gistfile1.txt

- (void)insertCell:(UIView *)cell atIndex:(NSInteger)index animated:(BOOL)animated {
    
    CGFloat duration = animated ? kHorizontalTableViewAnimationDuration : 0;
        
    CGRect contentRect = [contentView frame];
    
    CGFloat colWidth = [dataSource horizontalTableView:self widthForCellAtIndex:index];
    CGFloat colHeight = [dataSource respondsToSelector:@selector(horizontalTableViewCellHeight:)] ? 
                            [dataSource horizontalTableViewCellHeight:self] : contentRect.size.height;
    
    CGFloat colSpacing = [dataSource respondsToSelector:@selector(horizontalTableViewCellSpacing:)] ? 
                            [dataSource horizontalTableViewCellSpacing:self] : 0;
    
    CGRect startRect = CGRectMake(0, 0, colWidth, colHeight);
            
    if (index > [[contentView subviews] count]) {
        
        [NSException raise:NSRangeException 
                    format:@"Index %d is out of bounds [0 ... %d].", index, [[contentView subviews] count]];
        
        return;
    }

    if (index > 0) {
    
        CGRect neighorRect = [[self viewForCellAtIndex:(index - 1)] frame];
        
        startRect.origin = neighorRect.origin;
    }
    
    CGFloat delay = 0.00;
    CGFloat increment = 0.02;

    [cell setFrame:startRect];
    [cell setAlpha:0.0];
    [contentView insertSubview:cell atIndex:([[contentView subviews] count] - index)];
    
    for (NSInteger i = ([[contentView subviews] count] - 1); i > index; i--) {

        UIView *nextCell = [self viewForCellAtIndex:i];
        CGRect nextRect = [nextCell frame];

        [UIView animateWithDuration:duration 
                              delay:delay 
                            options:UIViewAnimationCurveEaseIn 
                         animations:^(void) {

                             [nextCell setFrame:CGRectOffset(nextRect, colWidth + colSpacing, 0)];
                         } 
                         completion:^(BOOL finished) {

                         }];

        delay += increment;
    }
    
    [UIView animateWithDuration:kFrequencyDefaultAnimationDuration 
                          delay:delay 
                        options:UIViewAnimationCurveEaseIn 
                     animations:^{

                         [cell setFrame:CGRectOffset(startRect, colWidth + colSpacing, 0)];
                         [cell setAlpha:1.0];
                     } 
                     completion:^(BOOL finished) {
                         
                          [self setNeedsLayout];
                     }];                
}