1 files changed, 48 insertions, 0 deletions
diff --git a/src/quicknativestyle/items/qquickstyleitemtreeindicator.cpp b/src/quicknativestyle/items/qquickstyleitemtreeindicator.cpp
new file mode 100644
index 0000000000..1b0bd39b20
--- /dev/null
+++ b/src/quicknativestyle/items/qquickstyleitemtreeindicator.cpp
@@ -0,0 +1,48 @@
+// Copyright (C) 2021 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 "qquickstyleitemtreeindicator.h"
+
+QT_BEGIN_NAMESPACE
+
+void QQuickStyleItemTreeIndicator::connectToControl() const
+{
+    QQuickStyleItem::connectToControl();
+    auto delegate = control<QQuickTreeViewDelegate>();
+    connect(delegate, &QQuickTreeViewDelegate::expandedChanged, this, &QQuickStyleItem::markImageDirty);
+}
+
+StyleItemGeometry QQuickStyleItemTreeIndicator::calculateGeometry()
+{
+    QStyleOptionViewItem styleOption;
+    initStyleOption(styleOption);
+    StyleItemGeometry geometry;
+
+    geometry.minimumSize = QSize(20, 20);
+    geometry.implicitSize = geometry.minimumSize;
+    styleOption.rect = QRect(QPoint(0, 0), geometry.implicitSize);
+
+    return geometry;
+}
+
+void QQuickStyleItemTreeIndicator::paintEvent(QPainter *painter) const
+{
+    QStyleOptionViewItem styleOption;
+    initStyleOption(styleOption);
+    style()->drawPrimitive(QStyle::PE_IndicatorBranch, &styleOption, painter);
+}
+
+void QQuickStyleItemTreeIndicator::initStyleOption(QStyleOptionViewItem &styleOption) const
+{
+    initStyleOptionBase(styleOption);
+    auto delegate = control<QQuickTreeViewDelegate>();
+
+    styleOption.state |= QStyle::State_Children;
+
+    if (delegate->expanded())
+        styleOption.state |= QStyle::State_Open;
+}
+
+QT_END_NAMESPACE
+
+#include "moc_qquickstyleitemtreeindicator.cpp"