UIDynamicKit : Most commonly used animation behaviors

gistfile1.m

@interface RRHomeViewController ()
{
    UIButton *logoutButton;
    UIView *testAnimateView;
}
@property (nonatomic, strong) UIDynamicAnimator *animator;
@property (nonatomic, strong) UIDynamicItemBehavior *linearVelocity;
@end

@implementation RRHomeViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    logoutButton = [[UIButton alloc] initWithFrame:CGRectMake(0, 50 , 200, 50)];
    [logoutButton addTarget:self action:@selector(logoutFromFacebook) forControlEvents:UIControlEventTouchUpInside];
    [logoutButton setTitle:@"Logout from facebook" forState:UIControlStateNormal];
    [logoutButton setBackgroundColor:[UIColor blackColor]];
    [logoutButton.titleLabel setTextAlignment:NSTextAlignmentCenter];
    [self.view addSubview:logoutButton];
    
    testAnimateView = [[UIView alloc] initWithFrame:CGRectMake(0, self.view.frame.size.height , 200, 50)];
    [testAnimateView setBackgroundColor:[UIColor blackColor]];
    [self.view addSubview:testAnimateView];
    
    // initalize the animator over here
    self.animator = [[UIDynamicAnimator alloc] initWithReferenceView:self.view];

  }
  -(void) viewDidAppear:(BOOL)animated {
    [super viewDidAppear:YES];
    // [self pushUp];
    // [self testSnapBehavior];
    // [self pushDown];
  }
  // this will bring the button down
  -(void) pushDown {
    [self.animator removeAllBehaviors];
    
    UIGravityBehavior *gravityBehavior = [[UIGravityBehavior alloc] initWithItems:@[logoutButton]];
    [gravityBehavior setMagnitude:3.0f]; // increase the speed
    [self.animator addBehavior:gravityBehavior];
    
    UICollisionBehavior *collisionBehavior = [[UICollisionBehavior alloc] initWithItems:@[logoutButton]];
    // add the boundary here
    [collisionBehavior addBoundaryWithIdentifier:@"bottomCollisionBoundary"
                                       fromPoint:CGPointMake(0.0f, self.view.bounds.size.height - 100.0f)
                                         toPoint:CGPointMake(self.view.bounds.size.width,self.view.bounds.size.height - 100.0f)];
    [self.animator addBehavior:collisionBehavior];
    // uncomment this if you want to set the bounds to the actual view
    // and not stop at your boundary
    // collisionBehavior.translatesReferenceBoundsIntoBoundary = YES;
    UIDynamicItemBehavior *itemBehavior = [[UIDynamicItemBehavior alloc] initWithItems:@[logoutButton]];
    itemBehavior.elasticity = 0.4; // number of bounces
    [self.animator addBehavior:itemBehavior];
  }
  -(void) testSnapBehavior {
    [self.animator removeAllBehaviors];
    UISnapBehavior *snapBehavior = [[UISnapBehavior alloc] initWithItem:logoutButton snapToPoint:CGPointMake(100.0f, 300.0f)];
    snapBehavior.damping = 0.8;
    [self.animator addBehavior:snapBehavior];
  }
  -(void) pushUp {
    
    [self.animator removeAllBehaviors]; // remove all behaviors for this
    
    self.animator = [[UIDynamicAnimator alloc] initWithReferenceView:self.view];
    UIPushBehavior *pushBehavior = [[UIPushBehavior alloc] initWithItems:@[testAnimateView] mode:UIPushBehaviorModeInstantaneous];
    [pushBehavior setAngle:M_PI_2 magnitude:1.0];
    [self.animator addBehavior:pushBehavior];
    
    UIGravityBehavior *gravityBehavior = [[UIGravityBehavior alloc] initWithItems:@[testAnimateView]];
    // this should change the direction of the gravity
    [gravityBehavior setGravityDirection:CGVectorMake(0.0, -1.0)];
    [self.animator addBehavior:gravityBehavior];
    
    UICollisionBehavior *collisionBehavior = [[UICollisionBehavior alloc] initWithItems:@[testAnimateView]];
    [collisionBehavior addBoundaryWithIdentifier:@"alertCollisionBoundary"
                                       fromPoint:CGPointMake(testAnimateView.frame.origin.x,  self.view.frame.origin.y + 200.0)
                                         toPoint:CGPointMake(testAnimateView.frame.origin.y,  self.view.frame.origin.y + 200.0)];
    
    [self.animator addBehavior:collisionBehavior];
    
    UIDynamicItemBehavior *itemBehavior = [[UIDynamicItemBehavior alloc] initWithItems:@[testAnimateView]];
    itemBehavior.elasticity = 0.4; // number of bounces
    [self.animator addBehavior:itemBehavior];
  }
}
@end