TreeView focus/selection and button/mouse area delegate - delegates

Question

I have a TreeViewand I have an image with a MouseArea in one of the columns. By clicking on it, the focus (selection, highlighting?) doesn't move to the string because the MouseArea is above the TreeView (as far as I understand)
Here is the code:
TreeView
{
clip: true id: mapsTreeView
objectName: "mapsTreeView"
model: theModel
TableViewColumn {
width: 100
role: "name_role"
title: "Map"
}
TableViewColumn {
width: 50
role: "description_role"
}
TableViewColumn {
id: imageColumn
width: 20
role: "image_role"
delegate: Item {
MouseArea {
anchors.fill: parent
onClicked: {
mapsTreeView.sigChangeState()
}
}
Image {
anchors.fill: parent
width: 5
source: "icon" + styleData.value + ".png"
}
}
}
signal sigChangeState()
}
}
The same story applies to the button:
TableViewColumn {
id: imageColumn
width: 20
role: "image_role"
delegate: Button {
iconSource: "icon" + styleData.value + ".png"
onClicked: mapsTreeView.sigChangeState()
}
}
When I click on the button, the focus doesn't moves to the string that contains button.
So the question is, how to make the image/button delegate so that by clicking on it focus will move to the string that contains this object, and some signal is emitted.
In ListView, all I had to do was simply the following:
onClicked:{
mapsView.currentIndex=model.index
mapsState.sigChangeState()
}
But TreeView doesn't allow one to write CurrentIndex