UIView animation called twice, finished BOOL gets set to true before full completion

Question

Because of network issues, there's a possibility i'm calling a UIView animate function twice. Somehow that seems to mess up the finished boolean you get in the completion block.

During the animation I move a UIView off screen. At the end of the animation it should set the frame i'm animating to hidden. I notice that the finished BOOL in the completion block is always set to YES. So when I call the animation for the second time, before the first call to the animation is finished, it will set to BOOL to finished, even though i expect it to be set to NO as the animation was interrupted by a new call to that same animation.

    [UIView animateWithDuration:animated ? VOTE_ANIMATION_DURATION : 0.0 delay:2 options:UIViewAnimationOptionCurveEaseOut animations:^{
    self.waitingView.frame = CGRectMake(self.waitingView.frame.origin.x, (-self.waitingView.frame.size.height) - WAITINGVIEW_SHADOW_HEIGHT, self.waitingView.frame.size.width, self.waitingView.frame.size.height);

}                completion:^(BOOL finished) {
    if (finished) {
        DDLogInfo(@"set VotingView Animation is finished");
        self.waitingView.hidden = YES;
    }
}];

I tried adding the following line too, but did not help.

 [UIView setAnimationBeginsFromCurrentState:YES];

Any clues?

You should use UIViewAnimationOptionBeginFromCurrentState instead of the method call. But that is not the solution here. — Leo Natan

Kujey Kujey · Accepted Answer · 2014-05-30T08:35:25

Well, you could set a Boolean "isAnimating" property in your class and start the animation only when it's FALSE.

if (!self.isAnimating) {
    [UIView animateWithDuration:animated ? VOTE_ANIMATION_DURATION : 0.0 delay:2 options:UIViewAnimationOptionCurveEaseOut animations:^{
        self.isAnimating = YES;
        self.waitingView.frame = CGRectMake(self.waitingView.frame.origin.x, (-self.waitingView.frame.size.height) - WAITINGVIEW_SHADOW_HEIGHT, self.waitingView.frame.size.width, self.waitingView.frame.size.height);
    }              
    completion:^(BOOL finished) {
        if (finished) {
            DDLogInfo(@"set VotingView Animation is finished");
            self.waitingView.hidden = YES;
            self.isAnimating = NO;
        }
    }];
}

Of course this will work only if you don't need the animation to be played twice at the same time.

UIView animation called twice, finished BOOL gets set to true before full completion

1 Answers