title: QML bring child item to front
body: <p>I'm trying to implement a way to bring a <code>ListView</code> in front of parent's siblings (in the case below: trying to get <code>list</code> to show above <code>field</code> items). When typing "show" on any item other than the last, I would like to see the <code>list</code> above all others. I know how QML's visual parent/child stack works, I just want to be able to somehow bypass that. I have tried changing the <code>z</code> value, but that wouldn't work as the parent/child relation takes precedence over layers. Here's what I'm trying to do. <br></p>
  
  <pre><code>import QtQuick 2.12
  import QtQuick.Window 2.12
  import QtQuick.Controls 2.5
  
  Window {
      width: 400
      height: 400
      visible: true
  
      ListView {
          anchors.fill: parent
          anchors.margins: 20
  
          model: ListModel {
              ListElement {
                  text: "1"
              }
              ListElement {
                  text: "2"
              }
              ListElement {
                  text: "3"
              }
              ListElement {
                  text: "4"
              }
              ListElement {
                  text: "5"
              }
              ListElement {
                  text: "6"
              }
          }
          delegate: Item {
              width: parent.width
              height: 40
  
              TextField {
                  id: field
                  anchors.fill: parent
                  anchors.margins: 1
                  text: model.modelData
              }
              z:2
              ListView {
                  id: list
                  anchors.top: field.bottom
                  width: parent.width
                  height: 200
                  visible: field.text === "show"
                  clip: true
                  delegate: Text {
                      width: parent.width
                      height: 20
                      text: model.modelData
                  }
                  z:3
  
                  model: ListModel {
                      ListElement {
                          text: "11"
                      }
                      ListElement {
                          text: "11"
                      }
                      ListElement {
                          text: "11"
                      }
                      ListElement {
                          text: "11"
                      }
                      ListElement {
                          text: "11"
                      }
                      ListElement {
                          text: "11"
                      }
                      ListElement {
                          text: "11"
                      }
                      ListElement {
                          text: "11"
                      }
                      ListElement {
                          text: "11"
                      }
                      ListElement {
                          text: "11"
                      }
                      ListElement {
                          text: "11"
                      }
                      ListElement {
                          text: "11"
                      }
                      ListElement {
                          text: "11"
                      }
                      ListElement {
                          text: "11"
                      }
                      ListElement {
                          text: "11"
                      }
                      ListElement {
                          text: "11"
                      }
                      ListElement {
                          text: "11"
                      }
                      ListElement {
                          text: "11"
                      }
                  }
              }
          }
      }
  }
  </code></pre>
  
  <p><code>z</code> values to be ignored as they don't work.</p>