UICollectionViewCell flip and grow on tap

Question

How can I achieve the animation where a UICollectionViewCell with flip and grow to show modal view on tap?

Answer 1

Here is what I used in another project and it was working well :

- (BOOL)collectionView:(UICollectionView *)collectionView shouldSelectItemAtIndexPath:(NSIndexPath *)indexPath {
    UICollectionViewCell *cell = [collectionView cellForItemAtIndexPath:indexPath];
    if (cell.selected) {
        [collectionView deselectItemAtIndexPath:indexPath animated:YES];
        [UIView transitionWithView:cell
                          duration:0.2
                           options:UIViewAnimationOptionTransitionFlipFromLeft
                        animations:^{
                            [cell setFrame:self.selectedCellDefaultFrame];
                            cell.transform = self.selectedCellDefaultTransform;
                        }
                        completion:^(BOOL finished) {
                            self.selectedCellDefaultFrame = CGRectZero;
                            [collectionView reloadItemsAtIndexPaths:@[indexPath]];
                        }];
        return NO;
    }
    else {
        return YES;
    }
}
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
    UICollectionViewCell *cell = [collectionView cellForItemAtIndexPath:indexPath];
    [cell.superview bringSubviewToFront:cell];
    self.selectedCellDefaultFrame = cell.frame;
    self.selectedCellDefaultTransform = cell.transform;
    [UIView transitionWithView:cell
                      duration:0.2
                       options:UIViewAnimationOptionTransitionFlipFromRight
                    animations:^{
                        [cell setFrame:collectionView.bounds];
                        cell.transform = CGAffineTransformMakeRotation(0.0);
                    }
                    completion:^(BOOL finished) {}];
}

Different things here :

• The bringSubviewToFront: message call is used to prevent the cell to animate behind the other cells
• We use two properties declared in the controller : selectedCellDefaultFrameand selectedCellDefaultTransform to save the default state of the cell and reinitialize it when deselecting
• When deselecting, we call the reloadItemsAtIndexPaths: method of UICollectionView to be sure that the reset of the position is totally complete

Let me know if you have any trouble with this.

Good luck,

Answer 2

I haven't tried the grow animation, but I think I can help with the UICollectionViewCell flip animation.

Try:

UICollectionViewCell* cell = [collectionView cellForItemAtIndexPath:indexPath];

[UIView animateWithDuration:1.0
                      delay:0
                    options:(UIViewAnimationOptionAllowUserInteraction)
                 animations:^
                {
                     NSLog(@"starting animation");

                    [UIView transitionFromView:cell.contentView
                                        toView:newView
                                      duration:.5
                                       options:UIViewAnimationOptionTransitionFlipFromRight
                                    completion:nil];
                }
                 completion:^(BOOL finished)
                {
                     NSLog(@"animation end");
                }
 ];

Hope that helps!