Flip animation not working in GMGridview - iphone

Question

I am working in an app in which i have used the GMGridview. I have added the buttons in cellforItems method. -
(GMGridViewCell *)GMGridView:(GMGridView *)gridView cellForItemAtIndex:(NSInteger)index
{
NSLog(#"Creating view indx %d", index);
CGSize size = [self GMGridView:gridView sizeForItemsInInterfaceOrientation:[[UIApplication sharedApplication] statusBarOrientation]];
GMGridViewCell *cell = [gridView dequeueReusableCell];
if (!cell)
{
cell = [[GMGridViewCell alloc] init];
cell.deleteButtonIcon = [UIImage imageNamed:#"close_x.png"];
cell.deleteButtonOffset = CGPointMake(-15, -15);
}
[[cell.contentView subviews] makeObjectsPerformSelector:#selector(removeFromSuperview)];
btn = [UIButton buttonWithType:UIButtonTypeCustom];
[btn setTag:index];
[btn setFrame:CGRectMake(0, 0,size.width, size.height)];
NSLog(#"button frame is %#",btn);
[[btn layer] setBorderColor:[UIColor redColor].CGColor];
[[btn layer]setBorderWidth:2.0f];
[btn addTarget:self action:#selector(SegmentChange:) forControlEvents:UIControlEventTouchUpInside];
cell.contentView = btn;
//int btntag=btn.tag;
return cell;
then I have used the method to Flip all the buttons,but its not working , What i want is when i click on flip button all the buttons in the gridview should flip.how can i do this ,the code for flip i use is here,
for(ll=0;ll<[Image_array count];ll++)
{
// [UIView setAnimationDelay:2.0];
[UIView beginAnimations:#"BackButton" context:nil];
[UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
[UIView setAnimationDuration:12.0];
[UIView setAnimationTransition:UIViewAnimationTransitionFlipFromLeft forView:btn cache:YES];
[UIView setAnimationDelegate:self];
[UIView commitAnimations];
[btn setImage:[UIImage imageNamed:nil] forState:UIControlStateNormal];
[arr_check replaceObjectAtIndex:ll withObject:#"uncheck"];
front = NO;
}
[_gmGridView reloadData];

Answer 1

As the FOR loop is very much faster comparing to UIViewAnimation. So even if it is animating your view, you will not able to see the animation effect.
You can use NSTimer Or UIViewAnimation delegate method to determine if the one view flip event is completed or not. Then from the delegate method(of UIViewAnimation) you can start another views animation.

Answer 2

i have removed the code from for loop and used the same code in the cellForItemAtIndexpath and use the cell to flip than the button
here is the code :
[UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
[UIView setAnimationTransition:UIViewAnimationTransitionFlipFromLeft forView:cell cache:YES];
[UIView setAnimationDuration:0.7];
[UIView setAnimationDelegate:self];
[UIView commitAnimations];