title: QML - How to have a popup that doesn't get clipped
body: <p>I need to have a Popup that stays visible outside the bounds of the main window.
  I couldn't find anything in the Qt documentation.</p>
  <p>This is the code:</p>
  <pre><code>import QtQuick 2.15
  import QtQuick.Window 2.2
  import QtQuick.Controls 2.12
  
  ApplicationWindow {
      id: window
      width: 400
      height: 400
      visible: true
  
      Button {
          text: &quot;Open&quot;
          onClicked: popup.open()
      }
  
      Popup {
          id: popup
          x: 100
          y: 100
          width: 300
          height: 400
          modal: true
          focus: true
          dim: false
  
          contentItem: Rectangle
          {
              anchors.fill: parent
              color: &quot;red&quot;
          }
  
          closePolicy: Popup.CloseOnEscape | Popup.CloseOnPressOutsideParent
      }
  }
  
  </code></pre>
  <p>This is the output of this:
  <a href="https://i.stack.imgur.com/DfZGW.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DfZGW.png" alt="enter image description here" /></a></p>
  <p>I want the red to go beyond the window borders.
  Something like this:
  <a href="https://i.stack.imgur.com/iCew1.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/iCew1.png" alt="enter image description here" /></a></p>
  <p>I'd appreciate the help!</p>
  <p>Note: using a Dialog is no good for me.</p>