Add spinner to hide uninitialized layout after login

include/ui/OverlayModal.h

@@ -0,0 +1,60 @@
+/*
+ * nheko Copyright (C) 2017  Konstantinos Sideris <siderisk@auth.gr>
+ *
+ * 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/>.
+ */
+
+#ifndef UI_OVERLAY_MODAL_H
+#define UI_OVERLAY_MODAL_H
+
+#include <QGraphicsOpacityEffect>
+#include <QPaintEvent>
+#include <QPropertyAnimation>
+
+#include "OverlayWidget.h"
+
+class OverlayModal : public OverlayWidget
+{
+public:
+	explicit OverlayModal(QWidget *parent, QWidget *content);
+
+	void fadeIn();
+	void fadeOut();
+
+public:
+	inline void setDuration(int duration);
+	inline void setColor(QColor color);
+
+protected:
+	void paintEvent(QPaintEvent *event) override;
+
+private:
+	int duration_;
+	QColor color_;
+
+	QGraphicsOpacityEffect *opacity_;
+	QPropertyAnimation *animation_;
+};
+
+inline void OverlayModal::setDuration(int duration)
+{
+	duration_ = duration;
+}
+
+inline void OverlayModal::setColor(QColor color)
+{
+	color_ = color;
+}
+
+#endif  // UI_OVERLAY_MODAL_H