import QtQuick 2.0 Rectangle { default property alias children : inner_space.children width: 70 height: parent.height color: "#50888888" enabled: opacity > 0 Column { id: inner_space spacing: (parent.height - children.length * tool_terrain.height) / (children.length + 1) anchors.centerIn: parent } Behavior on opacity { PropertyAnimation { duration: 200 } } }