ListView highlight item isn't shown

Question

I'm trying to highlight the currently selected item in a ListView. Below is the code I'm using; for some reason, while a similar code works perfectly in another ListView of this application, here the SelectedRectangle item is never displayed, althought the selected item changes when it should.

Rectangle {
    id: deviceTree
    width: (window.width * 2) / 3
    height: 400

    border {
        width: 2
        color: "black"
    }

    ListView {
        id: deviceTreeView

        model: deviceTreeModel
        delegate: deviceTreeDelegate
        highlight: SelectionRectangle {}

        anchors.fill: parent
        anchors.margins: 6
    }

    Component {
        id: deviceTreeDelegate

        Rectangle {
            border.color: "#CCCCCC"
            width: deviceTree.width
            height: 30

            smooth: true
            radius: 2

            MouseArea {
                anchors.fill: parent
                onClicked: { deviceTreeView.currentIndex = index; window.selectedDeviceChanged(deviceName) }
            }
        }
    }
}

SelectedRectangle.qml

Rectangle
{
    id: selectionRectangle

    color: "lightsteelblue"
    smooth: true
    radius: 5
}

SOLUTION: The rectangle in deviceTreeDelegate was by default white and overlapped the selection rectangle. Using the property it's set as trasparent so that the selection can be seen.

Answer 1

This is due to the default Rectangle color being white and the highlight being stacked under the delegate. Setting the Rectangle color to "transparent" will allow the highlight to be visible through the delegate.