Add lyrics from stands4 (lyrics.com)

src/lyrics/stands4lyricsprovider.h

@@ -0,0 +1,57 @@
+/*
+ * Strawberry Music Player
+ * Copyright 2023, Jonas Kvinge <jonas@jkvinge.net>
+ *
+ * Strawberry 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.
+ *
+ * Strawberry 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 Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef STANDS4LYRICSPROVIDER_H
+#define STANDS4LYRICSPROVIDER_H
+
+#include <QtGlobal>
+#include <QObject>
+#include <QList>
+#include <QVariant>
+#include <QString>
+
+#include "lyricsprovider.h"
+#include "lyricsfetcher.h"
+
+class QNetworkReply;
+class NetworkAccessManager;
+
+class Stands4LyricsProvider : public LyricsProvider {
+  Q_OBJECT
+
+ public:
+  explicit Stands4LyricsProvider(NetworkAccessManager *network, QObject *parent = nullptr);
+  ~Stands4LyricsProvider() override;
+
+  bool StartSearch(const QString &artist, const QString &album, const QString &title, int id) override;
+  void CancelSearch(const int id) override;
+
+ private:
+  void Error(const QString &error, const QVariant &debug = QVariant()) override;
+  static QString StringFixup(QString string);
+
+ private slots:
+  void HandleSearchReply(QNetworkReply *reply, const int id, const QString &artist, const QString &title);
+
+ private:
+  static const char *kUrl;
+  QList<QNetworkReply*> replies_;
+};
+
+#endif  // STANDS4LYRICSPROVIDER_H