***I am trying to create af spinningWheel animation with my imageView spinning once the button is pressed. I found a youtube video with some java code i converted into kotlin. With the code below nothing happens when the button is pushed. I have used the rotateAnimation class and some calculations in the GameViewModel thus far, and call the spin() in the GameFragment class’ onCreateView().
The code below are the two classes i use for the rotateAnimation but it doesn’t seem to work. I am not sure which part is the problem. Does anyone know?***
class GameViewModel : ViewModel() {
private val fields = arrayOf("1","2","3","4","5","6","7")
private val fieldDegrees = IntArray(fields.size)
private var degree = 0
var isSpinning = false
fun getDegreesForSectors(){
val oneFieldsDegrees = 360/fields.size
for (i in fields.indices){
fieldDegrees[i] = (i+1) * oneFieldsDegrees
}
}
fun spin(imageView: ImageView){
isSpinning = true
degree = (0..fields.size).random()
val rotateAnimation = RotateAnimation(0.toFloat(),
(360 * fields.size + fieldDegrees[degree]).toFloat(),
RotateAnimation.RELATIVE_TO_SELF, 0.5f, RotateAnimation.RELATIVE_TO_SELF, 0.5f)
rotateAnimation.setDuration(3600)
rotateAnimation.setFillAfter(true)
rotateAnimation.setInterpolator(DecelerateInterpolator())
rotateAnimation.setAnimationListener(object : Animation.AnimationListener{
override fun onAnimationStart(animation: Animation) {}
override fun onAnimationEnd(animation: Animation) {
isSpinning = false
}
override fun onAnimationRepeat(animation: Animation) {}
})
imageView.startAnimation(rotateAnimation)
}
}
class GameFragment : Fragment() {
private lateinit var gameViewModel: GameViewModel
private var _binding: GameFragmentBinding? = null
// This property is only valid between onCreateView and
// onDestroyView.
private val binding get() = _binding!!
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View {
gameViewModel =
ViewModelProvider(this).get(GameViewModel::class.java)
val spinBtn: Button? = view?.findViewById(R.id.spinBtn)
val wheelImage: ImageView? = view?.findViewById(R.id.Spinning_Wheel)
gameViewModel.getDegreesForSectors()
spinBtn?.setOnClickListener() {
if (!gameViewModel.isSpinning) {
gameViewModel.spin(wheelImage!!)
}
}
_binding = GameFragmentBinding.inflate(inflater, container, false)
val root: View = binding.root
return root
}
override fun onDestroyView() {
super.onDestroyView()
_binding = null
}
}
>Solution :
You are accessing fragment view inside onCreateView(). This will return null since nothing has been inflated yet.
Use the binding variable to access the views.
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View {
gameViewModel = ViewModelProvider(this).get(GameViewModel::class.java)
_binding = GameFragmentBinding.inflate(inflater, container, false)
gameViewModel.getDegreesForSectors()
binding.spinBtn.setOnClickListener() {
if (!gameViewModel.isSpinning) {
gameViewModel.spin(binding.spinningWheel)
}
}
return binding.root
}