Initial work on creating .gp files

Currently this creates the zip contents, with the version entry and an empty score.gpif xml file

Refactored the Gp7::Document header a bit so that the code for converting to XML can belong in a separate file.

#350

source/formats/CMakeLists.txt

@@ -7,7 +7,8 @@ set( srcs
     gp7/converter.cpp
     gp7/gp7exporter.cpp
     gp7/gp7importer.cpp
-    gp7/parser.cpp
+    gp7/from_xml.cpp
+    gp7/to_xml.cpp
 
     gpx/bitstream.cpp
     gpx/filesystem.cpp
@@ -63,9 +64,9 @@ set( headers
     fileformatmanager.h
 
     gp7/converter.h
+    gp7/document.h
     gp7/gp7exporter.h
     gp7/gp7importer.h
-    gp7/parser.h
 
     gpx/bitstream.h
     gpx/filesystem.h

source/formats/gp7/converter.cpp

@@ -16,7 +16,7 @@
  */
 
 #include "converter.h"
-#include "parser.h"
+#include "document.h"
 
 #include <boost/date_time/gregorian/gregorian_types.hpp>
 #include <boost/rational.hpp>

source/formats/gp7/parser.h → source/formats/gp7/document.h

@@ -15,10 +15,9 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef FORMATS_GP7_PARSER_H
-#define FORMATS_GP7_PARSER_H
+#ifndef FORMATS_GP7_DOCUMENT_H
+#define FORMATS_GP7_DOCUMENT_H
 
-#include "score/timesignature.h"
 #include <bitset>
 #include <boost/rational.hpp>
 #include <optional>
@@ -391,7 +390,10 @@ struct Document
 };
 
 /// Parses the score.gpif XML file.
-Document parse(const pugi::xml_document &root, Version version);
+Document from_xml(const pugi::xml_document &root, Version version);
+
+/// Creates the score.gpif XML file from the intermediate representation.
+pugi::xml_document to_xml(const Document &doc);
 
 } // namespace Gp7
 

source/formats/gp7/parser.cpp → source/formats/gp7/from_xml.cpp

@@ -15,7 +15,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "parser.h"
+#include "document.h"
 
 #include <formats/fileformat.h>
 #include <score/generalmidi.h>
@@ -871,7 +871,7 @@ Gp7::Document::addRhythm(Beat &beat, Rhythm rhythm)
 }
 
 Gp7::Document
-Gp7::parse(const pugi::xml_document &root, Version version)
+Gp7::from_xml(const pugi::xml_document &root, Version version)
 {
     Gp7::Document doc;
 

source/formats/gp7/gp7exporter.cpp

@@ -18,14 +18,125 @@
 #include "gp7exporter.h"
 
 #include "gp7importer.h"
+#include "document.h"
+
+#include <memory>
+#include <minizip/zip.h>
+#ifdef _WIN32
+#include <minizip/iowin32.h>
+#endif
+
+#include <pugixml.hpp>
 
 Gp7Exporter::Gp7Exporter()
     : FileFormatExporter(Gp7Importer::getFileFormat())
 {
 }
 
