title: Rectangle does not take its parent height/width
body: <p>Is it a bug or a feature?</p>
  
  <pre><code>import QtQuick 2.5
  import QtQuick.Controls 1.4
  import QtQuick.Layouts 1.2
  
  ApplicationWindow {
      id: root
      height: 600
      width: 800
  
      ColumnLayout {
          id: rootLayout
          anchors.fill: parent
  //        width: parent.width
  //        height: parent.height
  
          Rectangle {
              color: "red"
              width: parent.width
              height: 200
          }
          Rectangle {
              color: "green"
              width: parent.width
              height: 200
          }
          Rectangle {
              color: "blue"
              width: parent.width
              height: 200
          }   
      }
  }
  </code></pre>
  
  <p>This code doesn't seems to do what I need. It should open a window and draw three <code>Rectangle</code>s in a column with <code>width</code> equals to parent <code>width</code> and <code>height</code> equals to <code>200</code>.</p>
  
  <p>It works fine, when in each <code>Rectangle</code> I change <code>width</code> and <code>height</code> property to a constans value (<code>200</code>, <code>300</code>, etc.) but I want to make it relative to parent layout. </p>
  
  <p>It also works when I type in <code>Rectangle</code> item <code>width: root.width</code>. So why it doesn't work when typed like in my code?</p>