CODEWITHSUNDEEP
iphoneobjective-c
samsam
samsam

Reputation: 3125

UIActivityIndicator in UITableViewCell not being displayed on "setSelected"

I've got a small problem that seems to haunt me. My UITableViewController Subclass loads Data in an asynchronous matter on Selection of a TableViewCell. like this...

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
NSLog(@"clickROW");

itemData *selectedItemData;;

selectedItemData = [[[DataManager sharedDataManger]getAllDataItems] objectAtIndex:indexPath.row];

[[DataManager sharedMischaManager] loadDataItemDetailsAsync:selectedItemData.Now];

Ok, so far so good, loadDataItemDetailsAsync posts a Notification after it has finished loading. Then my UITableViewController subclass gets properly notified, creates a new View and pushes it onto its NavigationController..

everything works fine so far...

but, because the asynchronous loading can take a while (depending on current bandwith), I want a UIActivityIndicatior being displayed / animated while the loading takes place.

So what i did was the following (in my UITableViewCell Subclass)

- (void)setSelected:(BOOL)selected animated:(BOOL)animated {

[super setSelected:selected animated:animated];

// Configure the view for the selected state


if(selected)
{
    [self.contentView bringSubviewToFront:loader];
    [tvImageView setHidden:YES];
    [loader setHidden:NO];
    [loader startAnimating];
    //[loader performSelectorInBackground: @selector(startAnimating) withObject: nil];      
}
else {
    //[loader performSelectorInBackground: @selector(stopAnimating) withObject: nil];   
    [loader stopAnimating];
    [loader setHidden:YES];
    [tvImageView setHidden:NO];

}

}

i tried both ways to "start the loader", the performSelectorInBackGround-way and the simple [loader startAnimating]-way. neither of them really work.

interestingly, the tvImageView doesn't get hidden either.

I guess I'm missing out on a basic step (something like redrawing / redisplaying , i don't know) I just seem to be unable to figure it out by myself :(

any help, tipps, hints veeeery appreciated

cheers

sam

Upvotes: 0

Views: 723

Answers (1)

Stefan Arentz
Stefan Arentz

Reputation: 34935

If you use Core Data (even with a simple in-memory database if you don't need to persist to disk) combined with a NSFetchedResultsController then you don't have to deal with all the state management.

You would simply make changes to the objects and the NSFetchedResultsController will then notify a delegate (which your UITabelViewController should implement) of any changed objects. In that delegate you would simply make changes to the UITableViewCell, like showing/hiding a activity indicator or status text.

All this with a simple and formal protocol.

Check NSFetchedResultsControllerDelegate Protocol Reference for a good overview.

Upvotes: 1

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