TreeView
    {
        id: treeView
        anchors.fill: parent
        anchors.leftMargin: 10
        anchors.rightMargin: 10
        
        model: ChapterTreeModel { id: model  }
        
        delegate: Item
        {
            id: treeDelegate
            
            implicitWidth: treeView.width
            implicitHeight: label.implicitHeight * 1.5
            
            
            readonly property real indent: 20
            readonly property real padding: 5
            
            // Assigned to by TreeView
            required property TreeView treeView
            required property bool isTreeNode
            required property bool expanded
            required property int hasChildren
            required property int depth
            
            Image
            {
                id: indicator
                x: padding + (treeDelegate.depth * treeDelegate.indent)
                anchors.verticalCenter: label.verticalCenter
                visible: treeDelegate.isTreeNode && treeDelegate.hasChildren
                source: Icons.arrowDownGray
                rotation: treeDelegate.expanded ? 0 : -90
                
                TapHandler
                {
                    onTapped: treeView.toggleExpanded(row)
                }
                
                
                Behavior on rotation
                {
                    NumberAnimation { duration: 150 }
                }
            }
            
            Rectangle
            {
                id: label
                color: "red"
                x: padding + (treeDelegate.isTreeNode ? (treeDelegate.depth + 1) * treeDelegate.indent : 0)
                width: treeDelegate.width - treeDelegate.padding - x
                implicitWidth: 100
                implicitHeight: 10
            }
        }
    }