1 files changed, 57 insertions, 0 deletions
diff --git a/src/quickcontrols/fusion/impl/qquickfusionknob.cpp b/src/quickcontrols/fusion/impl/qquickfusionknob.cpp
new file mode 100644
index 0000000000..00be4bd759
--- /dev/null
+++ b/src/quickcontrols/fusion/impl/qquickfusionknob.cpp
@@ -0,0 +1,57 @@
+// Copyright (C) 2017 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#include "qquickfusionknob_p.h"
+
+#include <QtCore/qmath.h>
+#include <QtGui/qpainter.h>
+#include <QtQuick/private/qquickpalette_p.h>
+#include <QtQuick/private/qquickitem_p.h>
+
+QT_BEGIN_NAMESPACE
+
+QQuickFusionKnob::QQuickFusionKnob(QQuickItem *parent)
+    : QQuickPaintedItem(parent)
+{
+    connect(this, &QQuickItem::paletteChanged, this, [this](){ update(); });
+}
+
+// extracted from QStyleHelper::drawDial()
+void QQuickFusionKnob::paint(QPainter *painter)
+{
+    const qreal w = width();
+    const qreal h = height();
+    if (w <= 0 || h <= 0)
+        return;
+
+    QColor color = QQuickItemPrivate::get(this)->palette()->button().toHsv();
+    color.setHsv(color.hue(),
+                 qMin(140, color .saturation()),
+                 qMax(180, color.value()));
+    color = color.lighter(104);
+    color.setAlphaF(0.8f);
+
+    const qreal sz = qMin(w, h);
+    QRectF rect(0, 0, sz, sz);
+    rect.moveCenter(QPointF(w / 2.0, h / 2.0));
+    const QPointF center = rect.center();
+
+    QRadialGradient gradient(center.x() + rect.width() / 2,
+                             center.y() + rect.width(),
+                             rect.width() * 2,
+                             center.x(), center.y());
+    gradient.setColorAt(1, color.darker(140));
+    gradient.setColorAt(qreal(0.4), color.darker(120));
+    gradient.setColorAt(0, color.darker(110));
+
+    painter->setRenderHint(QPainter::Antialiasing);
+    painter->setBrush(gradient);
+    painter->setPen(QColor(255, 255, 255, 150));
+    painter->drawEllipse(rect);
+    painter->setPen(QColor(0, 0, 0, 80));
+    painter->drawEllipse(rect.adjusted(1, 1, -1, -1));
+}
+
+QT_END_NAMESPACE
+
+#include "moc_qquickfusionknob_p.cpp"