iphone - How can I move (animated) UICollectionView cells in and out of a circular shape [PICS] -

i using custom layout position uicollectionviewcells so:

this works great. now, when press button in bottom-left corner, have of cells animatedly return center of view, so:

i kind of have working, isn't animating @ all. kind of pops in way. here code using reload action:

- (ibaction)animate:(id)sender { [self.collectionview performbatchupdates:^{     [self.collectionview reloadsections:[nsindexset indexsetwithindex:0]]; } completion:nil]; } 

and in layout class, have flag flipping each time preparelayout called adjusts center of cell in layoutattributesforitematindexpath this:

- (uicollectionviewlayoutattributes*) layoutattributesforitematindexpath:(nsindexpath *)path { uicollectionviewlayoutattributes *attributes = [uicollectionviewlayoutattributes layoutattributesforcellwithindexpath:path]; attributes.size = cgsizemake(item_sizew, item_sizeh);  if (self.iscircle) {     attributes.center = cgpointmake(_center.x +_radius *                                 cosf(2 * path.item * m_pi / _cellcount),                                 _center.y + _radius *                                 sinf(2 * path.item * m_pi/ _cellcount)); } else {     attributes.center = [self collectionview].center; }  return attributes; } 

how can animate cell's movement center of view?

well, found answer. make different layout , switch animation:

[self.collectionview setcollectionviewlayout:home animated:yes];