Changing instance variable bugs animation in UIView - ios

Question

I am having a problem while trying to make a custom "sliding" object from scratch. I have a view self.taskView which should either stick to the left or stick to the right. This is working fine until I try to change the state of an instance variable called self.task.
This is a (webm) animation of it working "correctly": working.webm
But this only works when I do NOT change the instance variable self.task.state
This is a (webm) animation of it NOT working "correctly": not_working.webm
So I know that it is the code that changes the state of the task that is bugging it because if I just comment out all the [self setState:BOOL] statements it works as seen in "working.webm".
Any tips or ideas are appreciated. But I am a novice so please keep it simple if it is possible.
// Code to move the green UIview right or left
-(IBAction)handlePan:(UIPanGestureRecognizer *)sender {
if (sender.state == UIGestureRecognizerStateBegan) {
self.origin = CGPointMake(self.taskView.frame.origin.x, self.taskView.frame.origin.y);
} else if (sender.state == UIGestureRecognizerStateChanged) {
CGPoint touchLocation = [sender locationInView:self];
CGPoint location = CGPointMake(touchLocation.x, (self.taskView.frame.size.height/2));
self.taskView.center = location;
} else if (sender.state == UIGestureRecognizerStateEnded) {
if (self.origin.x == 0) {
// Stick right
if (self.taskView.center.x > ((self.frame.size.width/10)*4)) {
[self setPosition:NO]; // This sets the position of the view
[self setState:NO]; // This code is bugging the "animation"
} else { // Else stick to the left
[self setPosition:YES];
[self setState:YES];
}
} else {
// Stick left
if (self.taskView.center.x < ((self.frame.size.width/10)*6)) {
[self setPosition:YES];
[self setState:YES];
} else { // Else stick right
[self setPosition:NO];
[self setState:NO];
}
}
/*[UIView animateWithDuration:0.2
delay:0.01
options:UIViewAnimationOptionAllowUserInteraction
animations:^
{
[self.taskView setFrame:position];
} completion:^(BOOL finished){
}];*/
} else if (sender.state == UIGestureRecognizerStateCancelled) {
}
}
// THIS METHOD IS BUGGING THE "ANIMATION"
- (void)setState:(BOOL)state {
self.task.state = [NSNumber numberWithBool:state];
}

Answer 1

I think the problem is that you're trying to run a time-consuming method on the main thread, and that's why your animations are choppy.
Your problem as you mentioned resides here:
- (void)setState:(BOOL)state {
self.task.state = [NSNumber numberWithBool:state];
}
This is a method that probably does something more than just changing a property (to my understanding from your comments this is a database object)
What you could do, is to update this object on a background thread:
- (void)setState:(BOOL)state {
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0),^{
self.task.state = [NSNumber numberWithBool:state];
});
}