size)
-		throw std::overflow_error("Border too large");
-	
-	std::ostringstream sb;
-	sb << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";
-	sb << "<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\" \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n";
-	sb << "<svg xmlns=\"http://www.w3.org/2000/svg\" version=\"1.1\" viewBox=\"0 0 ";
-	sb << (size + border * 2) << " " << (size + border * 2) << "\" stroke=\"none\">\n";
-	sb << "\t<rect width=\"100%\" height=\"100%\" fill=\"#FFFFFF\"/>\n";
-	sb << "\t<path d=\"";
-	for (int y = 0; y < size; y++) {
-		for (int x = 0; x < size; x++) {
-			if (getModule(x, y)) {
-				if (x != 0 || y != 0)
-					sb << " ";
-				sb << "M" << (x + border) << "," << (y + border) << "h1v1h-1z";
-			}
-		}
-	}
-	sb << "\" fill=\"#000000\"/>\n";
-	sb << "</svg>\n";
-	return sb.str();
-}
-
-
 void QrCode::drawFunctionPatterns() {
 	// Draw horizontal and vertical timing patterns
 	for (int i = 0; i < size; i++) {
diff --git a/cpp/QrCode.hpp b/cpp/QrCode.hpp
index 2a1e987..8a71501 100644
--- a/cpp/QrCode.hpp
+++ b/cpp/QrCode.hpp
@@ -369,13 +369,6 @@ class QrCode final {
 	public: bool getModule(int x, int y) const;
 	
 	
-	/* 
-	 * Returns a string of SVG code for an image depicting this QR Code, with the given number
-	 * of border modules. The string always uses Unix newlines (\n), regardless of the platform.
-	 */
-	public: std::string toSvgString(int border) const;
-	
-	
 	
 	/*---- Private helper methods for constructor: Drawing function modules ----*/
 	
diff --git a/cpp/QrCodeGeneratorDemo.cpp b/cpp/QrCodeGeneratorDemo.cpp
index 017dcbe..3419902 100644
--- a/cpp/QrCodeGeneratorDemo.cpp
+++ b/cpp/QrCodeGeneratorDemo.cpp
@@ -24,10 +24,12 @@
  *   Software.
  */
 
+#include <climits>
 #include <cstdint>
 #include <cstdlib>
 #include <cstring>
 #include <iostream>
+#include <sstream>
 #include <string>
 #include <vector>
 #include "QrCode.hpp"
@@ -42,6 +44,7 @@ static void doBasicDemo();
 static void doVarietyDemo();
 static void doSegmentDemo();
 static void doMaskDemo();
+static std::string toSvgString(const QrCode &qr, int border);
 static void printQr(const QrCode &qr);
 
 
@@ -66,7 +69,7 @@ static void doBasicDemo() {
 	// Make and print the QR Code symbol
 	const QrCode qr = QrCode::encodeText(text, errCorLvl);
 	printQr(qr);
-	std::cout << qr.toSvgString(4) << std::endl;
+	std::cout << toSvgString(qr, 4) << std::endl;
 }
 
 
@@ -186,6 +189,36 @@ static void doMaskDemo() {
 
 /*---- Utilities ----*/
 
+// Returns a string of SVG code for an image depicting the given QR Code, with the given number
+// of border modules. The string always uses Unix newlines (\n), regardless of the platform.
+static std::string toSvgString(const QrCode &qr, int border) {
+	if (border < 0)
+		throw std::domain_error("Border must be non-negative");
+	if (border > INT_MAX / 2 || border * 2 > INT_MAX - qr.getSize())
+		throw std::overflow_error("Border too large");
+	
+	std::ostringstream sb;
+	sb << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";
+	sb << "<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\" \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n";
+	sb << "<svg xmlns=\"http://www.w3.org/2000/svg\" version=\"1.1\" viewBox=\"0 0 ";
+	sb << (qr.getSize() + border * 2) << " " << (qr.getSize() + border * 2) << "\" stroke=\"none\">\n";
+	sb << "\t<rect width=\"100%\" height=\"100%\" fill=\"#FFFFFF\"/>\n";
+	sb << "\t<path d=\"";
+	for (int y = 0; y < qr.getSize(); y++) {
+		for (int x = 0; x < qr.getSize(); x++) {
+			if (qr.getModule(x, y)) {
+				if (x != 0 || y != 0)
+					sb << " ";
+				sb << "M" << (x + border) << "," << (y + border) << "h1v1h-1z";
+			}
+		}
+	}
+	sb << "\" fill=\"#000000\"/>\n";
+	sb << "</svg>\n";
+	return sb.str();
+}
+
+
 // Prints the given QrCode object to the console.
 static void printQr(const QrCode &qr) {
 	int border = 4;