[Interest] Why is QtQuick TreeView in QT 5.5.0/5.5.1rc not supported by Qt Quick Designer/Editor?

[anton]

Hi,

only a small question.

I wanted to give QT 5.5.0 a try,
and started a new QTQuick Project in QTCreator.

I Open the MainForm.ui.qml in the Designer,
and would like to play with the TreeView but its not available.

QTCreator created the MainForm.ui.qml file when I created the project.

It starts with:

 import QtQuick 2.5
 import QtQuick.Controls 1.4
 import QtQuick.Dialogs 1.2
 ...

So all should be here.

In the doc Its mentioned as part of QT 5.5.0.

I use Linux + qt open source.

Is this a bug which will be fixed in 5.5.1 or is
there some workaround?
I did a small test with QT 5.5.1 rc by installing
qt-opensource-linux-x64-5.5.1_190.run

... but its the same

If I add 

 TreeView {}

in the qml file and click on "Design" in QT creator
I get an error:

  This QML file contains features which are not 
  supported by Qt Quick Designer.
  
  Line: 88: Unknown component.(M300)

.. and in the editor "TreeView" has a red underline.

Thanks for a small hint.

Anton