Cannot use scrolling with mouse wheel on QML Types

Steps to reproduce:

• create/open Qt Quick 2 Application
• switch to Designer
• on the Library select one of the QML Types
• use the mouse wheel to scroll down or up

Current behavior:

• nothing happens - you have to drag the scrollbar to see other QML Types

Expected behavior:

• scrolling with mouse wheel supported (as it is for the Navigator above for example)