旋转UITableViewCells

Question

I have a UITableView loading its data from the Web, and while the data is loading there are few cells, to indicate the process. Each cell got an UIImageView inside which i want to be spinning constantly.

Inside the UITableViewController i got this:

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:    (NSInteger)section
{
    //there are three "default" cells
    return self.datasource.count > 0 ? self.datasource.count : 3;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    if(self.datasource.count)
    {
    //return a cell with loaded data
    }
    else
    {
        LoadingTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"LoadingIndicationCell"];

        return cell;
    }
}

LoadingTableViewCell has a *.xib file with a corresponding reference outlet to the UIImageView, called "circle"

- (void)awakeFromNib {
    self.circle.alpha = .3f;
    self.spinning = NO;
    [self startSpin];
}
- (void) spinWithOptions: (UIViewAnimationOptions) options {
    NSLog(@"SPINNIN'");
    // this spin completes 360 degrees every 2 seconds
    [UIView animateWithDuration: 0.5f
                          delay: 0.0f
                        options: options
                     animations: ^{
                         _circle.transform =     CGAffineTransformRotate(_circle.transform, M_PI / 2);
                     }
                     completion: ^(BOOL finished) {
                         if (finished) {
                             if (_spinning) {
                             [self spinWithOptions: UIViewAnimationOptionCurveLinear];
                         } else if (options != UIViewAnimationOptionCurveEaseOut) {
                             [self spinWithOptions: UIViewAnimationOptionCurveEaseOut];
                         }
                     }
                 }];
}

- (void) startSpin {
    if (!self.spinning) {
        self.spinning = YES;
        [self spinWithOptions: UIViewAnimationOptionCurveEaseIn];
    }
}

- (void) stopSpin {
    self.spinning = NO;
}

It seems to spin 2 times and then stops. In the console there are 6 "SPINNIN'" outputs, two for each cell, i suppose.

I'm very new to iOS-development, been tryin' to figure this out the entire evening. Btw, what will happen to these cell objects when they will get replaced by cells with loaded data? Where do i call stopSpin then?

Answer 1

Eventually i ended up with this code:

- (void) spinWithOptions: (UIViewAnimationOptions) options {
    if([self isHidden]) [self stopSpin]; //stop spinning when the cell got replaced
    // this spin completes 360 degrees every 2 seconds
    [UIView animateWithDuration: 1.0f
                      delay: 0.0f
                    options: options
                 animations: ^{
                     _circle.transform = CGAffineTransformRotate(_circle.transform, M_PI / 2);
                 }
                 completion: ^(BOOL finished) {
                        if (_spinning) {
                             [self spinWithOptions: UIViewAnimationOptionCurveLinear];
                        }
                 }];
}