UIDynamics and CCMotionManager

UIDynamics-CCMotionManager.m

//
//  ViewController.m
//  DynamicMotion
//
//  Created by Alberto Pasca on 20/05/15.
//  Copyright (c) 2015 Alberto Pasca. All rights reserved.
//

#import "ViewController.h"
#import <CoreMotion/CoreMotion.h>

@interface ViewController ()
{
    IBOutlet UILabel                    *_lbl1;
    IBOutlet UILabel                    *_lbl2;
    IBOutlet UILabel                    *_lbl3;
    IBOutlet UILabel                    *_lbl4;
    IBOutlet UILabel                    *_lbl5;
    IBOutlet UILabel                    *_lbl6;
    IBOutlet UIView                     *_view1;
    IBOutlet UIView                     *_view2;
    IBOutlet UIButton                   *_button;
    IBOutlet UISwitch                   *_switch;
    IBOutlet UISegmentedControl         *_seg;
    IBOutlet UITextField                *_txt;
    IBOutlet UIActivityIndicatorView    *_spin;
}

@property (nonatomic, strong) UIDynamicAnimator *animator;
@property (nonatomic, strong) CMMotionManager   *motionManager;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];


    NSArray *items = @[_lbl1, _lbl2, _lbl3, _lbl4, _lbl5, _lbl6, _view1, _view2,
                       _button, _switch, _seg, _txt, _spin];

    self.animator = [[UIDynamicAnimator alloc] initWithReferenceView:self.view];

    UIGravityBehavior* gravityBehavior = [[UIGravityBehavior alloc] initWithItems:items];
    [self.animator addBehavior:gravityBehavior];

    UICollisionBehavior* collisionBehavior = [[UICollisionBehavior alloc] initWithItems:items];
    collisionBehavior.translatesReferenceBoundsIntoBoundary = YES;
    [self.animator addBehavior:collisionBehavior];

    UIDynamicItemBehavior *elasticityBehavior = [[UIDynamicItemBehavior alloc] initWithItems:items];
    elasticityBehavior.elasticity = 0.5f;
    [self.animator addBehavior:elasticityBehavior];

    self.motionManager = [[CMMotionManager alloc] init];
    [self.motionManager startDeviceMotionUpdatesToQueue:[NSOperationQueue mainQueue]  withHandler:^(CMDeviceMotion *motion, NSError *error) {
        CMAcceleration gravity = motion.gravity;
        dispatch_async(dispatch_get_main_queue(), ^{
            gravityBehavior.gravityDirection = CGVectorMake(gravity.x, -gravity.y);
        });
    }];

}

@end

Hi Pasca,

Now I had a requirement of let some tag rotate from an anchor point with the gravity, can you tell me which property should I set to the UIDynamicItemBehavior?

Thanks very much
Henry