Move fancy tabbar classes into separate files

src/widgets/fancytabbar.h

@@ -0,0 +1,52 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2018, Vikram Ambrose <ambroseworks@gmail.com>
+ * Copyright 2018-2024, 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 FANCYTABBAR_H
+#define FANCYTABBAR_H
+
+#include <QTabBar>
+#include <QString>
+
+class QEvent;
+class QMouseEvent;
+class QPaintEvent;
+
+class FancyTabBar : public QTabBar {
+  Q_OBJECT
+
+ public:
+  explicit FancyTabBar(QWidget *parent = nullptr);
+
+  QString TabText(const int index) const;
+  QSize sizeHint() const override;
+  int width() const;
+
+ protected:
+  QSize tabSizeHint(const int index) const;
+  void leaveEvent(QEvent *event) override;
+  void mouseMoveEvent(QMouseEvent *event) override;
+  void paintEvent(QPaintEvent *pe) override;
+
+ private:
+  int mouseHoverTabIndex;
+};
+
+#endif  // FANCYTABBAR_H