smartlist: draw tabs for conversation filter switch

Change-Id: I835b229dcad51afdcf3dfea2794697a14fdfba90
diff --git a/bezierconnectorwidget.cpp b/bezierconnectorwidget.cpp
new file mode 100644
index 0000000..75dcab5
--- /dev/null
+++ b/bezierconnectorwidget.cpp
@@ -0,0 +1,66 @@
+/***************************************************************************
+ * Copyright (C) 2019 by Savoir-faire Linux                                *
+ * Author: Andreas Traczyk <andreas.traczyk@savoirfairelinux.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 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/>.   *
+ **************************************************************************/
+
+#pragma once
+
+#include "bezierconnectorwidget.h"
+
+#include <QPainter>
+#include <QDebug>
+
+BezierConnectorWidget::BezierConnectorWidget(QWidget* parent) : QWidget(parent)
+{
+}
+
+BezierConnectorWidget::~BezierConnectorWidget()
+{
+}
+
+void
+BezierConnectorWidget::paintEvent(QPaintEvent* event)
+{
+    Q_UNUSED(event);
+    QPainter painter(this);
+
+    painter.setRenderHints(QPainter::Antialiasing, true);
+
+    QPen pen(painter.pen());
+    pen.setWidth(2.0);
+    pen.setColor(QColor(240, 240, 240));
+    painter.setPen(pen);
+
+    QPainterPath bezierPath;
+    double c = 0.551915024494;
+    QPointF p0, p1, p2, p3;
+
+    if (this->objectName().contains("right", Qt::CaseInsensitive)) {
+        p0 = rect().topLeft();
+        p3 = rect().bottomRight();
+        p1 = QPointF(p0.x() + c * rect().width(), p0.y());
+        p2 = QPointF(p0.x() + rect().width(), p0.y() + rect().height() - (c * rect().height()));
+    } else if (this->objectName().contains("left", Qt::CaseInsensitive)) {
+        p0 = rect().bottomLeft();
+        p3 = rect().topRight();
+        p1 = QPointF(p0.x(), p0.y() - c * rect().height());
+        p2 = QPointF(p3.x() - c * rect().width(), p3.y());
+    }
+
+    bezierPath.moveTo(p0);
+    bezierPath.cubicTo(p1, p2, p3);
+    painter.drawPath(bezierPath);
+}