+namespace
+{
+/// Custom deleter for use with std::unique_ptr.
+struct ZipFileCloser
+{
+    using pointer = zipFile;
+
+    void operator()(zipFile f)
+    {
+        if (f)
+            zipClose(f, nullptr);
+    }
+};
+
+/// Handle to a zipFile. Calls zipClose() when it goes out of scope.
+using ZipFileHandle = std::unique_ptr<zipFile, ZipFileCloser>;
+
+/// Opens a zip file for writing.
+static ZipFileHandle
+createZipFile(const std::filesystem::path &filename)
+{
+    zlib_filefunc64_def ffunc;
+#ifdef _WIN32
+    // Ensure wide strings are used, matching boost::filesystem::path.
+    fill_win32_filefunc64W(&ffunc);
+#else
+    fill_fopen64_filefunc(&ffunc);
+#endif
+
+    ZipFileHandle zip_file;
+    zip_file.reset(zipOpen2_64(filename.c_str(), 0, nullptr, &ffunc));
+    if (!zip_file)
+        throw FileFormatException("Failed to create zip file.");
+
+    return zip_file;
+}
+
+/// RAII wrapper for creating a file in the archive.
+struct ZipFileEntry
+{
+    ZipFileEntry(zipFile file, const char *filename) : myFile(file)
+    {
+        if (zipOpenNewFileInZip64(myFile, filename, nullptr, nullptr, 0,
+                                  nullptr, 0, nullptr, Z_DEFLATED,
+                                  Z_DEFAULT_COMPRESSION, 1) != ZIP_OK)
+        {
+            throw FileFormatException("Failed to create file entry.");
+        }
+    }
+
+    ~ZipFileEntry()
+    {
+        [[maybe_unused]] const int ret = zipCloseFileInZip(myFile);
+        assert(ret == ZIP_OK);
+    }
+
+    zipFile myFile;
+};
+
+static void
+writeVersionInfo(zipFile file)
+{
+    ZipFileEntry entry(file, "VERSION");
+
+    const char *contents = "7.0";
+    zipWriteInFileInZip(file, contents, strlen(contents));
+}
+
+/// pugi::xml_writer implementation for writing chunks to a zip entry.
+struct zip_entry_writer : public pugi::xml_writer
+{
+    zip_entry_writer(zipFile file) : myFile(file)
+    {
+    }
+
+    void write(const void *data, size_t size) override
+    {
+        zipWriteInFileInZip(myFile, data, size);
+    }
+
+    zipFile myFile;
+};
+
+static void
+writeScore(zipFile file, const Score &score)
+{
+    ZipFileEntry entry(file, "Content/score.gpif");
+
+    // TODO - convert score to GP7
+    Gp7::Document doc;
+    pugi::xml_document xml_doc = Gp7::to_xml(doc);
+
+    zip_entry_writer writer(file);
+    xml_doc.save(writer);
+}
+
+} // namespace
+
 void
 Gp7Exporter::save(const std::filesystem::path &filename, const Score &score)
 {
-    // TODO
+    // The .gp file format is just a zip file with a different extension.
+    ZipFileHandle zip_file = createZipFile(filename);
+
+    writeVersionInfo(zip_file.get());
+    writeScore(zip_file.get(), score);
 }

source/formats/gp7/gp7importer.cpp

@@ -18,7 +18,7 @@
 #include "gp7importer.h"
 
 #include "converter.h"
-#include "parser.h"
+#include "document.h"
 
 #include <minizip/unzip.h>
 #ifdef _WIN32
@@ -145,6 +145,6 @@ void Gp7Importer::load(const std::filesystem::path &filename, Score &score)
     if (!result)
         throw FileFormatException(result.description());
 
-    Gp7::Document doc = Gp7::parse(xml_doc, Gp7::Version::V7);
+    Gp7::Document doc = Gp7::from_xml(xml_doc, Gp7::Version::V7);
     Gp7::convert(doc, score);
 }

source/formats/gp7/to_xml.cpp

@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2022 Cameron White
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "document.h"
+
+namespace Gp7
+{
+pugi::xml_document
+to_xml(const Document &doc)
+{
+    pugi::xml_document root;
+
+    // TODO
+
+    return root;
+}
+} // namespace Gp7

source/formats/gpx/gpximporter.cpp

@@ -19,7 +19,7 @@
 
 #include "filesystem.h"
 
-#include <formats/gp7/parser.h>
+#include <formats/gp7/document.h>
 #include <formats/gp7/converter.h>
 #include <score/score.h>
 
@@ -53,6 +53,6 @@ GpxImporter::load(const std::filesystem::path &filename, Score &score)
     xml_doc.print(std::cerr);
 #endif
 
-    Gp7::Document doc = Gp7::parse(xml_doc, Gp7::Version::V6);
+    Gp7::Document doc = Gp7::from_xml(xml_doc, Gp7::Version::V6);
     Gp7::convert(doc, score);
 }

source/formats/guitar_pro/gp345to7converter.h

@@ -19,7 +19,7 @@
 #define FORMATS_GP_GP345TO7CONVERTER_H
 
 #include "document.h"
-#include <formats/gp7/parser.h>
+#include <formats/gp7/document.h>
 
 namespace Gp
 {

source/formats/guitar_pro/guitarproimporter.cpp

@@ -19,7 +19,7 @@
 #include "gp345to7converter.h"
 
 #include <formats/gp7/converter.h>
-#include <formats/gp7/parser.h>
+#include <formats/gp7/document.h>
 #include <formats/guitar_pro/document.h>
 #include <formats/guitar_pro/inputstream.h>
 #include <fstream>