Disable buffering of repeated button clicks - objective-c

Question

When the user clicks a button, an action is started but if the user quickly clicks the button 10 times, it will execute 10 times. I guess the disable doesn't take effect until control returns from the event.
- (IBAction)btnQuickCheckClick:(id)sender {
#try {
self.btnQuickCheck.enabled = NO ;
// Next line takes about 3 seconds to execute:
[self pollRouter] ;
}
#finally {
self.btnQuickCheck.enabled = YES ;
}
}

Answer 1

You can update the UI by running the run loop after disabling the button before polling:
- (IBAction)btnQuickCheckClick:(id)sender {
self.btnQuickCheck.enabled = NO;
// give some time for the update to take place
[self performSelector:#selector(pollRouterMethod) withObject:nil afterDelay:0.1];
}
- (void)pollRouterMethod {
#try {
[self pollRouter];
} #catch (NSException * e) { }
// re-enable the button
self.btnQuickCheck.enabled = YES;
}
Of course, this method is no substitute for running a time intensive task on another thread. For long tasks, multithreading is almost always the way to go.

Answer 2

another way to do this is with blocks :
Big Pro : you don't need to create an extra method :)
- (IBAction)btnQuickCheckClick:(id)sender {
//UI changes must be done in the main thread
self.btnQuickCheck.enabled = NO;
//do your thing in a background thread
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT ,0);
dispatch_async(queue, ^(){
#try {
//do your thing here
[self pollRouter];
} #catch (NSException * e) {
//handle the exception, if needed
} #finally {
//change to the main thread again and re-enable the UI
dispatch_queue_t mainQueue = dispatch_get_main_queue();
dispatch_async(mainQueue, ^(){
self.btnQuickCheck.enabled = YES;
});
}
});
}
This will run pollRouter in a background thread. So if you are not modifying the UI or other non thread safe things in there you want to use this approach :) Otherwise go for #Alex's approach