qrcode example

fix boostorg#419

doc/qbk/6.0.examples.qbk

@@ -12,6 +12,10 @@
 [section Examples]
 [block'''<?dbhtml stop-chunking?>''']
 
+[section Qr Code]
+[example_qrcode]
+[endsect]
+
 [section Magnet Link]
 [example_magnet]
 [endsect]

example/CMakeLists.txt

@@ -7,5 +7,6 @@
 # Official repository: https://github.com/boostorg/url
 #
 
+add_subdirectory(qrcode)
 add_subdirectory(magnet)
 add_subdirectory(route)

example/Jamfile

@@ -7,5 +7,6 @@
 # Official repository: https://github.com/boostorg/url
 #
 
+build-project qrcode ;
 build-project magnet ;
 build-project route ;

example/qrcode/CMakeLists.txt

@@ -0,0 +1,19 @@
+#
+# Copyright (c) 2022 Alan de Freitas (alandefreitas@gmail.com)
+#
+# Distributed under the Boost Software License, Version 1.0. (See accompanying
+# file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+#
+# Official repository: https://github.com/boostorg/url
+#
+
+source_group("" FILES
+        qrcode.cpp
+        )
+
+add_executable(qrcode
+        qrcode.cpp
+        )
+
+set_property(TARGET qrcode PROPERTY FOLDER "Examples")
+target_link_libraries(qrcode PRIVATE Boost::url)

example/qrcode/Jamfile

@@ -0,0 +1,17 @@
+#
+# Copyright (c) 2022 Alan de Freitas (alandefreitas@gmail.com)
+#
+# Distributed under the Boost Software License, Version 1.0. (See accompanying
+# file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+#
+# Official repository: https://github.com/boostorg/url
+#
+
+project : requirements  ;
+
+project
+    : requirements
+      <library>/boost/url//boost_url
+    ;
+
+exe qrcode : qrcode.cpp ;

example/qrcode/qrcode.cpp

@@ -0,0 +1,87 @@
+//
+// Copyright (c) 2022 alandefreitas (alandefreitas@gmail.com)
+//
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+//
+
+//[example_qrcode
+
+/*
+    This example shows how to compose and mutate
+    URLs to consume a third party API to
+    generate QR Codes.
+    https://developers.google.com/chart/infographics/docs/qr_codes
+*/
+
+#include <boost/url/url.hpp>
+#include <boost/url/parse.hpp>
+#include <iostream>
+
+namespace urls = boost::urls;
+
+int main(int argc, char** argv)
+{
+    if (argc < 2) {
+        std::cout << argv[0] << "\n";
+        std::cout << "Usage: qrcode <data> <width> <height> <output encoding> <error correction> <border>\n"
+                     "options:\n"
+                     "    <data>:             The data to encode (required)\n"
+                     "    <width>:            Image width (default: 100)\n"
+                     "    <height>:           Image height (default: width)\n"
+                     "    <output encoding>:  UTF-8, Shift_JIS, ISO-8859-1 (default: utf8)\n"
+                     "    <error correction>: percentage of error correction (default: 7)\n"
+                     "    <margin>:           border width (default: 4)\n"
+                     "examples:\n"
+                     "qrcode \"Hello world\"\n";
+        return EXIT_FAILURE;
+    }
+
+    urls::url u =
+        urls::parse_uri(
+            "https://chart.googleapis.com/chart?cht=qr").value();
+    auto ps = u.params();
+
+    // Data
+    ps.append({"chl", argv[1]});
+
+    // Size
+    std::size_t width = argc < 3 ? 100 : std::stoll(argv[2]);
+    std::size_t height = argc < 4 ? width : std::stoll(argv[3]);
+    ps.append({"chs", std::to_string(width) + "x" + std::to_string(height)});
+
+    // Encoding
+    if (argc >= 5)
+    {
+         urls::string_view output_encoding =
+            urls::string_view(argv[3]) == "Shift_JIS" ||
+            urls::string_view(argv[3]) == "ISO-8859-1" ?
+                argv[4] : "UTF-8";
+         ps.append({"choe", output_encoding});
+    }
+
+    // Error
+    if (argc >= 6)
+    {
+        std::size_t err = std::stoll(argv[5]);
+        std::string chld;
+        if (err < 11)
+            chld = "L";
+        else if (err < 20)
+            chld = "M";
+        else if (err < 27)
+            chld = "Q";
+        else
+            chld = "H";
+        std::size_t margin = argc < 7 ? 4 : std::stoll(argv[6]);
+        chld += "|";
+        chld += std::to_string(margin);
+        ps.append({"chld", chld});
+    }
+
+    std::cout << u << '\n';
+
+    return EXIT_SUCCESS;
+}
+
+//]