TabWidget: Separate GUI from state

src/widgets/TabWidgetWidget.cpp

@@ -0,0 +1,43 @@
+/*
+  This file is part of KDDockWidgets.
+
+  Copyright (C) 2018-2019 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com
+  Author: Sérgio Martins <sergio.martins@kdab.com>
+
+  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 2 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/>.
+*/
+
+/**
+ * @file
+ * @brief The QWidget counter part of TabWidgetWidget. Handles GUI while TabWidget handles state.
+ *
+ * @author Sérgio Martins \<sergio.martins@kdab.com\>
+ */
+
+#include "TabWidgetWidget_p.h"
+
+using namespace KDDockWidgets;
+
+TabWidgetWidget::TabWidgetWidget(QWidget *parent)
+    : TabWidget(parent)
+{
+}
+
+void TabWidgetWidget::paintEvent(QPaintEvent *p)
+{
+    // When count is 1 we want to use the same background as a regular QWidget
+    // Otherwise it looks weird because the colors change when transforming a QDockWidget into FloatingWindow
+    if (count() > 1)
+        QTabWidget::paintEvent(p);
+}