MyExpander{
  GridLayout{
    Rectangle{
      Text { }
      Text { }
    }
    Rectangle{
      Text { }
      Text { }
    }
  }
}

MyExpander is my new component. I would like to reuse this MyExpander object in other qml.
Under the MyExpander should be able to control its children collapsible.

Rectangle {
    implicitHeight: header.implicitHeight + (collapsed ? listview.contentHeight : 0)
    Item {} // header
    Listview {}
}

Sorry @raven-worx , I don't get any reference from your keyword in google.

come on... do you want me really to believe that?!

Example 1, Example 2

Actually
I try to use 'Loader' to make similar putting Component or null in sourceComponent property.

        Loader {
            id: itemLoader
            anchors.fill: parent
            visible: !collapsed
            sourceComponent: collapsed ? null : componentItem
        }

But, I don't think it is best. Because I need to put component in it still.

    MyExpander{
        componentItem: Component{
            Rectangle{
                Text {
                }
        }
    }

It would be nice to design as other layout components to hold children in it.
Do you have any idea?

    GridLayout{
        Rectangle{
            Text {
            }
        }
    }