GenericTag: Create a generic tag that other tag classes can use

This implements the basics so I don't need to keep reimplementing
everything.

Signed-off-by: Anna Schumaker <Anna@OcarinaProject.net>

core/tags/generic.cpp

@@ -0,0 +1,39 @@
+/**
+ * @file
+ * Copyright 2014 (c) Anna Schumaker.
+ */
+#include <core/filter.h>
+#include <core/tags/generic.h>
+
+GenericTag :: GenericTag() {}
+
+GenericTag :: GenericTag(const std::string &name)
+	    : _name(name), _lower(filter :: lowercase(name))
+{
+}
+
+const std::string GenericTag :: primary_key() const
+{
+	return _name;
+}
+
+void GenericTag :: read(File &file)
+{
+	_name  = file.getline();
+	_lower = filter :: lowercase(_name);
+}
+
+void GenericTag :: write(File &file)
+{
+	file << _name;
+}
+
+const std::string &GenericTag :: name()
+{
+	return _name;
+}
+
+const std::string &GenericTag :: lowercase()
+{
+	return _lower;
+}

include/core/tags/generic.h

@@ -0,0 +1,74 @@
+/**
+ * @file
+ * Copyright 2014 (c) Anna Schumaker.
+ */
+#ifndef OCARINA_CORE_TAGS_GENERIC_H
+#define OCARINA_CORE_TAGS_GENERIC_H
+
+#include <core/database.h>
+
+/**
+ * The GenericTag class implements the basic functions that all
+ * tag classes need.  All other tag structures should inherit
+ * from this class to have access to all the basic features.
+ *
+ * When writing a GenericTag to disk, only the _name field needs
+ * to be written.
+ *
+ * 	... << name1
+ * 	... << name2
+ * 	... << name3
+
+ */
+class GenericTag : public DatabaseEntry {
+private:
+	std::string _name;	/**< The name associated with this tag. */
+	std::string _lower;	/**< The lowercase form of ::_name. */
+
+public:
+	GenericTag(); /**< GenericTag constructor. */
+
+	/**
+	 * Generic tag constructor.
+	 *
+	 * @param  name  Name to associate with this tag.
+	 */
+	GenericTag(const std::string &);
+
+	/**
+	 * Called to access the generic tag's primary key.
+	 *
+	 * @return ::_name.
+	 */
+	virtual const std::string primary_key() const;
+
+	/**
+	 * Read ::_name from file and find the lowercase form.
+	 *
+	 * @param  file  The file to read from.
+	 */
+	virtual void read(File &);
+
+	/**
+	 * Write ::_name to file.
+	 *
+	 * @param  file  The file to write to.
+	 */
+	virtual void write(File &);
+
+	/**
+	 * Called to access the name associated with this tag.
+	 *
+	 * @return ::_name.
+	 */
+	const std::string &name();
+
+	/**
+	 * Called to access the lowercase form of ::_name.
+	 *
+	 * @return ::_lower.
+	 */
+	const std::string &lowercase();
+};
+
+#endif /* OCARINA_CORE_TAGS_GENERIC_H */

tests/core/Sconscript

@@ -14,6 +14,7 @@ test(	"index"		)
 test(	"filter"	)
 test(	"idle"		)
 
+test(	"tags/generic"	)
 test(	"tags/artist"	)
 
 test_env.UsePackage("taglib")

tests/core/tags/.gitignore

@@ -1 +1,2 @@
 artist
+generic

tests/core/tags/generic.cpp

@@ -0,0 +1,39 @@
+/**
+ * @file
+ * Copyright 2014 (c) Anna Schumaker.
+ */
+#include <core/tags/generic.h>
+#include <tests/test.h>
+
+static void test_generic_tag()
+{
+	GenericTag tag("Generic Tag");
+	File f("generic_tag", 0);
+
+	test_equal(tag.name(),        (std::string)"Generic Tag");
+	test_equal(tag.lowercase(),   (std::string)"generic tag");
+	test_equal(tag.primary_key(), (std::string)"Generic Tag");
+
+	f.open(OPEN_WRITE);
+	tag.write(f);
+	f.close();
+
+	tag = GenericTag();
+	test_equal(tag.name(),        (std::string)"");
+	test_equal(tag.lowercase(),   (std::string)"");
+	test_equal(tag.primary_key(), (std::string)"");
+
+	f.open(OPEN_READ);
+	tag.read(f);
+	f.close();
+
+	test_equal(tag.name(),        (std::string)"Generic Tag");
+	test_equal(tag.lowercase(),   (std::string)"generic tag");
+	test_equal(tag.primary_key(), (std::string)"Generic Tag");
+}
+
+int main(int argc, char **argv)
+{
+	run_test("Generic Tag Test", test_generic_tag);
+	return 0;
+}