Question

I’m downloading data from the web that is then showed on a UITableView. Because I want a responsive UI I’m using background downloading with GCD. So while the data is downloading there is an empty UITableView displaying (which is not so pretty). And over that there is a UIActivtyIndicatorView (setup in IB) spinning.

What I would like is to instead of showing a empty table to display a gray screen with the UIActivityIndicatorView over it.

The code I have so far is this:

dispatch_async(dispatch_get_global_queue(0, 0), ^{

    NSArray *downloadedCareerIds = [CareersParser idsFrom:@"web"];
    NSArray *diskCareerIds = [CareersParser idsFrom:@"disk"];

    BOOL equalIds = [downloadedCareerIds isEqualToArray:diskCareerIds];

    if (!equalIds) {

        DLog(@"ids not equal");

        dispatch_async(dispatch_get_main_queue(), ^{
            /* Send UI updates back to the main thread. */

            // I think here would be a good idead to insert the gray view over the table

            [loadingIndicator startAnimating];
            // Do GUI stuff on the main thread ...
            [loadingIndicator stopAnimating];
            // Remove the gray view?

        });
    }
});

Answer 1

Just make a gray view with the bounds of the UITableView, and add it as a subview of the tableView. Remove the gray view once you’ve finished loading.