魅せるUIの作り方 | iOS 7エンジニア勉強会10. UIGravityBehavior UIGravityBehavior* gravityBeahavior = [[UIGravityBehavior alloc] initWithItems:@[self.square1]]; gravityBeahavior.gravityDirection = CGVectorMake(0.0f, 1.0f); gravityBeahavior.magnitude = 1.0f; gravityBeahavior.angle = -M_PI/2.0; •重力の強さと方向を設定可能 11. UICollisionBehavior UICollisionBehavior* collisionBehavior = [[UICollisionBehavior alloc] initWithItems: @[self.square1, self.squ
