MBProgressHUD while logging out - objective-c

Question

Im using the MBProgressHUD to make an overview loading screen while logging out in my ipad app. That progress takes some time because I have to encrypt some bigger files.
Because Im doing it in a background thread and the MBProgressHUD is animating on the main thread, I had to do something to know when my background thread is finished.
As a test, I did it like that:
MBProgressHUD *hud = [MBProgressHUD showHUDAddedTo:self.view animated:YES];
hud.mode = MBProgressHUDAnimationFade;
hud.labelText = #"Do something...";
[self performSelectorInBackground:#selector(doSomethingElse) withObject:nil];
And method doSomethingElse:
-(void)doSomethingElse
{
[self encrypt];
[self performSelectorOnMainThread:#selector(doSomethingElseDone) withObject:nil waitUntilDone:YES];
}
And method doSomethingElseDone:
-(void)logoutInBackgroundDone
{
[MBProgressHUD hideHUDForView:self.view animated:YES];
}
The solution works but I think there must be a better way? How can I do that on a better way?
Any help is really appreciated.

Answer 1

You can directly dismiss the MBProgressHUD from doSomethingElse method using dispatch_async
-(void)doSomethingElse
{
[self encrypt];
dispatch_async(dispatch_get_main_queue(), ^{
[MBProgressHUD hideHUDForView:self.view animated:YES];
});
}

Answer 2

Create an atomic property you can get to
#property BOOL spinning;
and
- (void)myTask
{
while ( self.spinning )
{
usleep(1000*250); // 1/4 second
}
}
then use something in your view controller like
HUD = [[MBProgressHUD alloc] initWithView:self.view];
[self.view addSubview:HUD];
[HUD showWhileExecuting:#selector(myTask) onTarget:self withObject:nil animated:YES];
This way the HUD will remove itself when spinning becomes false. The spinner has to be atomic since it will be referenced in a background thread. Whatever you are waiting on can simply set the spinner property to false from any thread to indicate it's done.
This is under ARC.