How to use QML inside libraries

Hello, All!
Suppose there is a library which contains implementation of various UI widgets (QGraphicItems, QGraphicWidgets). Other applications are able to display these widgets through library's API. Can I somehow to reimplement UI widgets so that they can be used in QML applications? How this will affect applications which already use old API (will we have to use QDeclarativeView in these applications)? Is there any developer's guide of how to do UI porting if UI widgets are encapsulated into separate library? Thanks a lot in advance

You can use Qt libraries in QML application. Justify the need for re-implementation.

[QUOTE=divanov;809913]You can use Qt libraries in QML application[/QUOTE]
But am I able to use QML elements in Qt applications? Examples and demos use QDeclarativeView to work with QML. Is it possible for old Qt applications (which use the UI library) to not use QDeclarativeView for displaying QtQuick UI?

[QUOTE=divanov;809913]Justify the need for re-implementation.[/QUOTE]
The need is to port existing UI to use powerful and simple Qt Quick UI :-)

[QUOTE=mnosov;810098]But am I able to use QML elements in Qt applications?[/QUOTE]
No, you cannot.