rantlab 1.4

gistfile1.m

- (void)wiggleFromPath:(CGPathRef)path target:(CGPoint)target amount:(CGFloat)amount
{
    
    CGPoint middle = CGPointMake(CGRectGetMidX(self.bounds), CGRectGetMidY(self.bounds));
    CGPathRef endPath = [RLArrowView createPathWithArrowFromPoint:middle
                                                          toPoint:target
                                                        tailWidth:2.0
                                                        headWidth:10.0
                                                       headLength:20.0
                                                           wiggle:amount];
    
    [NSAnimationContext runAnimationGroup:^(NSAnimationContext *context){
        
        CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"path"];
        animation.duration = 0.1;
        animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
        animation.repeatCount = 0;
        animation.autoreverses = NO;
        animation.fromValue = (__bridge id)path;
        animation.toValue = (__bridge id)endPath;
        [arrow addAnimation:animation forKey:@"animatePath"];
        arrow.path = endPath;
        
    } completionHandler:^{
        if (fabs(amount)>0.02) [self wiggleFromPath:endPath target:target amount:amount*-0.7];
    }];
}