[solved]QListView dynamic item height

[kernel_panic]

Hi all,
im trying to implement a listview with model and delegate which items should resize dynamicaly.
for example if i press an item and its selected the height should be 2*normal height.
i tried to reimplement sizeHint of QItemDelegate, but the sizeHint isnt catched dynamically. it seems its only used on initialising the view.
I found no methods in QAbstractItemModel or QItemDelegate or QListView that could handle this.
Any suggestions?